Template-Type: ReDIF-Article 1.0 Author-Name: H. Kang Author-X-Name-First: H. Author-X-Name-Last: Kang Author-Name: S. Lim Author-X-Name-First: S. Author-X-Name-Last: Lim Title: High isolation transmitter and receiver antennas using high-impedance surfaces for repeater applications Abstract: This paper proposes novel high isolation transmitter and receiver antennas that make use of high-impedance surfaces (HISs) for repeater applications. Both the microstrip antennas and HISs are designed to operate at a frequency of 2.05 GHz for Korean WCDMA services. The HIS proposed in this paper can effectively absorb back radiation and surface waves from each antenna, and this reduces coupling between the two antennas. Therefore, it is experimentally demonstrated that the use of HISs improves isolation by 6 and 10 dB, depending on the orientation of the two antennas. Journal: Journal of Electromagnetic Waves and Applications Pages: 2281-2287 Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.832395 File-URL: http://hdl.handle.net/10.1080/09205071.2013.832395 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:2281-2287 Template-Type: ReDIF-Article 1.0 Author-Name: W.-J. Liu Author-X-Name-First: W.-J. Author-X-Name-Last: Liu Author-Name: M. Lei Author-X-Name-First: M. Author-X-Name-Last: Lei Title: All-optical switches using solitons within nonlinear fibers Abstract: A type of all-optical switches using solitons within nonlinear fibers is studied in this paper. Analytic two-soliton solutions for the coupled nonlinear Schrödinger equations are derived with symbolic computation and Hirota method. Inelastic interactions between solitons are displayed, and the all-optical switching dynamics is analyzed. The high-intensity light is controlled with the low-intense light in the anomalous dispersion regime of fibers. Besides, the bright solitons for the all-optical switches are obtained in the normal dispersion regime of fibers. Influences of the fiber nonlinearity, group-velocity dispersion, and reciprocal of the group velocity are discussed. Nonlinear effects in the normal dispersion regime of fibers has less impact than them in the anomalous dispersion regime, and the switching threshold power is adapted through changing the group velocity. All-optical switches can be achieved with a short fiber length through increasing the group-velocity dispersion, and the size of optical circuits can be reduced without the dispersion limit. Results of this paper may drive potential applications of all-optical switches for computing, information processing, and networking. Journal: Journal of Electromagnetic Waves and Applications Pages: 2288-2297 Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.839961 File-URL: http://hdl.handle.net/10.1080/09205071.2013.839961 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:2288-2297 Template-Type: ReDIF-Article 1.0 Author-Name: S. Khan Author-X-Name-First: S. Author-X-Name-Last: Khan Author-Name: M.J. Mughal Author-X-Name-First: M.J. Author-X-Name-Last: Mughal Title: General solution for TEM, TE, and TM waves in fractional dimensional space and its application in rectangular waveguide filled with fractional space Abstract: This work presents general solution to the Maxwell’s equations inside a waveguide or transmission line where space is assumed to be of noninteger dimensions. The solution is a generalization of wave equation inside a waveguide or transmission line from integer dimensional space to fractional dimensional space. General analytical expressions for TE, TM, and TEM waves in fractal medium are also developed from the obtained general solution. Using the same notion, wave propagation inside rectangular waveguide is mathematically modeled and analyzed when it is filled fractal medium. The results obtained are analyzed and compared with the waveguide filled with nonfractal medium and substantial changes are observed to be present between the two cases. It is also observed that the classical results are recovered from all our results by considering integer dimensional space. Journal: Journal of Electromagnetic Waves and Applications Pages: 2298-2307 Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.840543 File-URL: http://hdl.handle.net/10.1080/09205071.2013.840543 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:2298-2307 Template-Type: ReDIF-Article 1.0 Author-Name: Clarissa de Lucena Nóbrega Author-X-Name-First: Clarissa Author-X-Name-Last: de Lucena Nóbrega Author-Name: Marcelo Ribeiro da Silva Author-X-Name-First: Marcelo Author-X-Name-Last: Ribeiro da Silva Author-Name: Paulo Henrique da Fonseca Silva Author-X-Name-First: Paulo Henrique Author-X-Name-Last: da Fonseca Silva Author-Name: Adaildo Gomes D’Assunção Author-X-Name-First: Adaildo Gomes Author-X-Name-Last: D’Assunção Title: A compact frequency selective surface with angular stability based on the Sierpinski fractal geometry Abstract: The Sierpinski fractal geometry is used to design frequency-selective surface (FSS) band-stop filters for microwave applications. The design’s main goals are FSS structure size compactness and angular stability at the resonant frequencies, as well as dual-band and dual-polarized performance. The proposed FSS structure is composed of a periodic array of fractal patch elements printed on a dielectric substrate layer. A parametric investigation of the FSS frequency response is accomplished to find out the effect of the fractal patch element’s cell size and iteration-number (level). Tuning possibilities are observed at the FSS resonance bands when the fractal patch element level is increased. To validate the used methodology, three prototypes are built and measured in the frequency range from 3.0 to 14 GHz. It is shown that the proposed FSS structure presents the spatial filters’ most desired characteristics such as compactness, with high frequency compression factor values (up to 66.08%), dual-polarization, and excellent angular stability. Journal: Journal of Electromagnetic Waves and Applications Pages: 2308-2316 Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.842939 File-URL: http://hdl.handle.net/10.1080/09205071.2013.842939 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:2308-2316 Template-Type: ReDIF-Article 1.0 Author-Name: Alireza Aghajamali Author-X-Name-First: Alireza Author-X-Name-Last: Aghajamali Author-Name: Mozhgan Hayati Author-X-Name-First: Mozhgan Author-X-Name-Last: Hayati Author-Name: Chien-Jang Wu Author-X-Name-First: Chien-Jang Author-X-Name-Last: Wu Author-Name: Mahmood Barati Author-X-Name-First: Mahmood Author-X-Name-Last: Barati Title: Properties of the defect modes in 1D lossy photonic crystals containing two types of negative-index-material defects Abstract: In this paper, the characteristic matrix method is employed to theoretically investigate the propagation of electromagnetic waves through one-dimensional defective lossy photonic crystals composed of negative-index materials (NIMs) and positive-index materials. We consider symmetric and asymmetric geometric structures with two different types of NIM defect layers at the center of the structure. The effects of polarization and the angle of incidence on the defect modes in the transmission spectra of both the structures are investigated. The results show that the number of the defect modes within the photonic band gap depends on the type of the NIM defect layer and is independent of the geometrical structure. Moreover, it is shown that the defect mode frequency increases as the angle of incidence increases. This property is also independent of the geometry of the structure. The results can lead to designing new types of narrowband and multichannel transmission filters. Journal: Journal of Electromagnetic Waves and Applications Pages: 2317-2329 Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.843475 File-URL: http://hdl.handle.net/10.1080/09205071.2013.843475 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:2317-2329 Template-Type: ReDIF-Article 1.0 Author-Name: Deshuang Zhao Author-X-Name-First: Deshuang Author-X-Name-Last: Zhao Author-Name: Feng Wu Author-X-Name-First: Feng Author-X-Name-Last: Wu Author-Name: Bing-Zhong Wang Author-X-Name-First: Bing-Zhong Author-X-Name-Last: Wang Author-Name: Yuanwei Jin Author-X-Name-First: Yuanwei Author-X-Name-Last: Jin Title: Basis function selection for compressed sensing and sparse representations of pulsed radar echoes Abstract: Compressed sensing theory supposes that a sparse signal can be sampled at a rate much lower than the Nyquist–Shannon rate and reconstructed with high probability. Such lower sampling rate commonly requires finding a set of the optimal basis functions to sparsely represent the signal first. This paper provides a simple and effective working process to select the basis functions for a family of pulsed radar echoes. The selection process is performed in two steps. First,the waveform matching based on the the known array excitation is carried out to select a mother function from a wavelet dictionary. Second, the spectrum matching principle is used to produce a small set of basis functions from the selected mother function. The proposed method is numerically validated by a pulsed radar system equipped with two different dipole arrays. The results demonstrate that the new method is quite effective. With the selected basis functions, all echoes can be under-sampled at a rate lower than 5%$ 5\% $ of the conventional Nyquist–Shannon rate and reconstructed with the root mean-squared error of less than 2%$ 2\% $. Journal: Journal of Electromagnetic Waves and Applications Pages: 2330-2340 Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.847386 File-URL: http://hdl.handle.net/10.1080/09205071.2013.847386 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:2330-2340 Template-Type: ReDIF-Article 1.0 Author-Name: Juan-Carlos Iriarte Author-X-Name-First: Juan-Carlos Author-X-Name-Last: Iriarte Author-Name: Iñigo Ederra Author-X-Name-First: Iñigo Author-X-Name-Last: Ederra Author-Name: Ramón Gonzalo Author-X-Name-First: Ramón Author-X-Name-Last: Gonzalo Title: High dielectric constant EBG technology to avoid gratings lobes and scan blindness in array configurations Abstract: High dielectric electromagnetic band gap (EBG) substrates can be used in patch antenna configurations to reduce size and mitigate substrate modes propagation with reasonable radiation efficiency values (ηrad > 0.55). Furthermore, EBG substrate structures applied in array configurations are able to avoid grating lobes and scan blindness phenomena as distance and coupling between patch antenna-radiating elements can be reduced at the same time. In this paper, a 2 × 2 array configuration using Zirconium Tin Titanate EBG substrate with high dielectric constant is presented. The array has been simulated showing 9 dB coupling reduction obtained by the inclusion of the EBG substrate in between the patch antennas placed to a distance lower than 0,5λ0. This short distance together with the coupling reduction results in a configuration which does not suffer from grating lobes and scan blindness problems, obtaining a 30º scan angle for the 2 × 2 configuration which is the maximum achievable angle due to a 2 × 2 array factor. A scan angle larger than 70º can be seen for the infinite configuration. Journal: Journal of Electromagnetic Waves and Applications Pages: 2341-2354 Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.848174 File-URL: http://hdl.handle.net/10.1080/09205071.2013.848174 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:2341-2354 Template-Type: ReDIF-Article 1.0 Author-Name: Cheng-Yu Ho Author-X-Name-First: Cheng-Yu Author-X-Name-Last: Ho Author-Name: Kai-Syuan Chen Author-X-Name-First: Kai-Syuan Author-X-Name-Last: Chen Author-Name: Tzyy-Sheng Horng Author-X-Name-First: Tzyy-Sheng Author-X-Name-Last: Horng Author-Name: Jian-Ming Wu Author-X-Name-First: Jian-Ming Author-X-Name-Last: Wu Author-Name: Chien-Hsiang Huang Author-X-Name-First: Chien-Hsiang Author-X-Name-Last: Huang Title: Prediction of radiated emissions from microstrip components for RF/microwave circuits using measurement of common-mode current Abstract: This work presents a novel method of using a vector network analyzer with a bulk current injection probe to measure the common-mode current of microstrip components in a RF/microwave circuit. Based on the proposed measurement, the far-field radiated emissions are determined, which correlate with measurements obtained in a fully-anechoic chamber. In this study, the proposed method is developed to determine the radiated emissions from a microstrip resonator and a microstrip bandpass filter. Full-wave electromagnetic simulations demonstrate the accuracy of the proposed measurement. Journal: Journal of Electromagnetic Waves and Applications Pages: 2355-2365 Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.849209 File-URL: http://hdl.handle.net/10.1080/09205071.2013.849209 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:2355-2365 Template-Type: ReDIF-Article 1.0 Author-Name: Supeng Chen Author-X-Name-First: Supeng Author-X-Name-Last: Chen Author-Name: Weimin Huang Author-X-Name-First: Weimin Author-X-Name-Last: Huang Title: Maneuvering target tracking from nautical radar images using particle-Kalman filters Abstract: In this paper, a new combined particle-Kalman filter (PF-KF)-based visual tracking approach is designed for maneuvering target tracking from X-band nautical radar images. Unlike existing target tracking approaches used by nautical radar, this approach incorporates a histogram-based visual tracking strategy to estimate the target position and velocity. It applies a sampling importance resampling (SIR) particle filter to obtain preliminary target positions, and then a Kalman filter to derive refined target position and velocity. A Bhattacharyya coefficient-based similarity function is employed to compare the reference target and candidate target models, which are constructed by a kernel-based histogram in radar images. An enhanced reference target model construction method that employs constant false alarm rate (CFAR) processing to enable automatic determination of reference region is proposed to improve the tracking stability and accuracy. Comparison of the target information obtained by the proposed PF-KF method from various field X-band nautical radar image sequences with those measured by GPS shows the proposed approach can provide a reliable and flexible online target tracking for nautical radar application. It is also shown that, in the scenario of strong sea clutter, the proposed approach outperforms the PF-only-based approach and the classical tracking approach which combines order-statistics (OS) CFAR processing and the Kalman filter. Journal: Journal of Electromagnetic Waves and Applications Pages: 2366-2378 Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.849577 File-URL: http://hdl.handle.net/10.1080/09205071.2013.849577 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:2366-2378 Template-Type: ReDIF-Article 1.0 Author-Name: Hong-wei Deng Author-X-Name-First: Hong-wei Author-X-Name-Last: Deng Author-Name: Yong-jiu Zhao Author-X-Name-First: Yong-jiu Author-X-Name-Last: Zhao Author-Name: Yong Fu Author-X-Name-First: Yong Author-X-Name-Last: Fu Author-Name: Ying He Author-X-Name-First: Ying Author-X-Name-Last: He Author-Name: Lu Zhang Author-X-Name-First: Lu Author-X-Name-Last: Zhang Title: High CM suppression balanced broadband BPF with hybrid hairpin-interdigital structure Abstract: A compact, high selectivity and good common-mode (CM) suppression balanced broadband bandpass filter (BPF) is proposed using hybrid hairpin-interdigital structure. Under the differential-mode (DM) excitation, the filtering topology is formed by n + 1 quarter-wavelength resonators (QWRs) and n hairpin resonators (HRs) instead of QWRs with coupled-line I/O coupling structure. But, the DM circuit still maintains high selectivity and broadband characteristics of the interdigital BPF. By reasonably choosing the coupling length and the length of the HR, the balanced BPF can not only obtain the desired DM frequency response, but the CM harmonic generated by the HR can be well suppressed by the CM transmission zero created by the coupling between the HR and half-wavelength resonator (HWR). No via-hole ground for the balanced broadband BPF is required, reducing the implementation complexity. Finally, the third-, fifth-, and seventh-order balanced broadband BPF prototypes are designed and fabricated, and the simulated and measured results show a good agreement. The CM signal for seventh-order case has been suppressed below −46.5 dB in the whole DM frequency band. Journal: Journal of Electromagnetic Waves and Applications Pages: 2379-2389 Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.851010 File-URL: http://hdl.handle.net/10.1080/09205071.2013.851010 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:2379-2389 Template-Type: ReDIF-Article 1.0 Author-Name: Carlos A. Leal-Sevillano Author-X-Name-First: Carlos A. Author-X-Name-Last: Leal-Sevillano Author-Name: José R. Montejo-Garai Author-X-Name-First: José R. Author-X-Name-Last: Montejo-Garai Author-Name: Jorge A. Ruiz-Cruz Author-X-Name-First: Jorge A. Author-X-Name-Last: Ruiz-Cruz Author-Name: Jesús M. Rebollar Author-X-Name-First: Jesús M. Author-X-Name-Last: Rebollar Title: Experimental comparison of waveguide filters at W-band implemented by different machining processes and split-block Abstract: The aim of this work is to explore different machining processes and different split-block, getting important experimental information for the design of passive waveguide components at W-band. To this end, two all-pole response filters are machined by different techniques: electro-discharge and milling, and split-block: H-plane and E-plane. Some interesting results, obtained in the design, fabrication, and measure of waveguide filters at W-band, such as tolerances of the different processes and level of insertion loss, are reported. Journal: Journal of Electromagnetic Waves and Applications Pages: 2390-2394 Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.851011 File-URL: http://hdl.handle.net/10.1080/09205071.2013.851011 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:2390-2394 Template-Type: ReDIF-Article 1.0 Author-Name: S.-X. Gong Author-X-Name-First: S.-X. Author-X-Name-Last: Gong Author-Name: Z.-L. LV Author-X-Name-First: Z.-L. Author-X-Name-Last: LV Author-Name: P.-F. Zhang Author-X-Name-First: P.-F. Author-X-Name-Last: Zhang Author-Name: J. Ling Author-X-Name-First: J. Author-X-Name-Last: Ling Author-Name: H.-L. Dong Author-X-Name-First: H.-L. Author-X-Name-Last: Dong Title: Two-dimensional extrapolation technique combined adaptive frequency-sampling method with the best uniform rational approximation Abstract: The mature two-dimensional (2-D) Stoer–Bulirsch extrapolation algorithm originated by L. Monroe was used in Ising model on the square lattice analytic results in 2002. This paper presents a novel 2-D Stoer–Bulirsch adaptive frequency-sampling method via the bivariate Chebyshev series that combines with integral equations (IE) for the fast analysis of electromagnetic scattering involving dielectric objects in both the frequency and angular domains simultaneously. In addition to its efficiency, Beale’s MATHEMATICA program is substituted by the bivariate Chebyshev series and the Chebyshev nodes performed by rational function are chosen as the initial samples for the Stoer–Bulirsch algorithm employing an adaptive frequency sampling. The innovative recursive rules are proceeding along the concept of the minimal rectangular region in both the frequency and angular domains simultaneously. Compared to the traditional 2-D fast sweep techniques based on the best uniform rational approximation, no more information is needed except the initial value. Besides the original advantages, the hybrid approach also makes the least number of sampling points required to satisfy the precision criteria in the meantime. By the 2-D extensive application of Stoer–Bulirsch adaptive frequency-sampling method, the accurate and fast radar cross-section results turn into precision adjusted, complexity simplified, and reliable in high stability. To reduce the high computational costs of the conventional PMCHWT approach, the Fourier transform (FFT) is introduced into the scheme. Numerical results demonstrate our proposed 2-D sampling strategy that performs well for two canonical dielectric scatterers. Journal: Journal of Electromagnetic Waves and Applications Pages: 2395-2406 Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.852072 File-URL: http://hdl.handle.net/10.1080/09205071.2013.852072 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:2395-2406 Template-Type: ReDIF-Article 1.0 Author-Name: Abhik Gorai Author-X-Name-First: Abhik Author-X-Name-Last: Gorai Author-Name: Anirban Karmakar Author-X-Name-First: Anirban Author-X-Name-Last: Karmakar Author-Name: Manimala Pal Author-X-Name-First: Manimala Author-X-Name-Last: Pal Author-Name: Rowdra Ghatak Author-X-Name-First: Rowdra Author-X-Name-Last: Ghatak Title: Multiple fractal-shaped slots-based UWB antenna with triple-band notch functionality Abstract: A planar elliptical shape band-notched UWB antenna with multiple fractal-shaped slots and a Sierpinski fractal curve-shaped ring resonator at the back of the substrate is introduced in this paper. The proposed antenna exhibits a triple-band notch characteristic. Koch fractal slot etched from the radiator is responsible for creating notched band centred at 5.5 GHz for wireless local area network rejection. The Minkowski fractal slots in the ground planes create rejection characteristics at 8.1 GHz to avoid interference with X-band uplink satellite communication systems. The RFID rejection band centred at 6.8 GHz is achieved by using a Sierpinski fractal curve-shaped ring resonator at the back of the substrate. Sierpinski fractal slot of third iteration on the radiator contributes to an impedance bandwidth of 2.8–12 GHz with VSWR < 2 by improving matching at lower frequencies except at three notched bands. The antenna gain varies from 1.5 to 4 dBi over the band. Stable radiation patterns are obtained throughout its operating frequency. The antenna has a compact size of 41 mm × 45 mm. Journal: Journal of Electromagnetic Waves and Applications Pages: 2407-2415 Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.852486 File-URL: http://hdl.handle.net/10.1080/09205071.2013.852486 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:2407-2415 Template-Type: ReDIF-Article 1.0 Author-Name: Jingcheng Li Author-X-Name-First: Jingcheng Author-X-Name-Last: Li Author-Name: Jacob Carr Author-X-Name-First: Jacob Author-X-Name-Last: Carr Author-Name: Joseph Waynert Author-X-Name-First: Joseph Author-X-Name-Last: Waynert Author-Name: Peter Kovalchik Author-X-Name-First: Peter Author-X-Name-Last: Kovalchik Title: Environmental impact on the magnetic field distribution of a magnetic proximity detection system in an underground coal mine Abstract: A magnetic proximity detection system mounted on an underground mobile mining machine detects whether a worker is hazardously close to the machine. The system generates magnetic fields covering the extended spaces around the machine. A magnetic detector worn by the worker measures the magnetic field flux density and determines the distance from it to the machine. The system is frequently in close proximity to coal as the machine moves, causing the magnetic field flux, in part, to enter massive in situ coal. This has the potential to have an adverse effect on the accuracy of the system and on the safety of the worker if the coal were to significantly alter the magnetic flux density distribution. Two experiments were conducted to study the impact of in situ coal on these magnetic fields. Measurements in one mine show that coal mass has no significant impact on the magnetic field flux distribution. Journal: Journal of Electromagnetic Waves and Applications Pages: 2416-2429 Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.852487 File-URL: http://hdl.handle.net/10.1080/09205071.2013.852487 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:2416-2429 Template-Type: ReDIF-Article 1.0 Author-Name: Ayman Ayd R. Saad Author-X-Name-First: Ayman Ayd R. Author-X-Name-Last: Saad Author-Name: Mohamed Mamdouh M. Ali Author-X-Name-First: Mohamed Mamdouh M. Author-X-Name-Last: Ali Author-Name: Elsayed Esam M. Khaled Author-X-Name-First: Elsayed Esam M. Author-X-Name-Last: Khaled Title: An integrated 3G/Bluetooth and UWB antenna with a band-notched feature Abstract: In this article, the design and analysis of a compact slot antenna that covers 3G, Bluetooth, and the UWB bands with the standard band-notched function at 3.6 GHz are presented and investigated. A rectangular wide-slot etched off the ground plane is used to control the low operating frequency band and the impedance matching of the proposed antenna. A manipulated rectangular tuning stub is used to enhance and control the operating bandwidth at the high frequency band. The proposed antenna is fabricated and is successfully simulated and measured. The results indicate that the proposed antenna yields an impedance bandwidth of about 7.75 GHz (from 1.9 to 9.65 GHz) defined by VSWR ≤ 2 for UMTS (1.920–2.170 GHz)/Bluetooth (2.4–2.484 GHz)/3GPP (2.57–2.62 GHz), and UWB (3.1–9.65 GHz) applications with good radiation characteristics. To reduce interference between the UWB system and the WiMAX system (3.3–3.9 GHz), a U-shaped slot is employed in the microstrip feeding line to create notched band of 3.2–4.0 GHz. Furthermore, a mathematical circuit model compatible with time-domain circuit simulators, which is based on a vector fitting technique, is also illustrated to investigate the proposed antenna characteristics. Journal: Journal of Electromagnetic Waves and Applications Pages: 2430-2441 Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.854179 File-URL: http://hdl.handle.net/10.1080/09205071.2013.854179 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:2430-2441 Template-Type: ReDIF-Article 1.0 Author-Name: The Editors Title: Editorial Board Journal: Journal of Electromagnetic Waves and Applications Pages: ebi-ebi Issue: 18 Volume: 27 Year: 2013 Month: 12 X-DOI: 10.1080/09205071.2013.861132 File-URL: http://hdl.handle.net/10.1080/09205071.2013.861132 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:18:p:ebi-ebi Template-Type: ReDIF-Article 1.0 Author-Name: S.S. Olokede Author-X-Name-First: S.S. Author-X-Name-Last: Olokede Author-Name: M.F. Ain Author-X-Name-First: M.F. Author-X-Name-Last: Ain Title: A linear array quasi-lumped element resonator antenna with a corporate-feed network Abstract: A linear array quasi-lumped element resonator antenna with parallel feed network is presented. The proposed antenna was excited by a corporate feed network. The antenna element consists of the interdigital capacitor in parallel with a straight narrow strip inductor. The inductor is the centre finger and shorted across the interdigital capacitor. With the pads connected at both ends of the structure, adjustment to tune the resonant frequency of the resonator is possible. Seeing that the proposed antenna is a lumped element, it is estimated that significant size reduction is realizable with attendant low mass, low volume, and low cost. Therefore, the individual radiating element has a small footprint area of 0.112λ0 × 0.108λ0, and thus reduced the overall antenna real estate moderately. The measured gain of the array operating at 5.8 GHz is 16.20 dBi. The proposed antenna exhibits moderate bandwidth enhancement and reasonable directional characteristics. Journal: Journal of Electromagnetic Waves and Applications Pages: 1-12 Issue: 1 Volume: 28 Year: 2014 Month: 1 X-DOI: 10.1080/09205071.2013.850454 File-URL: http://hdl.handle.net/10.1080/09205071.2013.850454 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:1:p:1-12 Template-Type: ReDIF-Article 1.0 Author-Name: Gholamreza Karimi Author-X-Name-First: Gholamreza Author-X-Name-Last: Karimi Author-Name: Sohrab Majidifar Author-X-Name-First: Sohrab Author-X-Name-Last: Majidifar Title: A novel chipless RFID tag using spiral resonator to achieve the pentamerous data encoding form Abstract: In this paper, a new method of data encoding is presented to increase the number of coded bits in a chipless RF identification (chipless RFID) tag. To achieve this purpose, different values of an equation between the phase of scattering parameters (S-parameters) at a certain frequency are considered as different coded bits. In this proposed tag, a transition zero is produced by the spiral resonator. The different phases of S parameters created by different coupling positions of the spiral resonator are considered as coded bits at the frequency of transition zero (carrier frequency). The chipless RFID tags are designed at 1.7 GHz with five different states and the measurement results are in good agreement with the EM simulation results. Journal: Journal of Electromagnetic Waves and Applications Pages: 13-27 Issue: 1 Volume: 28 Year: 2014 Month: 1 X-DOI: 10.1080/09205071.2013.854178 File-URL: http://hdl.handle.net/10.1080/09205071.2013.854178 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:1:p:13-27 Template-Type: ReDIF-Article 1.0 Author-Name: Dang-Oh Kim Author-X-Name-First: Dang-Oh Author-X-Name-Last: Kim Author-Name: Che-Young Kim Author-X-Name-First: Che-Young Author-X-Name-Last: Kim Title: A short-ended CRLH coaxial cavity resonator with zeroth-order resonance Abstract: This paper introduces a coaxial cavity resonator structure with a new configuration based on the composite right/left-handed transmission line (CRLH–TL). In order to create the CRLH–TL, the shunt inductance coils and the series capacitance gaps are added to a conventional half-wavelength short-ended coaxial cavity resonator. The final resonator is composed of three periodically connected CRLH unit cells. Through the adjustment of the diameter of the inserted coils and the gaps of created capacitances, the proposed resonator was able to support the desired zeroth-order resonance (ZOR) in the balanced mode. In order to verify the applicability of the proposed resonator to the CRLH metamaterial, a dispersion diagram and the constitutive parameters of a unit cell were determined using three-dimensional EM simulation. The resonant frequencies and quality factors associated with each resonance modes were then computed through eigenmode analysis for the overall resonator formation. In addition, the electromagnetic field distributions of the resonator at the ZOR frequency have been described and discussed. These results enable us to validate that the proposed CRLH coaxial cavity resonator can be utilized as a zeroth-order resonator based on the CRLH–TL structure. As a result the proposed resonator has a 69% reduction in size compared to traditional short-ended coaxial cavity resonators. Journal: Journal of Electromagnetic Waves and Applications Pages: 28-38 Issue: 1 Volume: 28 Year: 2014 Month: 1 X-DOI: 10.1080/09205071.2013.855147 File-URL: http://hdl.handle.net/10.1080/09205071.2013.855147 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:1:p:28-38 Template-Type: ReDIF-Article 1.0 Author-Name: Li Zhang Author-X-Name-First: Li Author-X-Name-Last: Zhang Author-Name: Xin-Huai Wang Author-X-Name-First: Xin-Huai Author-X-Name-Last: Wang Author-Name: Zhu-Dan Wang Author-X-Name-First: Zhu-Dan Author-X-Name-Last: Wang Author-Name: Yan-Fu Bai Author-X-Name-First: Yan-Fu Author-X-Name-Last: Bai Author-Name: Xiao-Wei Shi Author-X-Name-First: Xiao-Wei Author-X-Name-Last: Shi Title: Compact electronically tunable microstrip dual-band filter using stub-loaded SIRs Abstract: A compact electronically tunable dual-bandpass filter (BPF) with harmonic suppression is investigated in this paper. The BPF is composed of a step-impedance resonator, a T-stub with a varactor diode and a filtering network. The second passband can be independently tuned by varying the bias voltage across the varactor, whereas the first passband is fixed. The proposed filter exhibits wide stopband due to the introduction of the filtering network suppressing harmonics. A prototype of a tunable dual-band BPF, in which the second passband is tuned from 1.58 to 2.21 GHz and the first passband is fixed at 0.98 GHz, is designed and fabricated. The simulated and measured results are in good agreement with each other. Journal: Journal of Electromagnetic Waves and Applications Pages: 39-48 Issue: 1 Volume: 28 Year: 2014 Month: 1 X-DOI: 10.1080/09205071.2013.855148 File-URL: http://hdl.handle.net/10.1080/09205071.2013.855148 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:1:p:39-48 Template-Type: ReDIF-Article 1.0 Author-Name: Wenyan Liu Author-X-Name-First: Wenyan Author-X-Name-Last: Liu Author-Name: Xiaotao Huang Author-X-Name-First: Xiaotao Author-X-Name-Last: Huang Title: Analysis of energy detection receiver for TOA estimation in IR UWB ranging and a novel TOA estimation approach Abstract: Ultra wideband (UWB) localization has attracted a lot of attention, as it offers the capability of penetration and high precision positioning with low cost. Time-based UWB ranging can take full advantage of the characteristics of impulse radio (IR) signal. The energy detection (ED) receiver instead of the matched filter is used a lot in the area for its low complexity. In the ED receiver, many factors, such as the integration interval, signal waveform, the upper or lower limit of integration, noise floor and pulse width, affect the ranging performance. These factors have not been studied thoroughly on energy collection in ED-based receivers, while energy collection is very important for IR UWB ranging and localization. Many studies focus on how to estimate the time of arrival (TOA) based on the output of the ED receiver. In the study, we will examine the effects of these factors on energy collection and TOA estimation. Some qualitative conclusions are given. We propose an approach to solve some problems caused by these factors and further improve the ranging accuracy. The approach can break through the performance limitation of TOA estimation with the ED receiver to some extent with some low-cost delayers instead of the high sampling rate analog to digital converters. Simulation results prove that the approach works effectively compared with traditional methods under different channels. Journal: Journal of Electromagnetic Waves and Applications Pages: 49-63 Issue: 1 Volume: 28 Year: 2014 Month: 1 X-DOI: 10.1080/09205071.2013.855149 File-URL: http://hdl.handle.net/10.1080/09205071.2013.855149 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:1:p:49-63 Template-Type: ReDIF-Article 1.0 Author-Name: Magdy A. Ezzat Author-X-Name-First: Magdy A. Author-X-Name-Last: Ezzat Author-Name: Ahmed S. El-Karamany Author-X-Name-First: Ahmed S. Author-X-Name-Last: El-Karamany Author-Name: A.A. El-Bary Author-X-Name-First: A.A. Author-X-Name-Last: El-Bary Author-Name: Mohsen A. Fayik Author-X-Name-First: Mohsen A. Author-X-Name-Last: Fayik Title: Fractional ultrafast laser-induced magneto-thermoelastic behavior in perfect conducting metal films Abstract: An ultrafast fractional magneto-thermoelasticity model utilizing the modified hyperbolic heat conduction model with fractional order is formulated to describe the thermoelastic behavior of a thin perfect conducting metal film irradiated by a femtosecond laser pulse. Some theorems of generalized thermoelasticity follow as limit cases. The temporal profile of the ultrafast laser was regarded as being non-Gaussian. An analytical–numerical technique based on the Laplace transform was used to solve the governing equations and the time histories of the temperature, displacement, stress, strain, and induced electric/magnetic fields in a gold film were analyzed. Some comparisons have been shown in figures to estimate the effects of some parameters on all the studied fields. Journal: Journal of Electromagnetic Waves and Applications Pages: 64-82 Issue: 1 Volume: 28 Year: 2014 Month: 1 X-DOI: 10.1080/09205071.2013.855616 File-URL: http://hdl.handle.net/10.1080/09205071.2013.855616 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:1:p:64-82 Template-Type: ReDIF-Article 1.0 Author-Name: Subash Vegesna Author-X-Name-First: Subash Author-X-Name-Last: Vegesna Author-Name: Yanhan Zhu Author-X-Name-First: Yanhan Author-X-Name-Last: Zhu Author-Name: Yong Zhao Author-X-Name-First: Yong Author-X-Name-Last: Zhao Author-Name: Zhaoyang Fan Author-X-Name-First: Zhaoyang Author-X-Name-Last: Fan Author-Name: Ayrton Bernussi Author-X-Name-First: Ayrton Author-X-Name-Last: Bernussi Author-Name: Mohammad Saed Author-X-Name-First: Mohammad Author-X-Name-Last: Saed Title: Terahertz frequency selective surface with reconfigurable polarization characteristics using vanadium dioxide Abstract: In this paper, we present a design technique to realize reconfigurable terahertz (THz) frequency selective surface (FSS) polarizer. Our approach relies on combining vanadium dioxide (VO2) patches with metallic resonators. Vanadium dioxide behaves as an insulator at room temperatures and as a metal at high temperatures with a characteristic insulator–metal transition temperature of ~68 °C. We used this attribute to realize a reconfigurable single- to dual-polarized bandpass FSS structure at 0.5 THz. Along with the simulation results, FSS structures fabricated on sapphire substrates were measured using THz time-domain spectroscopy. Measured extinction ratio of ~25 dB was achieved for the THz polarizer with just a single FSS layer. Good agreement between simulation and experiments were obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 83-90 Issue: 1 Volume: 28 Year: 2014 Month: 1 X-DOI: 10.1080/09205071.2013.857278 File-URL: http://hdl.handle.net/10.1080/09205071.2013.857278 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:1:p:83-90 Template-Type: ReDIF-Article 1.0 Author-Name: Sudipta Maity Author-X-Name-First: Sudipta Author-X-Name-Last: Maity Author-Name: Bhaskar Gupta Author-X-Name-First: Bhaskar Author-X-Name-Last: Gupta Title: Simplified analysis for 30°–60°–90° triangular microstrip antenna Abstract: Cavity model analysis is performed for 30°–60°–90° triangular microstrip antenna. Field expressions for various modes are given. Current is modeled as one dimensional ribbon to find the input impedance. Far field radiation patterns for fundamental mode are evaluated using equivalence principle. Results are verified with measures and/or 3D simulated data. It is found that our theory shows close agreement with measured and/or simulated data. It is much less complex and generalized in terms of modal analysis but at the same time more accurate than the other reported analytical techniques for the structure. It is believed that the results can be efficiently utilized to design broad-side 30°–60°–90° triangular microstrip antenna. Journal: Journal of Electromagnetic Waves and Applications Pages: 91-101 Issue: 1 Volume: 28 Year: 2014 Month: 1 X-DOI: 10.1080/09205071.2013.857279 File-URL: http://hdl.handle.net/10.1080/09205071.2013.857279 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:1:p:91-101 Template-Type: ReDIF-Article 1.0 Author-Name: J. Córcoles Author-X-Name-First: J. Author-X-Name-Last: Córcoles Author-Name: M.Á. González de Aza Author-X-Name-First: M.Á. Author-X-Name-Last: González de Aza Author-Name: J. Zapata Author-X-Name-First: J. Author-X-Name-Last: Zapata Title: Full-wave analysis of finite periodic cylindrical conformal arrays with Floquet spherical modes and a hybrid finite element – generalized scattering matrix method Abstract: This work reports a novel approach for the full-wave analysis of a finite conformal array made up of antennas which are periodically arranged on a metallic cylindrical surface. The analysis methodology is based on a hybrid finite element and modal analysis method, and it allows the computation of the generalized scattering matrix of the structure. In this case, spherical vector modes are used to characterize the radiating region and because of the periodic nature of the conformal array, Floquet’s theory is used to render the methodology efficient and accurate. Therefore, the formulation is derived to be able to characterize the whole structure from the analysis of only one semi-period. Numerical results of arrays made up of rectangular apertures and microstrip patches are presented and compared with the ones obtained with commercial software and infinite models both for conformal and planar arrays. Journal: Journal of Electromagnetic Waves and Applications Pages: 102-111 Issue: 1 Volume: 28 Year: 2014 Month: 1 X-DOI: 10.1080/09205071.2013.857280 File-URL: http://hdl.handle.net/10.1080/09205071.2013.857280 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:1:p:102-111 Template-Type: ReDIF-Article 1.0 Author-Name: Yu-Xue Ji Author-X-Name-First: Yu-Xue Author-X-Name-Last: Ji Author-Name: Jin Xu Author-X-Name-First: Jin Author-X-Name-Last: Xu Title: Compact BPF and diplexer using capacitively loaded λ/4 shorted meander line resonator Abstract: This paper presents a novel capacitively loaded λ/4 shorted meander line resonator (SMLR). The grounded microstrip lines inserted inside the spaces of SMLR can construct the grounded inter-digital capacitors, which leads to a lower fundamental resonance frequency of capacitively loaded λ/4 SMLR than the λ/4 SMLR. Based on the proposed resonator, two compact fourth order Chebychev response bandpass filters (BPFs) centered at 0.9/1.57 GHz with 3 dB fractional bandwidth (FBW) of 12.5%/15% is designed and fabricated firstly. Then, on the basis of these two BPFs, a BPF-based diplexer operating at 0.9/1.57 GHz with 3 dB FBW of 12.5%/15% is exploited. The designed diplexer employs a novel hybrid microstrip line and phase shifter common T-junction. The phase shifter is implemented by quasi-lumped elements. The designed diplexer exhibits a very high isolation up to 73/68 dB at two channels, respectively. The fabricated diplexer also has a compact size of 0.239λg × 0.06λg. Good agreement can be observed between the simulations and the measurements. Journal: Journal of Electromagnetic Waves and Applications Pages: 112-118 Issue: 1 Volume: 28 Year: 2014 Month: 1 X-DOI: 10.1080/09205071.2013.857617 File-URL: http://hdl.handle.net/10.1080/09205071.2013.857617 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:1:p:112-118 Template-Type: ReDIF-Article 1.0 Author-Name: The-Nan Chang Author-X-Name-First: The-Nan Author-X-Name-Last: Chang Author-Name: Jyun-Ming Lin Author-X-Name-First: Jyun-Ming Author-X-Name-Last: Lin Title: Circularly polarized antenna with two edge-coupled open-loops Abstract: A wide-band circularly polarized antenna with two rectangular open-loops coupled by a printed monopole is presented. The two open-loops are placed side by side and are coplanar with the ground plane of the monopole. The gap of one open-loop is on the top-edge, while the gap of another open-loop is on the bottom-edge. The return-loss and the axial-ratio bandwidths of the antenna are tuned by varying the position and the size of the two gaps. For an optimized antenna without a back-up metallic reflector, return-loss bandwidth of 68.7% (2.2–4.5 GHz) and axial-ratio bandwidth of 53% (2.2–3.8 GHz) can be achieved. The axial-ratio bandwidth of the antenna with a back-up reflector is 38%. Journal: Journal of Electromagnetic Waves and Applications Pages: 119-128 Issue: 1 Volume: 28 Year: 2014 Month: 1 X-DOI: 10.1080/09205071.2013.858608 File-URL: http://hdl.handle.net/10.1080/09205071.2013.858608 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:1:p:119-128 Template-Type: ReDIF-Article 1.0 Author-Name: Yi Ren Author-X-Name-First: Yi Author-X-Name-Last: Ren Author-Name: Yanwen Zhao Author-X-Name-First: Yanwen Author-X-Name-Last: Zhao Author-Name: Zhiqin Zhao Author-X-Name-First: Zhiqin Author-X-Name-Last: Zhao Author-Name: Bin Wang Author-X-Name-First: Bin Author-X-Name-Last: Wang Author-Name: Honggang Hao Author-X-Name-First: Honggang Author-X-Name-Last: Hao Title: A novel adaptive sampling method for interpolation/extrapolation in time and frequency domains Abstract: This paper studies the sampling method for interpolation/extrapolation of electromagnetic response in time and frequency domains. To avoid sub-sampling or over-sampling, a new adaptive sampling method is proposed. With the proposed approach, the length of sampling depends on the required accuracy of interpolation/extrapolation, while its calculation format needs little modification. Finally, this adaptive sampling method is used to calculate the wideband electromagnetic response through interpolation/extrapolation, and some numerical results are given to prove the effectiveness of this method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1167-1174 Issue: 10 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.906328 File-URL: http://hdl.handle.net/10.1080/09205071.2014.906328 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:10:p:1167-1174 Template-Type: ReDIF-Article 1.0 Author-Name: Teng-Kai Chen Author-X-Name-First: Teng-Kai Author-X-Name-Last: Chen Author-Name: Gregory H. Huff Author-X-Name-First: Gregory H. Author-X-Name-Last: Huff Title: Transmission line analysis of the Archimedean spiral antenna in free space Abstract: This paper examines the transmission line structure of a planar Archimedean spiral antenna. A novel analysis is performed by unwinding the spiral into an equivalent straight transmission line to understand its impedance properties and the radiating mechanism. A relation between the input impedance of the spiral antenna and the characteristic impedance of our proposed model is established. The analytical solution completes the lossy transmission line modelling for the input impedance of the spiral antenna. The value of the stable input resistance in the spiral’s radiation region is found not due to the radiation resistance of the loop antenna, but it is dominated by the propagation characteristics of the slot-line mode, that is the travelling wave on the spiral. The accuracy of this proposed model is verified by full-wave simulations, the Babinet’s principle, and measurements. Examination of the radiation mechanism and discussion on the effects of other parameters such as feeding design are also provided. Journal: Journal of Electromagnetic Waves and Applications Pages: 1175-1193 Issue: 10 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.909295 File-URL: http://hdl.handle.net/10.1080/09205071.2014.909295 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:10:p:1175-1193 Template-Type: ReDIF-Article 1.0 Author-Name: L.X. Zhou Author-X-Name-First: L.X. Author-X-Name-Last: Zhou Author-Name: W. Hu Author-X-Name-First: W. Author-X-Name-Last: Hu Author-Name: Y.Z. Yin Author-X-Name-First: Y.Z. Author-X-Name-Last: Yin Author-Name: X. Yang Author-X-Name-First: X. Author-X-Name-Last: Yang Title: Design of a novel wideband quasi-elliptic filter based on SIR and asymmetric coupled lines Abstract: Stepped impedance resonator (SIR) and asymmetric coupled-line sections are used to design a novel fifth-order wideband bandpass filter in this paper. Even- and odd-mode technique is introduced to design and analyze the filter. The proposed filter possesses the characteristics of spurious-free response up to the third harmonic frequency with two transmission zeros on each side of the passband, thus resulting in the improved selectivity. One prototype with 3-dB fractional bandwidth of 53% (2.2–3.79 GHz) is fabricated for demonstration, and good agreement can be observed between simulated and measured results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1194-1202 Issue: 10 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.910143 File-URL: http://hdl.handle.net/10.1080/09205071.2014.910143 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:10:p:1194-1202 Template-Type: ReDIF-Article 1.0 Author-Name: Shengjun Wei Author-X-Name-First: Shengjun Author-X-Name-Last: Wei Author-Name: Quanyuan Feng Author-X-Name-First: Quanyuan Author-X-Name-Last: Feng Title: Design of a planar tunable antenna based on the rectangular aperture Abstract: In this paper, a coplanar waveguide (CPW)-fed planar antenna with frequency tuning capability and broadband characteristic is proposed. The antenna consists of a CPW feeding line, an arrow-shaped stub, a rectangular aperture, and two symmetric square apertures carved on the ground plane. Based on the narrow slot etched out, two varactors are employed as tunable elements to load into the slot. With the configuration adopted, the low frequency narrow band and the high frequency wide band are obtained. Results show that the low frequency tunable channel ranging from 1.5 to 2.05 GHz is achieved while the high frequency wide band maintaining. Further, the measured radiation patterns and gains exhibit relatively stable characteristics. Journal: Journal of Electromagnetic Waves and Applications Pages: 1203-1211 Issue: 10 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.910145 File-URL: http://hdl.handle.net/10.1080/09205071.2014.910145 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:10:p:1203-1211 Template-Type: ReDIF-Article 1.0 Author-Name: Guihong Li Author-X-Name-First: Guihong Author-X-Name-Last: Li Author-Name: Huiqing Zhai Author-X-Name-First: Huiqing Author-X-Name-Last: Zhai Author-Name: Xiaoyan Ma Author-X-Name-First: Xiaoyan Author-X-Name-Last: Ma Author-Name: Tong Li Author-X-Name-First: Tong Author-X-Name-Last: Li Author-Name: Changhong Liang Author-X-Name-First: Changhong Author-X-Name-Last: Liang Title: Design of a CPW-fed slot antenna with small size and ultra-broadband circularly polarized radiation Abstract: In this research, a coplanar waveguide (CPW)-fed slot antenna is proposed with a compact size and an ultra-broadband circularly polarized (CP) radiation. The proposed antenna, just with a small size of 40 mm × 40 mm × 1 mm in overall configuration, achieves an ultra-broad CP bandwidth of 68.1% from 3.05 to 6.2 GHz, suitable for both WiMAX (3.3–3.8 GHz) and WLAN (5.15–5.35 GHz/5.725–5.825 GHz) systems. The presented antenna proposes two linked rectangular slots in the ground to obtain CP radiations. The linked slots can also be considered as a square slot with two perturbations in the corners. The perturbations can split the fundamental resonant mode into two near-degenerate modes, leading to CP waves. The adjacent excited CP modes are merged for ultra-wideband CP radiation. With a symmetric series impedance line connected to CPW feedline, broadband input impedance matching from 2.65 to 6.8 GHz can be obtained. The proposed design has been verified by the simulated and measured results. The future MIMO potential of the proposed CP antenna has also been studied. Journal: Journal of Electromagnetic Waves and Applications Pages: 1212-1220 Issue: 10 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.911123 File-URL: http://hdl.handle.net/10.1080/09205071.2014.911123 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:10:p:1212-1220 Template-Type: ReDIF-Article 1.0 Author-Name: Hui Zhao Author-X-Name-First: Hui Author-X-Name-Last: Zhao Author-Name: Fushun Zhang Author-X-Name-First: Fushun Author-X-Name-Last: Zhang Author-Name: Chunyang Wang Author-X-Name-First: Chunyang Author-X-Name-Last: Wang Author-Name: Xiaokuan Zhang Author-X-Name-First: Xiaokuan Author-X-Name-Last: Zhang Title: A universal methodology for designing a UWB diversity antenna Abstract: A universal methodology for designing a ultra-wideband (UWB) diversity antenna is presented in this paper. The main advantage of the methodology is that by using only a familiar symmetrical UWB antenna, a UWB diversity antenna with a compact size, wide impedance bandwidth and good isolation between two feeding ports can be designed conventionally. Another advantage of the methodology is that the distance between two radiators is almost equal to the distance between two feeding lines, thus a complicated structure to decouple the mutual interaction between two radiators is not necessary in the antenna design, and the configuration of the UWB diversity antenna is simple. As an example, a UWB diversity antenna with a compact size of 36 mm × 36 mm operating at a frequency range of 3.1–10.6 GHz designed by using a circular disc monopole UWB antenna is constructed, measured and analysed. The simulated and measured results show that across the UWB, the antenna can achieve a broad impedance bandwidth with good isolation of <−15 dB. The radiation patterns, gain and envelope correlation coefficient are also measured. Furthermore, to demonstrate the effectiveness of the methodology, another UWB diversity antenna designed by using another symmetrical UWB antenna which is a bevelled rectangular monopole UWB one is simulated. Journal: Journal of Electromagnetic Waves and Applications Pages: 1221-1235 Issue: 10 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.911667 File-URL: http://hdl.handle.net/10.1080/09205071.2014.911667 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:10:p:1221-1235 Template-Type: ReDIF-Article 1.0 Author-Name: O. Karabayir Author-X-Name-First: O. Author-X-Name-Last: Karabayir Author-Name: O.M. Yucedag Author-X-Name-First: O.M. Author-X-Name-Last: Yucedag Author-Name: S. Makal Yucedag Author-X-Name-First: S. Author-X-Name-Last: Makal Yucedag Author-Name: S. Kent Author-X-Name-First: S. Author-X-Name-Last: Kent Title: Performance analysis of compressive ISAR imaging for complex targets Abstract: In this paper, performance efficiency analysis of compressive inverse synthetic aperture radar (ISAR) imaging for a complex, electrically large target is presented. In this context, physical optics (PO) is used as a high-frequency scattered field prediction technique and compressive sensing (CS) theory is applied to ISAR imaging by exploiting the sparse point scatterer structure of the target. Results prove that CS provides high resolution and accuracy in ISAR imaging even under the Nyquist sampling rate and linearly decreases computational time. Journal: Journal of Electromagnetic Waves and Applications Pages: 1236-1245 Issue: 10 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.913506 File-URL: http://hdl.handle.net/10.1080/09205071.2014.913506 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:10:p:1236-1245 Template-Type: ReDIF-Article 1.0 Author-Name: Essam M.A. Elkaramany Author-X-Name-First: Essam M.A. Author-X-Name-Last: Elkaramany Author-Name: Fayza G. Abo El-Hadeed Author-X-Name-First: Fayza G. Author-X-Name-Last: Abo El-Hadeed Author-Name: Ahmed S.S. Ahmed Author-X-Name-First: Ahmed S.S. Author-X-Name-Last: Ahmed Title: Resonant frequencies of arbitrarily shaped microstrip patch antennas using two-dimensional circuit model Abstract: Two-dimensional circuit is used to determine the resonant frequencies of the arbitrarily shaped, single-layer microstrip patch antennas. This circuit is based on the long transmission line model in the frequency domain. Derivation, analysis, and treatment of boundaries are given. Simple matrix form is obtained and the problem is reduced to an eigenvalue problem which is solved to get the required solution. The resonant frequencies of the resulting circuit are the required resonant frequencies of the patch antenna. Numerical results are given and are compared with the available analytical and experimental results reported by others. Journal: Journal of Electromagnetic Waves and Applications Pages: 1246-1256 Issue: 10 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.913507 File-URL: http://hdl.handle.net/10.1080/09205071.2014.913507 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:10:p:1246-1256 Template-Type: ReDIF-Article 1.0 Author-Name: Shivangi Mishra Author-X-Name-First: Shivangi Author-X-Name-Last: Mishra Author-Name: Manas Sarkar Author-X-Name-First: Manas Author-X-Name-Last: Sarkar Author-Name: Anitha Daniel Author-X-Name-First: Anitha Author-X-Name-Last: Daniel Title: Optimization of radome wall and joint for X-band reflector antenna using Floquet modal analysis Abstract: The performance of high frequency weather radars becomes questionable when the antenna system is enclosed by a radome because losses are more at higher frequency. To achieve high performance and accuracy, the radome wall and joints should be designed and optimized properly. Current manuscript presents the detailed study of A-sandwich radome wall and joint characteristics derived for polarimetric Doppler Weather Radar reflector antenna at X-band frequency. The diameter of the reflector antenna is 2.4 m which will be protected by a spherical A-sandwich radome of diameter 4.2 m. Radome wall is optimized by parametric variation of skin and core thickness using Floquet’s modal analysis in Ansoft HFSS Software package. Performances of radome panel with three different joint cross-sections have been compared in terms of insertion loss and phase variation and the best one is proposed for X-band antenna radome. Measurement was carried out at Compact Antenna Test Facility where the joint of two flat rectangular radome panels was hanged vertically in front of reflector antenna. Simulated results are compared with measured results to validate the proposed design. Journal: Journal of Electromagnetic Waves and Applications Pages: 1257-1268 Issue: 10 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.914859 File-URL: http://hdl.handle.net/10.1080/09205071.2014.914859 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:10:p:1257-1268 Template-Type: ReDIF-Article 1.0 Author-Name: Yu He Author-X-Name-First: Yu Author-X-Name-Last: He Author-Name: Xin Wu Author-X-Name-First: Xin Author-X-Name-Last: Wu Author-Name: Chang-jun Liu Author-X-Name-First: Chang-jun Author-X-Name-Last: Liu Title: Novel miniaturized low-pass filters from artificial transmission line structures Abstract: A novel design on miniaturized low-pass filters from artificial transmission line structures is proposed. Reactance components, i.e. capacitors and inductors, are directly constructed from microstrip structures based on electromagnetic simulation and parameter extraction. The constructed reactance components are integrated to build low-pass filters. The results of a fifth-order Butterworth, 0.25, 0.5, and 1 dB ripple Chebyshev filters, which are realized by the proposed method, are presented. The proposed low-pass filters are compact and their sizes are about 20% of conventional microstrip low-pass filters. The simulation agrees well with the measurements, which shows the validation of the proposed design method. The miniaturized low-pass filters may be applied to many microwave systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 1269-1274 Issue: 10 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.915201 File-URL: http://hdl.handle.net/10.1080/09205071.2014.915201 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:10:p:1269-1274 Template-Type: ReDIF-Article 1.0 Author-Name: Xiaolong Wang Author-X-Name-First: Xiaolong Author-X-Name-Last: Wang Author-Name: Atsushi Mase Author-X-Name-First: Atsushi Author-X-Name-Last: Mase Author-Name: Hiroyuki Ikezi Author-X-Name-First: Hiroyuki Author-X-Name-Last: Ikezi Author-Name: Masaaki Inutake Author-X-Name-First: Masaaki Author-X-Name-Last: Inutake Author-Name: Yuichiro Kogi Author-X-Name-First: Yuichiro Author-X-Name-Last: Kogi Author-Name: Kiichiro Uchino Author-X-Name-First: Kiichiro Author-X-Name-Last: Uchino Title: Synthetic aperture radar using ultra-wideband microwave-modulated laser Abstract: Ultra-wideband microwave-modulated laser radar is designed and fabricated for the improvement of spatial resolution both in the range and in the azimuth directions. The frequency modulation (1–18 GHz chirp) is applied to an infrared laser source in 1550 nm wavelength. A prototype of laser radar system with a beam expander has been constructed and applied to the measurement of the distance (position) of an object. In the experiment, it has been proved that the spatial resolution in the range direction is less than ±2 cm. Journal: Journal of Electromagnetic Waves and Applications Pages: 1275-1281 Issue: 11 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.917994 File-URL: http://hdl.handle.net/10.1080/09205071.2014.917994 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:11:p:1275-1281 Template-Type: ReDIF-Article 1.0 Author-Name: Clarissa de Lucena Nóbrega Author-X-Name-First: Clarissa Author-X-Name-Last: de Lucena Nóbrega Author-Name: Marcelo Ribeiro da Silva Author-X-Name-First: Marcelo Author-X-Name-Last: Ribeiro da Silva Author-Name: Paulo Henrique da Fonseca Silva Author-X-Name-First: Paulo Henrique Author-X-Name-Last: da Fonseca Silva Author-Name: Adaildo Gomes D’Assunção Author-X-Name-First: Adaildo Gomes Author-X-Name-Last: D’Assunção Title: Analysis and design of frequency selective surfaces using teragon patch elements for WLAN applications Abstract: This paper describes a fractal design methodology for frequency selective surfaces (FSSs) composed of teragon metallic patches on a single-layer fiberglass dielectric. Shapes presented by teragons are exploited to design compact FSSs acting as dual-band band-stop spatial filters. An FSS parametric analysis is performed in terms of the fractal dimension and unit cell size of fractal patches. The transmission properties of the proposed periodic arrays are initially investigated through simulations performed by Ansoft DesignerTM commercial software. To validate the used methodology, three FSS prototypes are selected for fabrication, and one of them is designed to reject wireless local area network signals in the bands of 2.4–2.5 GHz (IEEE 802.11b) and 5.0–6.0 GHz (IEEE 802.11a). Experimental characterization of the FSS prototypes is accomplished through an alternative setup with elliptical monopole microstrip antennas for low-cost FSS measurements. The obtained results point to interesting features for FSS spatial filters: compactness, with high values of frequency compression factor (up to 80.4%); dual polarization; dual-band frequency responses; and stable resonance frequencies at oblique incidence. Journal: Journal of Electromagnetic Waves and Applications Pages: 1282-1292 Issue: 11 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.919240 File-URL: http://hdl.handle.net/10.1080/09205071.2014.919240 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:11:p:1282-1292 Template-Type: ReDIF-Article 1.0 Author-Name: Hongguang Wang Author-X-Name-First: Hongguang Author-X-Name-Last: Wang Author-Name: Hui Han Author-X-Name-First: Hui Author-X-Name-Last: Han Author-Name: Fang Sun Author-X-Name-First: Fang Author-X-Name-Last: Sun Author-Name: Zhensen Wu Author-X-Name-First: Zhensen Author-X-Name-Last: Wu Author-Name: Jinpeng Zhang Author-X-Name-First: Jinpeng Author-X-Name-Last: Zhang Title: Modeling signal amplitude of ground-based GPS occultation in marine tropospheric ducts Abstract: The propagation characteristics of Global Positioning System (GPS) signals at very low elevation angles are frequently affected by tropospheric refraction as the satellite rises or sets at the horizon. Previous research indicated that the signal can be used to detect normal and surface-based duct refractive conditions. Using reciprocity, we develop a model to predict ground-based GPS occultation signal propagation in the presence of marine tropospheric ducts. To involve the effects of refraction, sea surface impedance, roughness, and the Earth’s curvature, the parabolic equation (PE) method is adopted in the low atmosphere. In implementing the PE numerically using the split-step discrete mixed Fourier transform algorithm, we propose a new approach of utilizing the relationship between the impedance coefficient and the reflection coefficient to modeling the right-hand circularly polarized GPS signal. The refraction effects from the top of the PE region to the satellite are modeled by ray tracing technique. Data measured by a ground-based receiver are presented and compared to the model under normal and duct refraction conditions, which show the validity of the propagation model in ground-based GPS occultation events. Potential applications of the ground-based occultation signal are also discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1293-1304 Issue: 11 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.919877 File-URL: http://hdl.handle.net/10.1080/09205071.2014.919877 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:11:p:1293-1304 Template-Type: ReDIF-Article 1.0 Author-Name: Sun-Gu Sun Author-X-Name-First: Sun-Gu Author-X-Name-Last: Sun Author-Name: Byung-Lae Cho Author-X-Name-First: Byung-Lae Author-X-Name-Last: Cho Author-Name: Jung-Soo Lee Author-X-Name-First: Jung-Soo Author-X-Name-Last: Lee Author-Name: Gyu-Churl Park Author-X-Name-First: Gyu-Churl Author-X-Name-Last: Park Author-Name: Jong-Soo Ha Author-X-Name-First: Jong-Soo Author-X-Name-Last: Ha Title: Ultra-wideband imaging radar to reveal obstacles concealed in vegetation to improve navigation of unmanned ground vehicles Abstract: To increase mobility of an unmanned ground vehicle (UGV), this study describes the use of forward-looking imaging radar applying ultra-wideband radar technology. If radar is able to visualize images with high resolution in front of a UGV, the radar can be used to support the vehicle by detecting obstacles through foliage. This system employs the multi-input/double-output configuration with two transmitting horn antennas to increase cross-range resolution. Also, two rows of physical receiving antenna arrays provide the height information of targets using an interferometer principle. For visualizing objects in front of the radar, the back-projection method is applied to the data acquired from the receivers. A field test is used to verify the effectiveness of the new radar system. The performance of the radar is proved experimentally by the analysis of image resolution, grass-penetrating capability, and target height information. Journal: Journal of Electromagnetic Waves and Applications Pages: 1305-1315 Issue: 11 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.919878 File-URL: http://hdl.handle.net/10.1080/09205071.2014.919878 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:11:p:1305-1315 Template-Type: ReDIF-Article 1.0 Author-Name: Xinzhi Shi Author-X-Name-First: Xinzhi Author-X-Name-Last: Shi Author-Name: Chang Qi Author-X-Name-First: Chang Author-X-Name-Last: Qi Author-Name: Meiling Qu Author-X-Name-First: Meiling Author-X-Name-Last: Qu Author-Name: Shuangli Ye Author-X-Name-First: Shuangli Author-X-Name-Last: Ye Author-Name: Gaofeng Wang Author-X-Name-First: Gaofeng Author-X-Name-Last: Wang Author-Name: Lingling Sun Author-X-Name-First: Lingling Author-X-Name-Last: Sun Author-Name: Zhiping Yu Author-X-Name-First: Zhiping Author-X-Name-Last: Yu Title: Effects of coil shapes on wireless power transfer via magnetic resonance coupling Abstract: The wireless system with four coil resonators is a popular configuration for mid-range wireless power transfer (WPT) via magnetic resonance coupling. The design parameters of four coils have strong impact on efficiency, bandwidth, and transfer distance of the WPT system. In this work, a comprehensive study on effects of coil shapes is conducted. In particular, helix coils, planar spiral coils, and square helix coils are studied. It is shown that the helix coils offer the best performance (e.g. the highest efficiency, the widest bandwidth, and the longest transfer distance) under optimal load whereas the planar spiral coils exhibit the worst performance among these three types of coils. Nevertheless, the performance of the WPT system with helix coils degrades more rapidly than these with other two types of coils when the distance between the transmitting and receiving coils increases. Journal: Journal of Electromagnetic Waves and Applications Pages: 1316-1324 Issue: 11 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.919879 File-URL: http://hdl.handle.net/10.1080/09205071.2014.919879 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:11:p:1316-1324 Template-Type: ReDIF-Article 1.0 Author-Name: L.Z. Song Author-X-Name-First: L.Z. Author-X-Name-Last: Song Author-Name: Y.M. Nie Author-X-Name-First: Y.M. Author-X-Name-Last: Nie Title: A dual-polarized printed monopole antenna for C-band radar systems Abstract: A new low-cost printed monopole antenna for C-band dual-polarized radar systems is presented. The antenna is well suited for C-band radar systems requiring wide-angle scanning and ease of integration with printed monopole using low-cost commercial substrate. Irregular reflector for upper monopole is employed to obtain regular radiation pattern. Prototypes of the optimized designs have been fabricated and tested. Both simulated and measured results show that the proposed antenna has promising attributes with return loss less than -10$ -10 $ dB and both port isolation higher than 28 dB from 4.8 to 5.2 GHz. Moreover, stable radiation pattern with high gain (>6.8dBi$ {>}6.8~\mathrm{dBi} $) and reduced cross-polarization (<-20dB$ {<}-20~\mathrm{dB} $) is also obtained within the desired bandwidth. Journal: Journal of Electromagnetic Waves and Applications Pages: 1325-1332 Issue: 11 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.920698 File-URL: http://hdl.handle.net/10.1080/09205071.2014.920698 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:11:p:1325-1332 Template-Type: ReDIF-Article 1.0 Author-Name: Hanru Shao Author-X-Name-First: Hanru Author-X-Name-Last: Shao Author-Name: Jun Hu Author-X-Name-First: Jun Author-X-Name-Last: Hu Author-Name: Zaiping Nie Author-X-Name-First: Zaiping Author-X-Name-Last: Nie Author-Name: Lijun Jiang Author-X-Name-First: Lijun Author-X-Name-Last: Jiang Title: Simulation of multiscale structures using equivalence principle algorithm with grid-robust higher order vector basis Abstract: In this paper, equivalence principle algorithm (EPA) with grid-robust higher order vector basis (GRHOVB) is proposed to solve the multiscale problems. The EPA is a kind of domain decomposition method which transforms the interaction of objects into the interaction between virtual equivalence surfaces. Compared with traditional Curvilinear Rao–Wilton–Glisson function, GRHOVB can be used on the equivalence surface to reduce the number of unknowns and also to improve the accuracy. The tap basis is utilized to deal with current continuity when the object is intercepted by an equivalence surface. The equations are simplified further to improve the tap basis scheme. Moreover, to accelerate the solution, multilevel fast multipole algorithm is utilized in EPA. Numerical results are shown to demonstrate the accuracy and efficiency of the proposed method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1333-1346 Issue: 11 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.921123 File-URL: http://hdl.handle.net/10.1080/09205071.2014.921123 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:11:p:1333-1346 Template-Type: ReDIF-Article 1.0 Author-Name: Hai-Feng Zhang Author-X-Name-First: Hai-Feng Author-X-Name-Last: Zhang Author-Name: Shao-Bin Liu Author-X-Name-First: Shao-Bin Author-X-Name-Last: Liu Title: The properties of unusual surface plasmon modes and switching gaps in the three-dimensional photonic crystals composed of plasma-coated spheres Abstract: In this paper, the surface plasmon modes and switching gaps of three-dimensional (3D) photonic crystals (PCs) with diamond lattices, which are composed of core isotropic dielectric spheres surrounded by plasma shells inserted in air, are theoretically investigated in detail based on a modified plane wave expansion method. The equations for computing band structures for such 3D PCs are presented. Our analyses show that the proposed double-shell structure can produce the complete photonic band gaps (PBGs) which can be worked as an optical switching by manipulating the parameters of such PCs. However, the switching state cannot be tuned by the plasma collision frequency. Numerical results also demonstrate that a flatbands region and the stop band gaps (SBGs) in the (1 0 0) and (1 1 1) directions which are above the flatbands region can be achieved. The SBGs also can be tuned by the parameters as mentioned above. There is also a threshold value for the thickness of plasma shell, which can make the band structures of the 3D PCs with double-shell structures similar to those obtained from the same PC structure containing the pure plasma spheres. In this case, the dielectric function of the inserted core sphere will not affect the band structures. It means that the PBGs can be achieved by replacing the pure plasma spheres with such double-shell structures to make fabrication possible and save the material in the realization. It is also noticed that the flatbands region is determined by the existence of surface plasmon modes, and the upper edge of flatbands region does not depend on the topology of lattice. Journal: Journal of Electromagnetic Waves and Applications Pages: 1347-1359 Issue: 11 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.921124 File-URL: http://hdl.handle.net/10.1080/09205071.2014.921124 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:11:p:1347-1359 Template-Type: ReDIF-Article 1.0 Author-Name: Saeed Hatamzadeh-Varmazyar Author-X-Name-First: Saeed Author-X-Name-Last: Hatamzadeh-Varmazyar Author-Name: Zahra Masouri Author-X-Name-First: Zahra Author-X-Name-Last: Masouri Title: A numerical approach for calculating the radar cross-section of two-dimensional perfect electrically conducting structures Abstract: The focus of this article is on calculation of the radar cross-section (RCS) of two-dimensional closed-surface perfect electrically conducting scatterers of arbitrary cross-section in TM polarization. For this purpose, two-dimensional magnetic field integral equation (MFIE), formulated for TM polarization, is used as the mathematical model of the scattering problem. For solving the MFIE model, a numerical method based on cardinal basis functions is proposed to obtain the current distribution induced on the scatterer and then the RCS is calculated. The method is numerically evaluated via calculation of RCS for some structures of various cross-sections by which the accuracy and computational efficiency of the method will be demonstrated. Journal: Journal of Electromagnetic Waves and Applications Pages: 1360-1375 Issue: 11 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.924438 File-URL: http://hdl.handle.net/10.1080/09205071.2014.924438 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:11:p:1360-1375 Template-Type: ReDIF-Article 1.0 Author-Name: Ahmed A. Sakr Author-X-Name-First: Ahmed A. Author-X-Name-Last: Sakr Author-Name: Ezzeldin A. Soliman Author-X-Name-First: Ezzeldin A. Author-X-Name-Last: Soliman Author-Name: Alaa K. Abdelmageed Author-X-Name-First: Alaa K. Author-X-Name-Last: Abdelmageed Title: Electromagnetic TE scattering by a conducting cylinder coated with an inhomogeneous dielectric/magnetic material Abstract: The problem of electromagnetic TE scattering by an infinitely long conducting cylinder coated with an inhomogeneous dielectric/magnetic material is analyzed. A volume-surface integral equation (VSIE) approach is utilized to model the problem. By imposing the boundary conditions on the conducting surface, a surface magnetic field integral equation (MFIE) is developed. Inside the volume of the coating region, volume MFIEs are applied. The resultant integral equations are solved using the moment method. Numerical results for the bistatic radar cross section for different structures are presented. The results are validated using the exact series solution for a conducting circular cylinder coated with multilayers of homogeneous materials. Two types of coating materials are studied: the conventional or double positive (DPS) materials and the double negative (DNG) materials. Journal: Journal of Electromagnetic Waves and Applications Pages: 1376-1387 Issue: 11 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.924439 File-URL: http://hdl.handle.net/10.1080/09205071.2014.924439 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:11:p:1376-1387 Template-Type: ReDIF-Article 1.0 Author-Name: I.V. Andronov Author-X-Name-First: I.V. Author-X-Name-Last: Andronov Author-Name: D.A. Shevnin Author-X-Name-First: D.A. Author-X-Name-Last: Shevnin Title: High-frequency scattering by perfectly conducting prolate spheroids Abstract: The high-frequency asymptotics of the far-field amplitude for the electromagnetic scattering by a perfectly conducting strongly elongated spheroid is constructed in the case of near axial incidence. The leading order term of the asymptotics provides an accurate approximation for the radar cross-section, which can be concluded from the comparison with test results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1388-1396 Issue: 11 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.924882 File-URL: http://hdl.handle.net/10.1080/09205071.2014.924882 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:11:p:1388-1396 Template-Type: ReDIF-Article 1.0 Author-Name: The Editors Title: Corrigendum Journal: Journal of Electromagnetic Waves and Applications Pages: 1397-1397 Issue: 11 Volume: 28 Year: 2014 Month: 7 X-DOI: 10.1080/09205071.2014.922448 File-URL: http://hdl.handle.net/10.1080/09205071.2014.922448 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:11:p:1397-1397 Template-Type: ReDIF-Article 1.0 Author-Name: P. K. Choudhury Author-X-Name-First: P. K. Author-X-Name-Last: Choudhury Author-Name: M. Abou El-Nasr Author-X-Name-First: M. Author-X-Name-Last: Abou El-Nasr Title: Invited reviews Journal: Journal of Electromagnetic Waves and Applications Pages: 1399-1400 Issue: 12 Volume: 28 Year: 2014 Month: 8 X-DOI: 10.1080/09205071.2014.937931 File-URL: http://hdl.handle.net/10.1080/09205071.2014.937931 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:12:p:1399-1400 Template-Type: ReDIF-Article 1.0 Author-Name: Elias A. Alwan Author-X-Name-First: Elias A. Author-X-Name-Last: Alwan Author-Name: Abe A. Akhiyat Author-X-Name-First: Abe A. Author-X-Name-Last: Akhiyat Author-Name: Waleed Khalil Author-X-Name-First: Waleed Author-X-Name-Last: Khalil Author-Name: John L. Volakis Author-X-Name-First: John L. Author-X-Name-Last: Volakis Title: Analytical and experimental evaluation of a novel wideband digital beamformer with on-site coding Abstract: In this paper, we present a review of the state-of-the-art analog and digital beamformer architectures. In addition, an analytical and experimental evaluation of a novel transceiver architecture with on-site coding is conducted. The architecture features agile beam forming, jamming mitigation, and MIMO capability. The proposed architecture departs from traditional digital beamforming approaches. Specifically, a single analog to digital converter (ADC) is assigned to a group of array elements instead of having one ADC per element. To facilitate this approach, code division multiplexing is applied to each received antenna signal prior to combining them for digitization using a single ADC. In this paper, a detailed systematic evaluation of the proposed on-site coding receiver is carried out. We examine the trade-offs using non-ideal components (e.g. filters), including finite resolution ADCs and their impact on the system’s noise floor. It is concluded that the bit error rate shows minimal SNR degradation using filters of order 4 and ADCs with 10 bit resolution along with Walsh–Hadamard (WH) codes to realize on-site coding. We also present a two-channel implementation with components off-the-shelf assuming a modulated binary phase shift keying input signal and WH codes of length 8. Measurements show full signal recovery with minimal degradation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1401-1429 Issue: 12 Volume: 28 Year: 2014 Month: 8 X-DOI: 10.1080/09205071.2014.938175 File-URL: http://hdl.handle.net/10.1080/09205071.2014.938175 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:12:p:1401-1429 Template-Type: ReDIF-Article 1.0 Author-Name: Tae-Hong Kim Author-X-Name-First: Tae-Hong Author-X-Name-Last: Kim Author-Name: Yong-Hoon Kim Author-X-Name-First: Yong-Hoon Author-X-Name-Last: Kim Title: Human effect exposed to UWB signal for WBAN application Abstract: In this paper, the specific absorption (SA) distribution in a human body, exposed to ultra-wideband (UWB) pulse, has been analyzed by taking into account the dispersion characteristics of biological tissues. The dispersive properties of biological tissues are characterized by the 4-pole Cole-Cole model. However, implementing the finite-difference time-domain (FDTD) method of the 4-pole Cole-Cole model requires many resources and the calculation time. The complicated dispersive characteristics of biological tissues create difficulties in the analysis of exposure assessment by on-body devices. Because UWB frequency band is from 3.1 to 10.6 GHz, the dispersive characteristic may be sufficient to the 1-pole Cole-Cole model. In this paper, we fitted the 4-pole Cole-Cole model by the 1-pole Cole-Cole model for the given UWB band. The fitted results are in good agreement with the 4-pole Cole-Cole model. The FDTD method with the dispersive algorithm for the 1-pole Cole-Cole model was applied using SA analysis of the human body exposed to a UWB pulse signal. Journal: Journal of Electromagnetic Waves and Applications Pages: 1430-1444 Issue: 12 Volume: 28 Year: 2014 Month: 8 X-DOI: 10.1080/09205071.2014.914450 File-URL: http://hdl.handle.net/10.1080/09205071.2014.914450 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:12:p:1430-1444 Template-Type: ReDIF-Article 1.0 Author-Name: Hai-Yan Chen Author-X-Name-First: Hai-Yan Author-X-Name-Last: Chen Author-Name: Yan Guan Author-X-Name-First: Yan Author-X-Name-Last: Guan Author-Name: Pei-Heng Zhou Author-X-Name-First: Pei-Heng Author-X-Name-Last: Zhou Author-Name: Jian-Liang Xie Author-X-Name-First: Jian-Liang Author-X-Name-Last: Xie Author-Name: Long-Jiang Deng Author-X-Name-First: Long-Jiang Author-X-Name-Last: Deng Title: Microwave transmission of free-standing metasurfaces consisting of square metal patch Abstract: The transmission characteristics of free-standing metasurfaces consisting of square metal patch, which rotated 45° (which is defined as the rotated metasurfaces) or 0° (which is defined as the regular metasurfaces) around their array arrangement direction, have been studied at microwave frequencies. The proposed metasurfaces in vacuum environment, considered as free-standing planar frequency selective surfaces, are analyzed for searching its transmission characteristics with variable dimension at different frequencies. For the rotated metasurfaces, a bizarre phenomenon, in which transmission will increase inversely as the size of the rotated square metal patch is increased, can be observed at the periodicity of these arrays between 2λ/3 and 4λ/5, where λ is the considered wavelength. But for the regular metasurfaces, this phenomenon cannot be observed. In addition, the rotated metasurfaces and the regular metasurfaces loading on infinite resistive sheet are also studied for discussing its transmission and reflection properties with similar conditions. It is found that the regular metasurfaces loading on infinite resistive sheet show almost linear variable electromagnetic characteristic with the variable size of the regular metasurfaces at a broad frequency range. However, because of the scattering mechanism of evanescent diffraction, the similar linear relationship of electromagnetic characteristic cannot be obtained from the rotated case. These results can be used as a guide for realizing tensor impedance surfaces with various gradient properties. Journal: Journal of Electromagnetic Waves and Applications Pages: 1445-1454 Issue: 12 Volume: 28 Year: 2014 Month: 8 X-DOI: 10.1080/09205071.2014.926841 File-URL: http://hdl.handle.net/10.1080/09205071.2014.926841 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:12:p:1445-1454 Template-Type: ReDIF-Article 1.0 Author-Name: Cemile Bardak Author-X-Name-First: Cemile Author-X-Name-Last: Bardak Author-Name: Mohammad Saed Author-X-Name-First: Mohammad Author-X-Name-Last: Saed Title: Microwave imaging with a time-reversed finite-difference time-domain technique Abstract: A novel approach to microwave imaging in three dimensions based on time-reversed finite-difference time-domain method (FDTD-TR) is presented. The proposed computationally efficient technique allows the reconstruction of detailed images of scattering objects. Transmissions as well as reflection imaging modalities in the near-field and far-field were investigated. In this study, we implemented the FDTD-TR algorithm in three dimensions using time-reversed convolutional perfectly matching layers as boundaries to truncate the simulation domain. The method works for dielectric as well as conducting objects. The method’s capabilities in imaging multiple objects and behind-the-wall imaging are also presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 1455-1467 Issue: 12 Volume: 28 Year: 2014 Month: 8 X-DOI: 10.1080/09205071.2014.929048 File-URL: http://hdl.handle.net/10.1080/09205071.2014.929048 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:12:p:1455-1467 Template-Type: ReDIF-Article 1.0 Author-Name: Sergio Fernandez Romero Author-X-Name-First: Sergio Fernandez Author-X-Name-Last: Romero Author-Name: Guadalupe Gutierrez Author-X-Name-First: Guadalupe Author-X-Name-Last: Gutierrez Author-Name: Ivan Gonzalez Author-X-Name-First: Ivan Author-X-Name-Last: Gonzalez Title: Prediction of the maximum electric field level inside a metallic cavity using a quality factor estimation Abstract: This paper presents a method for predicting the maximum electric field level inside a metallic cavity making use of the quality factor (Q) estimation. This calculation requires a two-step approach combining several theoretical models which can be found in the literature. A very good agreement in the frequency range between 100 MHz and 40 GHz has been achieved with the data obtained from the validation of two reverberation chambers made of different conductive materials. The wide frequency band analyzed permits us to draw conclusions about the main contributions in the cavity Q and their relationships with the maximum electric field level. This paper also describes and identifies the relationships between the antenna parameters and dissipation mechanisms vs. frequency for the different models. This estimation could be used to calculate a possible EMC threat of a spurious emission of EM signals which could produce a susceptibility problem in other equipments installed in the same cavity. Journal: Journal of Electromagnetic Waves and Applications Pages: 1468-1477 Issue: 12 Volume: 28 Year: 2014 Month: 8 X-DOI: 10.1080/09205071.2014.929049 File-URL: http://hdl.handle.net/10.1080/09205071.2014.929049 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:12:p:1468-1477 Template-Type: ReDIF-Article 1.0 Author-Name: Ben Ma Author-X-Name-First: Ben Author-X-Name-Last: Ma Author-Name: Shaobin Liu Author-X-Name-First: Shaobin Author-X-Name-Last: Liu Author-Name: Borui Bian Author-X-Name-First: Borui Author-X-Name-Last: Bian Author-Name: Xiangkun Kong Author-X-Name-First: Xiangkun Author-X-Name-Last: Kong Author-Name: Haifeng Zhang Author-X-Name-First: Haifeng Author-X-Name-Last: Zhang Author-Name: Zhiwen Mao Author-X-Name-First: Zhiwen Author-X-Name-Last: Mao Author-Name: Beiyin Wang Author-X-Name-First: Beiyin Author-X-Name-Last: Wang Title: Novel three-band microwave metamaterial absorber Abstract: In this paper, a novel three-band microwave metamaterial absorber is presented. The proposed absorber consists of a metallic planar cross and square layer on the top and a metallic ground plane at the bottom. They are separated by a dielectric layer. The experimental results show that the proposed absorber exhibits triple band absorption responses lying in C-band, X-band, and Ku-band. The proposed absorber can perform absorption peaks at three resonant frequencies of 6.16, 8.76, and 12.54 GHz with the absorption of 99.87, 99.98, and 99.99% can be acquired, respectively. In addition, the absorber can operate at large incident angles for both TE and TM polarization. Journal: Journal of Electromagnetic Waves and Applications Pages: 1478-1486 Issue: 12 Volume: 28 Year: 2014 Month: 8 X-DOI: 10.1080/09205071.2014.929050 File-URL: http://hdl.handle.net/10.1080/09205071.2014.929050 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:12:p:1478-1486 Template-Type: ReDIF-Article 1.0 Author-Name: Sule Colak Author-X-Name-First: Sule Author-X-Name-Last: Colak Author-Name: Tan F. Wong Author-X-Name-First: Tan F. Author-X-Name-Last: Wong Author-Name: A. Hamit Serbest Author-X-Name-First: A. Hamit Author-X-Name-Last: Serbest Title: Frequency domain analysis of UWB dipole arrays Abstract: In this paper, behavior of dipole arrays for Ultra-Wideband (UWB) signals is investigated using an approach in the frequency domain. Energy formulas and correlation coefficient expressions are derived for an array of thin dipoles at the transmitting side and one dipole at the receiving side. Beam-scanning characteristics of UWB dipole arrays are also investigated in the same manner. Different element lengths are used in the array to improve the detection and beam-scanning capabilities. Derived frequency domain expressions can easily be evaluated numerically, allowing us to obtain reasonably accurate results. This approach which is an alternative to numerical methods in time domain serves as a different viewpoint and will be a significant step to make progress in UWB antenna design. Journal: Journal of Electromagnetic Waves and Applications Pages: 1487-1501 Issue: 12 Volume: 28 Year: 2014 Month: 8 X-DOI: 10.1080/09205071.2014.931828 File-URL: http://hdl.handle.net/10.1080/09205071.2014.931828 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:12:p:1487-1501 Template-Type: ReDIF-Article 1.0 Author-Name: O.M. Yücedag̃ Author-X-Name-First: O.M. Author-X-Name-Last: Yücedag̃ Author-Name: A.S. Türk Author-X-Name-First: A.S. Author-X-Name-Last: Türk Title: Design of horn fed offset parabolic reflector antennas with analytical regularization method Abstract: This paper presents two-dimensional (2D) parametric design of offset parabolic reflectors with horn feeders to achieve pencil beam and cosecant-squared (csc2) patterns for communication systems and surveillance radars. Analytical regularization method (ARM) is used as a fast and accurate pre-design tool to compute radiation characteristics of the feeders and the reflectors. The numerical procedure is initially verified by the analytical methods and the calculated results are presented for the proposed novel designs. Journal: Journal of Electromagnetic Waves and Applications Pages: 1502-1511 Issue: 12 Volume: 28 Year: 2014 Month: 8 X-DOI: 10.1080/09205071.2014.932056 File-URL: http://hdl.handle.net/10.1080/09205071.2014.932056 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:12:p:1502-1511 Template-Type: ReDIF-Article 1.0 Author-Name: Chao Sun Author-X-Name-First: Chao Author-X-Name-Last: Sun Author-Name: Huili Zheng Author-X-Name-First: Huili Author-X-Name-Last: Zheng Author-Name: Lingfei Zhang Author-X-Name-First: Lingfei Author-X-Name-Last: Zhang Author-Name: Ying Liu Author-X-Name-First: Ying Author-X-Name-Last: Liu Title: Wideband compact circularly polarized patch antenna loaded with shorting probe for GNSS applications Abstract: In this paper, a novel design of wideband compact patch antenna is proposed for the handheld application of global navigation satellite system (GNSS). In order to meet the size requirement of the handheld application, the shorting load is employed as the miniaturization technique and the overall size of the proposed antenna is only 70 mm (length) × 70 mm (width) × 25 mm (height). Due to the narrow bandwidth of the shorting loaded patch antenna, shorting probe with enlarged width, as well as the air substrate, is adopted to enhance the bandwidth of the proposed antenna and make it fulfil the GNSS bandwidth requirement. Simulation and measured results show that the proposed antenna has a bandwidth of 41.5% for VSWR < 1.5 from 1.05 to 1.6 GHz and 35.7% 3-dB axial ratio bandwidth from 1.15 to 1.65 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1512-1521 Issue: 12 Volume: 28 Year: 2014 Month: 8 X-DOI: 10.1080/09205071.2014.932259 File-URL: http://hdl.handle.net/10.1080/09205071.2014.932259 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:12:p:1512-1521 Template-Type: ReDIF-Article 1.0 Author-Name: A. Khodja Author-X-Name-First: A. Author-X-Name-Last: Khodja Author-Name: D. Abbou Author-X-Name-First: D. Author-X-Name-Last: Abbou Author-Name: M.C.E. Yagoub Author-X-Name-First: M.C.E. Author-X-Name-Last: Yagoub Author-Name: R. Touhami Author-X-Name-First: R. Author-X-Name-Last: Touhami Author-Name: H. Baudrand Author-X-Name-First: H. Author-X-Name-Last: Baudrand Title: Novel dispersive modal approach for fast analysis of asymmetric coplanar structures on isotropic/anisotropic substrates Abstract: In this paper, an original modal technique is proposed as promising tool for fast and accurate analysis of asymmetric coplanar-type structures on isotropic/anisotropic substrates. For this aim, a new quasi-symmetric approach was introduced, using C- and π-mode trial functions along with the mathematical operator formalism used in electromagnetism. It efficiently evaluates the dispersion effect of coplanar structures leading to smaller-size dispersion matrix and thus, reducing the CPU time without losing the overall design accuracy. The proposed approach was demonstrated through successful comparisons with published data to further confirm the adequate choice of trial functions used in this quasi-symmetric model. Journal: Journal of Electromagnetic Waves and Applications Pages: 1522-1540 Issue: 12 Volume: 28 Year: 2014 Month: 8 X-DOI: 10.1080/09205071.2014.932260 File-URL: http://hdl.handle.net/10.1080/09205071.2014.932260 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:12:p:1522-1540 Template-Type: ReDIF-Article 1.0 Author-Name: J.Y. Rhee Author-X-Name-First: J.Y. Author-X-Name-Last: Rhee Author-Name: Y.J. Yoo Author-X-Name-First: Y.J. Author-X-Name-Last: Yoo Author-Name: K.W. Kim Author-X-Name-First: K.W. Author-X-Name-Last: Kim Author-Name: Y.J. Kim Author-X-Name-First: Y.J. Author-X-Name-Last: Kim Author-Name: Y.P. Lee Author-X-Name-First: Y.P. Author-X-Name-Last: Lee Title: Metamaterial-based perfect absorbers Abstract: Metamaterials are artificially-engineered materials, possessing properties which are not readily observable in materials existing in nature. Since they show very novel properties such as left-handed behavior, negative refractive index, classical analog of electromagnetically-induced transparency, extraordinary transmission, negative Doppler effect, and so on, they can be used for perfect lens, invisibility cloaking, perfect absorption and transmission, etc. Metamaterial-based perfect absorbers (MMPAs) are promising candidates for the practical application of perfect absorbers. MMPA is usually composed of three layers. The first layer is periodically-arranged metallic patterns, whose structure and geometrical parameters should be carefully adjusted to fulfill the impedance-matching condition with the ambient, allowing no reflection of incident electromagnetic (EM) waves. The second layer is a dielectric layer, which allows a space for the EM waves to be dissipated, and sometimes plays a role of resonance cavity to prolong the time taken by the EM waves inside the second layer. Finally, the third layer is a continuous metallic plate, blocking remnant transmission. For practical usage, several aspects of MMPAs are to be considered seriously. Some of them are broadband operation, polarization-independent response, omni-directional response, and tunability. These aspects are basically determined by the structures of MMPA. Another important aspect is flexibility, which is determined by the material used in the fabrication. In this review, the basic operating principles of MMPAs and brief introduction of recent progresses in the field of MMPAs operating in different frequency ranges (GHz, THz and infrared/visible) are presented. Perspectives and future works for the investigation and the real application of MMPAs are also presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 1541-1580 Issue: 13 Volume: 28 Year: 2014 Month: 9 X-DOI: 10.1080/09205071.2014.944273 File-URL: http://hdl.handle.net/10.1080/09205071.2014.944273 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:13:p:1541-1580 Template-Type: ReDIF-Article 1.0 Author-Name: J.A. Brandão Faria Author-X-Name-First: J.A. Author-X-Name-Last: Brandão Faria Title: A multimodal approach to the analysis of the attenuation properties of MF communication systems in mine tunnels Abstract: Low-attenuation medium-frequency communications are still utilized in mine tunnels as useful backup systems. Previous research on the topic has addressed the evaluation and measurement of the wave propagation parameters of these communication structures considering the presence of a single conductor inside the tunnel. In this work, the presence of multiple conductors is considered and a multimodal approach is developed to determine the expected attenuation as a function of the distance and frequency. The examples provided in the paper concern a three-conductor structure, consisting of one power cable and two rail tracks, where three basic modes propagate. Simulation results show that the expected attenuation depends on the set of initial currents injected into the conductors and that, in the case of randomly injected currents, the expected attenuation constant decreases with distance, tending to the attenuation constant of the least attenuated mode. Journal: Journal of Electromagnetic Waves and Applications Pages: 1581-1595 Issue: 13 Volume: 28 Year: 2014 Month: 9 X-DOI: 10.1080/09205071.2014.932261 File-URL: http://hdl.handle.net/10.1080/09205071.2014.932261 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:13:p:1581-1595 Template-Type: ReDIF-Article 1.0 Author-Name: Guang-Xiao Luo Author-X-Name-First: Guang-Xiao Author-X-Name-Last: Luo Author-Name: Xing-Chang Wei Author-X-Name-First: Xing-Chang Author-X-Name-Last: Wei Author-Name: Ran Hao Author-X-Name-First: Ran Author-X-Name-Last: Hao Author-Name: Xiang Cui Author-X-Name-First: Xiang Author-X-Name-Last: Cui Author-Name: Er-Ping Li Author-X-Name-First: Er-Ping Author-X-Name-Last: Li Title: Full RLGC model extraction of Through Silicon Via (TSV) with charge distribution effects Abstract: The analytical model based on Poisson–Boltzmann equation in a cylindrical coordinate system is developed for simulating the electrical parameters of the three-dimensional Through Silicon Via (TSV) interconnection. Considering the effects of bias voltage, the accurate charge distribution and the high-frequency capacitance in the depletion layer of the semiconductor is obtained. Moreover, the resistance and inductance parameters of TSV are extracted by using the partial element equivalent circuit method. Finally, the full resistance–inductance–capacitance–conductance electrical model of TSV interconnection is presented first time with the semiconductor behaviour, and the transmission characteristics of signal-ground TSV structure are studied. Journal: Journal of Electromagnetic Waves and Applications Pages: 1596-1609 Issue: 13 Volume: 28 Year: 2014 Month: 9 X-DOI: 10.1080/09205071.2014.933086 File-URL: http://hdl.handle.net/10.1080/09205071.2014.933086 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:13:p:1596-1609 Template-Type: ReDIF-Article 1.0 Author-Name: Zusheng Jin Author-X-Name-First: Zusheng Author-X-Name-Last: Jin Author-Name: Liangfeng Ye Author-X-Name-First: Liangfeng Author-X-Name-Last: Ye Author-Name: Guohui Zhou Author-X-Name-First: Guohui Author-X-Name-Last: Zhou Author-Name: Hu Yang Author-X-Name-First: Hu Author-X-Name-Last: Yang Author-Name: Giorgio Montisci Author-X-Name-First: Giorgio Author-X-Name-Last: Montisci Title: A robust and accurate method for the computation of mixed potential Green’s function in cylindrically stratified media Abstract: Accurate computation of the spatial-domain mixed potential Green’s function (MPGF) in cylindrically stratified media is achieved by a judicious cooperation of two recent works on the same topic. An improved procedure is devised to provide accurate values of the MPGF both in the near and far field, including the axial line region. A numerical approach based on the generalized pencil-of-function method is applied to eliminate the axial line problem, and the rational function fitting method is employed to improve accuracy and stability in the far field. As a result, a robust and efficient method is developed, and good accuracy is achieved both in the near and far field, and along the axial line. Journal: Journal of Electromagnetic Waves and Applications Pages: 1610-1621 Issue: 13 Volume: 28 Year: 2014 Month: 9 X-DOI: 10.1080/09205071.2014.935488 File-URL: http://hdl.handle.net/10.1080/09205071.2014.935488 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:13:p:1610-1621 Template-Type: ReDIF-Article 1.0 Author-Name: Bin Xia Author-X-Name-First: Bin Author-X-Name-Last: Xia Author-Name: Lin-Sheng Wu Author-X-Name-First: Lin-Sheng Author-X-Name-Last: Wu Author-Name: Junfa Mao Author-X-Name-First: Junfa Author-X-Name-Last: Mao Author-Name: Lin Yang Author-X-Name-First: Lin Author-X-Name-Last: Yang Title: A new quad-band Wilkinson power divider Abstract: In this paper, a new quad-band Wilkinson power divider (WPD) is proposed and designed with an analytical method. A quad-band impedance transformer built up by three transmission lines and two loaded shorted-stubs is firstly proposed. The related design equations are deduced by matrix transformation. With proper assumption, a simple analytical design method is presented for the quad-band WPD, and the derived equations and plotted curves can be used for the design. The designed quad-band WPD is an equal power division structure and only one surface-mounted resistor is needed. It has been demonstrated that our proposed WPD possesses simple configuration, small size, low cost, and good performance, i.e. high isolation, low insertion, and return losses, for the quad bands simultaneously from the simulated and measured results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1622-1634 Issue: 13 Volume: 28 Year: 2014 Month: 9 X-DOI: 10.1080/09205071.2014.938170 File-URL: http://hdl.handle.net/10.1080/09205071.2014.938170 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:13:p:1622-1634 Template-Type: ReDIF-Article 1.0 Author-Name: Li Xi Author-X-Name-First: Li Author-X-Name-Last: Xi Author-Name: Yang Lin Author-X-Name-First: Yang Author-X-Name-Last: Lin Title: A novel design of dual-band Wilkinson power divider with simple structure and wide band-ratios characteristics Abstract: The design and analysis of a dual-band equal-split Wilkinson power divider are presented in this paper. It is proved that a coupled line with a pair of stubs structure is capable of the dual-band operation in the Wilkinson power divider. Moreover, the overall structure of power divider can be simplified with small number of transmission line sections using the proposed method, and the proposed divider can achieve dual-band operation over a wide range of band-ratios. For verification, a microwave power divider operating at 1 and 2.5 GHz is fabricated, and the experimental results show that the designed power divider fulfills all the features of a conventional Wilkinson power divider, such as an equal power split and impedance matching at ports. Journal: Journal of Electromagnetic Waves and Applications Pages: 1635-1641 Issue: 13 Volume: 28 Year: 2014 Month: 9 X-DOI: 10.1080/09205071.2014.938171 File-URL: http://hdl.handle.net/10.1080/09205071.2014.938171 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:13:p:1635-1641 Template-Type: ReDIF-Article 1.0 Author-Name: M. Kiani Author-X-Name-First: M. Author-X-Name-Last: Kiani Author-Name: A. Abdolali Author-X-Name-First: A. Author-X-Name-Last: Abdolali Author-Name: M.M. Salary Author-X-Name-First: M.M. Author-X-Name-Last: Salary Title: Analysis of scattering from cylindrical structures coated by radially inhomogeneous layer using Taylor’s series method Abstract: Consider a cylindrical structure with an arbitrary core coated by a radially inhomogeneous layer in a general case. The core of the structure may be PEC, PMC, PEMC, impedance boundary, dielectric, or metamaterial. Contrary to the scattering problems of homogeneous media, scattering problems of inhomogeneous media do not have exact solutions except for special inhomogeneous profiles. In this paper, a general frequency domain method is proposed to analyze scattering from such structures on the basis of Taylor’s series concept for obliquely incident electromagnetic (EM) waves with arbitrary polarizations. The validity of the suggested method is verified by comparison with the exact solutions of some special profiles for the coating layer. Furthermore, a comparison is made between the proposed method and other commonly used methods in the literature, which confirms that the proposed method is general, fast, and has good convergence toward the solution. Moreover, as an application, we employed the method for optimization of the scattering echo width of a PEC cylinder. Journal: Journal of Electromagnetic Waves and Applications Pages: 1642-1660 Issue: 13 Volume: 28 Year: 2014 Month: 9 X-DOI: 10.1080/09205071.2014.938172 File-URL: http://hdl.handle.net/10.1080/09205071.2014.938172 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:13:p:1642-1660 Template-Type: ReDIF-Article 1.0 Author-Name: X.-Z. Ren Author-X-Name-First: X.-Z. Author-X-Name-Last: Ren Author-Name: L.-N. Chen Author-X-Name-First: L.-N. Author-X-Name-Last: Chen Title: Four-dimensional SAR imaging algorithm using Bayesian compressive sensing Abstract: The compressive sensing (CS) based 4-D synthetic aperture radar (SAR) imaging method performs well in the case of high signal-to-noise ratios (SNR). However, in the presence of strong noises, the performance of CS-based method degrades and the number of false targets increases rapidly. In this paper, a novel 4-D SAR imaging method is proposed based on Bayesian compressive sensing (BCS). Assume that the target scattering field follows the Cauchy distribution, the 4-D SAR imaging is transformed into signal reconstruction via maximum a posteriori estimation. In addition, Poisson disk sampling is utilized to generate the radar positions of 4-D SAR in the baseline-time plane. Experimental results show that the proposed method is capable of effective suppression of the noise by exploiting the sparseness prior distribution of the image scene, and a well-focused image could also be achieved even under the condition of low SNR. Journal: Journal of Electromagnetic Waves and Applications Pages: 1661-1676 Issue: 13 Volume: 28 Year: 2014 Month: 9 X-DOI: 10.1080/09205071.2014.938174 File-URL: http://hdl.handle.net/10.1080/09205071.2014.938174 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:13:p:1661-1676 Template-Type: ReDIF-Article 1.0 Author-Name: J.A. Brandão Faria Author-X-Name-First: J.A. Author-X-Name-Last: Brandão Faria Title: Multimodal propagation in multiconductor transmission lines Abstract: This paper is devoted to the analysis of the multiconductor transmission line (MTL) – a type of structure that is encountered in very many applications ranging from power systems to microwave engineering. Our aim is to provide the reader with a self-contained presentation of the subject where MTL frequency-domain equations are formulated and their solution is established. Matrix techniques are made intense use in order to permit a compact analysis of the problem. Solutions to MTL equations are presented in two different useful formats; at first we consider a solution in the form of a superposition of natural modes of propagation, later, a relationship between voltages and currents at the MTL ports is established by employing the transmission matrix formalism. The presentation is not limited to the simple case of uniform MTL, the important problem of nonuniform MTL is also encompassed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1677-1702 Issue: 14 Volume: 28 Year: 2014 Month: 9 X-DOI: 10.1080/09205071.2014.960536 File-URL: http://hdl.handle.net/10.1080/09205071.2014.960536 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:14:p:1677-1702 Template-Type: ReDIF-Article 1.0 Author-Name: Himangshu Bhusan Baskey Author-X-Name-First: Himangshu Bhusan Author-X-Name-Last: Baskey Author-Name: M. Jaleel Akhtar Author-X-Name-First: M. Jaleel Author-X-Name-Last: Akhtar Author-Name: T.C. Shami Author-X-Name-First: T.C. Author-X-Name-Last: Shami Title: Investigation and performance evaluation of carbon black- and carbon fibers-based wideband dielectric absorbers for X-band stealth applications Abstract: This paper presents the design, preparation, and electromagnetic testing of wideband dielectric absorbers based on carbon fibers and carbon black powders for stealth applications. The specially prepared absorbers are characterized using the partially filled waveguide technique for the complex permittivity, and the return loss of the sample is measured using the free-space system in the X-band frequency region. A maximum return loss of 29 dB i.e. absorption of 99% at 10.3 GHz is achieved with minimum 97% absorption throughout the X-band frequency region. The fabricated absorber having density of 0.28 gm/cc and thickness of 2 mm makes it a potential candidate for stealth applications especially for the defense targets. A multilevel fast multipole method-based electromagnetic simulation is carried out on the artillery shell model, and on the leading edge model of the aircraft using the measured electromagnetic properties of designed absorber for the radar cross-section (RCS) reduction. The maximum RCS reduction of 27 and 20 dB has been observed for the artillery shell model, and for the leading edge of stealthy aircraft model, respectively, as compared to that of the PEC structure at 10.3 GHz frequency. Journal: Journal of Electromagnetic Waves and Applications Pages: 1703-1715 Issue: 14 Volume: 28 Year: 2014 Month: 9 X-DOI: 10.1080/09205071.2014.933680 File-URL: http://hdl.handle.net/10.1080/09205071.2014.933680 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:14:p:1703-1715 Template-Type: ReDIF-Article 1.0 Author-Name: ZongXin Wang Author-X-Name-First: ZongXin Author-X-Name-Last: Wang Author-Name: Bo Xiang Author-X-Name-First: Bo Author-X-Name-Last: Xiang Author-Name: MinMin He Author-X-Name-First: MinMin Author-X-Name-Last: He Author-Name: WenBin Dou Author-X-Name-First: WenBin Author-X-Name-Last: Dou Title: A waveguide-based millimeter-wave power combining network Abstract: A waveguide-based four-way millimeter-wave power combining network is designed in this paper. The power combining network is composed of a power divider sub-network, four metal PCB cavities, and a power combiner sub-network. A compact waveguide directional coupler is designed to act as the power combiner and power divider. Parameters and shapes of the PCB cavities are carefully studied to avoid the resonant modes of the cavities, and a rhombus-like PCB cavity which has good transmission coefficient is presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 1716-1725 Issue: 14 Volume: 28 Year: 2014 Month: 9 X-DOI: 10.1080/09205071.2014.934923 File-URL: http://hdl.handle.net/10.1080/09205071.2014.934923 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:14:p:1716-1725 Template-Type: ReDIF-Article 1.0 Author-Name: Hamad S. Alsuhaim Author-X-Name-First: Hamad S. Author-X-Name-Last: Alsuhaim Author-Name: Vuk Vojisavljevic Author-X-Name-First: Vuk Author-X-Name-Last: Vojisavljevic Author-Name: Elena Pirogova Author-X-Name-First: Elena Author-X-Name-Last: Pirogova Title: Effects of low power microwaves at 1.8, 2.1, and 2.3 GHz on l-Lactic dehydrogenase and Glutathione peroxidase enzymes Abstract: Radiofrequency/microwave (RF/MW) radiation has been integrated in almost every aspect of today’s modern life and applied in radar, telecommunication systems, health/medical devices, and food sterilization technology. However, the increasing rate of exposures to RF/MW radiation, especially exposures from mobile phones, has raised health concerns and stimulated much research into biological and health effects of low power MWs. The heating effect of the MWs is already well known and documented; however, a doubt remains on the existence of non-thermal biological effects. This study evaluates the effects of low power MWs on kinetics of l-Lactic dehydrogenase and Glutathione peroxidase enzymes irradiated at the frequencies of 1.8, 2.1, and 2.3 GHz and power of 10 dBm using the commercial Transverse Electro-Magnetic cell. The selected frequencies are used frequently in G4 and G5 mobile networks. The findings reveal that MWs at the studied parameters induce changes in the enzymes’ kinetics, which lead to modulation of rate of change in corresponding reactions these enzymes catalyze. Journal: Journal of Electromagnetic Waves and Applications Pages: 1726-1735 Issue: 14 Volume: 28 Year: 2014 Month: 9 X-DOI: 10.1080/09205071.2014.934924 File-URL: http://hdl.handle.net/10.1080/09205071.2014.934924 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:14:p:1726-1735 Template-Type: ReDIF-Article 1.0 Author-Name: Yawen Liu Author-X-Name-First: Yawen Author-X-Name-Last: Liu Author-Name: Yiwang Chen Author-X-Name-First: Yiwang Author-X-Name-Last: Chen Author-Name: Pin Zhang Author-X-Name-First: Pin Author-X-Name-Last: Zhang Author-Name: Xin Xu Author-X-Name-First: Xin Author-X-Name-Last: Xu Title: Implementation and application of a convolution PML using the MRTD algorithm Abstract: In this paper, a novel implementation of convolution perfectly matched layer (CPML) is proposed for the multiresolution time-domain (MRTD) method. The implementation is completely independent of the host material and easier to obtain than that of the popularly used anisotropic perfectly matched layer, when treating more generalized media. The absorbing effectiveness of the CPML is discussed and validated in a two-dimensional case, and we apply the CPML in three-dimensional cases with different microwave circuit components. Numerical results show that the CPML performs well for absorbing electromagnetic waves in the MRTD scheme. Journal: Journal of Electromagnetic Waves and Applications Pages: 1736-1745 Issue: 14 Volume: 28 Year: 2014 Month: 9 X-DOI: 10.1080/09205071.2014.937507 File-URL: http://hdl.handle.net/10.1080/09205071.2014.937507 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:14:p:1736-1745 Template-Type: ReDIF-Article 1.0 Author-Name: Hany M. Zamel Author-X-Name-First: Hany M. Author-X-Name-Last: Zamel Author-Name: Essam El Diwany Author-X-Name-First: Essam Author-X-Name-Last: El Diwany Author-Name: Hadia El Hennawy Author-X-Name-First: Hadia Author-X-Name-Last: El Hennawy Title: Electromagnetic scattering by approximately cloaked cylindrical bodies with nonhomogeneous anisotropic cloaking material Abstract: In cloaking, a body is hidden from detection by surrounding it by a coating consisting of an unusual anisotropic nonhomogeneous material. The permittivity and permeability of such a cloak are determined by the coordinate transformation of compressing a hidden body into a point (3D or spherical configuration) or a line (2D or cylindrical configuration). Some components of the electrical parameters of the cloaking material ε,μ$ \left( {{\varepsilon },{\mu }} \right) $ are required to have infinite or zero value at the boundary of the hidden object. Approximate cloaking can be achieved by transforming the cylindrical bodies (dielectric and conducting) virtually into a small cylinder rather than a line, which eliminates the zero or infinite values of the electrical parameters but produces scattering. The solution is obtained by rigorously solving Maxwell equations using angular harmonics expansion. In this work, the scattering pattern and the back-scattering cross-section against the frequency for cloaked conducting and dielectric cylinders are studied for both transverse magnetic (TMz) and transverse electric (TEz) polarizations of the incident plane wave for different transformed body radii. Journal: Journal of Electromagnetic Waves and Applications Pages: 1746-1765 Issue: 14 Volume: 28 Year: 2014 Month: 9 X-DOI: 10.1080/09205071.2014.938173 File-URL: http://hdl.handle.net/10.1080/09205071.2014.938173 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:28:y:2014:i:14:p:1746-1765 Template-Type: ReDIF-Article 1.0 Author-Name: Arooj Hameed Author-X-Name-First: Arooj Author-X-Name-Last: Hameed Author-Name: Muhammad Omar Author-X-Name-First: Muhammad Author-X-Name-Last: Omar Author-Name: Aqeel Abbas Syed Author-X-Name-First: Aqeel Abbas Author-X-Name-Last: Syed Author-Name: Qaisar Abbas Naqvi Author-X-Name-First: Qaisar Abbas Author-X-Name-Last: Naqvi Title: Power tunneling and rejection from fractal chiral–chiral interface Abstract: In this article, the reflection and transmission coefficients for a chiral–chiral interface of non-integer dimension has been determined theoretically. In order to realize the so-called fractal chiral–chiral interface, one of the two chiral media, forming the interface, is assumed to be of fractal dimensions. The fields inside the fractal chiral media are expressed using a fractional parameter 10.5%) at low frequencies. Dielectric constant correlated positively with glycosuria level at frequency above 40 GHz while loss factor correlated negatively with glycosuria level at frequency above 15 GHz. The experimental data closely matched the Debye model. Journal: Journal of Electromagnetic Waves and Applications Pages: 2278-2292 Issue: 17 Volume: 29 Year: 2015 Month: 11 X-DOI: 10.1080/09205071.2015.1072480 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1072480 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:17:p:2278-2292 Template-Type: ReDIF-Article 1.0 Author-Name: Petrishia Arockiasamy Author-X-Name-First: Petrishia Author-X-Name-Last: Arockiasamy Author-Name: Sasikala Mohan Author-X-Name-First: Sasikala Author-X-Name-Last: Mohan Title: Partition lens system for focusing field from PSIRA with TSVS feed on biological target Abstract: The Impulse Radiating Antenna (IRA) is suited for radiating picosecond electromagnetic impulse for the treatment of skin cancer. The feed of the reflector IRA is an ultra-wideband antenna. In this proposed work, a Tapered Slot Vivaldi Shaped (TSVS) feed arm is designed for Prolate Spheroidal Reflector (PSR). The feed antenna is placed at the first focal point of the PSR. The picosecond electric pulse is launched from the first focal point and is focused at the second focal point where the target is placed. Next Partition dielectric lens system is designed to enhance the electric field and reduce the spot size of the focused pulse. The TSVS feed arm is matched from 500 MHz to 10 GHz. The 3 dB angular beam width of the proposed IRA with 50 cm aperture diameter is 4.3°, and the radiation efficiency is 63% at 10 GHz. Simulation results show that the full width half maximum of electric field intensity is reduced by 57% in the axial direction and 20% in the lateral direction when compared to the conical feed IRA without lens. The three layer partition lens system greatly reduces the spot size from 1.187 to 0.75 cm, when compared to five layer spherical dielectric lens and increases the electric field by 65%. Journal: Journal of Electromagnetic Waves and Applications Pages: 2293-2307 Issue: 17 Volume: 29 Year: 2015 Month: 11 X-DOI: 10.1080/09205071.2015.1061461 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1061461 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:17:p:2293-2307 Template-Type: ReDIF-Article 1.0 Author-Name: A.R. Eskandari Author-X-Name-First: A.R. Author-X-Name-Last: Eskandari Author-Name: M.R. Eskandari Author-X-Name-First: M.R. Author-X-Name-Last: Eskandari Title: Microwave imaging of two-dimensional objects using an enhancement method Abstract: A 2D complete identification algorithm for dielectric and multiple objects immersed in air is presented. The employed technique consists of initially retrieving the shape and position of the scattering object using a linear sampling method and then determining the electric permittivity and conductivity of the scatterer using adjoint sensitivity analysis. This inversion algorithm results in high computational speed and efficiency, and it can be generalized for any scatterer structure. Also, this method is robust with respect to noise. The numerical results clearly show that this hybrid approach provides accurate reconstructions of various objects. Journal: Journal of Electromagnetic Waves and Applications Pages: 2308-2320 Issue: 17 Volume: 29 Year: 2015 Month: 11 X-DOI: 10.1080/09205071.2015.1024334 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1024334 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:17:p:2308-2320 Template-Type: ReDIF-Article 1.0 Author-Name: Masih Ghasemi Author-X-Name-First: Masih Author-X-Name-Last: Ghasemi Author-Name: P.K. Choudhury Author-X-Name-First: P.K. Author-X-Name-Last: Choudhury Author-Name: Arash Dehzangi Author-X-Name-First: Arash Author-X-Name-Last: Dehzangi Title: Nanoengineered thin films of copper for the optical monitoring of urine – a comparative study of the helical and columnar nanostructures Abstract: The use of nanoengineered metallic complex mediums in the monitoring of urine is investigated in this study. As to the mediums used, nanoscaled thin films comprised of (i) copper nanohelix structures of two different numbers of helical turns and (ii) columnar thin films of copper nanorods of two different slanting angles grown over planar glass surface – a dielectric medium – are taken into account. Turbadar–Kretschmann–Raether (TKR) configuration is used to couple light with the metallic nanoengineered thin films, and the absorption spectra are monitored corresponding to two different optical wavelengths. The void regions in nanoengineered metallic films are filled up with urine as the analyte, which causes to alter the constitutive properties, resulting thereby shifts in the peaks in absorption spectra. Prominent shifts in absorption peaks corresponding to nanoengineered mediums infiltrated with urine essentially confirm prudent optical sensing characteristics of the devices under consideration. Journal: Journal of Electromagnetic Waves and Applications Pages: 2321-2329 Issue: 17 Volume: 29 Year: 2015 Month: 11 X-DOI: 10.1080/09205071.2015.1070107 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1070107 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:17:p:2321-2329 Template-Type: ReDIF-Article 1.0 Author-Name: S. Imaculate Rosaline Author-X-Name-First: S. Author-X-Name-Last: Imaculate Rosaline Author-Name: S. Raghavan Author-X-Name-First: S. Author-X-Name-Last: Raghavan Title: Design and analysis of a SRR superstrate for SAR reduction Abstract: This paper focuses on the design and analysis of a split-ring resonator (SRR) superstrate for a patch antenna, operating in the 1.75 GHz band, in view of reducing the specific absorption rate (SAR). The power radiation from the antenna with and without the superstrate is discussed. Transmission spectra of the SRR are retrieved using the classic waveguide theory approach. Higher order stop band of the superstrate around 1.75 GHz is responsible for the reduction in the electromagnetic absorption. SAR is measured for various layers of the human head such as skin, fat, bone, dura, CSF and brain individually. It is inferred that the superstrate is capable of obtaining at most 86% of SAR10g reduction with promising antenna performances. The conventional patch antenna along with the SRR superstrate is fabricated and measured to validate the simulation results. Journal: Journal of Electromagnetic Waves and Applications Pages: 2330-2338 Issue: 17 Volume: 29 Year: 2015 Month: 11 X-DOI: 10.1080/09205071.2015.1091384 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1091384 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:17:p:2330-2338 Template-Type: ReDIF-Article 1.0 Author-Name: Heba A. Shaban Author-X-Name-First: Heba A. Author-X-Name-Last: Shaban Author-Name: Mohamad Abou El-Nasr Author-X-Name-First: Mohamad Author-X-Name-Last: Abou El-Nasr Title: BER performance and data throughput of body sensor networks for reliable biological signal transmission over the human body Abstract: According to the IEEE 802.15 task group 6, human body communication (HBC) is a wireless body area network (WBAN) that operates at frequency band 5–50 MHz. In particular, communication between nodes is through body surface to body surface, and the human body acts as the transmission channel. This paper designs the link budget signaling parameters required for reliable transmission of biological signals over the IEEE 802.15.6a HBC channel model, and investigates the bit-error-rate (BER) and data throughput performances of different modulation schemes. These modulation schemes include non-coherent binary frequency shift keying (NcBFSK) with non-coherent detection, in addition to the commonly used schemes for HBC communications, namely coherent binary phase shift keying (CBPSK), coherent binary frequency shift keying (CBFSK), and on-off keying (OOK). According to the numerical results based on theoretical analysis, experimental results, as well as Monte-Carlo simulations, NcBFSK with non-coherent detection and bandwidth-integration window product BT=30$ BT = 30 $, CBPSK, CBFSK, and OOK, represent appropriate solutions for the reliable transmission of biological signals over HBC-based WBANs. The results are based on BER=1e-10$ \text{ BER} = 1\text{ e}-10 $ and 1 Mbps data rate for low data rate applications, and BER=1e-3$ \text{ BER} = 1\text{ e}-3 $ and data rate = 10 Mbps for high data rate applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 2339-2354 Issue: 17 Volume: 29 Year: 2015 Month: 11 X-DOI: 10.1080/09205071.2015.1102653 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1102653 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:17:p:2339-2354 Template-Type: ReDIF-Article 1.0 Author-Name: Ana Vazquez Alejos Author-X-Name-First: Ana Vazquez Author-X-Name-Last: Alejos Author-Name: Muhammad Dawood Author-X-Name-First: Muhammad Author-X-Name-Last: Dawood Author-Name: Erik Aguirre Author-X-Name-First: Erik Author-X-Name-Last: Aguirre Author-Name: Francisco Falcone Author-X-Name-First: Francisco Author-X-Name-Last: Falcone Author-Name: David Alvarez Outerelo Author-X-Name-First: David Alvarez Author-X-Name-Last: Outerelo Author-Name: Azzedin Naghar Author-X-Name-First: Azzedin Author-X-Name-Last: Naghar Author-Name: Otman Agzhout Author-X-Name-First: Otman Author-X-Name-Last: Agzhout Title: Influence of impairments due to dispersive propagation on the antenna design for body-based applications Abstract: In this paper, we analyze the frequency-dependent feature of the human body as radio propagation channel and the influence of that characteristic on the design of antennas for body-based applications. We describe the main impairments due to the frequency dispersion propagation through the body channel. Firstly, we describe the formation of the electromagnetic fields called Brillouin precursors which are responsible for another vital impairment: broadening of the time width of a transmitted signal. Later, we show a theoretical radio channel characterization of a human tissue that is affected by the frequency dispersion. Following, we describe three solutions to the described problematic optimal design of waveforms matched to the body channel, anti-dispersive filtering, and optimal antenna design. We introduce two broadband antennas offering a flat frequency response, minimizing the formation of precursors that ensures optimal time domain performance for ultrawideband body-based applications. Finally, we discuss the relation between the precursor formation and the parameters adopted to quantify the electromagnetic absorption inside biological tissues in order to review its definition under the dispersive perspective. Journal: Journal of Electromagnetic Waves and Applications Pages: 2355-2364 Issue: 17 Volume: 29 Year: 2015 Month: 11 X-DOI: 10.1080/09205071.2015.1103667 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1103667 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:17:p:2355-2364 Template-Type: ReDIF-Article 1.0 Author-Name: M. Cvetković Author-X-Name-First: M. Author-X-Name-Last: Cvetković Author-Name: D. Poljak Author-X-Name-First: D. Author-X-Name-Last: Poljak Title: Electromagnetic-thermal dosimetry comparison of the homogeneous adult and child brain models based on the SIE approach Abstract: The results of the absorbed electromagnetic (EM) energy in brain models of adults and children due to incident plane wave of 900 MHz and 1800 MHz are presented in this paper. The specific absorption rate (SAR) in the human brain is determined using the EM model based on the surface integral equation formulation. The thermal dosimetry model is based on the form of Pennes’ equation of heat transfer in biological tissue featuring the homogeneous Neumann boundary conditions. The thermal model is handled via the finite elements method. The models of a 10-year and a 5-year-old child brain, respectively, are obtained by linearly reducing the adult one. Although the anatomical accuracy of these models is low compared to MRI-based child models, they may be found useful for rapid dosimetric assessment. The models take into account age-dependent parameters of the brain tissue via total body water concept. The numerical results of the surface electric field obtained by the three brain models are compared, as well as the calculated results of the peak and average SAR and the related temperature increase. Journal: Journal of Electromagnetic Waves and Applications Pages: 2365-2379 Issue: 17 Volume: 29 Year: 2015 Month: 11 X-DOI: 10.1080/09205071.2015.1092896 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1092896 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:17:p:2365-2379 Template-Type: ReDIF-Article 1.0 Author-Name: Alessandro Fanti Author-X-Name-First: Alessandro Author-X-Name-Last: Fanti Author-Name: Sergio Casu Author-X-Name-First: Sergio Author-X-Name-Last: Casu Author-Name: Francesco Desogus Author-X-Name-First: Francesco Author-X-Name-Last: Desogus Author-Name: Giorgio Montisci Author-X-Name-First: Giorgio Author-X-Name-Last: Montisci Author-Name: Marco Simone Author-X-Name-First: Marco Author-X-Name-Last: Simone Author-Name: Giovanni Andrea Casula Author-X-Name-First: Giovanni Andrea Author-X-Name-Last: Casula Author-Name: Paolo Maxia Author-X-Name-First: Paolo Author-X-Name-Last: Maxia Author-Name: Giuseppe Mazzarella Author-X-Name-First: Giuseppe Author-X-Name-Last: Mazzarella Author-Name: Renzo Carta Author-X-Name-First: Renzo Author-X-Name-Last: Carta Title: Evaluation of a microwave resonant cavity as a reactor for enzyme reactions Abstract: We present here the design and analysis of a microwave resonant cavity to evaluate the effect of RF electromagnetic field on enzyme reactions. The cavity has been first designed using CST Microwave Studio. Then, its behaviour in the actual use has been evaluated using the COMSOL multiphysics. The presented results show that such cavity can be quite effective. Journal: Journal of Electromagnetic Waves and Applications Pages: 2380-2392 Issue: 17 Volume: 29 Year: 2015 Month: 11 X-DOI: 10.1080/09205071.2015.1091385 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1091385 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:17:p:2380-2392 Template-Type: ReDIF-Article 1.0 Author-Name: Cumali Sabah Author-X-Name-First: Cumali Author-X-Name-Last: Sabah Author-Name: Furkan Dincer Author-X-Name-First: Furkan Author-X-Name-Last: Dincer Author-Name: Muharrem Karaaslan Author-X-Name-First: Muharrem Author-X-Name-Last: Karaaslan Author-Name: Mehmet Bakir Author-X-Name-First: Mehmet Author-X-Name-Last: Bakir Author-Name: Emin Unal Author-X-Name-First: Emin Author-X-Name-Last: Unal Author-Name: Oguzhan Akgol Author-X-Name-First: Oguzhan Author-X-Name-Last: Akgol Title: Biosensor applications of chiral metamaterials for marrowbone temperature sensing Abstract: In this paper, we have designed, simulated, and analyzed a microwave biosensor based on chiral metamaterials (MTMs) to detect pig biological tissues which are widely used as a trial for medical explorations and researches. There are various types of biosensor structures based on MTMs in the literature. However, only a limited number of study is conducted on biosensors based on chiral MTMs; therefore, our study is one of the pioneer works for this type of research. The proposed diamond-shaped resonator-based structures are numerically investigated and analyzed in detail in the microwave frequency regime. The results are in good agreement which lead us to conclude that our structure can be easily used as an effective instrument for biosensing applications in medical technologies. Journal: Journal of Electromagnetic Waves and Applications Pages: 2393-2403 Issue: 17 Volume: 29 Year: 2015 Month: 11 X-DOI: 10.1080/09205071.2015.1084894 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1084894 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:17:p:2393-2403 Template-Type: ReDIF-Article 1.0 Author-Name: The Editors Title: Complex metamaterial mediums and THz applications Journal: Journal of Electromagnetic Waves and Applications Pages: 2405-2407 Issue: 18 Volume: 29 Year: 2015 Month: 12 X-DOI: 10.1080/09205071.2015.1109180 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1109180 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:18:p:2405-2407 Template-Type: ReDIF-Article 1.0 Author-Name: M.A. Baqir Author-X-Name-First: M.A. Author-X-Name-Last: Baqir Author-Name: Masih Ghasemi Author-X-Name-First: Masih Author-X-Name-Last: Ghasemi Author-Name: P.K. Choudhury Author-X-Name-First: P.K. Author-X-Name-Last: Choudhury Author-Name: B.Y. Majlis Author-X-Name-First: B.Y. Author-X-Name-Last: Majlis Title: Design and analysis of nanostructured subwavelength metamaterial absorber operating in the UV and visible spectral range Abstract: The design of broadband metamaterial perfect absorber (MPA) is proposed that operates in the ultraviolet and the visible regions of the electromagnetic spectrum. The MPA structure is of nanoscale in size and comprised of three layers – the U-shaped resonators (made of gold) of subwavelength size are embedded over a nanolayer of dielectric medium (silica glass), which is backed by a copper nanolayer surface. It is found that the proposed structure yields absorption peaks with the absorptivity over 99% in the aforesaid spectral range corresponding to both the transverse electric and the transverse magnetic polarizations of the incident electromagnetic wave. Furthermore, the angular dependence (of the incident light) of absorption characteristics is also analyzed along with the behavior of the absorber under varying thickness of nanosized resonators. It is expected that the proposed kind of perfect absorber would be highly useful in integrated heat-absorbing mediums that would include sensors, integrated photodetectors, thermal imaging, solar cells, etc. Journal: Journal of Electromagnetic Waves and Applications Pages: 2408-2419 Issue: 18 Volume: 29 Year: 2015 Month: 12 X-DOI: 10.1080/09205071.2015.1073124 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1073124 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:18:p:2408-2419 Template-Type: ReDIF-Article 1.0 Author-Name: Yongshun Xu Author-X-Name-First: Yongshun Author-X-Name-Last: Xu Author-Name: Wei Yuan Author-X-Name-First: Wei Author-X-Name-Last: Yuan Author-Name: Shaowei Bie Author-X-Name-First: Shaowei Author-X-Name-Last: Bie Author-Name: Haibing Xu Author-X-Name-First: Haibing Author-X-Name-Last: Xu Author-Name: Qian Chen Author-X-Name-First: Qian Author-X-Name-Last: Chen Author-Name: Jianjun Jiang Author-X-Name-First: Jianjun Author-X-Name-Last: Jiang Title: Broadband microwave absorption property of a thin metamaterial containing patterned magnetic sheet Abstract: A new type of thin and broadband metamaterial absorbers containing patterned magnetic sheet as the middle layer in the tri-layer structure are presented in this article. Those absorbers with more than 12 GHz absorption bandwidth which reflectivity is below −10 dB in the measured frequency 2–18 GHz were designed and experimentally realized by the thickness only in 1.8 mm. Design and experiment results display a huge expanded absorption bandwidth comparing to tri-layer absorber with complete sheet (not patterned sheet) as middle layer. By analysing the electric field distribution, it is found that the scattering effect caused by the patterned magnetic sheet plays a vital role in the feature of expanded bandwidth. Our results demonstrate that the great practicable method of broadening the absorption bandwidth and achieving lower total weight of thin magnetic absorber can be realized by the incorporation of patterned magnetic sheet. Journal: Journal of Electromagnetic Waves and Applications Pages: 2420-2427 Issue: 18 Volume: 29 Year: 2015 Month: 12 X-DOI: 10.1080/09205071.2015.1077751 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1077751 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:18:p:2420-2427 Template-Type: ReDIF-Article 1.0 Author-Name: Nitin Kumar Author-X-Name-First: Nitin Author-X-Name-Last: Kumar Author-Name: S.C. Gupta Author-X-Name-First: S.C. Author-X-Name-Last: Gupta Title: Analyzing the performance of a microstrip patch antenna with metamaterial cover by varying the distance and dielectric constant in between Abstract: A metamaterial slab applied as cover in front of a patch antenna focuses the radiations from patch, reduces the beam-width, thus enhancing the Gain and Directivity. Usually the slab is placed at quarter wave distance from the patch; this paper focuses on investigating the effects of varying this distance. Also, if a dielectric is placed in between metamaterial cover and patch antenna, the effects of changing the value of dielectric constant are presented in this paper. The metamaterial under consideration is a modification of Pendry’s SRR structure, its unit cell is formed by connecting metallic traces of two-edge-coupled split ring resonators to form the infinity symbol on one side of the substrate and an array of conducting wires on the other. The unit cells were arranged to form an array and an investigation of S-parameters was done to check the negative index property. A conventional patch antenna generally shows 3 dB beam-width of ~80° and 5–6 dB gain, whereas the antenna presented in this paper with the metamaterial cover shows improved 3 dB beam-width of ~53° with gain more than 9 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 2428-2443 Issue: 18 Volume: 29 Year: 2015 Month: 12 X-DOI: 10.1080/09205071.2015.1035810 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1035810 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:18:p:2428-2443 Template-Type: ReDIF-Article 1.0 Author-Name: Furkan Dincer Author-X-Name-First: Furkan Author-X-Name-Last: Dincer Title: Electromagnetic energy harvesting application based on tunable perfect metamaterial absorber Abstract: This paper introduces an electromagnetic (EM) energy harvesting application based on tunable dual-band metamaterial absorber (MA) which includes a ring resonator with gap loaded varactor diode that operates in the microwave frequency regime. Although the suggested tunable structure has a very simple geometry, it provides perfect absorption of 99.91 and 84.79% for both frequencies of 5.01 and 4.79 GHz, respectively. It is concluded from the numerical analysis that it can be obtained higher voltage value on varactor diode when the metal plate is added on the structure, to achieve perfect absorber with EM energy harvesting. We also present a numerical analysis in order to explain physical interpretation of the harvesting mechanism in detail. A sensor application of the proposed structure is introduced in order to show an additional feature of the model. Moreover, the proposed tunable model is also suitable for a wide variety of microwave EM energy harvesting applications such as power transfer to any component, wireless power transmitter etc. Journal: Journal of Electromagnetic Waves and Applications Pages: 2444-2453 Issue: 18 Volume: 29 Year: 2015 Month: 12 X-DOI: 10.1080/09205071.2015.1027794 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1027794 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:18:p:2444-2453 Template-Type: ReDIF-Article 1.0 Author-Name: D. Omri Author-X-Name-First: D. Author-X-Name-Last: Omri Author-Name: M. Aidi Author-X-Name-First: M. Author-X-Name-Last: Aidi Author-Name: T. Aguili Author-X-Name-First: T. Author-X-Name-Last: Aguili Title: Marching-on in degree method for electromagnetic coupling analysis of carbon nanotubes (CNT) dipoles array Abstract: Transient electromagnetic analysis of carbon nanotubes (CNT) dipoles is presented. The thin wire approximation and the scattering theory are employed to formulate the problem. Therefore, an accurate system of coupled time domain electric field integral equations (TD-EFIE) is developed in order to predict the responses of the CNT dipoles excited by transient electromagnetic waves. To obtain stable and accurate solutions based on proposed system, the marching-on in degree method is applied with piecewise functions as space basis and weighted Laguerre Polynomials as temporal basis. Numerical results involving transient currents on each CNT dipole are presented. The electromagnetic coupling analysis between the CNT dipoles is conducted depending on the separate distances and the number of the CNT dipoles. Hence, the physical coupling effects are proved. Journal: Journal of Electromagnetic Waves and Applications Pages: 2454-2471 Issue: 18 Volume: 29 Year: 2015 Month: 12 X-DOI: 10.1080/09205071.2015.1047000 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1047000 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:18:p:2454-2471 Template-Type: ReDIF-Article 1.0 Author-Name: Dongju Kim Author-X-Name-First: Dongju Author-X-Name-Last: Kim Author-Name: Jeong Min Woo Author-X-Name-First: Jeong Min Author-X-Name-Last: Woo Author-Name: Hyun-Woong Kim Author-X-Name-First: Hyun-Woong Author-X-Name-Last: Kim Author-Name: Jae-Hyung Jang Author-X-Name-First: Jae-Hyung Author-X-Name-Last: Jang Title: Quad-band THz frequency selective surface based on a split ring resonator loaded with multiple slots Abstract: A quad-band terahertz (THz) frequency selective surface with bandstop response is designed, fabricated, and characterized. The unit cell of the filter consists of a split ring resonator (SRR) and surrounding four groups of slots. Each group of slots has three slots with different lengths. The lowest frequency band is determined by the resonance of the SRR and the other three upper bands are selected by the resonance of the slots which exhibit bandstop characteristics rather than bandpass characteristics. The filter transformation characteristic originates from the slits placed between the unit cells which act as series-connected capacitive components. The fabricated quad-band THz filters exhibited bandstop characteristics with attenuation higher than 20 dB in all the operating frequency bands. Journal: Journal of Electromagnetic Waves and Applications Pages: 2472-2478 Issue: 18 Volume: 29 Year: 2015 Month: 12 X-DOI: 10.1080/09205071.2015.1053576 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1053576 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:18:p:2472-2478 Template-Type: ReDIF-Article 1.0 Author-Name: Himangshu Bhusan Baskey Author-X-Name-First: Himangshu Bhusan Author-X-Name-Last: Baskey Author-Name: M. Jaleel Akhtar Author-X-Name-First: M. Jaleel Author-X-Name-Last: Akhtar Author-Name: A.K. Dixit Author-X-Name-First: A.K. Author-X-Name-Last: Dixit Author-Name: T.C. Shami Author-X-Name-First: T.C. Author-X-Name-Last: Shami Title: Design, synthesis, characterization and performance evaluation of multi-band perfect metamaterial absorber Abstract: This paper presents the design, synthesis, characterization, and performance evaluation of a metamaterial absorber having four distinct absorption peaks. The proposed absorber is based on the periodic array of the hexagonal closed rings and octa-star structure printed over the dielectric substrate. The dimensions of unit cell are optimized such that the absorption takes place at the distinct frequency near the Federal Communications Commission defined radar spectrum e.g. at 4.10, 6.15, 10.05, and 15.52 GHz with the absorptivity of 0.98, 0.99, 0.99, and 0.99, respectively. The proposed structure is fabricated and the experimental result shows high absorptivity under transverse electric and magnetic polarization for the wide angle of incidence angles, which is in concurrence with the simulated results. The equivalent circuit model of the absorber has been developed sequentially for each of the structure. Furthermore, the complex refractive index of the metamaterial structure has been retrieved in order to have a detailed analysis, which supports the absorption phenomena at all the corresponding frequencies. The proposed metamaterial structure appears to be a potential candidate for absorber applications in the radar cross-section reduction, thermal detectors, and thermal imaging. Journal: Journal of Electromagnetic Waves and Applications Pages: 2479-2491 Issue: 18 Volume: 29 Year: 2015 Month: 12 X-DOI: 10.1080/09205071.2015.1075907 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1075907 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:18:p:2479-2491 Template-Type: ReDIF-Article 1.0 Author-Name: Furkan Dincer Author-X-Name-First: Furkan Author-X-Name-Last: Dincer Author-Name: Muharrem Karaaslan Author-X-Name-First: Muharrem Author-X-Name-Last: Karaaslan Author-Name: Cumali Sabah Author-X-Name-First: Cumali Author-X-Name-Last: Sabah Title: Design and analysis of perfect metamaterial absorber in GHz and THz frequencies Abstract: The new perfect metamaterial absorber (MA) based on square resonator with gap configuration is numerically (for GHz and THz frequency regime) and experimentally (for GHz frequency regime) presented and investigated. The proposed MA has a simple configuration which introduces flexibility to adjust its metamaterial properties and easily rescale the structure for other frequency regimes. In addition, polarization and incident angle independencies of the proposed model are analyzed for the THz frequency regime. The suggested structure could achieve very high absorption at wide angles of polarization and incident angles for both transverse electric and transverse magnetic waves. At resonance frequencies, absorption results are realized around 99.99% at 5.48 GHz and 99.92% at 0.865 THz for their respective frequency regimes. Besides numerical results in GHz and THz frequencies, experimental results are also obtained for GHz frequency regime. The proposed MA and its variations enable myriad potential applications in areas such as defense systems, communication, stealth technologies, and so on. Journal: Journal of Electromagnetic Waves and Applications Pages: 2492-2500 Issue: 18 Volume: 29 Year: 2015 Month: 12 X-DOI: 10.1080/09205071.2015.1043030 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1043030 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:18:p:2492-2500 Template-Type: ReDIF-Article 1.0 Author-Name: Dushyant Kumar Sharma Author-X-Name-First: Dushyant Kumar Author-X-Name-Last: Sharma Author-Name: Surya Kumar Pathak Author-X-Name-First: Surya Kumar Author-X-Name-Last: Pathak Title: ENG-cladded metamaterial-loaded helical waveguide for optoelectronics applications Abstract: In this article, we have studied propagation characteristics of ENG-cladded metamaterial-loaded helical waveguide (CMLHG) to control its slow-wave behaviour for various engineering applications such as realizing optical buffer and memory. An analytical equation has been derived and computed numerically to analyse its dispersion characteristics in THz frequency spectrum. Significant amount of phase velocity reduction is achieved in comparison with the helical guide when (i) it is in free space and not cladded and (ii) when it is cladded with doubly positive materials and loaded with metamaterial. We find that helical waveguide physical dimensions, mainly radius and pitch angle, act as a tuning tool to control the phase velocity. This type of waveguide does not require any active waveguide compensation in order to achieve slow wave at THz to optical frequency range. The electric field intensity distribution over the cross section of the waveguide has also been studied which attributes that as frequency increases, electric field distribution is more confined to the core region of the waveguide. Journal: Journal of Electromagnetic Waves and Applications Pages: 2501-2511 Issue: 18 Volume: 29 Year: 2015 Month: 12 X-DOI: 10.1080/09205071.2015.1051190 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1051190 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:18:p:2501-2511 Template-Type: ReDIF-Article 1.0 Author-Name: Chunya Luo Author-X-Name-First: Chunya Author-X-Name-Last: Luo Author-Name: Dan Li Author-X-Name-First: Dan Author-X-Name-Last: Li Author-Name: Jianquan Yao Author-X-Name-First: Jianquan Author-X-Name-Last: Yao Author-Name: Furi Ling Author-X-Name-First: Furi Author-X-Name-Last: Ling Title: Direct thermal tuning of the terahertz plasmonic response of semiconductor metasurface Abstract: In this study, the tunable depth of an array of semiconductor indium antimonide (InSb) subwavelength strips was studied by isothermally increasing the intrinsic carrier density, and then increasing the plasma frequency and the dielectric constant in the terahertz (THz) regime. It could be found that the tunable depth can attain 79.07% and the quality factor Q can be up to 7.1 in the window between 0 and 1.2 THz from 450 to 250 K. In order to improve the performance of the device, the strip array of semiconductor InSb on a ferroelectric strontium titanate film was also investigated. The results showed that when the temperature varied from 450 to 250 K, the modulation depth increased and attained 84.06%. These findings would facilitate the design of tunable components in the communication region of the THz regime. Journal: Journal of Electromagnetic Waves and Applications Pages: 2512-2522 Issue: 18 Volume: 29 Year: 2015 Month: 12 X-DOI: 10.1080/09205071.2015.1111170 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1111170 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:18:p:2512-2522 Template-Type: ReDIF-Article 1.0 Author-Name: The Editors Title: Editorial Board Journal: Journal of Electromagnetic Waves and Applications Pages: ebi-ebi Issue: 18 Volume: 29 Year: 2015 Month: 12 X-DOI: 10.1080/09205071.2015.1124617 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1124617 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:18:p:ebi-ebi Template-Type: ReDIF-Article 1.0 Author-Name: Zheyu Wang Author-X-Name-First: Zheyu Author-X-Name-Last: Wang Author-Name: Konstantinos Karathanasis Author-X-Name-First: Konstantinos Author-X-Name-Last: Karathanasis Author-Name: John L. Volakis Author-X-Name-First: John L. Author-X-Name-Last: Volakis Title: Axial ratio reduced ultra wideband slot spiral on hybrid impedance surfaces Abstract: This paper presents a low-profile ultra wideband slot spiral antenna backed by a hybrid impedance surface. A unique aspect of the spiral is its hybrid impedance surface cavity leading to reduced axial ratio over a wide bandwidth. This is an improvement over conventional cavity-backed wideband spirals. Measurements demonstrated that the slot spiral on the proposed hybrid impedance surface achieved a 10:1 bandwidth from 0.6 to 6 GHz with an axial ratio of <4 dB. The cavity depth is only 13 mm, corresponding to 0.03λ600 MHz at its lowest operational frequency. As such, this slot spiral is attractive in enabling low-profile ultra wideband antenna with excellent RF performance for conformal and wearable applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 143-153 Issue: 2 Volume: 29 Year: 2015 Month: 1 X-DOI: 10.1080/09205071.2014.981035 File-URL: http://hdl.handle.net/10.1080/09205071.2014.981035 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:2:p:143-153 Template-Type: ReDIF-Article 1.0 Author-Name: Junho Yeo Author-X-Name-First: Junho Author-X-Name-Last: Yeo Author-Name: Jong-Ig Lee Author-X-Name-First: Jong-Ig Author-X-Name-Last: Lee Title: Design of series-fed dipole pair antenna with split-ring resonator directors for dual-band operation Abstract: A dual-band series-fed dipole pair (SDP) antenna using split-ring resonator (SRR) directors is proposed. A pair of SRR directors is appended to a conventional SDP antenna to provide dual-band operation. The effects of the geometric parameters of the SRR directors on the input reflection coefficient and realized gain of the SDP antenna are investigated. A prototype of a dual-band SDP antenna with the SRR directors operating in the GPS L1 (1.563–1.587 GHz) and 1.7–2.7 GHz bands is designed and fabricated on an FR4 substrate. The experiment results show that the antenna has a dual-band characteristic in the frequency bands of 1.54–1.61 GHz and 1.71–2.81 GHz for a voltage standing wave ratio (VSWR) <2. Measured gain is 6.6–7.5 dBi in the first band, whereas it ranges 4.8–6.7 dBi in the second band. Journal: Journal of Electromagnetic Waves and Applications Pages: 154-168 Issue: 2 Volume: 29 Year: 2015 Month: 1 X-DOI: 10.1080/09205071.2014.985853 File-URL: http://hdl.handle.net/10.1080/09205071.2014.985853 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:2:p:154-168 Template-Type: ReDIF-Article 1.0 Author-Name: Joon-Ho Lee Author-X-Name-First: Joon-Ho Author-X-Name-Last: Lee Author-Name: So-Hee Jeong Author-X-Name-First: So-Hee Author-X-Name-Last: Jeong Title: Recursive implementation of GLRT-based radar target detection Abstract: We consider recursive implementation of the natural frequency-based radar target detection for an augmented data vector. In the previous study, it was shown that, the probability of detection can be calculated using the probability density function (PDF) of the non-central chi-square distribution and that non-centrality of the chi-square distribution is dependent on the eigenvectors of a matrix. The essential idea in this paper is that the eigenvectors of the augmented matrix can be recursively calculated without computationally intensive eigendecomposition. To do that, we make use of how the QR factorization of the row-augmented matrix can be updated from the QR factorization of the original matrix to get the probability of detection recursively. The recursive formulation is validated by comparing the detection performance using the recursive method with that using non-recursive method. Journal: Journal of Electromagnetic Waves and Applications Pages: 169-184 Issue: 2 Volume: 29 Year: 2015 Month: 1 X-DOI: 10.1080/09205071.2014.986292 File-URL: http://hdl.handle.net/10.1080/09205071.2014.986292 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:2:p:169-184 Template-Type: ReDIF-Article 1.0 Author-Name: Hai-Feng Zhang Author-X-Name-First: Hai-Feng Author-X-Name-Last: Zhang Author-Name: Shao-Bin Liu Author-X-Name-First: Shao-Bin Author-X-Name-Last: Liu Author-Name: Yu-Chi Jiang Author-X-Name-First: Yu-Chi Author-X-Name-Last: Jiang Title: Study on the magneto-optical Faraday effects in the properties of anisotropic photonic band gaps and surface plasmon modes for the three-dimensional magnetized photonic crystals as the mixed polarized waves considered Abstract: In this paper, the magneto-optical Faraday effects in the properties of anisotropic photonic band gaps (PBGs) and surface plasmon modes for the three-dimensional (3D) magnetized plasma photonic crystals (MPPCs) with body-centered cubic lattices are theoretically studied based on the modified plane wave expansion (PWE) method, in which the homogeneous Te (tellurium) spheres are immersed in the homogeneous magnetized plasma background, as the mixed polarized waves are considered. A more general case is investigated, and the anisotropic PBGs are not only for the left- and right-circular polarized waves but also for the mixed polarized waves. The equations for computing those anisotropic PBGs for all of the electromagnetic waves in such 3D MPPCs are theoretically deduced. Theoretical simulations show that the anisotropic PBGs and a flatbands region can be observed. Compared to the similar 3D MPPCs containing the isotropic dielectric or uniaxial material spheres, the largest PBG can be obtained as the extraordinary axis of inserted uniaxial material is along the Г-H symmetry line. The larger PBGs can also be achieved compared to the conventional PBGs for the right-circular polarized wave as the mixed polarized waves are considered. The interesting properties of surface plasmon modes can also be found, which are the upper edge of flatbands region cannot be tuned by the filling factor but almost can be linearly increased with increasing the plasma frequency and plasma cyclotron frequency, respectively. The effects of the filling factor, plasma frequency, and plasma cyclotron frequency (the external magnetic field) on the anisotropic PBGs are also investigated in detail. Theoretical simulations also show that such PBGs can be manipulated by the parameters as mentioned above. Journal: Journal of Electromagnetic Waves and Applications Pages: 185-198 Issue: 2 Volume: 29 Year: 2015 Month: 1 X-DOI: 10.1080/09205071.2014.987879 File-URL: http://hdl.handle.net/10.1080/09205071.2014.987879 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:2:p:185-198 Template-Type: ReDIF-Article 1.0 Author-Name: Marco Simone Author-X-Name-First: Marco Author-X-Name-Last: Simone Author-Name: Alessandro Fanti Author-X-Name-First: Alessandro Author-X-Name-Last: Fanti Author-Name: Giuseppe Mazzarella Author-X-Name-First: Giuseppe Author-X-Name-Last: Mazzarella Title: Ridge waveguide optimization with PSO algorithm Abstract: A technique of automatic optimization for guiding structures at microwave range is presented. Geometrical parameters have been optimized taking into account conflicting requirements (high bandwidth, high power handling capability and low attenuation constant) with PSO algorithm. Propagation performances are computed with a FDFD technique. Journal: Journal of Electromagnetic Waves and Applications Pages: 199-209 Issue: 2 Volume: 29 Year: 2015 Month: 1 X-DOI: 10.1080/09205071.2014.990113 File-URL: http://hdl.handle.net/10.1080/09205071.2014.990113 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:2:p:199-209 Template-Type: ReDIF-Article 1.0 Author-Name: Guo-cheng Wu Author-X-Name-First: Guo-cheng Author-X-Name-Last: Wu Author-Name: Guang-ming Wang Author-X-Name-First: Guang-ming Author-X-Name-Last: Wang Author-Name: Hua-xia Peng Author-X-Name-First: Hua-xia Author-X-Name-Last: Peng Author-Name: Xiang-jun Gao Author-X-Name-First: Xiang-jun Author-X-Name-Last: Gao Author-Name: Jia-jia Sun Author-X-Name-First: Jia-jia Author-X-Name-Last: Sun Title: Novel microstrip left-handed resonator with dual notched bands and its application in miniaturized triple-band 3-dB power divider Abstract: A novel microstrip left-handed resonator (LHR) is proposed in this paper by embedding narrow central symmetric spiral lines in the rectangular gap of the main microstrip line. According to the EM simulated results, the proposed LHR has two narrow notched bands, which is produced by the magnetic resonance and sudden change of the effective permeability and effective permittivity; the phase characteristics of the proposed LHR show that there are two frequency points with −90-degree phase shift and one frequency point with +90-degree phase shift in the passbands. According to the electromagnetic characteristics of the proposed LHR, we use it to replace the 70.7 Ω transmission line of conventional Wilkinson power divider, and a compact triple-band 3-dB power divider is presented. After fabrication, the presented triple-band power divider is measured by using Anritsu ME7808A vector network analyzer, the measured and simulated results are in good agreement with each other, showing that, the fabricated power divider operating at 2.20, 3.40, and 7.50 GHz with bandwidths of 84.5, 35.8, and 15.2%; in the passbands, the return loss is better than 15 dB, the insertion loss is between 3.4 ± 0.2 dB, and the isolation between port 2 and 3 is better than 20 dB. Moreover, the out-of-band rejection among three operating bands is also very good, which benefits from the two narrow notched bands. Simultaneously, the effective area of the fabricated power divider is 0.121 λg by 0.116 λg (where λg is the guided wavelength at 2.20 GHz), about 55.2% relative to that of conventional one operating at 2.20 GHz. Besides, the presented power divider is uniplanar, and there is no defected ground structure or lumped element. Journal: Journal of Electromagnetic Waves and Applications Pages: 210-217 Issue: 2 Volume: 29 Year: 2015 Month: 1 X-DOI: 10.1080/09205071.2014.993769 File-URL: http://hdl.handle.net/10.1080/09205071.2014.993769 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:2:p:210-217 Template-Type: ReDIF-Article 1.0 Author-Name: Lourdes Martinez-Lopez Author-X-Name-First: Lourdes Author-X-Name-Last: Martinez-Lopez Author-Name: Jorge Rodriguez-Cuevas Author-X-Name-First: Jorge Author-X-Name-Last: Rodriguez-Cuevas Author-Name: Alexander E. Martynyuk Author-X-Name-First: Alexander E. Author-X-Name-Last: Martynyuk Author-Name: Jose I. Martinez-Lopez Author-X-Name-First: Jose I. Author-X-Name-Last: Martinez-Lopez Title: Wideband-reconfigurable reflectarrays based on rotating loaded split rings Abstract: In this paper, reflective periodic arrays with rotating spiraphase-type elements based on loaded split rings are analyzed. It is proven that these arrays can be reconfigured over a wide frequency band with high reflection elevation angles, low conversion losses, and low axial ratios. A full-wave mathematical model has been developed to calculate their reflection characteristics. This model has been used to design a Ka-band reflectarray. The analysis of the designed reflectarray shows that an incident circularly polarized wave can be redirected at reflection elevation angles as high as 40° with conversion losses less than 1.8 dB and axial ratios less than 2 dB over the frequency band from 26.6 to 46.3 GHz. Additionally, the rotation of the reflectarray elements using minimotors is analyzed and discussed. In order to study the velocity properties of the electromechanical actuation, minimotor-driven antenna elements in the X-band have been designed, fabricated, and tested. Journal: Journal of Electromagnetic Waves and Applications Pages: 218-232 Issue: 2 Volume: 29 Year: 2015 Month: 1 X-DOI: 10.1080/09205071.2014.993770 File-URL: http://hdl.handle.net/10.1080/09205071.2014.993770 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:2:p:218-232 Template-Type: ReDIF-Article 1.0 Author-Name: I. Gil Author-X-Name-First: I. Author-X-Name-Last: Gil Author-Name: R. Fernández-García Author-X-Name-First: R. Author-X-Name-Last: Fernández-García Title: Differential- and common-mode radiofrequency interference filters based on complementary split ring resonators: a conduction and radiation impact analysis Abstract: This paper aims to analyse the design techniques of differential transmission lines loaded with metamaterials. Specifically, complementary split-ring resonators were etched on the ground plane of a microstrip transmission line in order to mitigate both differential- and common-mode propagation in differential signalling. Several prototypes were manufactured and characterised in printed circuit boards. The topologies under test were measured and compared as radiofrequency interference filters, taking into account frequency response, signal integrity, and near- and far-field radiation impact with regard to a reference (solid ground) board. Journal: Journal of Electromagnetic Waves and Applications Pages: 233-246 Issue: 2 Volume: 29 Year: 2015 Month: 1 X-DOI: 10.1080/09205071.2014.997372 File-URL: http://hdl.handle.net/10.1080/09205071.2014.997372 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:2:p:233-246 Template-Type: ReDIF-Article 1.0 Author-Name: Anirban Karmakar Author-X-Name-First: Anirban Author-X-Name-Last: Karmakar Author-Name: Rowdra Ghatak Author-X-Name-First: Rowdra Author-X-Name-Last: Ghatak Author-Name: R.K. Mishra Author-X-Name-First: R.K. Author-X-Name-Last: Mishra Author-Name: D.R. Poddar Author-X-Name-First: D.R. Author-X-Name-Last: Poddar Title: Sierpinski carpet fractal-based planar array optimization based on differential evolution algorithm Abstract: This paper considers fractal-based antenna array optimization using differential evolution algorithm (DEA). The proposed optimization technique of planar fractal array is based on Sierpinski carpet fractal array concept. Generally, fractal arrays like Sierpinski carpet may suffer from increased peak side lobe level (PSLL), as well as complex array factor computation that isolates it from the application of any evolutionary optimization techniques. Based on Sierpinski carpet array, a novel iterative feed matrix is proposed, whose inclusion eases the computation complexity of Sierpinski fractal array at different stages of growth and make them suitable for the application of any evolutionary optimization techniques. Thus, a novel method to compute Sierpinski carpet array factor has been proposed and DEA has been applied for element reduction as well as PSLL minimization of original Sierpinski carpet-patterned array at different stages of growth. The optimized version of Sierpinski carpet array produces lower PSLL with reduced radiating elements than its original counterpart. Journal: Journal of Electromagnetic Waves and Applications Pages: 247-260 Issue: 2 Volume: 29 Year: 2015 Month: 1 X-DOI: 10.1080/09205071.2014.997837 File-URL: http://hdl.handle.net/10.1080/09205071.2014.997837 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:2:p:247-260 Template-Type: ReDIF-Article 1.0 Author-Name: G. Di Massa Author-X-Name-First: G. Author-X-Name-Last: Di Massa Author-Name: S. Costanzo Author-X-Name-First: S. Author-X-Name-Last: Costanzo Author-Name: H.O. Moreno Author-X-Name-First: H.O. Author-X-Name-Last: Moreno Title: Planar Fabry–Perot directive antenna: a simplified analysis by equivalent circuit approach Abstract: A new approach is proposed for the analysis and design of a planar Fabry–Perot antenna. The complete modal analysis of the field into the cavity leads to a simplified equivalent circuit, able to provide a reliable description of the coupling with the feeding waveguide, as well as to compute the equivalent currents on the radiating apertures, thus obtaining the radiated far-field. The proposed approach is preliminary validated on a metallic Fabry–Perot antenna structure. Then, a modified configuration, based on a cavity partially-filled with a dielectric substrate, is assumed to obtain a Fabry–Perot antenna with improved bandwidth features. Experimental validations on array prototypes are successfully discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 261-274 Issue: 2 Volume: 29 Year: 2015 Month: 1 X-DOI: 10.1080/09205071.2014.997838 File-URL: http://hdl.handle.net/10.1080/09205071.2014.997838 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:2:p:261-274 Template-Type: ReDIF-Article 1.0 Author-Name: Xiao Fan Yang Author-X-Name-First: Xiao Fan Author-X-Name-Last: Yang Author-Name: Xian Qi Lin Author-X-Name-First: Xian Qi Author-X-Name-Last: Lin Author-Name: Jun Ye Jin Author-X-Name-First: Jun Ye Author-X-Name-Last: Jin Author-Name: Yuan Jiang Author-X-Name-First: Yuan Author-X-Name-Last: Jiang Title: A wideband mixer designed with low conversion loss through the entire W-band Abstract: In this paper, a mixer is designed with low conversion loss through the entire W-band. A novel low pass filter is proposed and used to select the intermediate frequency signal with large rejection of the local oscillator (LO) and radio frequency (RF) signals. A single slot is added on the LO passage to achieve impedance matching in a narrow frequency band, while two slots and one metal strip are added on the RF passage to achieve impedance matching in a wide frequency band. The detailed design process is presented, where a more accurate full-wave simulation model of the adopted diode is suggested. Difference in performances can be obtained by changing the key sizes of the matching structures. One sample is fabricated, and the measured conversion loss is less than 9.5 dB through the entire W-band (from 75 to 110 GHz) under fixed LO condition. The measured return loss of RF port is between 5 and 13.5 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 275-282 Issue: 2 Volume: 29 Year: 2015 Month: 1 X-DOI: 10.1080/09205071.2014.1002632 File-URL: http://hdl.handle.net/10.1080/09205071.2014.1002632 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:2:p:275-282 Template-Type: ReDIF-Article 1.0 Author-Name: A.R. Prasanna Author-X-Name-First: A.R. Author-X-Name-Last: Prasanna Title: On photon trajectories and electromagnetics near strongly gravitating cosmic sources Abstract: We see and understand the Universe around us through the medium of the electromagnetic spectrum, ranging from the low-frequency radio waves extending up to the high-frequency γ-rays. These electromagnetic waves, generated by different processes within or nearby the various astronomical bodies get modified in their transit through the vast distances of spacetime and its contents that make up the Universe. Depending upon the various physical features of the media they are transiting through, characteristics such as dispersion, polarization and frequency modulation can occur by the intervening forces and fields. While electric and magnetic fields could be strong sources of influence, the weaker force gravity also can be a modifying factor both in the generation and propagation of the electromagnetic waves from distant cosmos. In fact, it is well known that the influence of gravity on light, making it bend while passing near Sun, was the predicted and observed experimental fact that confirmed Einstein’s theory of general relativity as the most successful theory of the twentieth century. It is well known that the passage of electromagnetic waves through plasma leads to several changes in the dispersed waves, a systematic study of which could give information about the characteristics of the medium through which they arrived. Over the past century, several detailed studies have been carried out to analyse the structure and properties of electromagnetic fields of cosmic objects and their behaviour in the presence of gravitational fields. We give a brief review of the subject, starting with the gravitational bending of light and its consequences, viz., gravitational lensing and then consider the influence of gravity on the electromagnetic fields close to compact objects and the behaviour of charged particles in such electromagnetic fields. The changes in their trajectories, that occur because of the curved geometry, can have direct influence on the electromagnetic and plasma processes near bodies like neutron stars and black holes. Further, introduction of a possible non-minimal coupling of electromagnetism and gravity seems to be a possible source for the generation of the cosmic primordial magnetic field, a precursor to the presently observed magnetic field in the Universe. Journal: Journal of Electromagnetic Waves and Applications Pages: 283-330 Issue: 3 Volume: 29 Year: 2015 Month: 2 X-DOI: 10.1080/09205071.2014.993043 File-URL: http://hdl.handle.net/10.1080/09205071.2014.993043 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:3:p:283-330 Template-Type: ReDIF-Article 1.0 Author-Name: Seung-Phil Lee Author-X-Name-First: Seung-Phil Author-X-Name-Last: Lee Author-Name: Byung-Lae Cho Author-X-Name-First: Byung-Lae Author-X-Name-Last: Cho Author-Name: Jong-Soo Ha Author-X-Name-First: Jong-Soo Author-X-Name-Last: Ha Author-Name: Young-Soo Kim Author-X-Name-First: Young-Soo Author-X-Name-Last: Kim Title: Target angle estimation of multifunction radar in search mode using digital beamforming technique Abstract: We propose a new target angle estimation method for a multifunction radar in search mode using the digital beamforming technique. The conventional center of mass-based method (CM method) used in mechanical scanning radar or two-dimensional digital beamforming radar is not very useful for a three-dimensional multifunction radar due to many problems. We suggest a three-beam-based angle estimation method (3B method) to reduce the target angle estimation error by the CM method. The 3B method estimates the target angle in search mode with less error than the CM method for all Swerling cases and signal-to-noise ratio. Journal: Journal of Electromagnetic Waves and Applications Pages: 331-342 Issue: 3 Volume: 29 Year: 2015 Month: 2 X-DOI: 10.1080/09205071.2014.990111 File-URL: http://hdl.handle.net/10.1080/09205071.2014.990111 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:3:p:331-342 Template-Type: ReDIF-Article 1.0 Author-Name: Joon-Ho Lee Author-X-Name-First: Joon-Ho Author-X-Name-Last: Lee Author-Name: So-Hee Jeong Author-X-Name-First: So-Hee Author-X-Name-Last: Jeong Author-Name: In-Sik Choi Author-X-Name-First: In-Sik Author-X-Name-Last: Choi Author-Name: Dae-Young Chae Author-X-Name-First: Dae-Young Author-X-Name-Last: Chae Title: Natural frequency-based recursive LRT detection using the Lagrange polynomial Abstract: We consider the performance analysis of the natural frequency-based radar target detection. By making the Lagrange polynomial approximation of the standard normal distribution, the probability of detection for an augmented input vector can be recursively calculated. We present the bound of the error due to the Lagrange polynomial approximation, and it is illustrated that the actual error is within the derived error bound. We also present how to determine the optimal first-order Lagrange polynomial. Journal: Journal of Electromagnetic Waves and Applications Pages: 343-363 Issue: 3 Volume: 29 Year: 2015 Month: 2 X-DOI: 10.1080/09205071.2014.992551 File-URL: http://hdl.handle.net/10.1080/09205071.2014.992551 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:3:p:343-363 Template-Type: ReDIF-Article 1.0 Author-Name: Haiyan Tian Author-X-Name-First: Haiyan Author-X-Name-Last: Tian Author-Name: Jinchun Gao Author-X-Name-First: Jinchun Author-X-Name-Last: Gao Author-Name: Ming Su Author-X-Name-First: Ming Author-X-Name-Last: Su Author-Name: Yongle Wu Author-X-Name-First: Yongle Author-X-Name-Last: Wu Author-Name: Yuanan Liu Author-X-Name-First: Yuanan Author-X-Name-Last: Liu Title: A novel 3D two-ways folded microstrip line and its application in super-miniaturized microwave wireless components Abstract: A novel 3D folded two-ways microstrip lines (MLs) are proposed for realizing the super-miniaturization of electron devices. The 3D structure realized with two-ways folded MLs, which consists of several groups of cross-connected MLs and conductive vias, has the potential to have an advanced performance than the corresponding conventional, meandering and 3D one-way MLs. Longer MLs can be arranged in limited space. The superficial area of the 3D folded structure is significantly smaller than those proposed MLs in similar return loss. The methodology is validated with the design of single band, reduced size Wilkinson power divider (WPD), and branch-line hybrid coupler (BLHC) at 433 MHz. Reduction of the transmission line segments is from λ/4 to λ/32. The physical sizes have been reduced by 98.15 and 95.54%, compared with the conventional WPD and BLHC. This paper summarizes the longest 50 Ω MLs in a particular size and gets the conclusion that the structure could be used more effectively in the lower working frequency. Journal: Journal of Electromagnetic Waves and Applications Pages: 364-374 Issue: 3 Volume: 29 Year: 2015 Month: 2 X-DOI: 10.1080/09205071.2014.995835 File-URL: http://hdl.handle.net/10.1080/09205071.2014.995835 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:3:p:364-374 Template-Type: ReDIF-Article 1.0 Author-Name: Sungjin Choi Author-X-Name-First: Sungjin Author-X-Name-Last: Choi Author-Name: Sungjoon Lim Author-X-Name-First: Sungjoon Author-X-Name-Last: Lim Title: Foldable thin electro-textile antenna array for 4 × 4 multiple-input multiple-output mobile router applications Abstract: A novel foldable thin electro-textile antenna array is proposed for 4 × 4 multiple-input multiple-output mobile router applications. The proposed antenna array consists of four antenna elements and is fabricated on a thin-felt textile substrate using adhesive electro-textile. To minimize the overall space, two antennas are designed from a single rectangular conductor with two ports. Isolation is enhanced using a decoupling slit between the two antennas. Because the four antennas share the same system ground plane, a decoupling slit is also employed on the ground plane. The performance is successfully validated by the simulation and measurement results. Journal: Journal of Electromagnetic Waves and Applications Pages: 375-385 Issue: 3 Volume: 29 Year: 2015 Month: 2 X-DOI: 10.1080/09205071.2014.997839 File-URL: http://hdl.handle.net/10.1080/09205071.2014.997839 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:3:p:375-385 Template-Type: ReDIF-Article 1.0 Author-Name: Zubair Akhter Author-X-Name-First: Zubair Author-X-Name-Last: Akhter Author-Name: M. Jaleel Akhtar Author-X-Name-First: M. Jaleel Author-X-Name-Last: Akhtar Title: Time domain microwave technique for dielectric imaging of multi-layered media Abstract: In this paper, a novel time domain practical scheme is proposed to reconstruct the dielectric image of the inhomogeneous multi-layered media. The overall process is noninvasive and noncontacting, which employs the measured scattering data of the test media in equivalent time domain. The measurement system consists of a modern vector network analyzer, a wide-band lens horn antenna, and the associated microwave components. The main focus here is to determine both the relative permittivity and the thickness of each layer in terms of the partial reflection coefficient calculated for the corresponding interface. It is also demonstrated here that the proposed approach can be used to characterize the lossy media under some approximation. The proposed approach is quite useful under situations such as the through-wall imaging, where only reflection measurements can be carried out due to restricted access of the object from the other side. The proposed scheme is validated here by determining the permittivity, the thickness, and the effective conductivity of a number of multi-layered media obtained by stacking few reference dielectric samples whose data are available in literature. Journal: Journal of Electromagnetic Waves and Applications Pages: 386-401 Issue: 3 Volume: 29 Year: 2015 Month: 2 X-DOI: 10.1080/09205071.2014.997840 File-URL: http://hdl.handle.net/10.1080/09205071.2014.997840 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:3:p:386-401 Template-Type: ReDIF-Article 1.0 Author-Name: S. Trinh-Van Author-X-Name-First: S. Author-X-Name-Last: Trinh-Van Author-Name: K.C. Hwang Author-X-Name-First: K.C. Author-X-Name-Last: Hwang Author-Name: Y. Yang Author-X-Name-First: Y. Author-X-Name-Last: Yang Author-Name: K.-Y. Lee Author-X-Name-First: K.-Y. Author-X-Name-Last: Lee Title: A printed quasi-Yagi antenna with a coupled slotline feed Abstract: In this study, a printed quasi-Yagi antenna with a coupled slotline feed is proposed and designed. In this design, a driven dipole is excited by a slotline mode with 1 × 2 CPW-slotline divider output instead of the coplanar strip mode used in conventional quasi-Yagi antennas. A prototype antenna with dimensions of 17 mm × 34.5 mm was fabricated to demonstrate the performance of the proposed feeding scheme. Measurements show that the proposed antenna has a wide −10 dB reflection bandwidth of 41.5% (7.32–11.15 GHz) and a gain ranging from 2.0 to 8.6 dBi. The measured radiation patterns of the antenna are also presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 402-409 Issue: 3 Volume: 29 Year: 2015 Month: 2 X-DOI: 10.1080/09205071.2015.1005176 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1005176 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:3:p:402-409 Template-Type: ReDIF-Article 1.0 Author-Name: T. Cai Author-X-Name-First: T. Author-X-Name-Last: Cai Author-Name: G.-M. Wang Author-X-Name-First: G.-M. Author-X-Name-Last: Wang Author-Name: J.F. Zhao Author-X-Name-First: J.F. Author-X-Name-Last: Zhao Author-Name: M. Yao Author-X-Name-First: M. Author-X-Name-Last: Yao Title: Two-dimensional fractal metasurface and its application to low profile circularly polarized antennas Abstract: Two-dimensional (2D) Wunderlich-shaped fractal reactive impedance surface (WRIS) is designed and extensively investigated to reduce the dielectric substrate thickness without deteriorating the electromagnetic characteristic. Slot resonators, Hilbert-shaped complementary single ring resonator (HCSRR), and the complementary three-turns spiral resonator have been used to achieve antenna miniaturization and also to render the circularly polarized (CP) wave. For demonstration, WRIS-inspired HCSRR- and TCSR-loaded CP antennas are optimized, fabricated, and measured. Numerical and experimental results indicate that both antennas owe compact size smaller than 0.18λ0 × 0.25λ0  ×  0.017λ0, exhibit comparable impedance, and axial ratio (AR) bandwidth better than 1.60% and pure CP performances. Furthermore, the antennas are free of metallic via holes and easy of fabrication, indicating promising applications in wireless communication systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 410-423 Issue: 3 Volume: 29 Year: 2015 Month: 2 X-DOI: 10.1080/09205071.2015.1005177 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1005177 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:3:p:410-423 Template-Type: ReDIF-Article 1.0 Author-Name: Zijian Xing Author-X-Name-First: Zijian Author-X-Name-Last: Xing Author-Name: Ling Wang Author-X-Name-First: Ling Author-X-Name-Last: Wang Author-Name: Martin S. Sandikie Author-X-Name-First: Martin S. Author-X-Name-Last: Sandikie Author-Name: Jianying Li Author-X-Name-First: Jianying Author-X-Name-Last: Li Author-Name: Jiadong Xu Author-X-Name-First: Jiadong Author-X-Name-Last: Xu Author-Name: Zhaolin Zhang Author-X-Name-First: Zhaolin Author-X-Name-Last: Zhang Title: Mutual coupling efficient analysis of rectangle microstrip circular polarization antenna array Abstract: Mutual coupling performance of the microstrip circular polarization (CP) antenna array is analyzed in this study. Compared with the single antenna application, in the antenna array, the S11, the radiation pattern, and the axial ratio will all be changed due to the mutual coupling and the axial ratio will be more sensitive. To further prove the concept and performance effect, a model of the microstrip antenna array is developed and analyzed in theory. The simulation and measurement results demonstrate that the relative position of antennas in the array exert different effect on the performances of the antenna. Thus, the study provides some very useful results of the CP antenna array. Journal: Journal of Electromagnetic Waves and Applications Pages: 425-435 Issue: 4 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2014.990112 File-URL: http://hdl.handle.net/10.1080/09205071.2014.990112 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:4:p:425-435 Template-Type: ReDIF-Article 1.0 Author-Name: Shengmei Yan Author-X-Name-First: Shengmei Author-X-Name-Last: Yan Author-Name: Wei Su Author-X-Name-First: Wei Author-X-Name-Last: Su Author-Name: Ao Xu Author-X-Name-First: Ao Author-X-Name-Last: Xu Author-Name: Yajun Wang Author-X-Name-First: Yajun Author-X-Name-Last: Wang Title: Analysis of multi-beam folded waveguide traveling-wave tube for terahertz radiation Abstract: A new proposal, multi-beam (MB) and power combining (PC) folded waveguide (FW) circuit, which can enhance the interaction efficiency and output power of terahertz (THz) traveling wave tubes, is presented in the paper. Operating with multiple electron beams and PC means that a larger beam current and higher combining power can be obtained. Firstly, equivalent circuit model of MB-FW is used to analyze its cold characteristics. Secondly, small signal model of MB-FW is also applied to evaluate its Pierce gain. Lastly, CST code is implemented to simulate high frequency, transmission, and interaction characteristics of MB-PC-FW. The results show this circuit can produce output power of over 15 W with six electron beams in 3 dB bandwidth range of 129–146 GHz when input power, each beam voltage, and current are set to 20 mW, 15.55 kV, and 12 mA, respectively. The output power, gain, and efficiency are 25 W, 31.02 dB, and 2.23% at 0.14 THz, respectively. Whereas, the single-beam folded waveguide circuit can only produce output power of 0.8 W in 3 dB bandwidth range of 135–147 GHz, and the output power, gain and efficiency are only 1.6 W, 22.03 dB, and 0.85% at 0.14 THz, respectively. The output power is raised tens of times and the interaction efficiency is raised several times in 3 dB bandwidth, and the 3 dB bandwidth is wider. In 3 dB bandwidth, the combining efficiency is not below 90%. Journal: Journal of Electromagnetic Waves and Applications Pages: 436-447 Issue: 4 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2014.992552 File-URL: http://hdl.handle.net/10.1080/09205071.2014.992552 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:4:p:436-447 Template-Type: ReDIF-Article 1.0 Author-Name: Heba A. Shaban Author-X-Name-First: Heba A. Author-X-Name-Last: Shaban Author-Name: Mohamad Abou El-Nasr Author-X-Name-First: Mohamad Author-X-Name-Last: Abou El-Nasr Title: Near–optimal rake receivers for green UWB radio communications in NLOS underground mine tunnels Abstract: This paper proposes a novel green radio (GR)-mismatched Rake receiver structure for ultra-wideband (UWB) communications in non-line-of-sight (NLOS) underground mine tunnels. The proposed architecture provides a promising solution for wireless GR communications in underground mine tunnels with greater than 90% reduction in power consumption. The bit error rate (BER) and maximum allowable data throughput (MADTh) of the proposed receiver structure are investigated via theoretical analysis as well as Monte-Carlo simulations in UWB NLOS underground mine tunnels and are compared to the corresponding optimal structures. The proposed mismatched receivers achieve an approaching MADTh and BER performance to the corresponding optimal structures with ≈$ \approx $ 1.5 dB BER performance degradation. Journal: Journal of Electromagnetic Waves and Applications Pages: 448-464 Issue: 4 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2014.998775 File-URL: http://hdl.handle.net/10.1080/09205071.2014.998775 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:4:p:448-464 Template-Type: ReDIF-Article 1.0 Author-Name: Zhigang Wang Author-X-Name-First: Zhigang Author-X-Name-Last: Wang Author-Name: Bo Yan Author-X-Name-First: Bo Author-X-Name-Last: Yan Author-Name: Ruimin Xu Author-X-Name-First: Ruimin Author-X-Name-Last: Xu Title: A millimeter-wave gain equalizer using E-plane microstrip-line probe and waveguide resonator Abstract: This paper presents a millimeter-wave wideband gain equalizer-based metallic waveguide, which is implemented by E-plane microstrip-line probe, metallic waveguide resonator, waveguide coupling groove, and millimeter-wave absorber. The proposed gain equalizer has advantages of high Q-factor and high power-handling capacity. In order to validate the new proposed topology, an ultra-wideband millimeter-wave gain equalizer, operating from 26.8 to 40 GHz, is designed and fabricated using rectangular waveguide. The R320 standard waveguide is used as main transmission line for convenient measurement. The fabricated gain equalizer exhibits excellent performances: the input return loss and the output return loss are all less than −14 dB in whole operating frequency band, and the maximum equalization value is about 11 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 465-473 Issue: 4 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2014.1002629 File-URL: http://hdl.handle.net/10.1080/09205071.2014.1002629 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:4:p:465-473 Template-Type: ReDIF-Article 1.0 Author-Name: F. Hamza Author-X-Name-First: F. Author-X-Name-Last: Hamza Author-Name: A.M. Abd El-Latief Author-X-Name-First: A.M. Author-X-Name-Last: Abd El-Latief Author-Name: M. Fayik Author-X-Name-First: M. Author-X-Name-Last: Fayik Title: Memory time effect on electromagnetic-thermoelastic materials Abstract: In this work, new mathematical model of Maxwell’s equations in an electromagnetic field is derived using the physical principles of fractional calculus. The advantage of our model appears according to the comparison between our model and a previous fractional electromagnetic model which was introduced by Gomez et al. Our model is applied to fractional thermoelastic material associated with one relaxation time interaction due to periodically varying heat source. The Laplace–Fourier double transform technique has been used to get the solution. The inversion of the Fourier transform has been done using residual calculus, where poles of the integrand are obtained numerically in a complex domain using Leguerre’s method and the inversion of the Laplace transformation is done numerically using a method based on a Fourier series expansion technique. Numerical results of temperature, displacement, stress, strain, and induced electric/magnetic fields are obtained for a hypothetical material. Finally, some comparisons have been shown in figures to estimate the effect of fractional-order parameters on all the studied variable fields. Journal: Journal of Electromagnetic Waves and Applications Pages: 474-501 Issue: 4 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2014.1002630 File-URL: http://hdl.handle.net/10.1080/09205071.2014.1002630 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:4:p:474-501 Template-Type: ReDIF-Article 1.0 Author-Name: Dinghong Jia Author-X-Name-First: Dinghong Author-X-Name-Last: Jia Author-Name: Quanyuan Feng Author-X-Name-First: Quanyuan Author-X-Name-Last: Feng Author-Name: Xiaoguo Huang Author-X-Name-First: Xiaoguo Author-X-Name-Last: Huang Author-Name: Qianyin Xiang Author-X-Name-First: Qianyin Author-X-Name-Last: Xiang Title: Tunable 3-pole bandpass filter with constant absolute bandwidth and >60 dB rejection at desired location of stopband Abstract: This paper presents a novel design approach for tunable 3-pole bandpass filter (BPF) with constant bandwidth (ABW) and deep rejection at the desired stopband. First, by properly designing the coupling coefficient and Qext, the tunable 3-pole BPF is designed with the characteristic of constant ABW. Only two bias voltages are adopted to complete the tuning, among which one of them is used to tune the center frequency and the other one is adopted to control the Qext. Then, bandstop resonators are introduced to provide deep rejection at desired stopband. A deep rejection level >60 dB can be easily controlled by varying the loaded capacitor Cbs among the stopband. Furthermore, the designed deep rejection point can be constant and produces little influence on the passband. For demonstration, a 3-pole tunable BPF is designed, fabricated, and measured. The filter can be tuned from 0.98 to 1.4 GHz with constant ABW, a wide fractional tuning range up to 40% can be attained. High rejection level >60 dB is realized at the pre-designed stopband point 0.65 GHz. The measurement shows good agreement with the simulation. Journal: Journal of Electromagnetic Waves and Applications Pages: 502-513 Issue: 4 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2014.1002631 File-URL: http://hdl.handle.net/10.1080/09205071.2014.1002631 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:4:p:502-513 Template-Type: ReDIF-Article 1.0 Author-Name: Mohd Hafizuddin Mat Author-X-Name-First: Mohd Hafizuddin Author-X-Name-Last: Mat Author-Name: Mohd Fareq Abd Malek Author-X-Name-First: Mohd Fareq Author-X-Name-Last: Abd Malek Author-Name: William George Whittow Author-X-Name-First: William George Author-X-Name-Last: Whittow Author-Name: Richard Bibb Author-X-Name-First: Richard Author-X-Name-Last: Bibb Title: Ear prosthesis evaluation: specific absorption rate levels in the head due to different angles and frequencies of electromagnetic exposure Abstract: This study presents a numerical analysis of the specific absorption rate in a head model exposed to electromagnetic fields when a real implant-retained prosthetic ear is attached to the side of the head. A set of dipole antennas operating at 900, 1800 and 2100 MHz were rotated to investigate the effect of frequency and polarisation. The maximum average 1 and 10 g specific absorption rates (SAR) have been presented to show the relative enhancement factor of the implant. A comparison of the mass-averaged SAR in the head with the implanted ear prosthesis shows that the 1 g SAR is doubled at 900 and 1800 MHz with different polarisations. Journal: Journal of Electromagnetic Waves and Applications Pages: 514-524 Issue: 4 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2014.1003982 File-URL: http://hdl.handle.net/10.1080/09205071.2014.1003982 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:4:p:514-524 Template-Type: ReDIF-Article 1.0 Author-Name: Wajid Ali Author-X-Name-First: Wajid Author-X-Name-Last: Ali Author-Name: Faiz Ahmad Author-X-Name-First: Faiz Author-X-Name-Last: Ahmad Author-Name: Aqeel A. Syed Author-X-Name-First: Aqeel A. Author-X-Name-Last: Syed Author-Name: Q.A. Naqvi Author-X-Name-First: Q.A. Author-X-Name-Last: Naqvi Title: Effects of negative permittivity and/or permeability on reflection and transmission from planar, circular cylindrical, and fractal chiral–chiral interfaces Abstract: In this article, we present a study on the effects of negative permittivity and/or permeability on the transmission and reflection of electromagnetic waves from a variety of chiral–chiral interfaces. Specifically, three topological shapes – planar, circular cylindrical, and fractal – of the interface are considered with variety of parametric differences. For each case, the reflected and transmitted power of electromagnetic waves is determined and numerical results are given for various values, positive as well as negative, of permittivity and permeability. It has been noted that combinations of negative permittivity and/or permeability along with suitable values of chirality of two media give rise to diverse transmission/reflection characteristics, in case of planar interfaces, and change of focusing field intensity in case of circular cylindrical interface. Moreover, it is noted that the fractionality of dimensions provides yet another parameter to alter any given interface characteristics. Journal: Journal of Electromagnetic Waves and Applications Pages: 525-537 Issue: 4 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2015.1006375 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1006375 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:4:p:525-537 Template-Type: ReDIF-Article 1.0 Author-Name: Elena Abdo-Sánchez Author-X-Name-First: Elena Author-X-Name-Last: Abdo-Sánchez Author-Name: Carlos Camacho-Peñalosa Author-X-Name-First: Carlos Author-X-Name-Last: Camacho-Peñalosa Author-Name: Jaime Esteban Author-X-Name-First: Jaime Author-X-Name-Last: Esteban Author-Name: Teresa M. Martín-Guerrero Author-X-Name-First: Teresa M. Author-X-Name-Last: Martín-Guerrero Title: Planar multiband sequentially rotated array with polarisation agility based on the complementary strip-slot element Abstract: A novel planar travelling-wave ring array with polarisation agility is introduced. The array is built by applying the sequential rotation technique with the complementary strip-slot element. This element is a conventional microstrip series-fed slot with the special feature of very broad impedance bandwidth thanks to the strip superimposed into it on the microstrip layer. The feeding of the array elements and the required phase shift between them are provided by a ring-shaped microstrip line, which is terminated in two ports. Vertical linear polarisation, horizontal linear polarisation, right-handed circular polarisation and left-handed circular polarisation can be generated with this very simple planar structure, just by controlling the phase and amplitude of the excitation at the two ports. Moreover, thanks to the wide impedance bandwidth of the element, multiband behaviour is achievable. A design example that operates at three different bands (centred around 6, 9 and 12 GHz) is analysed, which presents very good matching (|S11|<-15$ |S_{11}|<-15 $ dB), polarisation purity and broadside radiation pattern. Journal: Journal of Electromagnetic Waves and Applications Pages: 538-550 Issue: 4 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2015.1006734 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1006734 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:4:p:538-550 Template-Type: ReDIF-Article 1.0 Author-Name: S. Ramesh Author-X-Name-First: S. Author-X-Name-Last: Ramesh Author-Name: T. Rama Rao Author-X-Name-First: T. Rama Author-X-Name-Last: Rao Title: Indoor radio link characterization studies for millimeter wave wireless communications utilizing dielectric-loaded exponentially tapered slot antenna Abstract: A trend that is pragmatic in today’s wireless communications is the demand for the supportof increasing data rates over short distances. Through the last decade, ample knowledge about the 60 GHz millimeter wave (MmW) channel has been gathered and different architectures have been analyzed to develop MmW communication systems for commercial applications. The usage of MmW frequencies is perceived as a resilient entrant for realizing future, gigabit wireless communications as it offer vast bandwidths for short-range indoor communications. In this work, the MmW antenna solutions for exponentially tapered slot (ETS) antenna using substrate integrated waveguide (SIW) technology and indoor radio wave propagations are studied at 60 GHz for wireless communications. The SIW is used to feed the antenna, and a dielectric loading is utilized in front of the antenna to increase the gain. The antenna with elliptical-shaped dielectric loaded is fabricated using printed circuit board process. The measurement results are compared with simulated results. Then, the indoor short-range radio wave propagation study is carried out using ETS antenna with RF measurement equipment to measure and model propagation channels at 60 GHz. The attained simulations are compared to the experimental results. Journal: Journal of Electromagnetic Waves and Applications Pages: 551-564 Issue: 4 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2015.1011349 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1011349 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:4:p:551-564 Template-Type: ReDIF-Article 1.0 Author-Name: Wen-feng Chen Author-X-Name-First: Wen-feng Author-X-Name-Last: Chen Author-Name: Shu-xi Gong Author-X-Name-First: Shu-xi Author-X-Name-Last: Gong Author-Name: Bo Zhao Author-X-Name-First: Bo Author-X-Name-Last: Zhao Author-Name: Peng-fei Zhang Author-X-Name-First: Peng-fei Author-X-Name-Last: Zhang Author-Name: Hai-lin Dong Author-X-Name-First: Hai-lin Author-X-Name-Last: Dong Title: Fast wideband analysis of antennas around large platforms using hybrid numerical modeling technique Abstract: The efficient iterative method of moments and physical optics (EI-MoM–PO) hybrid formulation combined with the best uniform approximation is proposed to analyze the antenna array around the electrically large platform in this paper. In the conventional MoM–PO method, the computation of the mutual interaction matrix between the MoM and PO region is very time consuming. To facilitate the analysis of electrically large problems, the EI-MoM–PO method provides a possible way to avoid the calculation of the PO contribution in matrix form. On the other hand, the best uniform approximation is utilized to obtain the frequency response of antennas quickly and easy to be applied in EI-MoM–PO method. Finally, the frequency response of the bowtie antenna array around the electrically large platform is analyzed by the presented algorithm and the conventional one. Numerical results demonstrate the capability of the proposed technique. Journal: Journal of Electromagnetic Waves and Applications Pages: 565-573 Issue: 5 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2015.1009176 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1009176 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:5:p:565-573 Template-Type: ReDIF-Article 1.0 Author-Name: Yang Su Author-X-Name-First: Yang Author-X-Name-Last: Su Author-Name: Weixing Sheng Author-X-Name-First: Weixing Author-X-Name-Last: Sheng Author-Name: Yubing Han Author-X-Name-First: Yubing Author-X-Name-Last: Han Title: An accurate time-domain algorithm using high-order spatial basis functions for bodies of revolution Abstract: In this article, a time-domain algorithm using high-order spatial basis functions is proposed to obtain the induced currents and scattering field for bodies of revolution accurately and effectively. The third-order Hermite polynomials are used as the spatial basis functions, and the Laguerre polynomials are employed as the temporal basis functions. The marching-on-in-degree method is applied to solve the time-domain magnetic field integral equation and ensures the late-time stability. The formulas are derived and numerical results are evaluated. We also compared the traditional method which uses the low-order spatial basis functions with the method proposed which shows to be more accurate and needs fewer computational loads. Journal: Journal of Electromagnetic Waves and Applications Pages: 574-588 Issue: 5 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2015.1009641 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1009641 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:5:p:574-588 Template-Type: ReDIF-Article 1.0 Author-Name: Chuan Wu Author-X-Name-First: Chuan Author-X-Name-Last: Wu Author-Name: Feng Yang Author-X-Name-First: Feng Author-X-Name-Last: Yang Author-Name: Jun Ouyang Author-X-Name-First: Jun Author-X-Name-Last: Ouyang Author-Name: Peng Yang Author-X-Name-First: Peng Author-X-Name-Last: Yang Title: Floquet mode phenomena over 1-D infinite array illuminated by a CSB for reflectarray applications Abstract: For reflectarray antenna applications, radiation field of the one-dimensional infinite array which is illuminated by a complex source beam (CSB) is analyzed in this paper. The CSB is an excellent basis function to expand any slowly varying radiation field of reflectarray’s feed. By analytically continuing the source which is used to illuminate reflectarray from real space to complex space, CSB is generated simply. By adopting Poisson transformation, the slowly convergent superposition of individual radiation field from reflectarray is transformed to terms of Floquet modes. Asymptotic evaluation technique is utilized to calculate the Floquet mode integral in closed form. The propagation characteristic of Floquet mode follows the geometric optic ray theory in complex space. Numerical results are presented to demonstrate this approach. Journal: Journal of Electromagnetic Waves and Applications Pages: 589-601 Issue: 5 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2015.1011347 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1011347 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:5:p:589-601 Template-Type: ReDIF-Article 1.0 Author-Name: Zheng Liu Author-X-Name-First: Zheng Author-X-Name-Last: Liu Author-Name: Ying-Gui Wang Author-X-Name-First: Ying-Gui Author-X-Name-Last: Wang Author-Name: Le Yang Author-X-Name-First: Le Author-X-Name-Last: Yang Author-Name: Wen-Li Jiang Author-X-Name-First: Wen-Li Author-X-Name-Last: Jiang Title: Synthesized multitask compressive sensing for block-sparse signal recovery Abstract: The paper considers the problem of reconstructing blocks-sparse signals. A new algorithm, called synthesized multitask compressive sensing (SMCS), is proposed. In contrast to existing methods that rely on the availability of the sparsity structure information, the SMCS algorithm resorts to the multitask compressive sensing (MCS) technique for signal recovery. The SMCS algorithm synthesizes new compressive sensing (CS) tasks via circular-shifting operations and utilizes the minimum description length (MDL) principle to determine the proper set of the synthesized CS tasks for signal reconstruction. An outstanding advantage of SMCS is that it can achieve good signal reconstruction performance without using prior information on the block-sparsity structure. Simulations corroborate the theoretical developments. Journal: Journal of Electromagnetic Waves and Applications Pages: 602-614 Issue: 5 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2015.1011348 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1011348 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:5:p:602-614 Template-Type: ReDIF-Article 1.0 Author-Name: Haiyang Wang Author-X-Name-First: Haiyang Author-X-Name-Last: Wang Author-Name: Huan Zou Author-X-Name-First: Huan Author-X-Name-Last: Zou Author-Name: Yihong Zhou Author-X-Name-First: Yihong Author-X-Name-Last: Zhou Author-Name: Hao Li Author-X-Name-First: Hao Author-X-Name-Last: Li Title: Electro-thermal coupled modeling of PIN diode limiter used in high-power microwave effects simulation Abstract: A major failure mode of positive-intrinsic-negative (PIN) diode limiter is the diode junction thermal burnout due to the high-power microwave (HPM) irradiation. Based on the time domain circuit approach, an electro-thermal coupled model including junction transient self-heating effects is presented via analogous between thermal dynamic and electronic circuit topology. Moreover, the proposed model takes into account feedback updating of physical parameters as device junction temperature varying. The diode junction thermal behavior is simulated and verified by the device manufacture measurements. The PIN limiter circuit numerical results of the microwave pulse width dependence on power level under HPM interference validate the well-known semi-empirical Wunsch–Bell relationship. And the turning point value of microwave pulse width obtained in simulations is very close to that specified in Wunsch–Bell formula. Journal: Journal of Electromagnetic Waves and Applications Pages: 615-625 Issue: 5 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2015.1011350 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1011350 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:5:p:615-625 Template-Type: ReDIF-Article 1.0 Author-Name: L. Villard Author-X-Name-First: L. Author-X-Name-Last: Villard Author-Name: P. Borderies Author-X-Name-First: P. Author-X-Name-Last: Borderies Title: On the use of virtual ground scatterers to localize double and triple bounce scattering mechanisms for bistatic SAR Abstract: In Radar remote sensing, the electromagnetic (em) modeling of scattering contributions from natural or man-made scatterers has often to deal with coupling scattering mechanisms due to the underlying reflecting surface (ground or water). For the monostatic configuration, this contribution is commonly associated with the so-called double bounce scattering mechanism, which is also known to be located in synthetic aperture radar (SAR) images at the vertical projection of the scatterer onto the ground. To explore this phenomenon in the more general case of bistatic SAR but also for triple bounce scattering, a new formalism using virtual scatterers is introduced in this paper. Based upon image theory and on far-field assumption, these virtual points are defined by simple interaction scatterers located on the reflecting surface, and involving the same traveling wave path than the considered scattering mechanism. Depending only on the incidence and scattering angles, elegant formulae in their simplicity are highlighted to construct these fictitious scatterers. The resulting reduction of multiple to simple interaction scattering mechanisms simplifies the finding of their location within bistatic SAR images, generalizing thereby migration effects associated to coupling mechanisms in the bistatic configuration. Journal: Journal of Electromagnetic Waves and Applications Pages: 626-635 Issue: 5 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2015.1012594 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1012594 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:5:p:626-635 Template-Type: ReDIF-Article 1.0 Author-Name: J.F. Valenzuela-Valdés Author-X-Name-First: J.F. Author-X-Name-Last: Valenzuela-Valdés Author-Name: F. Luna Author-X-Name-First: F. Author-X-Name-Last: Luna Author-Name: R.M. Luque-Baena Author-X-Name-First: R.M. Author-X-Name-Last: Luque-Baena Author-Name: J.L. Padilla Author-X-Name-First: J.L. Author-X-Name-Last: Padilla Author-Name: P. Padilla Author-X-Name-First: P. Author-X-Name-Last: Padilla Title: Measuring cooperative massive MIMO in reverberation chamber Abstract: Cooperative or distributed multiple-input multiple-output (MIMO) systems are promising techniques for achieving large performance gains in wireless networks. Recently, a novel method for measuring these systems on a reverberation chamber has been proposed. In this letter, this technique is used to measure different cooperative massive MIMO (CM-MIMO) systems. The correlations of these systems have been shown, and capacities under different conditions are provided for different CM-MIMO systems. In addition, the behavior of these systems with Rician fading is also analyzed. These results show the impact of these new propagations channels on the fifth-generation mobile communication systems, which will be basic for the development of such systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 636-646 Issue: 5 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2015.1012595 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1012595 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:5:p:636-646 Template-Type: ReDIF-Article 1.0 Author-Name: E. Tahanian Author-X-Name-First: E. Author-X-Name-Last: Tahanian Author-Name: G.R. Dadashzadeh Author-X-Name-First: G.R. Author-X-Name-Last: Dadashzadeh Author-Name: M.R. Khorshidi Author-X-Name-First: M.R. Author-X-Name-Last: Khorshidi Title: Pierce gain analysis for sheet-beam multiple-circuits traveling-wave amplifiers Abstract: A pierce type analysis for multiple-circuits sheet-beam traveling wave amplifiers is presented. The introduced analysis effectively reduces the required time for the initial design and optimization procedure of these kinds of tubes. The one-dimensional linearized Pierce theory is extended to multiple circuits coupled to the sheet beam using equivalent circuit of slow-wave structures as well as dividing the sheet beam into many discrete beams, and then, the amplifier gain is calculated. Furthermore, this analysis is used to calculate the gain of two sheet-beam TWTs with single and double slow-wave structures, and the results are compared with those of particle-in-cell simulations. Good agreement between these results verifies the correctness and accuracy of the presented analysis. Journal: Journal of Electromagnetic Waves and Applications Pages: 647-658 Issue: 5 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2015.1012596 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1012596 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:5:p:647-658 Template-Type: ReDIF-Article 1.0 Author-Name: Ahlam Harhouz Author-X-Name-First: Ahlam Author-X-Name-Last: Harhouz Author-Name: Abdesselam Hocini Author-X-Name-First: Abdesselam Author-X-Name-Last: Hocini Title: Design of high-sensitive biosensor based on cavity-waveguides coupling in 2D photonic crystal Abstract: In this work, we design a new biosensor concept that uses a microcavity in 2D photonic crystal (PhC) to sense small refractive index (RI) changes. The RI sensor is formed by a point-defect resonant cavity in the sandwiched waveguide with triangular lattice of air holes. The properties of the sensor are simulated using the finite-difference time-domain method. The calculation results show that a change in ambient RI is apparent; the sensitivity of the sensor is achieved. We succeeded to obtain a new sensitivity value of 425 nm/RIU with a detection limit of 0.001 RIU, which proves the ability of the structure to produce biosensor PhC. Journal: Journal of Electromagnetic Waves and Applications Pages: 659-667 Issue: 5 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2015.1012597 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1012597 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:5:p:659-667 Template-Type: ReDIF-Article 1.0 Author-Name: Chien-Jen Wang Author-X-Name-First: Chien-Jen Author-X-Name-Last: Wang Author-Name: Jhong-Wei Wu Author-X-Name-First: Jhong-Wei Author-X-Name-Last: Wu Title: Analysis of the mallet-like slotted-ground-plane resonator Abstract: The frequency response characteristics, such as resonance condition and spurious harmonic, of a mallet-like slotted-ground-plane resonator have been shown in this work. Unlike the conventional slotted-ground-plane resonator with a half wavelength, the length of this proposed structure is only quarter-wavelength long so that compactness can be achieved. The technique of size reduction for the resonator is furthermore presented by modifying the impedance ratio of the mallet-like slot segments. Owing to the semi-ground plane, decrease of the quality factor causes enhancement of the rejection bandwidth. We analytically derive design equations with respect to the impedance ratio of the mallet-like slot resonator and can predict resonant modes without utilizing EM simulation software. In addition, by utilizing the thru-reflect-line calibration technique and theoretical methods, parameter extraction of the equivalent circuit of the mallet-like open-slot resonator is presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 668-682 Issue: 5 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2015.1014573 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1014573 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:5:p:668-682 Template-Type: ReDIF-Article 1.0 Author-Name: Zhe Wang Author-X-Name-First: Zhe Author-X-Name-Last: Wang Author-Name: Bing-Zhong Wang Author-X-Name-First: Bing-Zhong Author-X-Name-Last: Wang Author-Name: Wei Shao Author-X-Name-First: Wei Author-X-Name-Last: Shao Title: Efficient construction and solution of MoM matrix equation with compressed sensing technique Abstract: A novel method which employs the recently developed theory of compressed sensing (CS) in method of moments (MoMs) is presented. With linear transform, the construction of the impedance matrix and the solving of the unknown vector in MoM are converted into the construction of a sparse matrix and the solving of a sparse vector, respectively. Under this framework of sparsity, the CS technique can be introduced to construct highly underdetermined equations, which can be solved with the orthogonal matching pursuit algorithm. Thus, the computational cost of both impedance matrix construction and MoM equation solving can be saved dramatically. The performance of the proposed method is illustrated by numerical studies of electromagnetic field integral equations. Journal: Journal of Electromagnetic Waves and Applications Pages: 683-692 Issue: 5 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2015.1014574 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1014574 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:5:p:683-692 Template-Type: ReDIF-Article 1.0 Author-Name: Linyan Guo Author-X-Name-First: Linyan Author-X-Name-Last: Guo Author-Name: Boxun Xiao Author-X-Name-First: Boxun Author-X-Name-Last: Xiao Author-Name: Minhua Li Author-X-Name-First: Minhua Author-X-Name-Last: Li Author-Name: Helin Yang Author-X-Name-First: Helin Author-X-Name-Last: Yang Author-Name: Hai Lin Author-X-Name-First: Hai Author-X-Name-Last: Lin Title: A high-gain and frequency-tunable bow tie antenna with epsilon-negative metasurface Abstract: Various wireless communication systems require simple and high-gain radiating element operating in different working frequency bands. In this paper, an epsilon-negative metasurface antenna (ENG-MS antenna) with high-gain and frequency-tunable properties is proposed, fabricated and studied. This antenna is composed of an original double-sided printed bow tie antenna (source antenna) and an ENG-MS frequency selecting reflection layer. The strong electric interaction between ENG-MS (allowing evanescent wave only) and source antenna exhibits a significant effect on antenna’s radiation pattern and gain. Antenna’s gain can be selectively enhanced over the source antenna’s working frequency band. It is demonstrated that the resonant frequencies of this ENG-MS antenna can be continuously tuned by changing the distance between source antenna and ENG-MS. The proposed ENG-MS antenna in this paper shows a promising result to introduce metamaterials/metasurfaces in microwave device to realize high-gain and frequency-tunable functionality. Journal: Journal of Electromagnetic Waves and Applications Pages: 693-702 Issue: 5 Volume: 29 Year: 2015 Month: 3 X-DOI: 10.1080/09205071.2015.1018393 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1018393 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:5:p:693-702 Template-Type: ReDIF-Article 1.0 Author-Name: Shin-Yinn Tan Author-X-Name-First: Shin-Yinn Author-X-Name-Last: Tan Author-Name: Yun-Thung Yong Author-X-Name-First: Yun-Thung Author-X-Name-Last: Yong Author-Name: Sheng-Chyan Lee Author-X-Name-First: Sheng-Chyan Author-X-Name-Last: Lee Author-Name: Faidz Abd Rahman Author-X-Name-First: Faidz Author-X-Name-Last: Abd Rahman Title: Review on an arc-induced long-period fiber grating and its sensor applications Abstract: This paper presents a systematic review on the long-period fiber grating (LPFG) formed by the electric arcing method. The basic concept of LPFG and the background of the electric arcing method are thoroughly discussed. The paper also discussed on the methods to improve the sensitivity of LPFG towards external perturbations. The LPFG has been reported to have potential usage as sensor, thus a section of the paper has focused on some application of arc-induced LPFG as sensors. Journal: Journal of Electromagnetic Waves and Applications Pages: 703-726 Issue: 6 Volume: 29 Year: 2015 Month: 4 X-DOI: 10.1080/09205071.2015.1021019 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1021019 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:6:p:703-726 Template-Type: ReDIF-Article 1.0 Author-Name: J.F. Gómez-Aguilar Author-X-Name-First: J.F. Author-X-Name-Last: Gómez-Aguilar Author-Name: H. Yépez-Martínez Author-X-Name-First: H. Author-X-Name-Last: Yépez-Martínez Author-Name: R.F. Escobar-Jiménez Author-X-Name-First: R.F. Author-X-Name-Last: Escobar-Jiménez Author-Name: C.M. Astorga-Zaragoza Author-X-Name-First: C.M. Author-X-Name-Last: Astorga-Zaragoza Author-Name: L.J. Morales-Mendoza Author-X-Name-First: L.J. Author-X-Name-Last: Morales-Mendoza Author-Name: M. González-Lee Author-X-Name-First: M. Author-X-Name-Last: González-Lee Title: Universal character of the fractional space-time electromagnetic waves in dielectric media Abstract: This work presents an alternative solution for the mathematical analysis of the fractional waves in dielectric media. For the fractional wave equation, the Caputo fractional derivative was considered, the order of the spatial and temporal fractional derivatives are 0<β,γ≤2$ 0<\beta ,\gamma \le 2 $, respectively. In this analysis, we introduce the appropriate fractional dimensional parameters which characterize consistently the existence of the fractional space and time derivatives into the fractional wave equation. We will consider source free Maxwell equations in isotropic and homogeneous dielectric medium. The general solutions obtained in our research have been expressed in terms of the multivariate Mittag–Leffler functions, these functions depend only on the parameters β$ \beta $ and γ$ \gamma $ preserving the appropriated physical units according to the system studied. Journal: Journal of Electromagnetic Waves and Applications Pages: 727-740 Issue: 6 Volume: 29 Year: 2015 Month: 4 X-DOI: 10.1080/09205071.2015.1016189 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1016189 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:6:p:727-740 Template-Type: ReDIF-Article 1.0 Author-Name: Yao Luo Author-X-Name-First: Yao Author-X-Name-Last: Luo Author-Name: Baichao Chen Author-X-Name-First: Baichao Author-X-Name-Last: Chen Author-Name: Hong Zhou Author-X-Name-First: Hong Author-X-Name-Last: Zhou Title: Field and inductance of coaxial circular coils shielded by cuboid of high permeability Abstract: The magnetic field of the circular coils shielded by a coaxial cuboid of high permeability is investigated and the field solutions are given by introducing a proper ansatz of the magnetic scalar potential (MSP), which is convenient to fulfill the boundary conditions on the surfaces of the cuboid. The axial factor of the ansatz is obtained by separating the total axial field into the primary and secondary parts, and the coefficients of the ansatz are found out with the help of the spring properties of the MSP and the orthogonal relation of the eigenfunctions. The results are further developed to obtain the self- and mutual inductance of the shielded coaxial circular coils with rectangular cross section by calculating the associated magnetic flux. Finally, the numerical results of the proposed method are compared with those of the finite element method (FEM) simulations, and the validity of our method is confirmed by the high consistency between them in all cases. Journal: Journal of Electromagnetic Waves and Applications Pages: 741-752 Issue: 6 Volume: 29 Year: 2015 Month: 4 X-DOI: 10.1080/09205071.2015.1016553 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1016553 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:6:p:741-752 Template-Type: ReDIF-Article 1.0 Author-Name: Christopher J. Stevens Author-X-Name-First: Christopher J. Author-X-Name-Last: Stevens Author-Name: Yue Li Author-X-Name-First: Yue Author-X-Name-Last: Li Author-Name: Christopher W.T. Chan Author-X-Name-First: Christopher W.T. Author-X-Name-Last: Chan Title: Forward magneto-inductive wave propagation in planar magnetically coupled capacitor grids Abstract: One-, two- and three-dimensional arrays of magnetically coupled resonant loop circuits have been shown to support propagating waves and are known as Magneto-Inductive waveguides (MIW). Planar configurations of such circuits exhibit negative mutual inductance and support backward waves. Here, we consider a similar planar structure in which the individual resonators have coalesced forming a planar 1D ladder circuit which we call a CapGrid. These structures’ cells now couple by both magnetic and electric interactions and exhibit positive coupling and forward wave propagation. The bandwidth and group velocity available for signals is then greater than that possible for planar MIW with similar dimensions whilst offering similar characteristic impedances. A simple demonstration device has been fabricated and tested and found to match very well to a simple model based only on first-order interactions and circuit theory. Journal: Journal of Electromagnetic Waves and Applications Pages: 753-762 Issue: 6 Volume: 29 Year: 2015 Month: 4 X-DOI: 10.1080/09205071.2015.1020072 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1020072 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:6:p:753-762 Template-Type: ReDIF-Article 1.0 Author-Name: K. Wang Author-X-Name-First: K. Author-X-Name-Last: Wang Author-Name: L. Chen Author-X-Name-First: L. Author-X-Name-Last: Chen Author-Name: W. Li Author-X-Name-First: W. Author-X-Name-Last: Li Author-Name: S. Wang Author-X-Name-First: S. Author-X-Name-Last: Wang Title: Evaluating the top electrode voltage distribution uniformity in radio frequency systems Abstract: Studies on the voltage distribution on the top electrode are important to improve the radio frequency (RF) heating uniformity of samples. The goal of this study was to evaluate the top electrode voltage distribution uniformity in RF systems. The voltages of five representative points on the top electrode were measured by a measuring device with 3 kg soybeans, and validated by the heating patterns using 0.9 kg soybeans located at five positions of the RF cavity. The results showed that the length effect of the copper straps used for connecting the measuring points and measuring device should be taken into account by ignoring little effects of the strap shapes. The final voltages away from the feed strip were higher than those near the feed strip and the deviations between the minimum and the maximum values among the five voltages were 694.3 and 440.9 V, corresponding to the highest voltage difference of 11.99 and 7.12% without and with load, respectively. The real top electrode voltage distribution could be potentially used in computer simulations to achieve the accurate RF heating patterns. Journal: Journal of Electromagnetic Waves and Applications Pages: 763-773 Issue: 6 Volume: 29 Year: 2015 Month: 4 X-DOI: 10.1080/09205071.2015.1021018 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1021018 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:6:p:763-773 Template-Type: ReDIF-Article 1.0 Author-Name: Huiqing Zhai Author-X-Name-First: Huiqing Author-X-Name-Last: Zhai Author-Name: Chuanhan Zhan Author-X-Name-First: Chuanhan Author-X-Name-Last: Zhan Author-Name: Lu Liu Author-X-Name-First: Lu Author-X-Name-Last: Liu Author-Name: Changhong Liang Author-X-Name-First: Changhong Author-X-Name-Last: Liang Title: A new tunable dual-band metamaterial absorber with wide-angle TE and TM polarization stability Abstract: In this research, a new tunable dual-band metamaterial absorber with wide-angle TE and TM polarization stability is proposed. The designed absorber exhibits two high absorption peaks at 5.1 and 8.5 GHz with absorption peaks of 96 and 97%, respectively. The unit cell consists of a metallic background plane and two closed rings including two groups of T-shaped resonators, separated by a low-cost dielectric layer with thickness of 0.9 mm. By tuning the distance between the T-shaped structures and closed ring, the corresponding two resonance frequencies can be effectively separated with high absorption over 95% while keeping the closed ring unchanged. The simulated results demonstrate that the designed absorber has good characteristics of high absorption rates, polarization-insensitiveness and wide angle of incident waves. A waveguide experiment is performed to verify the good agreement between the simulated and measured results. Journal: Journal of Electromagnetic Waves and Applications Pages: 774-785 Issue: 6 Volume: 29 Year: 2015 Month: 4 X-DOI: 10.1080/09205071.2015.1024335 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1024335 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:6:p:774-785 Template-Type: ReDIF-Article 1.0 Author-Name: Arman Afsari Author-X-Name-First: Arman Author-X-Name-Last: Afsari Title: Mixed basis function for radial point interpolation meshless method in electromagnetics Abstract: In this study, an efficient meshless method named mixed radial point interpolation meshless method supplemented by a new (mixed) basis function is proposed. The proposed basis function is the multiplication of two conventional basis functions and possesses some extraordinary properties in comparison with conventional ones. In order to investigate the improvements of this basis function, an important type of electromagnetic problems, i.e. parallel plate waveguide with an internal discontinuity is analyzed. It is seen that the mixed basis function possesses better precision and convergence rate with respect to other basis functions. Journal: Journal of Electromagnetic Waves and Applications Pages: 786-797 Issue: 6 Volume: 29 Year: 2015 Month: 4 X-DOI: 10.1080/09205071.2015.1024336 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1024336 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:6:p:786-797 Template-Type: ReDIF-Article 1.0 Author-Name: Wei Shen Author-X-Name-First: Wei Author-X-Name-Last: Shen Author-Name: Tao Zhao Author-X-Name-First: Tao Author-X-Name-Last: Zhao Title: Compact T-septum substrate integrated waveguide (TSSIW) filter with wide stopband Abstract: Proposed is a compact fourth-order band-pass filter based on T-septum substrate integrated waveguide (TSSIW) resonators. By introducing a T-septum in the conventional SIW cavity, the TSSIW resonator has lower resonant frequency and wider monomode bandwidth. In order to verify our theory, a TSSIW filter sample is fabricated in low-temperature co-fired ceramic technology, and good agreements are obtained between simulated and measured S-parameters. In comparison with planar SIW cavity filters, the proposed filter has compact size, better frequency selectivity, and wider stopband. Journal: Journal of Electromagnetic Waves and Applications Pages: 798-806 Issue: 6 Volume: 29 Year: 2015 Month: 4 X-DOI: 10.1080/09205071.2015.1024802 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1024802 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:6:p:798-806 Template-Type: ReDIF-Article 1.0 Author-Name: W.Y. Yang Author-X-Name-First: W.Y. Author-X-Name-Last: Yang Author-Name: H.J. Kim Author-X-Name-First: H.J. Author-X-Name-Last: Kim Author-Name: J.H. Park Author-X-Name-First: J.H. Author-X-Name-Last: Park Author-Name: J.W. Bae Author-X-Name-First: J.W. Author-X-Name-Last: Bae Author-Name: C.H. Kim Author-X-Name-First: C.H. Author-X-Name-Last: Kim Author-Name: N.H. Myung Author-X-Name-First: N.H. Author-X-Name-Last: Myung Title: Effective reconstruction of insufficient JEM signals based on the CS method Abstract: One of the major issues in multifunction radar is the allocation of time resources to maximize the ability of the radar. If jet engine modulation (JEM) is analyzed correctly in an insufficient dwell time environment, the remaining time can be allocated for other tasks. This paper presents effective reconstruction of insufficient JEM signals based on compressed sensing (CS) method. The CS method was employed to extract a refined spectrum from insufficient JEM signals. In the process of applying the CS method to JEM signals, we utilized the modified linear programming (LP) standard form of an optimization method. The approach proposed in this paper is significant because it enables reliable estimation in spite of the insufficient JEM signal. Its application to insufficient JEM signals demonstrated that the reconstruction method presented in this paper improved the accuracy of JEM analysis and is expected to be effective from the perspective of radar resource management. Journal: Journal of Electromagnetic Waves and Applications Pages: 807-818 Issue: 6 Volume: 29 Year: 2015 Month: 4 X-DOI: 10.1080/09205071.2015.1026409 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1026409 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:6:p:807-818 Template-Type: ReDIF-Article 1.0 Author-Name: Cumali Sabah Author-X-Name-First: Cumali Author-X-Name-Last: Sabah Author-Name: Mehmet Mert Taygur Author-X-Name-First: Mehmet Mert Author-X-Name-Last: Taygur Author-Name: Emine Yesim Zoral Author-X-Name-First: Emine Yesim Author-X-Name-Last: Zoral Title: Investigation of microwave metamaterial based on H-shaped resonator in a waveguide configuration and its sensor and absorber applications Abstract: A microwave metamaterial (MTM) based on H-shaped resonator in a waveguide configuration is introduced and investigated both numerically and experimentally for X-band frequencies. The proposed model is designed and fabricated on both sides of the substrate and exhibits strong magnetic resonance at around 10.5 GHz. Additionally, it has very simple design which improves and simplifies the fabrication process. Besides, only one single slab is used in the simulation and experiment which provides a reduction in the number of the required samples with respect to its free space and/or waveguide counterparts. The effective medium theory is employed for the characterization of the structure, and the left-handed region is identified using the simulation and experimental data. The measured results are in good agreement with the simulated ones which show that the proposed MTM operates well and can be used in waveguide miniaturization and waveguide-based applications such as antennas, filters, sensors, imaging systems, and so on. To validate this, sensor and absorber applications are selected and the simulation results show that the proposed devices operate well with a good efficiency under the defined conditions. Journal: Journal of Electromagnetic Waves and Applications Pages: 819-831 Issue: 6 Volume: 29 Year: 2015 Month: 4 X-DOI: 10.1080/09205071.2015.1025916 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1025916 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:6:p:819-831 Template-Type: ReDIF-Article 1.0 Author-Name: Xiaoqing Hu Author-X-Name-First: Xiaoqing Author-X-Name-Last: Hu Author-Name: Rushan Chen Author-X-Name-First: Rushan Author-X-Name-Last: Chen Author-Name: Xiao Chen Author-X-Name-First: Xiao Author-X-Name-Last: Chen Author-Name: Xin Liu Author-X-Name-First: Xin Author-X-Name-Last: Liu Author-Name: Hairong Zheng Author-X-Name-First: Hairong Author-X-Name-Last: Zheng Author-Name: Ye Li Author-X-Name-First: Ye Author-X-Name-Last: Li Title: Compressed representation of matrix decomposition algorithm-singular value decomposition for full-wave analysis microstrip problems Abstract: In order to efficiently solve large dense complex linear systems arising from electric field integral equations (EFIE) of electromagnetic problems, matrix decomposition algorithm-singular value decomposition (MDA-SVD) is used to accelerate the matrix-vector product (MVP) operations and decrease memory usage. Based on the symmetry of the impedance matrix resulting from the discretization of the EFIE, we introduce a compressed representation of MDA-SVD in this paper. We obtain a sparse representation of the far-field interaction parts of impedance matrix and perform a fast MVP operation. Numerical experiments demonstrate that the compressed representation of MDA-SVD can reduce both the MVP time and memory usage by around 50% with similar accuracy. Journal: Journal of Electromagnetic Waves and Applications Pages: 832-842 Issue: 6 Volume: 29 Year: 2015 Month: 4 X-DOI: 10.1080/09205071.2015.1017013 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1017013 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:6:p:832-842 Template-Type: ReDIF-Article 1.0 Author-Name: The-Nan Chang Author-X-Name-First: The-Nan Author-X-Name-Last: Chang Author-Name: Jyun-Ming Lin Author-X-Name-First: Jyun-Ming Author-X-Name-Last: Lin Title: Dual-band circularly polarized monopole antenna Abstract: A printed dual-band circularly polarized (CP) antenna is presented. The antenna is composed of a strip monopole on one side of a substrate. On the other side of the substrate, there are a perturbed patch and a slotted ground plane. Two sleeves are extended from two edges of the ground plane. It is investigated that the perturbed patch is mainly responsible for the CP wave centered at 5.5 GHz and the sleeves are mainly responsible for the CP wave centered at 2.5 GHz. The measured boresight gains are 4 dBic at 5.5 GHz and 2.5 dBic at 2.5 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 843-857 Issue: 7 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1022265 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1022265 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:7:p:843-857 Template-Type: ReDIF-Article 1.0 Author-Name: Honglei Wang Author-X-Name-First: Honglei Author-X-Name-Last: Wang Author-Name: Kunde Yang Author-X-Name-First: Kunde Author-X-Name-Last: Yang Author-Name: Kun Zheng Author-X-Name-First: Kun Author-X-Name-Last: Zheng Title: Electromagnetic field radiated in air from a horizontal/vertical magnetic dipole in sea Abstract: The propagation characteristics of electromagnetic (EM) waves across the seawater–air interface influence seawater to air communication. The type of underwater antenna determines EM wave propagation performance. However, studies rarely compared the performance of horizontal and vertical magnetic dipoles (HMD and VMD). In this study, the EM fields in air due to HMD/VMD immersed in sea were derived to provide a basis for selecting a suitable underwater antenna for EM wave propagation in undersea–air communication. Analytic results were obtained from the model of a three-layered conducting media. Associated expressions in air were numerically calculated using the fast Fourier Transform algorithm to present the propagation curves and the distribution patterns of the EM fields. A proof of concept measurement system was constructed, and sea experiments were conducted and compared with theoretical studies. The maximum transmitting–receiving distance in the experiment was achieved by the HMD. The theoretical and experimental results indicate that the HMD antenna is superior to the VMD antenna and that the suggested band of EM wave is feasible for transmission across the seawater–air interface. Journal: Journal of Electromagnetic Waves and Applications Pages: 858-873 Issue: 7 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1022636 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1022636 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:7:p:858-873 Template-Type: ReDIF-Article 1.0 Author-Name: S. Das Author-X-Name-First: S. Author-X-Name-Last: Das Author-Name: P.P. Sarkar Author-X-Name-First: P.P. Author-X-Name-Last: Sarkar Author-Name: S.K. Chowdhury Author-X-Name-First: S.K. Author-X-Name-Last: Chowdhury Title: Analysis of an open-ended inverted L-shaped slot-loaded microstrip patch antenna for size reduction and multifrequency operation Abstract: This paper proposes a detail analysis of a single layer, single-feed microstrip patch antenna for size reduction and multifrequency operation. An open-ended inverted L-shaped slot is introduced at the left-hand side radiating edge of the patch to reduce the size of the antenna by reducing the resonant frequency. Multiple resonant frequencies are also obtained by introducing the open-ended inverted L-shaped slot. The measured result shows that the size of the proposed antenna has been reduced by 74.3% when compared with conventional rectangular microstrip antenna with same patch area. The proposed antenna also provides increased frequency ratio (the ratio of second or higher resonant frequency to the first resonant frequency). The conventional and proposed antennas are designed and simulated by method of moment-based IE3D software. An extensive analysis of the antenna parameters (reflection coefficient, radiation pattern, gain, etc.) including surface current distribution is given in this paper. Journal: Journal of Electromagnetic Waves and Applications Pages: 874-890 Issue: 7 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1025914 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1025914 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:7:p:874-890 Template-Type: ReDIF-Article 1.0 Author-Name: Chien-Wen Chiu Author-X-Name-First: Chien-Wen Author-X-Name-Last: Chiu Author-Name: Chen-An Ou Author-X-Name-First: Chen-An Author-X-Name-Last: Ou Author-Name: Hwang-Cheng Wang Author-X-Name-First: Hwang-Cheng Author-X-Name-Last: Wang Title: Compact printed quadrifilar helix antenna for universal RFID hand-held reader Abstract: This paper presents a compact printed quadrifilar helix antenna (PQHA) for portable UHF RFID reader applications. The circularly polarized PQHA is fed by a feeding network with quadrature-phase and equal amplitude output signals. The quadrature-phase feeding network is composed of a 180° power splitter and two wideband quadrature hybrid couplers implemented by lumped-element circuits. The miniaturized antenna is a one-wavelength resonance type and can preserve high antenna gain. Moreover, the bandwidths of impedance and axial ratio cover the global UHF RFID band (860–960 MHz). The measured impedance bandwidth is about 34.1% and the axial ratio bandwidth covers 700–1,000 MHz. The measured maximum gain is 5.8 dBic and the 3-dB beamwidth is 168°. The height of the entire system is only 79 mm, the radius is 35 mm, and the FR4 substrate for the feeding network is only 80 × 80 × 1.6 mm3. The proposed antenna is suitable for handheld UHF RFID reader applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 891-904 Issue: 7 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1026407 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1026407 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:7:p:891-904 Template-Type: ReDIF-Article 1.0 Author-Name: Jinpil Tak Author-X-Name-First: Jinpil Author-X-Name-Last: Tak Author-Name: Seoungkyu Lee Author-X-Name-First: Seoungkyu Author-X-Name-Last: Lee Author-Name: Jaehoon Choi Author-X-Name-First: Jaehoon Author-X-Name-Last: Choi Title: Design of an all-textile circular patch antenna with corrugated ground for guided wave along the body surface for WBAN applications Abstract: An all-textile circular patch antenna with corrugated ground for guided wave along the body surface is proposed. The proposed antenna consists of center-coupled-fed circular patch and thread-corrugated ground. The thread-corrugated ground, made of conductive sewing threads, acts as an inductively reactive surface to support a body surface TM mode wave. The proposed antenna with a thickness of 7 mm (0.14λ0 at 6 GHz) operates in the 6-GHz band. Considering a practical on-body application, the proposed antenna is fabricated using all-textile materials, such as conductive fabric, conductive threads, fabric substrate, and conductive epoxy. To evaluate the human body effect, a two-thirds muscle-equivalent semi-solid phantom is utilized. The measured 10-dB return loss bandwidth of the antenna on the phantom is 9.5%, which ranges from 5.77 to 6.34 GHz. The gain enhancement on the phantom surface (θ = 90°) is 8.65 dB from –8.1 dBi for the antenna without a corrugated ground to 0.55 dBi for the antenna with a thread-corrugated ground. Journal: Journal of Electromagnetic Waves and Applications Pages: 905-924 Issue: 7 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1026408 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1026408 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:7:p:905-924 Template-Type: ReDIF-Article 1.0 Author-Name: J.A. Brandão Faria Author-X-Name-First: J.A. Author-X-Name-Last: Brandão Faria Title: Matrix theory of wave propagation in hybrid electric/magnetic multiwire transmission line systems Abstract: Matrix methods to deal with multimodal propagation in electric multiwire transmission lines are quite well known. However, the matrix theory of magnetic multiwire transmission lines (MMTL) has been established only very recently. In this study, we advance the new subject of hybrid electric and MMTL, which has never been addressed in the literature. A complex system composed of N + 1 electric wires and n + 1 magnetic wires is theoretically analyzed from the viewpoint of their interaction/coupling, transmission line matrix equations, ABCD matrix formalism, and superposition of propagation modes. Journal: Journal of Electromagnetic Waves and Applications Pages: 925-940 Issue: 7 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1026410 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1026410 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:7:p:925-940 Template-Type: ReDIF-Article 1.0 Author-Name: Rahman Sofiani Author-X-Name-First: Rahman Author-X-Name-Last: Sofiani Author-Name: Hamid Heidar Author-X-Name-First: Hamid Author-X-Name-Last: Heidar Author-Name: Morteza Kazerooni Author-X-Name-First: Morteza Author-X-Name-Last: Kazerooni Title: A smart meshing technique to speed up radar cross-section calculation of very large random rough surfaces Abstract: In this paper, smart triangular meshing algorithm (STMA) is proposed to calculate the radar cross-section of two-dimensional random rough surfaces. The focus is on the random sea surfaces. The electric field integral equation is solved by the method of moment (MOM) using the STMA meshing through breaking the surfaces into some sub-surfaces and including some modifications on the borders meshing. The Gaussian random distribution with Elfouhaily spectrum is applied to model the sea water as a rough surface. Respect to traditional triangular meshing techniques for MOM, this approach not only requires less memory and processing time, but also it is more efficient for larger surfaces using maximum capabilities of modern multi-core processors. We verify the method by comparing its output with FEKO suite 5.5 results. Finally, different cases are considered and the calculation time enhancement is examined. Journal: Journal of Electromagnetic Waves and Applications Pages: 941-952 Issue: 7 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1027415 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1027415 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:7:p:941-952 Template-Type: ReDIF-Article 1.0 Author-Name: H. Rahimi Author-X-Name-First: H. Author-X-Name-Last: Rahimi Title: Polarization-sensitive optical phase modulators based on aperiodic multilayers containing nano-scale fullerene and semiconductor layers Abstract: The band characteristics and the phase shift of electromagnetic waves in one-dimensional Fibonacci photonic structures composed of nano-scale fullerene and semiconductor layers are investigated theoretically in detail for both TE and TM polarizations and for different incident angles. We adopt the transmission matrix method to analyze the transmission properties of supposed sub-wavelength structure. We observe that within the stop band, the reflection phase difference changes smoothly and increases with the increasing of the incident angle. Furthermore, the phase shift decreases with the incident angle increasing for TE mode, and increases with the incident angle increasing for TM mode. Especially, at both the edges of the gap, the reflection phase difference keeps zero in spite of the change of incident angle. Based on our results, the supposed structure provides a convenient way to design very compact phase controllers such as phase retarders. Journal: Journal of Electromagnetic Waves and Applications Pages: 953-965 Issue: 7 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1027416 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1027416 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:7:p:953-965 Template-Type: ReDIF-Article 1.0 Author-Name: Giovanni Andrea Casula Author-X-Name-First: Giovanni Andrea Author-X-Name-Last: Casula Title: Design of a multiband printed LPDA for weather radar reflector systems Abstract: A printed Log-periodic dipole array (LPDA) is presented as a multiband feed for reflector antennas in weather radar applications. The antenna has been designed starting from Carrel’s theory, optimized using CST Microwave Studio 2012, and then realized. The comparison between simulated and measured results shows that the proposed antenna can be used for weather radar applications both in the S- (2.7–3 GHz) and C- (5.4–5.8 GHz) frequency bands, with a very good input matching and a satisfactory end-fire radiation pattern. Moreover, it has a compact size, is very easy to realize, and presents an excellent out-of-band rejection, without the use of stop-band filters, thus avoiding interferences out of the weather radars’ operating frequency band. In order to obtain the same beamwidth both in E-plane and H-plane, a V-shaped configuration is proposed, which allows to improve the aperture efficiency of a reflector antenna fed by the presented LPDA. Journal: Journal of Electromagnetic Waves and Applications Pages: 966-976 Issue: 7 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1029081 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1029081 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:7:p:966-976 Template-Type: ReDIF-Article 1.0 Author-Name: The Editors Title: Erratum Journal: Journal of Electromagnetic Waves and Applications Pages: i-i Issue: 7 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1080407 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1080407 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:7:p:i-i Template-Type: ReDIF-Article 1.0 Author-Name: Chengyang Yu Author-X-Name-First: Chengyang Author-X-Name-Last: Yu Author-Name: Feifei Tan Author-X-Name-First: Feifei Author-X-Name-Last: Tan Author-Name: Changjun Liu Author-X-Name-First: Changjun Author-X-Name-Last: Liu Title: A C-band microwave rectenna using aperture-coupled antenna array and novel Class-F rectifier with cavity Abstract: A rectenna (rectifying antenna) is usually applied to a microwave power transmission (MPT) system as a terminal, which receives microwave (MW) power and converts them into DC power. A 5.8 GHz aperture-coupled patch antenna array is developed with a gain of 19.5 dBi, which is a part of the rectenna. A novel Class-F rectifier with a series diode is proposed to achieve a high rectifying efficiency based on harmonic termination techniques. The input circuit of the proposed rectifier is taken into consideration to reach the Class-F condition, while mostly only the output circuit is involved in conventional Class-F designs. A low-pass filter based on defected ground structure is implemented, which not only blocks the harmonics produced in rectifying but also presents desired impedance at harmonics. The current and voltage waveforms on the diode are well enforced. The radiation feature of the rectifier is presented as well. It shows that an optimized cavity, which shields the parasite radiation, may achieve a 5% enhancement on the MW-to-DC conversion efficiency. A C-band rectifier based on HSMS-286 Schottky diode is fabricated and measured. A MPT simple demo system is constructed with the proposed rectifier and antenna. A measured maximum MW-to-DC conversion efficiency of 72% is achieved on the rectifier. The design method is extremely valuable in a high conversion efficiency rectenna design based on harmonic termination techniques. Journal: Journal of Electromagnetic Waves and Applications Pages: 977-991 Issue: 8 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1018394 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1018394 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:8:p:977-991 Template-Type: ReDIF-Article 1.0 Author-Name: Liping Yan Author-X-Name-First: Liping Author-X-Name-Last: Yan Author-Name: Xiang Zhao Author-X-Name-First: Xiang Author-X-Name-Last: Zhao Author-Name: Hang Zhao Author-X-Name-First: Hang Author-X-Name-Last: Zhao Author-Name: Haijing Zhou Author-X-Name-First: Haijing Author-X-Name-Last: Zhou Author-Name: Kama Huang Author-X-Name-First: Kama Author-X-Name-Last: Huang Title: Artificial neural network modeling of electromagnetic interference caused by nonlinear devices inside a metal enclosure Abstract: The artificial neural network (ANN) modeling of electromagnetic interference from a nonlinear device connected with transmission lines exposed to electromagnetic field to the linear device inside a metal enclosure is investigated in this paper. A rectangular loop antenna operating at 2.5 GHz is used to excite electromagnetic field inside an enclosure with dimension 99 × 49 × 44 cm3. Another wideband loop antenna welded with a HSMS-282C Schottky diode pair is used as the nonlinear device connected with the transmission line in order to enhance the coupling and radiating effects inside the enclosure. The linear devices are three monopole probes connected with spectrum analyzer to measure the output power. Experimental results show that the output power from probes near the wideband loop welding with a pair of diodes contains not only fundamental but harmonic components, which are caused by the nonlinear response of diodes excited by induced current. A three-layer ANN model is proposed to predict this nonlinear electromagnetic interference inside the metal enclosure. Results show that the trained BL-MLP model using 576 measured data can predict the response of probes (linear device) interfered by the loop antenna welding with diodes (nonlinear device) inside the cavity well. Journal: Journal of Electromagnetic Waves and Applications Pages: 992-1004 Issue: 8 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1025915 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1025915 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:8:p:992-1004 Template-Type: ReDIF-Article 1.0 Author-Name: Jinsik Mok Author-X-Name-First: Jinsik Author-X-Name-Last: Mok Author-Name: Hyoung-In Lee Author-X-Name-First: Hyoung-In Author-X-Name-Last: Lee Title: Optical chirality exhibited by two axially propagating electromagnetic waves in counter-rotations Abstract: The optical chirality of two axially propagating electromagnetic waves is investigated. These two waves of different nature are in counter-rotations, thereby being non-plane waves. From the resulting spatial distributions of energy and chirality, we find not only enhancements but also cancellations due to the interferences in these hybrid waves. In addition, the roles of the axial wave number and interference phase are illustrated by introducing a proper figure of merit for relevant device performances. Journal: Journal of Electromagnetic Waves and Applications Pages: 1005-1017 Issue: 8 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1027417 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1027417 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:8:p:1005-1017 Template-Type: ReDIF-Article 1.0 Author-Name: Magdy A. Ezzat Author-X-Name-First: Magdy A. Author-X-Name-Last: Ezzat Author-Name: Ahmed S. El-Karamany Author-X-Name-First: Ahmed S. Author-X-Name-Last: El-Karamany Author-Name: Alaa A. El-Bary Author-X-Name-First: Alaa A. Author-X-Name-Last: El-Bary Title: A novel magneto-thermoelasticity theory with memory-dependent derivative Abstract: In this work, a new model of magneto-thermoelasticity theory has been constructed in the context of a new consideration of heat conduction with memory-dependent derivative. One-dimensional application for a perfect electrically conducting half-space of elastic material, which is thermally shocked, in the presence of a constant magnetic field has been solved by using Laplace transform technique. According to the numerical results and its graphs, conclusion about the new theory of magneto-thermoelasticity has been constructed and compared with dynamic classical coupled theory. Journal: Journal of Electromagnetic Waves and Applications Pages: 1018-1031 Issue: 8 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1027795 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1027795 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:8:p:1018-1031 Template-Type: ReDIF-Article 1.0 Author-Name: Jui-Han Lu Author-X-Name-First: Jui-Han Author-X-Name-Last: Lu Author-Name: Feng-Chuan Tsai Author-X-Name-First: Feng-Chuan Author-X-Name-Last: Tsai Title: Planar small-size LTE/WWAN tablet computer antenna with eight-band operation Abstract: By attaching a C-shaped parasitic monopole strip on the backside of the antenna, a novel compact eight-band monopole antenna (MA) is proposed and embedded in the LTE/WWAN tablet computer. The operating impedance bandwidths of 264/997 MHz can be obtained across the LTE/WWAN bands, respectively. Given that the overall antenna size is only 35 × 10 × 0.8 mm3, the proposed planar MA provides more than 22% reduction in antenna size over that of the conventional ones. Meanwhile, this small-size MA provides the measured peak gains and antenna efficiencies of 2.0/3.2 dBi and 60/66% for the LTE/WWAN bands, respectively. Additionally, to fulfill the limitation of 1.6 W/kg of the 1-g body specific absorption rate (SAR) requirement for mobile device applications, the proposed planar compact MA is deposited inside the tablet computer for the study of radiating performance. Journal: Journal of Electromagnetic Waves and Applications Pages: 1032-1046 Issue: 8 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1029644 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1029644 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:8:p:1032-1046 Template-Type: ReDIF-Article 1.0 Author-Name: Ahsan Noor Author-X-Name-First: Ahsan Author-X-Name-Last: Noor Author-Name: Aqeel A. Syed Author-X-Name-First: Aqeel A. Author-X-Name-Last: Syed Author-Name: Qaisar A. Naqvi Author-X-Name-First: Qaisar A. Author-X-Name-Last: Naqvi Title: Quasi-static analysis of scattering from a layered plasmonic sphere in fractional space Abstract: Quasi-static analysis of scattering from a layered sphere in fractional dimensional space is presented. The layers to be considered include plasmonic and/or non-plasmonic materials. Additionally, the space surrounding and occupied by the sphere is assumed to be fractional. The effects of layers and fractionality of dimensions on polarizability and potential distribution of the sphere are investigated. Numerical results for the same are presented for various combinations of layers and fractionality of the space. Journal: Journal of Electromagnetic Waves and Applications Pages: 1047-1059 Issue: 8 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1032436 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1032436 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:8:p:1047-1059 Template-Type: ReDIF-Article 1.0 Author-Name: Alonso Corona-Chavez Author-X-Name-First: Alonso Author-X-Name-Last: Corona-Chavez Author-Name: Jose Luis Olvera-Cervantes Author-X-Name-First: Jose Luis Author-X-Name-Last: Olvera-Cervantes Author-Name: Carlos E. Saavedra Author-X-Name-First: Carlos E. Author-X-Name-Last: Saavedra Title: Balanced filter with parallel resonances for very wide band common mode rejection Abstract: A new type of balanced filter with a very wide common mode (CM) free band is presented. In this design, the filter’s symmetry line lies parallel to the resonator’s current flow. Therefore, when a differential signal is excited, a virtual open circuit is forced all along this symmetry line, which results in the excitation of parallel resonances on the resonators. However, for CM operation, a short circuit is forced all along the resonator, therefore eliminating any parallel CM resonances. The filter was designed with Chebyshev response using four poles at a differential frequency of 1.11 GHz. Its fractional bandwidth is 5%. It was fabricated on a substrate with εr = 10.2 and a thickness of 1.9 mm. Experimental and simulated results on the test filter show good agreement. The first CM resonance is excited at about 10 times the desired center frequency. This is due to orthogonal resonances of the resonator. Journal: Journal of Electromagnetic Waves and Applications Pages: 1060-1067 Issue: 8 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1033064 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1033064 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:8:p:1060-1067 Template-Type: ReDIF-Article 1.0 Author-Name: T. Gric Author-X-Name-First: T. Author-X-Name-Last: Gric Author-Name: M. Eldlio Author-X-Name-First: M. Author-X-Name-Last: Eldlio Author-Name: M. Cada Author-X-Name-First: M. Author-X-Name-Last: Cada Author-Name: J. Pistora Author-X-Name-First: J. Author-X-Name-Last: Pistora Title: Analytic solution to field distribution in two-dimensional inhomogeneous waveguides Abstract: We present a novel theoretical approach for analytically solving wave propagation through two-dimensional (2D) inhomogeneous slab waveguides. The validity and reliability of our analytical approach is verified by its application to electrical field distribution in 2D waveguides, when compared with numerically exact solution. The main advantage of this theoretical treatment is that the obtained solution is global and can be presented in an analytical form. The effects of the refractive index profile on the guided modes are analyzed by introducing the field distributions of the guided modes. Our analytical calculations show significant potential for use in various applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1068-1081 Issue: 8 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1034327 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1034327 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:8:p:1068-1081 Template-Type: ReDIF-Article 1.0 Author-Name: Fang-Pin Xiang Author-X-Name-First: Fang-Pin Author-X-Name-Last: Xiang Author-Name: Xing-Chang Wei Author-X-Name-First: Xing-Chang Author-X-Name-Last: Wei Author-Name: Er-Ping Li Author-X-Name-First: Er-Ping Author-X-Name-Last: Li Title: A hybrid domain decomposition and optimization method for predicting electromagnetic emissions from printed circuit boards Abstract: Electromagnetic emission characterization of printed circuit boards (PCBs) based on phaseless near-field measurement is increasingly concerned. Generally, the PCB is modelled by equivalent elemental dipoles, which are retrieved by optimization method. To accurately model the PCB, enough dipoles are required and consequently an inevitable trade-off occurs between the modelling accuracy and the model retrieval efficiency. To deal with this issue, an efficient hybrid method is here proposed for modelling the electromagnetic emissions from PCBs with equivalent magnetic dipoles. Hybrid domain decomposition and repeated particle swarm optimization method is used to retrieve the equivalent dipoles by fitting them to the amplitude-only magnetic near fields. Prediction of electromagnetic emissions from the PCBs can then be achieved once the equivalent dipole model is determined. The proposed method shows good performance in terms of convergence accuracy and convergence speed. Numerical results are presented to validate the effectiveness of the approach and its robustness against noisy magnetic near fields. Journal: Journal of Electromagnetic Waves and Applications Pages: 1082-1092 Issue: 8 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1034810 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1034810 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:8:p:1082-1092 Template-Type: ReDIF-Article 1.0 Author-Name: Mohamed Ahmed Fouad Hagag Author-X-Name-First: Mohamed Ahmed Fouad Author-X-Name-Last: Hagag Author-Name: Mahmoud A. Abdalla Author-X-Name-First: Mahmoud A. Author-X-Name-Last: Abdalla Title: Ultra compact CPW dual band filter based on π-generalized metamaterial NRI transmission line Abstract: This paper presents an ultra compact dual-band coplanar waveguide metamaterial filter based on generalized metamaterial transmission line. The detailed theoretical design steps of the filter are explained. The dual-band filter design performance has been validated using equivalent circuit modeling, electromagnetic full wave simulations, and practical measurement. The results illustrate the filter has dual passbands centered at 0.82 and 1.48 GHz with approximately 1 dB insertion loss and minimum 12 dB return loss. Good agreements between the circuit modeling, electromagnetic full wave simulations, and practical measurements are achieved. Moreover, the filter size is only (18 × 28 mm2) which is only less than (0.2λg × 0.31λg) at the center frequency of the first passband and (0.36λg × 0.56λg) at the center frequency of the second passband. Journal: Journal of Electromagnetic Waves and Applications Pages: 1093-1103 Issue: 8 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1044123 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1044123 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:8:p:1093-1103 Template-Type: ReDIF-Article 1.0 Author-Name: Narae Kim Author-X-Name-First: Narae Author-X-Name-Last: Kim Author-Name: Suhyun Kim Author-X-Name-First: Suhyun Author-X-Name-Last: Kim Author-Name: Yunho Jung Author-X-Name-First: Yunho Author-X-Name-Last: Jung Author-Name: Seongjoo Lee Author-X-Name-First: Seongjoo Author-X-Name-Last: Lee Title: A low-power antenna selective synchronization method for IEEE 802.11ac WLAN systems Abstract: This paper proposes an antenna selective timing synchronization method for multiple-input multiple-output orthogonal frequency division multiplexing-based IEEE 802.11ac wireless local area network systems. IEEE 802.11ac systems support up to eight antenna elements for adopting an MIMO technique. The increase in the number of antennas results in high power consumption due to the very high computational complexity involved. In addition, cyclic delay diversity applied for each antenna causes timing synchronization difficulties due to the pseudo-multipath problems. In order to solve these problems, a method to reduce the computational complexity of the synchronization is proposed by utilizing selective antennas with higher received signal power. The timing synchronization method with the adaptive accumulation window is also proposed to enhance synchronization performance. The simulation and power estimation results show that the proposed timing synchronization method not only improves the performance, but also reduces the computation power considerably. The proposed method is very useful for IEEE 802.11ac wireless LAN systems, where not only synchronization performance but also computation power is one of the most important issues. Journal: Journal of Electromagnetic Waves and Applications Pages: 1104-1116 Issue: 8 Volume: 29 Year: 2015 Month: 5 X-DOI: 10.1080/09205071.2015.1035865 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1035865 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:8:p:1104-1116 Template-Type: ReDIF-Article 1.0 Author-Name: Roberto B. Sardenberg Author-X-Name-First: Roberto B. Author-X-Name-Last: Sardenberg Author-Name: José M.A. Figueiredo Author-X-Name-First: José M.A. Author-X-Name-Last: Figueiredo Title: Evidence for undamped waves on ohmic materials Abstract: In this work, we present a historical review of the developments of the field of impedance spectroscopy technique, pointing out some recent advances toward accuracy improvements and new applications. The requirements for physically realizable impedances, which are provided by Linear System Theory, are summarized and discussed for a set of measured data. Some metrology issues are also mentioned and referenced. Original studies concerning a never before observed region of the impedance spectra of conducting materials are also presented. It was found that the real part of passive circuits may attain negative values. A first-principle model that permitted us to perform calculations that forecast this so far concealed part of the impedance spectra is presented. On these footings, it seems that a specific propagation mode of electromagnetic fields in matter is the cause for this unusual spectral response. Our predictions were confirmed by a set of carefully conducted experiments. Calculations and experiments were performed on metallic and carbon-made spires and coils, of specific geometry, in the MHz range. Our data demonstrate that, in fact, the impedance of a carefully engineered passive circuit may assume phase angle values belonging to the full trigonometric circle [−π, π]. Journal: Journal of Electromagnetic Waves and Applications Pages: 1117-1139 Issue: 9 Volume: 29 Year: 2015 Month: 6 X-DOI: 10.1080/09205071.2015.1045627 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1045627 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:9:p:1117-1139 Template-Type: ReDIF-Article 1.0 Author-Name: Tian-peng Li Author-X-Name-First: Tian-peng Author-X-Name-Last: Li Author-Name: Guang-ming Wang Author-X-Name-First: Guang-ming Author-X-Name-Last: Wang Author-Name: Guo-cheng Wu Author-X-Name-First: Guo-cheng Author-X-Name-Last: Wu Author-Name: Rui-lian Tan Author-X-Name-First: Rui-lian Author-X-Name-Last: Tan Author-Name: Lin Geng Author-X-Name-First: Lin Author-X-Name-Last: Geng Author-Name: Hai-peng Li Author-X-Name-First: Hai-peng Author-X-Name-Last: Li Title: Compact wideband antenna based on novel composite right/left handed transmission line Abstract: Based on a new type of composite right/left handed transmission line (CRLH TL), a novel compact wideband antenna is proposed. The CRLH TL is composed of a ground player with an etched complementary single split-ring resonator and a patch with two series gaps and two metal vias. Consistent simulated and measured results of the proposed antenna are shown that it operates at 3.46 GHz extended to 3.97 GHz (10 dB return loss bandwidth is 13.7%). The electrical size of the patch at the center frequency f = 3.72 GHz is only 0.25λ0 × 0.22λ0 × 0.01λ0, a 52.7% reduction in size comparing to the conventional patch antenna. The measured radiation efficiency was higher than 80% over the 10 dB return loss bandwidth. Additionally, the antenna attained a gain extended from 3.1 to 4.76 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 1140-1148 Issue: 9 Volume: 29 Year: 2015 Month: 6 X-DOI: 10.1080/09205071.2015.1029082 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1029082 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:9:p:1140-1148 Template-Type: ReDIF-Article 1.0 Author-Name: Lev Pazin Author-X-Name-First: Lev Author-X-Name-Last: Pazin Author-Name: Yehuda Leviatan Author-X-Name-First: Yehuda Author-X-Name-Last: Leviatan Title: Rotated-T slot antenna for cognitive radio operation in the 3.1–6 GHz frequency range Abstract: A reconfigurable rotated-T slot antenna for cognitive radio operation in the lower part (3.1–6 GHz) of the UWB frequency range is presented. The antenna can operate one at a time at six adjacent sub-bands. The switching from one sub-band to another is done electronically using PIN diodes. The antenna exhibits a nearly omnidirectional radiation pattern in the horizontal plane of operation with predominantly vertical polarization. Journal: Journal of Electromagnetic Waves and Applications Pages: 1149-1156 Issue: 9 Volume: 29 Year: 2015 Month: 6 X-DOI: 10.1080/09205071.2015.1030040 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1030040 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:9:p:1149-1156 Template-Type: ReDIF-Article 1.0 Author-Name: Hongye Qi Author-X-Name-First: Hongye Author-X-Name-Last: Qi Author-Name: Xiaoxing Yin Author-X-Name-First: Xiaoxing Author-X-Name-Last: Yin Author-Name: Hongxin Zhao Author-X-Name-First: Hongxin Author-X-Name-Last: Zhao Author-Name: Leilei Liu Author-X-Name-First: Leilei Author-X-Name-Last: Liu Author-Name: Yaming Bo Author-X-Name-First: Yaming Author-X-Name-Last: Bo Title: A current distortion parameter for characterizing coupling of antennas Abstract: A current distortion parameter for characterizing the coupling of antennas is proposed, which is based on the difference between the current distributions with and without the coupling. The parameter describes the influence of the mutual coupling between antennas on the current distribution comprehensively, and thus, it can act as a supplement to S parameters for the mutual coupling characterization and the decoupling structure evaluation. The current distortion parameter can also assess a coupling effect caused by a non-free-space environment on the antenna current and indicates the sensitivity of the antenna to the non-free-space environment. Several examples, including two thin dipole antenna arrays, two printed dipole antennas with a decoupling structure, an array of two patch antennas, and a thin dipole antenna with a metallic bar, demonstrate the usefulness of the current distortion parameter for the antennas coupling investigation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1157-1173 Issue: 9 Volume: 29 Year: 2015 Month: 6 X-DOI: 10.1080/09205071.2015.1034809 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1034809 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:9:p:1157-1173 Template-Type: ReDIF-Article 1.0 Author-Name: Xiao-Min Shi Author-X-Name-First: Xiao-Min Author-X-Name-Last: Shi Author-Name: Xiao-Li Xi Author-X-Name-First: Xiao-Li Author-X-Name-Last: Xi Author-Name: Yu-Chen Zhao Author-X-Name-First: Yu-Chen Author-X-Name-Last: Zhao Author-Name: Hai-Long Yang Author-X-Name-First: Hai-Long Author-X-Name-Last: Yang Title: A novel compact ultra-wideband (UWB) bandpass filter with triple-notched bands Abstract: A novel compact microstrip ultra-wideband (UWB) bandpass filter with three sharply notched bands and good selectivity is presented in this letter. Triple-notched bands filtering effects are achieved by adding open-circuited stubs and introducing asymmetric dual-line coupling structure to the feed lines, providing a high degree of adjusting freedom and not increasing the filter size. The frequencies of the notched bands and the upper stopband transmission zero can be independently controlled by adjusting the structural parameters of feed lines. Finally, a microstrip UWB filter with triple-notched bands is simulated and fabricated with good agreement. Journal: Journal of Electromagnetic Waves and Applications Pages: 1174-1180 Issue: 9 Volume: 29 Year: 2015 Month: 6 X-DOI: 10.1080/09205071.2015.1034811 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1034811 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:9:p:1174-1180 Template-Type: ReDIF-Article 1.0 Author-Name: Slobodan Babic Author-X-Name-First: Slobodan Author-X-Name-Last: Babic Author-Name: Cevdet Akyel Author-X-Name-First: Cevdet Author-X-Name-Last: Akyel Author-Name: José Martinez Author-X-Name-First: José Author-X-Name-Last: Martinez Author-Name: Bojan Babic Author-X-Name-First: Bojan Author-X-Name-Last: Babic Title: A new formula for calculating the magnetic force between two coaxial thick circular coils with rectangular cross-section Abstract: The magnetic force exerted by an array of two coaxial thick circular coils with rectangular cross-sections in air is important to both electrical and mechanical engineering applications. The magnetic force is typically calculated by taking the integral over the entire space defined by the array. This calculation even for this simple array is an intractable problem and numerical methods have been extensively used. In this work, the integration was subdivided into five regions, and in four of them, an analytical formula was found. The method proposed here is based on the Green’s function of the free space that leads to the elliptical integral of the first and second kind. The formula reveals new insights into how the geometry and relative positioning of the coils within the array determines the strength of the magnetic force. The thicker the coils are and the farther apart they are, the weaker the magnetic force is, and vice versa. This new formula is simpler and practically free of truncation errors, which are commonly encountered in numerical approximations. Several examples from the literature were used to corroborate the present formulation. The results show an excellent agreement with respect to the different numerical and semi-analytical approaches used by other authors. Journal: Journal of Electromagnetic Waves and Applications Pages: 1181-1193 Issue: 9 Volume: 29 Year: 2015 Month: 6 X-DOI: 10.1080/09205071.2015.1035807 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1035807 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:9:p:1181-1193 Template-Type: ReDIF-Article 1.0 Author-Name: Gobi Vetharatnam Author-X-Name-First: Gobi Author-X-Name-Last: Vetharatnam Author-Name: Ali Rashidifar Author-X-Name-First: Ali Author-X-Name-Last: Rashidifar Title: Comparison between microstrip and dipole antenna backed by a corner reflector Abstract: Microstrip antenna can be applied together with a corner reflector to achieve higher directivity, similar to the dipole antenna. In a microstrip antenna, the corner reflector reduces to four rectangular reflecting plates on the sides of the antenna. A significant portion of the corner reflector behind the microstrip is not needed, thus reducing the volume of corner reflector by 35% with the final reflecting structure resembling the flare of a horn antenna. The maximum feed-to-vertex distance reduces from 2λ/3$ 2\lambda/3 $ in a dipole to 0.4λ$ 0.4\lambda $ in a microstrip antenna, for the condition of only one radiation lobe within the included angle of the corner reflector. The highest directivity is obtained at feed-to-vertex distance of 0.4λ.$ 0.4\lambda. $ The gain of the microstrip antenna with reflectors is increased by 2.6 dB compared to an increase of 3 dB gain in a dipole backed by corner reflector. Journal: Journal of Electromagnetic Waves and Applications Pages: 1194-1205 Issue: 9 Volume: 29 Year: 2015 Month: 6 X-DOI: 10.1080/09205071.2015.1035808 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1035808 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:9:p:1194-1205 Template-Type: ReDIF-Article 1.0 Author-Name: Ziqiang Xu Author-X-Name-First: Ziqiang Author-X-Name-Last: Xu Author-Name: Guangliang Cao Author-X-Name-First: Guangliang Author-X-Name-Last: Cao Author-Name: Meijuan Xu Author-X-Name-First: Meijuan Author-X-Name-Last: Xu Author-Name: Peng Gao Author-X-Name-First: Peng Author-X-Name-Last: Gao Title: Dual-mode substrate integrated hexagonal cavity (SIHC) filter with uncoaxial feeding structure Abstract: Novel uncoaxial dual-mode substrate integrated hexagonal cavity (SIHC) filters are presented for high selectivity application. The SIHC filters with uncoaxial feeding structure can add two extra coupling paths to their topologies: one is a source–load coupling path, and the other is a non-physical higher order modes cross-coupling path. Under the circumstances, the proposed filter can generate up to three transmission zeros (TZs) for improving stopband performance. Meanwhile, the numbers and the locations of TZs can be controlled conveniently by tuning the uncoaxial feeding structure. Accordingly, the filter not only has good selectivity due to flexible TZs, but also has a small size by virtue of its single-cavity structure. Two experimental filters at the same central frequency of 10 GHz but with different fractional bandwidths of 2 and 5% and numbers of TZs from 2 to 3 are designed, fabricated, and measured to validate the proposed structure. The measured results agree well with the simulated ones, with their good performance just as pedicted. Journal: Journal of Electromagnetic Waves and Applications Pages: 1206-1217 Issue: 9 Volume: 29 Year: 2015 Month: 6 X-DOI: 10.1080/09205071.2015.1037018 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1037018 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:9:p:1206-1217 Template-Type: ReDIF-Article 1.0 Author-Name: S.-H. Jung Author-X-Name-First: S.-H. Author-X-Name-Last: Jung Author-Name: D.-H. Park Author-X-Name-First: D.-H. Author-X-Name-Last: Park Author-Name: H.-K. Song Author-X-Name-First: H.-K. Author-X-Name-Last: Song Title: Cooperative beamforming scheme using MIMO antenna array in LTE-A system Abstract: Beamforming (BF) technique using multiple input multiple output antenna array improves reliability, range of transmission, and cell capacity in the long-term evolution-advanced system. Especially, coordinated multi-point (CoMP) method based on the BF techniques has been studied to increase total cell capacity by reducing the inter-cell interference. If a downlink CoMP scheme is applied, more robust transmission is achieved to the user equipment located at the cell edge. There are several types of DL CoMP schemes already and system operator selects a proper scheme according to service property in a real wireless communication system. However, there is a trade-off between the reliability and the resource allocation. In this paper, the hybrid cooperative BF scheme considering this trade-off is proposed. The proposed scheme switches the transmission methods according to the channel state information. Consequently, this scheme can use resources more efficiently and the reliable transmission can be maintained even though a user is located at the cell edge. Journal: Journal of Electromagnetic Waves and Applications Pages: 1218-1227 Issue: 9 Volume: 29 Year: 2015 Month: 6 X-DOI: 10.1080/09205071.2015.1037932 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1037932 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:9:p:1218-1227 Template-Type: ReDIF-Article 1.0 Author-Name: Jitendra Kumar Author-X-Name-First: Jitendra Author-X-Name-Last: Kumar Author-Name: Navneet Gupta Author-X-Name-First: Navneet Author-X-Name-Last: Gupta Title: Linearly polarized asymmetric dielectric resonator antenna for 5.2-GHz WLAN applications Abstract: A rectangular shape of asymmetric dielectric resonator antenna (DRA) excited by a coaxial probe is proposed and investigated. The asymmetric DRA geometry can offer an impedance bandwidth up to 51% for |S11| < −10 dB from 4.1 to 6.7 GHz. The antenna covers most of the wireless systems like 5.2, 5.5, and 5.8 GHz WLAN/Wi-MAX applications. The experimentally measured result shows that the efficiency is above 90% for the bandwidth of operation. The simulated and measured radiation patterns are consistent throughout the operational bandwidth. The measured peak gain over the band is 8.2 dBi. It is also observed that the newly proposed configuration reduces the DRA volume by 26% as compared to conventional rectangular DRA, with compact volume of 8.24 cm3. Good match between the measured and simulated results has been obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 1228-1237 Issue: 9 Volume: 29 Year: 2015 Month: 6 X-DOI: 10.1080/09205071.2015.1038362 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1038362 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:9:p:1228-1237 Template-Type: ReDIF-Article 1.0 Author-Name: Ravi Panwar Author-X-Name-First: Ravi Author-X-Name-Last: Panwar Author-Name: Smitha Puthucheri Author-X-Name-First: Smitha Author-X-Name-Last: Puthucheri Author-Name: Vijaya Agarwala Author-X-Name-First: Vijaya Author-X-Name-Last: Agarwala Author-Name: Dharmendra Singh Author-X-Name-First: Dharmendra Author-X-Name-Last: Singh Title: An efficient use of waste material for development of cost-effective broadband radar wave absorber Abstract: Very few literatures are available on the utilization of natural waste composite materials for radar wave absorption. The main objective of this paper was to achieve good absorption with wide bandwidth corresponds to reflection loss (RL) ≤ −10 dB for less absorber layer thickness (≤2.0 mm) for a cost-effective production of radar wave absorber. In this study, mineral dust and beach sand-based waste composite material is critically analyzed for its application as broadband radar wave absorber in the frequency range of 8.2–12.4 GHz. A multilayer approach is applied for obtaining the good absorption, where thickness of different layers is optimized by genetic algorithm. The effective absorption bandwidth for two- and three-layer composite absorber is 3.5 and 2.8 GHz for the optimized thickness 1.9 and 1.8 mm, respectively. The two-layer absorber possesses measured RL of −27.20 dB at 10.8 GHz and for a three-layer absorber, RL reaches up to −32.58 dB at 11.2 GHz. The measured RL values agree quite well with the calculated ones, which show the effectiveness of absorber for various practical EM wave absorption applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1238-1255 Issue: 9 Volume: 29 Year: 2015 Month: 6 X-DOI: 10.1080/09205071.2015.1044125 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1044125 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:29:y:2015:i:9:p:1238-1255 Template-Type: ReDIF-Article 1.0 Author-Name: K.A. Michalski Author-X-Name-First: K.A. Author-X-Name-Last: Michalski Author-Name: J.R. Mosig Author-X-Name-First: J.R. Author-X-Name-Last: Mosig Title: The Sommerfeld half-space problem revisited: from radio frequencies and Zenneck waves to visible light and Fano modes Abstract: The classical Sommerfeld half-space problem is revisited, with generalizations to multilayer and plasmonic media and focus on the surface field computation. A new ab initio solution is presented for an arbitrarily oriented Hertzian dipole radiating in the presence of a material half-space with arbitrary horizontal stratification. The solution method combines the vector potential approach and the spectral domain transmission line analog of the medium, which results in the most compact formulation and facilitates the inclusion of any number of layers in the analysis. Following Sommerfeld, the solution is first expressed in terms of the Fourier–Bessel transforms, also known as Sommerfeld integrals. Analytical properties of the integrands in the complex plane are then investigated, including the location of the Sommerfeld pole, which gives rise to the Zenneck wave (ZW) or surface plasmon polariton (SPP), and alternative field representations are developed by a deformation of the integration path and analytic continuation of the integrand functions, using hyperbolic and vertical branch cuts. Closed-form expressions for the asymptotic surface fields are also derived and the rôle of the ZW and SPP is elucidated. Numerical examples are included to illustrate the theory, from radio frequencies to visible light. Journal: Journal of Electromagnetic Waves and Applications Pages: 1-42 Issue: 1 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1093964 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1093964 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:1:p:1-42 Template-Type: ReDIF-Article 1.0 Author-Name: Leyre Azpilicueta Author-X-Name-First: Leyre Author-X-Name-Last: Azpilicueta Author-Name: Erik Aguirre Author-X-Name-First: Erik Author-X-Name-Last: Aguirre Author-Name: Peio López-Iturri Author-X-Name-First: Peio Author-X-Name-Last: López-Iturri Author-Name: Francisco Falcone Author-X-Name-First: Francisco Author-X-Name-Last: Falcone Title: An accurate UTD extension to a ray-launching algorithm for the analysis of complex indoor radio environments Abstract: This paper deals with the efficient combination of two well-established electromagnetic methods, a shooting and bouncing Rays (SBR) algorithm on the basis of geometrical optics (GO) and diffraction calculation on the basis of the uniform theory of diffraction (UTD). While the conventional GO method is able to accurately calculate field contributions due to reflection and refraction, the further propagation of diffracted rays is generally not considered in SBR approaches. Thus, the aim of this work is to describe the implementation of diffracted rays according to the UTD concept into an SBR code. A convergence analysis to obtain the optimal calculation parameters for the diffracted rays is presented. This novel implementation with the optimal parameters allows modeling the radio wave propagation channel in complex indoor environments with a large number of obstacles. The comparison with real measurements proves that the proposed hybrid GO–UTD algorithm yields excellent results and that the UTD extension definitely improves the simulations of the ray-launching algorithm for realistic environments. Journal: Journal of Electromagnetic Waves and Applications Pages: 43-60 Issue: 1 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1053573 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1053573 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:1:p:43-60 Template-Type: ReDIF-Article 1.0 Author-Name: Hui Gu Author-X-Name-First: Hui Author-X-Name-Last: Gu Author-Name: Jianpeng Wang Author-X-Name-First: Jianpeng Author-X-Name-Last: Wang Author-Name: Gang Zhang Author-X-Name-First: Gang Author-X-Name-Last: Zhang Author-Name: Jia-Lin Li Author-X-Name-First: Jia-Lin Author-X-Name-Last: Li Title: Design of a SIW balun bandpass filter with high selectivity Abstract: A new balun bandpass filter (BPF) designed in the form of the substrate integrated waveguide is proposed in this article. To achieve 180° phase difference, two balanced output ports are placed on both sides of the substrate, respectively. To realize the BPF performance with high-frequency selectivity, a two-pole filter with the source and load coupling is introduced. A prototype was fabricated and measured. Both simulated and experimental results are provided with good agreements. The measured results indicate that the proposed balun BPF has nice balance performance with less than 0.2 dB amplitude imbalance and better than 3.5° phase imbalance, along with compact size and high selectivity. Journal: Journal of Electromagnetic Waves and Applications Pages: 61-69 Issue: 1 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1077750 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1077750 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:1:p:61-69 Template-Type: ReDIF-Article 1.0 Author-Name: Kishore Naik Mude Author-X-Name-First: Kishore Naik Author-X-Name-Last: Mude Author-Name: Manuele Bertoluzzo Author-X-Name-First: Manuele Author-X-Name-Last: Bertoluzzo Author-Name: Giuseppe Buja Author-X-Name-First: Giuseppe Author-X-Name-Last: Buja Author-Name: Rosanna Pinto Author-X-Name-First: Rosanna Author-X-Name-Last: Pinto Title: Design and experimentation of two-coil coupling for electric city-car WPT charging Abstract: The article deals with the two-coil coupling of an inductive wireless power transfer system intended to charge the battery of an electric city-car. At first, two-coil coupling structures with different arrangements for the coil windings and different shapes for the magnetic core are investigated. Investigation is carried out by help of a FEM code, and encompasses the determination of (i) the inductive parameters as a function of the coil distance and axial misalignment and (ii) the nearby electromagnetic fields to verify their admissibility for the humans. Afterwards the coil coupling is designed and then set up according to the results of the investigation. Measurements executed on the set-up validate the design for both the inductive parameters and the nearby electromagnetic fields. Journal: Journal of Electromagnetic Waves and Applications Pages: 70-88 Issue: 1 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1088404 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1088404 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:1:p:70-88 Template-Type: ReDIF-Article 1.0 Author-Name: Yingsong Li Author-X-Name-First: Yingsong Author-X-Name-Last: Li Author-Name: Raj Mittra Author-X-Name-First: Raj Author-X-Name-Last: Mittra Title: A three-dimensional circularly polarized antenna with a low profile and a wide 3-dB beamwidth Abstract: An improved three-dimensional circularly polarized quadrifilar helix antenna (QHA) with low profile and wide 3-dB beamwidth is proposed and its performance is investigated both numerically and experimentally. The proposed modified QHA is comprised of a short-circuited quadrifilar helical antenna printed on a thin FR4 substrate, with its four ports terminated by 50 Ω resistances. In addition, four monopoles with 90° phase progression are positioned around the quadrifilar helical antenna, and four Archimedean spirals are used to top-load the monopoles. Simulated and measured results show that the proposed antenna achieves a bandwidth of 23.8%, has a 3-dB beamwidth greater than 170°, and its axial ratio is less than three in the entire upper hemisphere over a wide frequency band. Journal: Journal of Electromagnetic Waves and Applications Pages: 89-97 Issue: 1 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1089794 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1089794 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:1:p:89-97 Template-Type: ReDIF-Article 1.0 Author-Name: Á. Parra-Cerrada Author-X-Name-First: Á. Author-X-Name-Last: Parra-Cerrada Author-Name: J.L. Jiménez-Martín Author-X-Name-First: J.L. Author-X-Name-Last: Jiménez-Martín Author-Name: D. Segovia-Vargas Author-X-Name-First: D. Author-X-Name-Last: Segovia-Vargas Author-Name: V. González-Posadas Author-X-Name-First: V. Author-X-Name-Last: González-Posadas Title: Advantages of NDF as oscillator linear design tool: design of a NIC active patch antenna Abstract: This paper shows one active patch antenna with a Negative Impedance Converters (NIC) and other one without it. The NIC works as negative admittance to increase the Q of the antenna. These circuits can be analysed using classic methods, but classic methods require the verification of the appropriated provisos. The chosen classic method depends on the oscillator topology, while the Normalized Determinant Function (NDF) is independent of topologies and it does not require any provisos. The NDF is suitable for Q estimation and noise optimization during linear analysis of any topology. The oscillators are designed using the NDF and the Admittance; then the phase noise is evaluated using the NDF. The Harmonic Balance (HB) analysis and the measurements of the prototypes confirm, in favour of NDF, the stability discrepancies between classic methods and NDF. The linear approximation of the improvements introduced by a NIC is questioned by the risk of instabilities and the introduction of new noise sources. Journal: Journal of Electromagnetic Waves and Applications Pages: 98-108 Issue: 1 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1093433 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1093433 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:1:p:98-108 Template-Type: ReDIF-Article 1.0 Author-Name: I. Angulo Author-X-Name-First: I. Author-X-Name-Last: Angulo Author-Name: O. Grande Author-X-Name-First: O. Author-X-Name-Last: Grande Author-Name: D. de la Vega Author-X-Name-First: D. Author-X-Name-Last: de la Vega Author-Name: D. Guerra Author-X-Name-First: D. Author-X-Name-Last: Guerra Author-Name: A. Arrinda Author-X-Name-First: A. Author-X-Name-Last: Arrinda Title: Method for avoiding near-field effects of wind turbines on microwave terrestrial radio links Abstract: Potential impact of wind turbines on telecommunication services is an increasing concern in wind farms deployment. The evaluation of the potential disturbance of a planned wind farm requires accurate and unbiased criteria applied in a comprehensive impact study. Near-field effects of wind turbines on microwave radio links is one of the less analyzed disturbances. In this article, new theoretical-based criteria and an easy to apply step-by-step calculation procedure are proposed. Results of the method are in the form of constraint masks, easy to apply by wind farm promoters in the layout design, by telecommunications operators in the evaluation of the potential impact, and by administrations involved in license tasks. In the article, the proposed method is applied to real cases of wind farms located close to radio links facilities and compared to current criteria. Journal: Journal of Electromagnetic Waves and Applications Pages: 109-123 Issue: 1 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1096838 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1096838 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:1:p:109-123 Template-Type: ReDIF-Article 1.0 Author-Name: Zhipeng Li Author-X-Name-First: Zhipeng Author-X-Name-Last: Li Author-Name: Hongyun Huang Author-X-Name-First: Hongyun Author-X-Name-Last: Huang Author-Name: Jingfu Bao Author-X-Name-First: Jingfu Author-X-Name-Last: Bao Title: X-band low phase noise push–push oscillator utilizing High-Q differential transmission line loaded with multiple split-ring resonator Abstract: In this study, a low phase noise X-band push–push oscillator is presented employing the differential transmission lines (TLs) loaded with multiple split-ring resonator (M-SRR). In order to enhance the coupling strength between TL and resonator cell, the single M-SRR is replaced by the coupled M-SRR cell-pair in differential TL to obtain high-frequency selectivity and deep insertion loss. The resonance properties of the differential TL have been discussed with different coupling configurations and coupling strengths of the M-SRR cell-pair, and the geometries of the proposed structure are investigated to obtain the optimum resonance properties. The loaded Q-factor of the proposed differential TL adopting 3-stages cascaded array of M-SRR cell-pairs configuration is 892 from measured results. Due to the high-Q and anti-phase current properties of the differential TL, a X-band push–push oscillator with low phase noise and superior fundamental frequency suppression performances is realized. The fabricated push–push oscillator operates at 9.52 GHz with an output power of 2.7 dBm and a fundamental frequency suppression of −54.55 dBc. It shows a measured phase noise of −115.48 dBc/Hz at 100 kHz offset frequency and a figure of merit of −201.23 dBc/Hz. Journal: Journal of Electromagnetic Waves and Applications Pages: 124-139 Issue: 1 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1096839 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1096839 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:1:p:124-139 Template-Type: ReDIF-Article 1.0 Author-Name: Kadappan Panayappan Author-X-Name-First: Kadappan Author-X-Name-Last: Panayappan Author-Name: Raj Mittra Author-X-Name-First: Raj Author-X-Name-Last: Mittra Title: A technique for handling multiscale electromagnetic problems using the finite difference time domain (FDTD) algorithm Abstract: With advances in system integration and packaging, the capabilities of hand-held devices and embedded bio-sensors have grown to a phenomenal scale. This in turn has led to a constant interaction between human beings and ambient electromagnetic waves. Hence there is a need for studying the effects of radiation on human physiology and also the performance of systems in such an environment. The system designers seek a full-wave solution of the entire system, taking into account a variety of environments in which it operates. However, attempts to do this substantially increase the complexities involved in computing full-wave solutions, especially when the problems involve multi-scale geometries with very fine features. For such problems, even the well-established numerical methods, such as the time domain technique finite difference time domain and the frequency domain techniques, e.g. the finite element method and the method of moments, are often challenged to the limits of their capabilities. In an attempt to address these challenges, we propose to handle the multiscale problems in three different ways, based on the dimension and the complexity of the fine features involved in the problem. Furthermore, we illustrate the efficacy of the above techniques via several examples, and the results obtained by the proposed techniques are compared with other existing numerical methods for the purpose of validation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1241-1264 Issue: 10 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1194235 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1194235 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:10:p:1241-1264 Template-Type: ReDIF-Article 1.0 Author-Name: Yunhua Wang Author-X-Name-First: Yunhua Author-X-Name-Last: Wang Author-Name: Yanmin Zhang Author-X-Name-First: Yanmin Author-X-Name-Last: Zhang Author-Name: Huimin Li Author-X-Name-First: Huimin Author-X-Name-Last: Li Author-Name: Ge Chen Author-X-Name-First: Ge Author-X-Name-Last: Chen Title: Doppler spectrum of microwave SAR signals from two-dimensional time-varying sea surface Abstract: Within the framework of the two-scale scattering model, Doppler shift and bandwidth of microwave scattering field from two-dimensional (2-D) sea surface have been simulated. And the comparisons of the simulated results with the Doppler anomaly measurements from Envisat ASAR demonstrate the rationality of the formulas proposed by us. Meanwhile, the influences of the tilt and the hydrodynamic modulations due to large-scale underlying waves on Doppler shift and bandwidth have also been discussed in detail. Numerical results show that the Doppler shifts for HH-and VV-polarizations are both observably affected by the tilt and the hydrodynamic modulations and the values of the predicted Doppler shifts are always larger than Bragg frequency. Because the radar scattering coefficient is more sensitive to sea surface slope in HH polarization than in VV, the predicted Doppler shifts in HH polarization are always somewhat larger than those in VV. Moreover, we also find that there is a remarkable difference between the Doppler shift predicted in upwind and downwind direction due to the hydrodynamic modulations. Relative to Doppler shift, bandwidth of Doppler spectrum is mainly affected by orbit velocity of large-scale waves and is insensitive to the modulations and radar polarizations. Journal: Journal of Electromagnetic Waves and Applications Pages: 1265-1276 Issue: 10 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1186575 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1186575 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:10:p:1265-1276 Template-Type: ReDIF-Article 1.0 Author-Name: A. M. Saleh Author-X-Name-First: A. M. Author-X-Name-Last: Saleh Author-Name: K. R. Mahmoud Author-X-Name-First: K. R. Author-X-Name-Last: Mahmoud Author-Name: I. I. Ibrahim Author-X-Name-First: I. I. Author-X-Name-Last: Ibrahim Author-Name: A. M. Attiya Author-X-Name-First: A. M. Author-X-Name-Last: Attiya Title: Metasurface-loaded dielectric rod leaky wave antenna Abstract: This paper introduces an analytical solution for a dielectric rod leaky wave antenna loaded by a metasurface. The advantage of adding metasurface on the dielectric rod is that it introduces an additional degree of freedom in the design of this antenna by controlling the outer boundary condition. Modified Generalized Sheet Transition Condition on a cylindrical geometry is used to model the metasurface on the dielectric rod. The analysis is based on developing the characteristic equation of the proposed structure. This characteristic equation is used to obtain the complex propagation constant of this structure and the corresponding field distribution inside and outside the rod including the resulting radiated fields. Parameters of the metasurface are extracted from the reflection and transmission properties of its elements in infinite periodic structure. An example of a dielectric rod loaded by a metasurface is presented analytically based on the introduced analysis and also simulated numerically for comparison. The effect of different polarizabilities of the loading metasurface on the leaky wave properties of the dielectric rod is discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1277-1291 Issue: 10 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1190302 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1190302 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:10:p:1277-1291 Template-Type: ReDIF-Article 1.0 Author-Name: Tariq Rahim Author-X-Name-First: Tariq Author-X-Name-Last: Rahim Author-Name: Naveed Ullah Author-X-Name-First: Naveed Author-X-Name-Last: Ullah Author-Name: Muhammad Ibrahim Author-X-Name-First: Muhammad Author-X-Name-Last: Ibrahim Author-Name: Murad Ali Shah Author-X-Name-First: Murad Ali Author-X-Name-Last: Shah Author-Name: Jiadong Xu Author-X-Name-First: Jiadong Author-X-Name-Last: Xu Title: Asymptotic method based on Maslov’s theory for the focusing of 3D elliptical lens placed in chiral medium Abstract: The high-frequency field expressions for the refracted waves from the dielectric 3D elliptical lens embedded in homogeneous and reciprocal chiral medium around the focal region are derived using an asymptotic method based on Maslov’s theory. Ray-based Geometric Optics (GO) technique was initially used to derive the expressions for the electrical field intensities for both left circular polarized and right circular polarized waves which are inherited in the chiral medium. However, GO method is not applicable at the focal points due to the shrinking of ray volume at these points which causes unreal singularities. Therefore, an asymptotic method based on Maslov’s theory is applied to derive the fields at the focal points. Moreover, the effect of chirality parameter kβ$ k\beta $ on the behavior of focal points electric field intensities are indicated using the line plots obtained from the numerical solution of the derived equations using MATLAB software. A special case of the dielectric 3D elliptical lens placed in achiral medium is also discussed using the expressions. Journal: Journal of Electromagnetic Waves and Applications Pages: 1292-1307 Issue: 10 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1196154 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1196154 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:10:p:1292-1307 Template-Type: ReDIF-Article 1.0 Author-Name: Amit Kumar Varshney Author-X-Name-First: Amit Kumar Author-X-Name-Last: Varshney Author-Name: Raktim Guha Author-X-Name-First: Raktim Author-X-Name-Last: Guha Author-Name: Subrata Kumar Datta Author-X-Name-First: Subrata Kumar Author-X-Name-Last: Datta Author-Name: B. N. Basu Author-X-Name-First: B. N. Author-X-Name-Last: Basu Title: Dispersion control of helical slow-wave structure by double-negative metamaterial loading Abstract: A helix supported by a double-negative metamaterial (DNG-MMT) surrounding it, in a metal envelope, was field-analyzed to show that the shape of the dispersion is more sensitive to the value of the relative permittivity of the metamaterial (MMT) than that of its relative permeability. The field analysis was validated against equivalent circuit analysis as well as against simulation. The values of the MMT support parameters were adjusted to obtain nearly flat, rather slightly negative, dispersion characteristics together with a high value of the interaction impedance of the structure as required for a wideband traveling-wave amplifier. Unlike in a conventional traveling-wave tube, the flow of power of RF wave supported by DNG-MMT loaded helix was found to be in a direction opposite to that of the RF phase velocity of the wave supported by the structure resulting in a negative value of the interaction impedance of the structure suggesting that the device using a helix with double-negative MMT supports would operate in the backward-wave mode analogously to a reversed Cherenkov amplifier. Journal: Journal of Electromagnetic Waves and Applications Pages: 1308-1320 Issue: 10 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1198277 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1198277 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:10:p:1308-1320 Template-Type: ReDIF-Article 1.0 Author-Name: Song Wanjun Author-X-Name-First: Song Author-X-Name-Last: Wanjun Author-Name: Zhang Hou Author-X-Name-First: Zhang Author-X-Name-Last: Hou Title: Analysis of electromagnetic wave propagation and scattering characteristics of plasma shealth via high order ADE-ADI FDTD Abstract: In order to avoid complicated transformations and convolutions compared with Z-transform ADI-FDTD and the PLJERC-ADI-FDTD method, the high order ADE-ADI FDTD method for unmagnetized plasma is proposed. The fourth-order spatial central difference approximation technique is used in the proposed method to reduce the numerical dispersion of the ADI scheme. The iteration method for solving equation set improves the computational efficiency. The proposed method can be easily extended to analyze other media through changing the coefficients of the auxiliary difference equation of polarization current. The validity of the proposed method is tested by calculating the reflection and transmission coefficients of a plasma slab. The simulation results show that the computational accuracy and efficiency of the proposed method are higher than those of the PLJERC-ADI-FDTD method. The plasma sheath around a hypersonic blunted cone is established by CFD-FANSTRAN, and the reflection, transmission, and attenuation coefficients of the modeled plasma sheath against frequency under different Mach numbers and heights are calculated through the proposed method. The backward RCS of the plasma sheath is also calculated through the proposed method. The electromagnetic wave propagation and scattering characteristics of the plasma sheath are analyzed via the calculation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1321-1333 Issue: 10 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1198727 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1198727 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:10:p:1321-1333 Template-Type: ReDIF-Article 1.0 Author-Name: C. Y. Wang Author-X-Name-First: C. Y. Author-X-Name-Last: Wang Title: Determination of TM and TE modes of the circular waveguide with a cross-shaped insert using eigenfunction expansions and domain matching Abstract: TM and TE modes and eigenvalues for the metallic circular waveguide with a cross-shaped insert are studied by the method of eigenfunction expansions and domain matching. As the cross size is increased from zero, the cut-off TM eigenvalue rises singularly. The cut-off TE eigenvalue falls singularly to zero as the cross approaches the outer circular shield. Higher modes are also determined. The structure can be utilized to promote TE mode propagation and increase frequency separation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1334-1344 Issue: 10 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1199331 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1199331 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:10:p:1334-1344 Template-Type: ReDIF-Article 1.0 Author-Name: Slawomir Koziel Author-X-Name-First: Slawomir Author-X-Name-Last: Koziel Author-Name: Adrian Bekasiewicz Author-X-Name-First: Adrian Author-X-Name-Last: Bekasiewicz Title: Low-cost surrogate-assisted statistical analysis of miniaturized microstrip couplers Abstract: In this work, a technique for low-cost yield estimation of compact microwave couplers has been presented. The analysis is carried out at the level of a fast surrogate model representing selected characteristic points of the coupler response that are critical to determine satisfaction/violation of the design specifications. Due to less nonlinear dependence of the characteristic points on geometry parameters (compared to the original response, i.e. S-parameters vs. frequency), a small number of training points is necessary to setup the surrogate. Our approach is demonstrated using a compact rat-race microstrip coupler. Numerical verification involving direct Monte Carlo analysis of the EM simulation model of the coupler confirms reliability of our approach. Journal: Journal of Electromagnetic Waves and Applications Pages: 1345-1353 Issue: 10 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1199332 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1199332 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:10:p:1345-1353 Template-Type: ReDIF-Article 1.0 Author-Name: Chao Li Author-X-Name-First: Chao Author-X-Name-Last: Li Author-Name: Raj Mittra Author-X-Name-First: Raj Author-X-Name-Last: Mittra Title: Controlling radiation patterns of antennas mounted on complex platforms using the characteristic basis functions (CBFs) Abstract: A novel approach for controlling the radiation patterns of antenna systems located on a complex platform is proposed in this paper. The proposed technique takes a cue from the traditional characteristic basis functions method and starts with the generation of characteristic basis functions (CBFs) by exciting a number of antenna elements on the platform. In order to account for the design constraints into consideration, the antennas are only placed at “allowable” locations (typically specified by the user). The CBFs are generated for the complex structure under analysis by using a suitable full-wave solver. Moreover, the antenna elements need not to be identical, and different types of antennas can be used at different locations on the platform depending on the application. A singular value decomposition can be employed to remove the redundancy of the CBFs, if necessary. Next, the corresponding characteristic basis function patterns are derived and used as basis functions in the “pattern space” to realize the desired radiation pattern. Rather than using a nonlinear optimization procedure to realize the desired pattern, the pattern design process is transformed into an eigenvalue problem – which is numerical considerably more efficient to solve – to find the best-fit solution that maximizes the energy radiated in the desired angular range, while minimizing the undesired radiation outside of this range. Journal: Journal of Electromagnetic Waves and Applications Pages: 1354-1365 Issue: 10 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1201435 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1201435 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:10:p:1354-1365 Template-Type: ReDIF-Article 1.0 Author-Name: Kee Ung Bae Author-X-Name-First: Kee Ung Author-X-Name-Last: Bae Author-Name: Hyungju Kim Author-X-Name-First: Hyungju Author-X-Name-Last: Kim Author-Name: YoungDam Kim Author-X-Name-First: YoungDam Author-X-Name-Last: Kim Author-Name: Woo-Yong Yang Author-X-Name-First: Woo-Yong Author-X-Name-Last: Yang Author-Name: Noh-Hoon Myung Author-X-Name-First: Noh-Hoon Author-X-Name-Last: Myung Title: Improvement of FDTD method regarding cloaking metamaterials by interpolation Abstract: The finite-difference time-domain (FDTD) algorithm is a powerful, versatile tool for electromagnetic analysis. In this work, the stability of FDTD is analyzed regarding metamaterials and improved by stably interpolating adjacent fields. The interpolation operation was applied to metamaterials such as the invisibility cloak, the field rotator, and the field concentrator. As a result, field distortion disappeared and computation efficiency was increased as large spatial step sizes became available. The proposed method also resulted in smaller dispersion compared with the conventional FDTD method. The suggested method is applicable to other metamaterials and can be used to efficiently analyze large-scale metamaterial structures with FDTD. Journal: Journal of Electromagnetic Waves and Applications Pages: 1366-1379 Issue: 10 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1202783 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1202783 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:10:p:1366-1379 Template-Type: ReDIF-Article 1.0 Author-Name: Dr.Wenjie Feng Author-X-Name-First: Dr.Wenjie Author-X-Name-Last: Feng Author-Name: Dr.Wenquan Che Author-X-Name-First: Dr.Wenquan Author-X-Name-Last: Che Title: Compact wideband differential filter using quarter-wavelength coupled lines Abstract: A compact wideband differential bandpass filter with wideband common-mode suppression using quarter-wavelength coupled lines is proposed. Third-order wide passband for the differential mode can be easily realized by the half wavelength ring resonator. A planar wideband differential filter with 3-dB fractional bandwidth of 60% is designed and fabricated. The theoretical and measured results agree well and show good in band filtering performances and high selectivity. Journal: Journal of Electromagnetic Waves and Applications Pages: 1381-1390 Issue: 11 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1202147 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1202147 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:11:p:1381-1390 Template-Type: ReDIF-Article 1.0 Author-Name: Licheng Zhou Author-X-Name-First: Licheng Author-X-Name-Last: Zhou Author-Name: Yang Ju Author-X-Name-First: Author-X-Name-Last: Yang Ju Author-Name: Yongmao Pei Author-X-Name-First: Yongmao Author-X-Name-Last: Pei Author-Name: Daining Fang Author-X-Name-First: Daining Author-X-Name-Last: Fang Title: Dual-band and thermo-mechanical design method for radome walls with graded porous structure Abstract: This paper provides a method for design of high-temperature dual-band radome walls with graded porous structure. Both of the dual-band performances and the thermo-mechanical properties under loading-free and loading conditions of the proposed structures are taken into account. Results demonstrate the effectiveness of the method for design of high-temperature dual-band structures, of which the design frequency can be arbitrarily selected and subsequently the pass-bands are selectable, rather than design of a structure with specific dimensions and pass-bands. Results also show that the dual-band structures with graded porous structure can achieve better thermo-mechanical properties compared to traditional A-sandwich structures, and assembly stress can enhance the thermal and mechanical bearing capabilities of the high-temperature dual-band structures as well. Journal: Journal of Electromagnetic Waves and Applications Pages: 1391-1406 Issue: 11 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1202149 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1202149 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:11:p:1391-1406 Template-Type: ReDIF-Article 1.0 Author-Name: Meng Zou Author-X-Name-First: Meng Author-X-Name-Last: Zou Author-Name: Jin Pan Author-X-Name-First: Jin Author-X-Name-Last: Pan Author-Name: Deqiang Yang Author-X-Name-First: Deqiang Author-X-Name-Last: Yang Author-Name: Guoan Xiong Author-X-Name-First: Guoan Author-X-Name-Last: Xiong Title: Investigation of dual-band omnidirectional rectangular dielectric resonator antenna Abstract: A dual-band omnidirectional rectangular dielectric resonator antenna (DRA) is presented in this paper. Higher order TE121x/TE211y$ TE_{121}^{x} /TE_{211}^{y} $ and TE141x/TE411y$ TE_{141}^{x} /TE_{411}^{y} $ modes of a rectangular DRA with square cross section are used to realize dual-band omnidirectional operation. Working principle of using TE141x/TE411y$ TE_{141}^{x} /TE_{411}^{y} $ modes for omnidirectional pattern is explained based on dielectric waveguide model (DWM) method. Frequency ratio of the two bands for different dimensions and permittivities is studied. A prototype antenna for 3.5-GHz WiMAX and 5.8-GHz WLAN bands was designed, fabricated, and measured. Proposed design concept is verified by the simulated and measured results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1407-1416 Issue: 11 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1202150 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1202150 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:11:p:1407-1416 Template-Type: ReDIF-Article 1.0 Author-Name: Guo-hua Wang Author-X-Name-First: Guo-hua Author-X-Name-Last: Wang Author-Name: Yu-fa Sun Author-X-Name-First: Yu-fa Author-X-Name-Last: Sun Author-Name: Zhi-ping Chen Author-X-Name-First: Zhi-ping Author-X-Name-Last: Chen Title: Fast computation of monostatic radar cross section using compressive sensing and ACA-accelerated block LU factorization method Abstract: Compressive sensing (CS) technique in conjunction with adaptive cross approximation (ACA) algorithm is applied to calculate the monostatic radar cross section with many required sampling angles based on block LU factorization method. CS technique is used to construct a new excitation matrix and reduce the number of right-hand side. ACA algorithm is applied to all steps of the solution including impedance matrix filling, block LU solve, and excitation matrix compression to accelerate the computation process and reduce the memory consumption. Finally, the real-induced currents can be recovered by the orthogonal matching pursuit algorithm or compressive sampling matching pursuit algorithm, which have relatively low computational complexity than computation by the traditional method of moments (MoM). Numerical results are presented to validate the efficiency and accuracy of this method through comparison with the traditional MoM and other rigorous solutions. Journal: Journal of Electromagnetic Waves and Applications Pages: 1417-1427 Issue: 11 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1202781 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1202781 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:11:p:1417-1427 Template-Type: ReDIF-Article 1.0 Author-Name: Fuwei Wang Author-X-Name-First: Fuwei Author-X-Name-Last: Wang Author-Name: Tao Hong Author-X-Name-First: Tao Author-X-Name-Last: Hong Author-Name: Shuxi Gong Author-X-Name-First: Shuxi Author-X-Name-Last: Gong Title: Left-handed material superstrate applied to the RCS reduction of microstrip antenna Abstract: Left-handed material (LHM) is applied to reduce the radar cross section (RCS) of microstrip antenna when the incident wave is non-perpendicular to antenna. The LHM having the magnitude of its refractive index close to zero can be used to the total reflection phenomenon and focus the electromagnetic wave. Therefore, the method of RCS reduction with LHM superstrate is presented. Two kinds of the LHM structure are proposed and two application examples are present. The simulated and measured results show that 5–20 dB RCS reduction under the condition of oblique incidence is obtained when the LHM superstrate is used. The RCS reduction angle range can be changed by adjusting the size of the LHM superstrate. Journal: Journal of Electromagnetic Waves and Applications Pages: 1428-1439 Issue: 11 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1202784 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1202784 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:11:p:1428-1439 Template-Type: ReDIF-Article 1.0 Author-Name: Hamed Alipour-Banaei Author-X-Name-First: Hamed Author-X-Name-Last: Alipour-Banaei Author-Name: Mehdi Ghorbanzadeh Rabati Author-X-Name-First: Mehdi Author-X-Name-Last: Ghorbanzadeh Rabati Author-Name: Parisa Abdollahzadeh-Badelbou Author-X-Name-First: Parisa Author-X-Name-Last: Abdollahzadeh-Badelbou Author-Name: Farhad Mehdizadeh Author-X-Name-First: Farhad Author-X-Name-Last: Mehdizadeh Title: Effect of self-collimated beams on the operation of photonic crystal decoders Abstract: In this paper, a 1 × 2 optical decoder is proposed by employing the self-collimation effect in 2D photonic crystals. The total structure of the proposed device is a combination of so called “beam splitters.” The simulation result indicates that this design can operate as a 1 × 2 optical decoder. We employed finite-difference time-domain method and plane wave expansion for simulating the proposed structure. Journal: Journal of Electromagnetic Waves and Applications Pages: 1440-1448 Issue: 11 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1202785 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1202785 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:11:p:1440-1448 Template-Type: ReDIF-Article 1.0 Author-Name: R. V. S. Ram Krishna Author-X-Name-First: R. V. S. Ram Author-X-Name-Last: Krishna Author-Name: Raj Kumar Author-X-Name-First: Raj Author-X-Name-Last: Kumar Title: A compact microstrip-fed open slot antenna for dual slant polarization with good isolation Abstract: A V-shape slot antenna for dual slant polarization is proposed. The slot is the union of two stepped rectangular slots tilted at ±45° with the vertical. Each section of the slot is excited using a microstrip feed line printed on the other side of the substrate. The feed is also stepped and bent so as to cross the slot at right angles. The decoupling between the ports is provided by means of narrow rectangular stubs placed at the intersection of the slot arms. Measurements taken on the fabricated prototype indicate an impedance bandwidth from 3.3 to 12 GHz with isolation better than 15 dB across the band. The aperture electric field distributions as well as far field radiation patterns are used to verify the dual slant polarization achieved with the antenna. The time domain characterization of the antenna is done by calculating the fidelity factor which is found to be >0.75 indicating suitability of the antenna for pulse transmission. For determining the diversity behavior, the envelope correlation coefficient is calculated and found to be below 0.004. The antenna has a peak gain from 4 to 6 dBi. A modified design of the antenna is also presented with impedance bandwidth from 3 to 12 GHz and isolation better than 20 dB from 3.7 GHz onwards. With compact features and wideband return loss and isolation, the antennas are expected to be useful for diversity applications in ultra wideband communication devices such as MIMO wifi, imaging radars, and polarimetric sensing devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 1449-1464 Issue: 11 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1202787 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1202787 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:11:p:1449-1464 Template-Type: ReDIF-Article 1.0 Author-Name: Youngje Sung Author-X-Name-First: Youngje Author-X-Name-Last: Sung Title: Stub-loaded square-ring antenna for circular polarization applications Abstract: In this paper, a simple mechanism for circular polarization (CP) operation is introduced for a square-ring antenna. The proposed antenna consists of a simple square ring with a short-circuited stub and a T-shaped feeding structure. A square-ring antenna is loaded with a short-circuited stub. This antenna shows dual resonance (f1 and f2) with linear polarizations that are orthogonal to each other. The second resonant frequency (f2) is controlled without varying the first resonant frequency (f1) by adjusting the dimensions of the short-circuited stub. By choosing suitable dimensions for the stub, the two resonant frequencies are close to each other, and two orthogonal resonant modes with a 90° phase difference are excited. As a result, good CP is achieved. Journal: Journal of Electromagnetic Waves and Applications Pages: 1465-1473 Issue: 11 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1202788 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1202788 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:11:p:1465-1473 Template-Type: ReDIF-Article 1.0 Author-Name: Jian-Feng Chen Author-X-Name-First: Jian-Feng Author-X-Name-Last: Chen Author-Name: Fu-Chang Chen Author-X-Name-First: Fu-Chang Author-X-Name-Last: Chen Title: Design of microstrip lowpass-bandpass quintuplexer Abstract: This paper presents a novel lowpass-bandpass multiplexer consisting of one lowpass channel and four bandpass channels. Dumb-bell defected ground structures and stepped impedance resonators are employed to extend the stopband of the lowpass filter and bandpass filters, respectively. Stepped impedance stubs are used to bring a sharp selectivity in the lowpass channel design. Good isolation between channels is obtained by careful design of the input signal splitting structure, which is realized by utilizing four shunt open stubs with electric length of quarter-wavelength at the center frequency of the four bandpass channels, respectively. To verify the above concept, a lowpass-bandpass quintuplexer is designed, fabricated, and measured. The cut-off frequency of the lowpass filter is selected to be 1 GHz. The central passband frequencies are chosen to be 2.4, 3.5, 4.6, 5.8 GHz. Experimental measurements are in good agreement with simulations. Journal: Journal of Electromagnetic Waves and Applications Pages: 1474-1480 Issue: 11 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1202789 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1202789 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:11:p:1474-1480 Template-Type: ReDIF-Article 1.0 Author-Name: Shu-Chuan Chen Author-X-Name-First: Shu-Chuan Author-X-Name-Last: Chen Author-Name: Yu-Chuan Tsou Author-X-Name-First: Yu-Chuan Author-X-Name-Last: Tsou Title: Bandwidth enhancement of a monopole exciter by using a chip-inductor-loaded shorted strip Abstract: This paper presents an internal uniplanar monopole exciter fabricated on a 0.8-mm thick FR4 substrate. It can be arranged in the hinge slot of a laptop computer for a long-term evolution/wireless wide area network operation in the 698–960 and 1710–2690 MHz bands. The monopole exciter, which comprises feeding and chip-inductor-loaded shorted strips, occupies a compact area of 25 × 8 mm with a volume of only 0.2 cm3. The exciter antenna not only integrates with the metal covers, but also excites several resonant modes of the hinge slot. The chip-inductor-loaded shorted strip is employed for exciting the hinge slot to enhance lower band bandwidths. The proposed monopole exciter antenna not only serves as an exciter, but also serves as a radiator for generating several of its resonant modes. It can be installed in the hinge slot and has wide operating bands with high radiation efficiency. Over the lower and upper bands, the antenna efficiencies are higher than 56%, which is favorable for practical applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1481-1492 Issue: 11 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1204251 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1204251 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:11:p:1481-1492 Template-Type: ReDIF-Article 1.0 Author-Name: J. F. Gomez-Aguilar Author-X-Name-First: J. F. Author-X-Name-Last: Gomez-Aguilar Author-Name: R. F. Escobar-Jimenez Author-X-Name-First: R. F. Author-X-Name-Last: Escobar-Jimenez Author-Name: M. G. Lopez-Lopez Author-X-Name-First: M. G. Author-X-Name-Last: Lopez-Lopez Author-Name: V. M. Alvarado-Martinez Author-X-Name-First: V. M. Author-X-Name-Last: Alvarado-Martinez Author-Name: T. Cordova-Fraga Author-X-Name-First: T. Author-X-Name-Last: Cordova-Fraga Title: Electromagnetic waves in conducting media described by a fractional derivative with non-singular kernel Abstract: In this paper, we present an alternative representation of the wave equation in a conducting material. We derive special solutions for the space-time derivatives using the Caputo-Fabrizio fractional operator in the range β,γ∈(0;1]$ \beta ,\gamma \in (0;1] $, respectively. Using an iterative technique that involves the Laplace transform and its inverse, we derive new coupled-solutions of the wave equation. Some numerical simulations obtained showed different behaviors when compared with classical model solutions. The corresponding solutions show fractal space-time geometry different from the classical integer-order model. Journal: Journal of Electromagnetic Waves and Applications Pages: 1493-1503 Issue: 11 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1204252 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1204252 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:11:p:1493-1503 Template-Type: ReDIF-Article 1.0 Author-Name: N. Iqbal Author-X-Name-First: N. Author-X-Name-Last: Iqbal Author-Name: P. K. Choudhury Author-X-Name-First: P. K. Author-X-Name-Last: Choudhury Author-Name: P. S. Menon Author-X-Name-First: P. S. Author-X-Name-Last: Menon Title: Scattering of waves by chiral medium-coated dielectric elliptical/circular cylinders with PEC sheath helix loading Abstract: The paper reports scattering of plane waves by elliptical/circular homogenous, isotropic, and non-magnetic dielectric cylinders coated with chiral medium and surrounded by a perfectly electrical conducting sheath helix structure. The effect of pitch angle on the echo width under the assumption of parallel polarization is discussed, and the results are compared taking into account dielectric cylinders of different dimensions. The introduction of negative refraction in chiral mediums, and its effects on both the elliptical- and circular-shaped scattering objects are evaluated. The results indicate significant impact of the used chiral medium coating as well as the embedded sheath helix structure to alter the bi-scattering echo width of the object. Journal: Journal of Electromagnetic Waves and Applications Pages: 1504-1518 Issue: 11 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1204956 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1204956 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:11:p:1504-1518 Template-Type: ReDIF-Article 1.0 Author-Name: The Editors Title: Correction to: Comparison of iterative solvers for electromagnetic analysis of plasmonic nanostructures using multiple surface integral equation formulations Journal: Journal of Electromagnetic Waves and Applications Pages: 1519-1519 Issue: 11 Volume: 30 Year: 2016 Month: 7 X-DOI: 10.1080/09205071.2016.1203474 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1203474 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:11:p:1519-1519 Template-Type: ReDIF-Article 1.0 Author-Name: Biswarup Rana Author-X-Name-First: Biswarup Author-X-Name-Last: Rana Author-Name: Susanta Kumar Parui Author-X-Name-First: Susanta Kumar Author-X-Name-Last: Parui Title: Direct microstrip line-fed dielectric resonator antenna array Abstract: In this paper, a 1×4 rectangular dielectric resonator antenna array is designed using direct microstrip lines at the center frequency of 6.7 GHz for obtaining higher directive gain. A prototype has been fabricated with Arlon AD270 substrate and experimental measurements have been carried out. The array offers an impedance bandwidth of 9.6% and a maximum gain of 11.8 dBi at the operating frequency. A close agreement between simulated and measured results has been obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 1521-1531 Issue: 12 Volume: 30 Year: 2016 Month: 8 X-DOI: 10.1080/09205071.2016.1202148 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1202148 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:12:p:1521-1531 Template-Type: ReDIF-Article 1.0 Author-Name: Neelaveni Ammal Murugan Author-X-Name-First: Neelaveni Ammal Author-X-Name-Last: Murugan Author-Name: Ramachandran Balasubramanian Author-X-Name-First: Ramachandran Author-X-Name-Last: Balasubramanian Author-Name: Hanumantha Rao Patnam Author-X-Name-First: Hanumantha Rao Author-X-Name-Last: Patnam Title: Printed ultra-wideband monopole U-slotted antenna for triple band-rejection Abstract: A low-profile microstrip-fed planar monopole ultra-wideband (UWB) antenna with triple band rejection characteristics is proposed. The proposed antenna configuration consists of a bevelled ground with multiple U-slots embedded on the radiation patch for realizing the band notch characteristics. The notched frequency bands can be controlled by adjusting the parameters of the slots. The measured results demonstrate that the fabricated antenna exhibits an impedance bandwidth from 3 to 11 GHz for a VSWR ˂ 2 with three rejection bands at 3.38‒3.73 GHz for WiMAX, 5.12‒5.84 GHz for WLAN and 7.23‒8.56 GHz for X-band satellite communication services. Band rejection function is confirmed by the three gain diminishes occurring at 3.7, 5.35, and 8 GHz and stable gain outside the rejection bands. Measured group delay ensures that the designed antenna has good transmission capability of UWB signal with minimum distortion. Journal: Journal of Electromagnetic Waves and Applications Pages: 1532-1544 Issue: 12 Volume: 30 Year: 2016 Month: 8 X-DOI: 10.1080/09205071.2016.1202782 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1202782 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:12:p:1532-1544 Template-Type: ReDIF-Article 1.0 Author-Name: Pablo Padilla Author-X-Name-First: Pablo Author-X-Name-Last: Padilla Author-Name: Juan F. Valenzuela-Valdés Author-X-Name-First: Juan F. Author-X-Name-Last: Valenzuela-Valdés Author-Name: Jose Luis Padilla Author-X-Name-First: Jose Luis Author-X-Name-Last: Padilla Author-Name: Jose Manuel Fernández-González Author-X-Name-First: Jose Manuel Author-X-Name-Last: Fernández-González Author-Name: Manuel Sierra-Castañer Author-X-Name-First: Manuel Author-X-Name-Last: Sierra-Castañer Title: Broadband electronically tunable reflection-based phase shifter for active-steering microwave reflectarray systems in Ku-band Abstract: This document provides the design of an electronically reconfigurable microwave phase shifter for reflectarray systems. The phase shifter is based on a hybrid coupler with reflective circuits in three ports. Each reflective circuit introduces a phase variation that can be modified due to the variable capacity value of a varactor inserted in it. The phase shifting process includes three different stages of phase shifting for the incoming signal in its way through the phase shifter: the signal is conducted through the device towards the reflective circuits in four different ways. The input port of the device is also the output one, providing the desired reflective phase shifting effect. This device is of great interest in reflectarray applications in order to provide more than 360° of controllable phase shifting at each array element. The document includes the complete design of the phase shifter along with its design parameters and circuital behaviour. Journal: Journal of Electromagnetic Waves and Applications Pages: 1545-1551 Issue: 12 Volume: 30 Year: 2016 Month: 8 X-DOI: 10.1080/09205071.2016.1202786 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1202786 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:12:p:1545-1551 Template-Type: ReDIF-Article 1.0 Author-Name: Hussein Hamed Mahmoud Ghouz Author-X-Name-First: Hussein Hamed Mahmoud Author-X-Name-Last: Ghouz Author-Name: Reham Hamdy Zaghloul Author-X-Name-First: Reham Hamdy Author-X-Name-Last: Zaghloul Title: A new compact stripline patch filtenna module Abstract: In this paper, a new compact stripline patch filtenna module (SLPFM) has been proposed, designed, and fully investigated using the well-known electromagnetic simulator (CST_MW simulator). The objective is to design and fabricate a movable and compact microstrip patch chip (MS-Chip) mounted on a microstrip motherboard (MS-motherboard). The main function of the MS-Chip is to operate as Flip-Chip microstrip filter-antenna module to achieve the desired applications for the microwave wireless devices. The proposed SLPFM can cover many wireless applications including GSM, WLAN, WiMAX, and LTE. A detailed parametric study has been conducted and investigated to optimize the main design parameters of the proposed SLPFM. These parameters include chip dimensions, chip dielectric constant relative to the motherboard, and the chip-to-motherboard interconnect geometry (configuration and dimensions). Simulation results showed that the design MS-Chip parameters can be used to control and adjust the filtenna passbands and stopbands to cover the desired applications. FR-4 substrate has been used to fabricate the presented stripline filtenna module (chip and motherboard). Reasonable agreement has been achieved between measured and simulated results. The presented design demonstrates the benefits of using a movable microwave MS-Chip antenna (Flip-Chip filter-antenna module). Therefore, the same MS-Motherboard of the wireless device can use different Flip-Chip filter-antenna modules to include different wireless applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1552-1565 Issue: 12 Volume: 30 Year: 2016 Month: 8 X-DOI: 10.1080/09205071.2016.1204955 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1204955 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:12:p:1552-1565 Template-Type: ReDIF-Article 1.0 Author-Name: Siroos Bahrami Author-X-Name-First: Siroos Author-X-Name-Last: Bahrami Author-Name: Saeed Fallahzadeh Author-X-Name-First: Saeed Author-X-Name-Last: Fallahzadeh Title: Near end crosstalk reduction using slow wave structures Abstract: Slow wave structures concept is used to mitigate near-end crosstalk by adjusting electrical length (phase velocity) of microstrip line. Proposed microstrip line configuration consists of periodic shunt capacitive stubs, which affect the phase constant and characteristic impedance of the line. Designed low-crosstalk microstrip line is simulated and feather fabricated. Near-end crosstalk reduction around 15 dB is achieved by means of slow wave technique. Measurement results are in good agreement with simulations. Proposed microstrip line shows promising technique in high-density printed circuit boards. Journal: Journal of Electromagnetic Waves and Applications Pages: 1566-1573 Issue: 12 Volume: 30 Year: 2016 Month: 8 X-DOI: 10.1080/09205071.2016.1205524 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1205524 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:12:p:1566-1573 Template-Type: ReDIF-Article 1.0 Author-Name: Humberto Lobato-Morales Author-X-Name-First: Humberto Author-X-Name-Last: Lobato-Morales Author-Name: Ricardo Chávez-Pérez Author-X-Name-First: Ricardo Author-X-Name-Last: Chávez-Pérez Author-Name: José Luis Medina-Monroy Author-X-Name-First: José Luis Author-X-Name-Last: Medina-Monroy Title: Leaky-wave antennas based on open-plates and defected-ground open-rings with omnidirectional radiation Abstract: A new type of planar leaky-wave antenna with omnidirectional radiation is presented in this paper. The structure is formed by a periodic array of unitary cells with open-plates and defected-ground open-rings. The proposed type of antenna presents steering capability covering broadside radiation toward backward and forward directions. Antenna parameters and circuit analysis, including return/insertion-loss, radiation pattern, gain, efficiency, and unitary-cell model are all provided. Simulated and measured results are shown. The proposed type of antenna possesses the advantage of low profile and low cost, providing high design flexibility for the real applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1574-1590 Issue: 12 Volume: 30 Year: 2016 Month: 8 X-DOI: 10.1080/09205071.2016.1206839 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1206839 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:12:p:1574-1590 Template-Type: ReDIF-Article 1.0 Author-Name: Muhammad Kamran Khattak Author-X-Name-First: Muhammad Kamran Author-X-Name-Last: Khattak Author-Name: S. Kahng Author-X-Name-First: S. Author-X-Name-Last: Kahng Title: A novel dipole antenna backed by a thin and small-area AMC for good impedance match and low SAR on human tissue Abstract: This paper presents a new dipole antenna that has robust input impedance matching and electromagnetic radiation, and low SAR for human body contact. It is made possible by backing the main radiator with a thin and small-area artificial magnetic conductor (AMC). Different from the conventional AMC which occupies a multi-layered large area based on the full PEC ground for a high antenna directivity, the proposed structure works for 2.4-GHz-ISM band, and has a 1-mm thickness and a 50 mm-by-50 mm footprint with good impedance matching and radiation performances even near human tissue, and a low SAR below 1.6 W/kg is obtained. This design method is validated by full-wave simulations and physical implementation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1591-1602 Issue: 12 Volume: 30 Year: 2016 Month: 8 X-DOI: 10.1080/09205071.2016.1207567 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1207567 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:12:p:1591-1602 Template-Type: ReDIF-Article 1.0 Author-Name: Soni Singh Author-X-Name-First: Soni Author-X-Name-Last: Singh Author-Name: Bhagirath Sahu Author-X-Name-First: Bhagirath Author-X-Name-Last: Sahu Author-Name: Surya Pal Singh Author-X-Name-First: Surya Pal Author-X-Name-Last: Singh Title: Conformal microstrip slot antenna with an AMC reflector for hyperthermia Abstract: This paper presents the simulation and experimental studies of a conformal microstrip slot antenna integrated with artificial magnetic conductor (AMC) for hyperthermia application. In the proposed applicator, an AMC consisting of an array of modified ring patches on a grounded dielectric substrate is located at optimized distance (=4 mm) from the microstrip slot antenna for improved performance of the applicator. The feed configuration of the proposed slot antenna consists of tapered microstrip line with curved tuning stub. The slot and feed configurations of the antenna are modified to widen its bandwidth so that changes in dielectric property of biological phantom medium can have minimal effect on its operating frequency and impedance bandwidth. In addition, the applicator with modified slot and feed arrangement provides enhanced heating depth in the phantom muscle medium. Provision for cooling of tissue surface is made by providing air gap between the slot antenna and phantom muscle medium. Moreover, the presence of AMC not only reduces the backfield but also enhances the penetration depth in the medium. Additionally, performance comparison of the proposed antenna–AMC and the antenna–perfect electric conductor(PEC) combinations in terms of input characteristics and specific absorption rate (SAR) parameters is also made. Finally, the effects of change in the radius of curvature of the substrate and bio-model on effective field size (EFS) for both homogeneous and tri-layered bio-models are also investigated. It is demonstrated through thermal simulation that temperature above 41 °C exists in the irregular-shaped tumor, which is embedded in the muscle region of the curved/planar tri-layered bio-model near its surface. Journal: Journal of Electromagnetic Waves and Applications Pages: 1603-1619 Issue: 12 Volume: 30 Year: 2016 Month: 8 X-DOI: 10.1080/09205071.2016.1207568 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1207568 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:12:p:1603-1619 Template-Type: ReDIF-Article 1.0 Author-Name: Son Xuat Ta Author-X-Name-First: Son Xuat Author-X-Name-Last: Ta Author-Name: Ikmo Park Author-X-Name-First: Ikmo Author-X-Name-Last: Park Title: Planar wideband circularly polarized metasurface-based antenna array Abstract: This paper presents a planar circularly polarized (CP) antenna array with a high-gain and wideband operation. The array is based on a sequentially rotated feeding network for a set of 2 × 2 CP metasurface-based antennas. The single element is a microstrip-line-fed slot antenna, which is coupled to a metasurface having 4 × 4 truncated corner square patches, to produce the CP radiation. The wideband characteristic of the design is obtained by a proper combination between the feeding network and the CP metasurface-based antennas. The proposed array, with an overall size of 50 × 50 × 2.032 mm3 (~1.60 × 1.60 × 0.065 λ0 at 9.6 GHz), has been fabricated and tested. The measurements resulted in an |S11| < –10 dB bandwidth of 7.88–12.0 GHz (41.45%) and a CP radiation bandwidth of 8.4–10.6 GHz (23.16%). In addition, the antenna yielded a broadside left-hand CP radiation with a peak gain of 13.5 dBic, a 3-dB gain bandwidth of 8.6–10.8 GHz (22.68%), and a radiation efficiency of >84%. Journal: Journal of Electromagnetic Waves and Applications Pages: 1620-1630 Issue: 12 Volume: 30 Year: 2016 Month: 8 X-DOI: 10.1080/09205071.2016.1210038 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1210038 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:12:p:1620-1630 Template-Type: ReDIF-Article 1.0 Author-Name: Xin Fu Author-X-Name-First: Xin Author-X-Name-Last: Fu Author-Name: Li-Jun Jiang Author-X-Name-First: Li-Jun Author-X-Name-Last: Jiang Author-Name: Hong Tat Ewe Author-X-Name-First: Hong Tat Author-X-Name-Last: Ewe Title: A novel relaxed hierarchical equivalent source algorithm (RHESA) for electromagnetic scattering analysis of dielectric objects Abstract: A novel relaxed hierarchical algorithm based on the surface equivalence principle for the volume integral equations (VIEs) is proposed in this work. The equivalent sources residing on relaxed spherical equivalence surfaces are established by exact integral formulations. The equivalence surfaces are exploited hierarchically to accelerate matrix–vector product in iterative solutions for the VIEs. The computation time and memory cost complexity of the proposed algorithm for dielectric scatters scale as O(N4/3)$ {{ \mathcal O }(N^{4/3})} $ and O(N)$ {{ \mathcal O }(N)} $, respectively. Numerical examples validate the accuracy and capability of the proposed algorithm. Journal: Journal of Electromagnetic Waves and Applications Pages: 1631-1642 Issue: 12 Volume: 30 Year: 2016 Month: 8 X-DOI: 10.1080/09205071.2016.1210544 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1210544 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:12:p:1631-1642 Template-Type: ReDIF-Article 1.0 Author-Name: H. Krraoui Author-X-Name-First: H. Author-X-Name-Last: Krraoui Author-Name: F. Mejri Author-X-Name-First: F. Author-X-Name-Last: Mejri Author-Name: T. Aguili Author-X-Name-First: T. Author-X-Name-Last: Aguili Title: Dielectric constant measurement of materials by a microwave technique: application to the characterization of vegetation leaves Abstract: A new microwave method proposed for modeling the plant leaves in the wave-guide is presented. In our model, we introduce a model based on the geometrical structure of vegetation leaves; water inside leaves is generally distributed between different tissues in not well-known proportions. To understand and predict its dielectric distribution behavior, it is necessary to involve its morphology; this leaf is parallel venation one with a midrib more developed than the minor veins. The physical phenomenon of diffraction occurs when a wave meets this type of structure. For this, we used the generalized equivalent circuit method. This dynamic method takes into account most of the involved physical phenomena. Calculating the permittivity of the material to be characterized from the measured reflection coefficient constitutes inverse problem. The complexity of the electromagnetic analysis does not allow to find an analytical relation between these two parameters. We have developed a computer code based on the genetic algorithm, to numerically solve the inverse problem. To validate this program, we performed measurements on standard materials of known permittivity. The method is verified with measurement of Teflon (PTFE), Flame Resistant 4, and Pure Acetone. Journal: Journal of Electromagnetic Waves and Applications Pages: 1643-1660 Issue: 12 Volume: 30 Year: 2016 Month: 8 X-DOI: 10.1080/09205071.2016.1208592 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1208592 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:12:p:1643-1660 Template-Type: ReDIF-Article 1.0 Author-Name: Liudmila Nickelson Author-X-Name-First: Liudmila Author-X-Name-Last: Nickelson Author-Name: Artūras Bubnelis Author-X-Name-First: Artūras Author-X-Name-Last: Bubnelis Author-Name: Romualdas Navickas Author-X-Name-First: Romualdas Author-X-Name-Last: Navickas Author-Name: Algirdas Baškys Author-X-Name-First: Algirdas Author-X-Name-Last: Baškys Author-Name: Juozas Bučinskas Author-X-Name-First: Juozas Author-X-Name-Last: Bučinskas Title: Electromagnetic analysis of the main and higher modes on the onion-like carbon tubes Abstract: The electric and magnetic field distributions as well as the dispersion characteristics of open cylindrical tube (hollow-core) waveguides are analysed in this work. The analysed waveguides are made of an onion-like carbon (OLC) material. The solution of the boundary problem was fulfilled by the partial area method. It was discovered the very complicated dependencies of the phase and attenuation constants on the waveguide radii. Such dependencies arise because the OLC material is the highly dispersive and absorbing one. The fundamental and four higher modes can propagate in our investigated waveguides. We have analysed the high-frequency cut-off frequency of modes that is dependent on the tube waveguide external radius. The certain electromagnetic (EM) mode can propagate only on the frequencies lower than the mentioned cut-off frequency. For this reason, this cut-off frequency has an important use in practical applications. We presented here the EM field distributions of modes. We discovered that it is possible to reach the one-mode regime of OLC tube waveguide at the certain external radius. The fundamental and first higher modes’ EM energy is concentrated in the OLC material between the internal and external surfaces of the waveguide. Journal: Journal of Electromagnetic Waves and Applications Pages: 1661-1669 Issue: 13 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1208117 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1208117 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:13:p:1661-1669 Template-Type: ReDIF-Article 1.0 Author-Name: Huilin Tu Author-X-Name-First: Huilin Author-X-Name-Last: Tu Author-Name: Shaoqiu Xiao Author-X-Name-First: Shaoqiu Author-X-Name-Last: Xiao Author-Name: Dominique Lesselier Author-X-Name-First: Dominique Author-X-Name-Last: Lesselier Author-Name: Mohammed Serhir Author-X-Name-First: Mohammed Author-X-Name-Last: Serhir Title: Super-resolution characteristics based on time-reversed single-frequency electromagnetic wave Abstract: A sub-wavelength three-antenna array that is able to perform super-resolution focusing with single-frequency signal excitations is investigated using time-reversal. The antenna array is loaded with a set of uniformly distributed thin metal wires, which when combined with single-frequency electromagnetic waves from a time-reversal mirror yields a 1/35 wavelength super-resolution focusing at the targeted antenna. The length of the metal wires in particular determines the frequency band enabling super-resolution performance. The results have significance for the super-resolution investigation of multi-band compact antenna arrays involving micro-structures, with potential linkage with recent studies on super-resolution mechanisms in deterministic complex media. Journal: Journal of Electromagnetic Waves and Applications Pages: 1670-1680 Issue: 13 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1210037 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1210037 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:13:p:1670-1680 Template-Type: ReDIF-Article 1.0 Author-Name: Philip H. Butler Author-X-Name-First: Philip H. Author-X-Name-Last: Butler Author-Name: Niels G. Gresnigt Author-X-Name-First: Niels G. Author-X-Name-Last: Gresnigt Title: Symmetric but non-local pure-field expression of EM interactions Abstract: A fields-only formulation of EM interactions that does not invoke charge explicitly is presented. The EM interaction ceases to be the result of an asymmetric action of a field on a point charge locally, but instead is the result of applying Hamilton’s principle of virtual work to the symmetric but non-local interaction of space-filling EM fields themselves. The fields themselves are therefore the only fundamental entities. A fields-only understanding of EM interactions is important in situations where the EM fields are knotted, for example in plasma confinement and nuclear magnetic resonance devices where EM knots have been realised, as well as in models of elementary particles as knotted solutions of EM fields. Journal: Journal of Electromagnetic Waves and Applications Pages: 1681-1688 Issue: 13 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1210543 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1210543 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:13:p:1681-1688 Template-Type: ReDIF-Article 1.0 Author-Name: Manisha Mathur Author-X-Name-First: Manisha Author-X-Name-Last: Mathur Author-Name: J. K. Rai Author-X-Name-First: J. K. Author-X-Name-Last: Rai Author-Name: N. Sridhar Author-X-Name-First: N. Author-X-Name-Last: Sridhar Title: Electromagnetic compatibility analysis of projected capacitive touch technology based panel computer for military application Abstract: Touch screens are gaining popularity in military display application. Projected capacitive touch screens offer feather touch experience to user apart from excellent image clarity, multitouch feature and resistance to surface contamination. The biggest limitation of capacitive screens in military application is that it is prone to electromagnetic radiations. Hence, its compliance to military standard 461F for electromagnetic compatibility is a challenge to designers. In this paper, results of various electromagnetic compatibility tests such as CE102, CS101, CS114, CS115, CS116, RE102 and RS103 are presented which are conducted as per guidelines given in military standard 461F to check the compliance and suitability for military application. Experimental test results show that the projected capacitive screens are showing problems with RS103 requirement and relaxation of 30 V/m is given to clear the tests. Another failure is that the radiated emission test RE102 overshoots beyond the limit line. Failure of RE102 suggests that projected capacitive touch screens are unsuitable for military display application unless electromagnetic compatibility issue is addressed specific to RE102 test. Journal: Journal of Electromagnetic Waves and Applications Pages: 1689-1701 Issue: 13 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1211559 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1211559 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:13:p:1689-1701 Template-Type: ReDIF-Article 1.0 Author-Name: Ming-Chun Tang Author-X-Name-First: Ming-Chun Author-X-Name-Last: Tang Author-Name: Zhiyuan Chen Author-X-Name-First: Zhiyuan Author-X-Name-Last: Chen Author-Name: Richard W. Ziolkowski Author-X-Name-First: Richard W. Author-X-Name-Last: Ziolkowski Title: Compact printed ultra-wideband antenna: corrugated monopole augmented with parasitic strips Abstract: A novel compact microstrip line-fed ultra-wideband (UWB) antenna is reported in this paper. The antenna consists of a corrugated half-ellipse monopole and three strips that act as near-field resonant parasitic (NFRP) elements. The entire UWB band (3.1–10.6 GHz) is covered from a very compact size: 19 mm × 10 mm. Two of the NFRP strips are utilized to cover more effectively the lower portion of the UWB frequency range; the third one improves the broadside gain values by 3.28 dB in the upper portion. As a consequence, this compact design maintains a stable radiation performance over the entire UWB band. Journal: Journal of Electromagnetic Waves and Applications Pages: 1702-1711 Issue: 13 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1211560 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1211560 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:13:p:1702-1711 Template-Type: ReDIF-Article 1.0 Author-Name: Walter Orozco-Tupacyupanqui Author-X-Name-First: Walter Author-X-Name-Last: Orozco-Tupacyupanqui Author-Name: Hector Perez-Meana Author-X-Name-First: Hector Author-X-Name-Last: Perez-Meana Author-Name: Mariko Nakano-Miyatake Author-X-Name-First: Mariko Author-X-Name-Last: Nakano-Miyatake Title: Adaptive beamformer based on the augmented complex least mean square algorithm Abstract: In this article, an adaptive beamforming system based on the augmented complex least mean square algorithm is analysed. In this approach, the adaptive filter is used as a widely linear system. The second-order statistical information of the signals involved in the array is exploited. Under this consideration, the ability of the adaptive array to minimize the effects of interferences and complex white noise could be enhanced. The equations for the optimal weights and the array factor are derived for the proposed beamforming system. Computer simulations have been performed to evaluate the performance of the adaptive array, and the results were compared with two of the most common standard adaptive beamforming algorithms: the least mean square and recursive least square. The numerical simulations show that the proposed adaptive array has a better performance in time and spatial domain as compared to the classical beamforming systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 1712-1730 Issue: 13 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2015.1133328 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1133328 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:13:p:1712-1730 Template-Type: ReDIF-Article 1.0 Author-Name: J. F. Valenzuela-Valdés Author-X-Name-First: J. F. Author-X-Name-Last: Valenzuela-Valdés Author-Name: J. L. Padilla Author-X-Name-First: J. L. Author-X-Name-Last: Padilla Author-Name: P. Padilla Author-X-Name-First: P. Author-X-Name-Last: Padilla Author-Name: F. Luna Author-X-Name-First: F. Author-X-Name-Last: Luna Author-Name: J. M. Fernández-González Author-X-Name-First: J. M. Author-X-Name-Last: Fernández-González Title: Design rules for antenna placement on MIMO system Abstract: In recent works, it is demonstrated that, depending on the different spatial distributions and distance between elements, there exists a different true polarization diversity (TPD) configuration that provides a high improvement in terms of capacity. This means that it is necessary to choose the appropriate TPD configuration to maximize the multiple-input-multiple-output (MIMO) capacity. In this work, a genetic algorithm is used to optimize the element positions for four new different configurations in combination with the TPD technique. It is shown that, for some configurations, the same polarization option is always found to reach the maximum capacity. Based on this, some novel design rules are provided to maximize MIMO capacity when the area for placing the antennas is very small. This is the case for most of the wireless devices, where the antenna design and location is one of the latest design constraints to be taken into consideration in the device design. Journal: Journal of Electromagnetic Waves and Applications Pages: 1731-1739 Issue: 13 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1204250 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1204250 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:13:p:1731-1739 Template-Type: ReDIF-Article 1.0 Author-Name: Hanru Shao Author-X-Name-First: Hanru Author-X-Name-Last: Shao Author-Name: Jun Hu Author-X-Name-First: Jun Author-X-Name-Last: Hu Title: Analysis of connected structures using equivalence principle algorithm with source reconstruction method Abstract: A new domain decomposition scheme based on equivalence principle algorithm (EPA) is proposed for analyzing electromagnetic scattering from connected structures. The EPA transforms the unknown of inside scatterers to the unknown on the equivalence surfaces which enclose the scatterers. The challenge arises when the equivalence surface intercepts the connected scatterers, because the current will be singular at the connection that is hard to model. In this paper, a new scheme based on source reconstruction method (SRM) is introduced to deal with the connected problems. This scheme can avoid the current singularity and keep the good convergence of EPA equations. Furthermore, generalized EPA (GEPA) is proposed to improve the theory of EPA and the ability to solve real life problems. Numerical results demonstrate the accuracy and efficiency of the proposed method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1740-1754 Issue: 13 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1213187 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1213187 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:13:p:1740-1754 Template-Type: ReDIF-Article 1.0 Author-Name: Shui-Rong Chai Author-X-Name-First: Shui-Rong Author-X-Name-Last: Chai Author-Name: Li-Xin Guo Author-X-Name-First: Li-Xin Author-X-Name-Last: Guo Title: Fast analysis of bistatic scattering problems with compressive sensing technique Abstract: This paper presents a new method hybriding compressive sensing (CS) and the method of moments (MoM) to efficiently analyze bistatic scattering problems. To perform a bistatic scattering analysis by the new method, the electric field integral equation is firstly constituted and discretized into matrix equation form based on MoM. And then the CS measurements are implemented to obtain the samples of the original signal (In our case, the original signal is the incident wave and induced currents over the surface of the object) by introducing a measurement matrix. Finally, a CS reversion is employed to reconstruct the original signal (the unknown currents) from its lower dimensional measured data. Therefore, by introducing the notion of CS theory, the new method stepped over the computational expensive matrix equation solving procedure in performing a bistatic scattering analysis. Numerical simulations show that the CS framework is able to provide good results, while reducing the number of computations requirement and providing computation acceleration. Journal: Journal of Electromagnetic Waves and Applications Pages: 1755-1762 Issue: 13 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1213665 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1213665 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:13:p:1755-1762 Template-Type: ReDIF-Article 1.0 Author-Name: Ángel Parra-Cerrada Author-X-Name-First: Ángel Author-X-Name-Last: Parra-Cerrada Author-Name: José L. Jiménez-Martín Author-X-Name-First: José L. Author-X-Name-Last: Jiménez-Martín Author-Name: Daniel Segovia-Vargas Author-X-Name-First: Daniel Author-X-Name-Last: Segovia-Vargas Author-Name: Vicente González-Posadas Author-X-Name-First: Vicente Author-X-Name-Last: González-Posadas Title: Analysis of new active antenna with a patch as feed-back network, using the NDF Method Abstract: This paper shows the design of an active patch antenna. First, an analysis of the electric field inside the patch is performed to determine the compatibility of the modes of the patch with the desired feeding. The desired feeding is as a serial two-port resonator, so the suitable mode is the “Mode 1”. Then a linear analysis of the active antenna is performed. In this particular example, it is possible to use the classic Loop Gain Method, but its use is not guaranteed. So, the proposed NDF Method is used because it is independent of the oscillator topology and it is valid without any restriction or proviso. Then a Harmonic Balance analysis is performed and the results are compared with the measurements of a prototype. Journal: Journal of Electromagnetic Waves and Applications Pages: 1763-1772 Issue: 13 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1215265 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1215265 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:13:p:1763-1772 Template-Type: ReDIF-Article 1.0 Author-Name: Xin Gao Author-X-Name-First: Xin Author-X-Name-Last: Gao Author-Name: Wenjie Feng Author-X-Name-First: Wenjie Author-X-Name-Last: Feng Author-Name: Chaoying Zhao Author-X-Name-First: Chaoying Author-X-Name-Last: Zhao Author-Name: Wenquan Che Author-X-Name-First: Wenquan Author-X-Name-Last: Che Title: Wideband balanced networks with wideband common mode suppression and arbitrary power-dividing ratio Abstract: Two novel wideband balanced networks with wideband common mode suppression and arbitrary power-dividing ratio are proposed in this paper. The differential/common mode equivalent circuits of the balanced networks can be easily reduced based on the matrix transformation. Microstrip-slotline 180° phase inverters loaded with four isolation resistors are used to realize high isolation for the power division output ports. Two planar wideband equal and unequal power division balanced networks with bandwidths of 33% of (1:1, equal) and 39% (1:2.22, unequal) for the differential mode and over 120% common mode suppression (0.96–3.6 GHz, |S cc21, 31| < –10 dB) are designed and fabricated. Journal: Journal of Electromagnetic Waves and Applications Pages: 1773-1784 Issue: 13 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1215267 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1215267 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:13:p:1773-1784 Template-Type: ReDIF-Article 1.0 Author-Name: Turgut Ozturk Author-X-Name-First: Turgut Author-X-Name-Last: Ozturk Author-Name: Amna Elhawil Author-X-Name-First: Amna Author-X-Name-Last: Elhawil Author-Name: Muharrem Düğenci Author-X-Name-First: Muharrem Author-X-Name-Last: Düğenci Author-Name: İlhami Ünal Author-X-Name-First: İlhami Author-X-Name-Last: Ünal Author-Name: İhsan Uluer Author-X-Name-First: İhsan Author-X-Name-Last: Uluer Title: Extracting the dielectric constant of materials using ABC-based ANNs and NRW algorithms Abstract: Five different Nicolson–Ross–Weir (NRW) extracting techniques are used to extract the dielectric constants of Teflon, Rexolite, Glass (borosilicate and soda-lime), Paper, and Ultralam 3850HT from S-parameters. The results of these extraction techniques are used to train the Artificial Neural Networks. In order to improve the accuracy of the results, the weights of ANNs are calculated using artificial bee colony estimation method. The results are compared with that obtained using NRW, Newton–Raphson, and genetic algorithm. The obtained results indicate that the proposed model gives good extracted parameters as compared with the previously published results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1785-1799 Issue: 13 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1215266 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1215266 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:13:p:1785-1799 Template-Type: ReDIF-Article 1.0 Author-Name: Hosam El-Ocla Author-X-Name-First: Hosam Author-X-Name-Last: El-Ocla Title: Impact of wave incidence parameters on laser radar detection of conducting targets with H-wave polarization Abstract: This work is to select precisely the proper frequency range that reduces the dependence of the laser radar cross-section (LRCS) on the incident wave parameters. In doing this, we investigate the effect of these parameters including incident angle and the beam width on the LRCS. We present a numerical analysis of the effect of the H-wave polarization on the radar detection capability in random medium and hence compare it with the freespace case. In doing this, our calculations use a boundary value method considering surface current on the whole contour of the object. As a result, the performance of the LRCS is studied with the target configuration assuming the creeping waves that have remarkable influence especially in the resonance range. Journal: Journal of Electromagnetic Waves and Applications Pages: 1801-1811 Issue: 14 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1211558 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1211558 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:14:p:1801-1811 Template-Type: ReDIF-Article 1.0 Author-Name: Dazhi Zhao Author-X-Name-First: Dazhi Author-X-Name-Last: Zhao Author-Name: Maokang Luo Author-X-Name-First: Maokang Author-X-Name-Last: Luo Title: A new axis symmetric exact solution of the Maxwell’s equations in a time-variant nonlinear medium Abstract: A new explicit exact solution of the Maxwell’s equations for cylindrical wave in a time-variant nonlinear medium where ε(E)=ϵ0ε1(rR)βh(t)exp(αE)$ \varepsilon (E) = \epsilon _{0}\varepsilon _{1}(\frac{r}{R})^{\beta }h(t)\exp (\alpha E) $ is derived in this paper. We also prove that the solution seeking routine is effective for a large class of wave equations and exponential nonlinearity is necessary for additively separable solution. Physical interpretation of the additively separable solution is given too. Meanwhile, this method is valid if there exists a time-independent or a time-linear excited source. Journal: Journal of Electromagnetic Waves and Applications Pages: 1812-1819 Issue: 14 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1216334 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1216334 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:14:p:1812-1819 Template-Type: ReDIF-Article 1.0 Author-Name: M. Cvetković Author-X-Name-First: M. Author-X-Name-Last: Cvetković Author-Name: D. Poljak Author-X-Name-First: D. Author-X-Name-Last: Poljak Author-Name: M. Rogić Vidaković Author-X-Name-First: M. Author-X-Name-Last: Rogić Vidaković Author-Name: Z. Ðogaš Author-X-Name-First: Z. Author-X-Name-Last: Ðogaš Title: Transcranial magnetic stimulation induced fields in different brain models Abstract: This paper gives a comparison of the numerical results for the induced electric field, electric current density, and the magnetic flux density inside the adult, 10-years-old, and 5-years-old homogeneous brain models, for three different transcranial magnetic stimulation (TMS) coils. The numerical results are obtained using the TMS model based on the surface integral equation formulation and efficient numerical solution via Method of Moments. The two child brain models are obtained by linearly scaling the adult brain model. The age-dependent parameters of the brain are taken into account as well. The results show that the decrease in the homogeneous brain size results in the increased values of all TMS-induced fields. Implementing the age-related parameters significantly increases the induced current density values while moving the point with half maximum electric field value closer to the surface. The analysis undertaken in this work has underlined the importance of the brain size and the brain tissue conductivity in the modeling of TMS in children. Knowledge about the differences of the TMS-induced fields in adult and child brain models could potentially contribute to development of optimal TMS coils and stimulating parameters, which is especially important when applying TMS on pediatric patients in hospitals. Journal: Journal of Electromagnetic Waves and Applications Pages: 1820-1835 Issue: 14 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1216807 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1216807 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:14:p:1820-1835 Template-Type: ReDIF-Article 1.0 Author-Name: Soni Singh Author-X-Name-First: Soni Author-X-Name-Last: Singh Author-Name: S. P. Singh Author-X-Name-First: S. P. Author-X-Name-Last: Singh Title: Investigation on improved water-loaded diagonal horn applicators for hyperthermia Abstract: This paper describes simulation, theoretical, and/or experimental studies of specific absorption rate (SAR) distribution in biological phantom (muscle)/tri-layered bio-media without and with irregular-shaped tumors in direct contact with improved water-loaded metal diagonal horns designed at 2450 and 915 MHz. Further, thermal simulation results based on Pennes’ bio-heat equation are also provided for each of the proposed applicators, which is in direct contact with realistic tri-layered bio-media without and with irregular-shaped tumor embedded within the muscle layer. The proposed horns are improved versions of the respective conventional metal diagonal horns in which the aperture fields, which are modified by introducing four conducting pins at appropriate locations near each antenna aperture, correspond to fundamental and higher order modes. The theoretical aperture field distributions of the proposed horns designed at 2450 and 915 MHz are compared with the corresponding simulated ones. Further, the theoretical SAR parameters (penetration depth (PD) and effective field size (EFS)) in the phantom muscle medium due to the proposed horns designed at 2450 and 915 MHz are compared with the corresponding simulated and/or experimental results as well as with those obtained due to the corresponding conventional horns of identical dimensions. Moreover, effects on PD, EFS/EFS25, and temperature distribution profiles due to presence of irregular-shaped tumor in the tri-layered bio-media at 2450 and 915 MHz are also investigated. It is demonstrated that desired temperature range 41–45 °C can be achieved and maintained for 60 min with input power of 4/10 W at the frequencies of 2450/915 MHz for treating superficial tumors. Journal: Journal of Electromagnetic Waves and Applications Pages: 1836-1857 Issue: 14 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1216808 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1216808 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:14:p:1836-1857 Template-Type: ReDIF-Article 1.0 Author-Name: Yabin Zhang Author-X-Name-First: Yabin Author-X-Name-Last: Zhang Author-Name: Yubin Gong Author-X-Name-First: Yubin Author-X-Name-Last: Gong Author-Name: Zhanliang Wang Author-X-Name-First: Zhanliang Author-X-Name-Last: Wang Author-Name: zhaoyun duan Author-X-Name-First: zhaoyun Author-X-Name-Last: duan Author-Name: yanyu wei Author-X-Name-First: yanyu Author-X-Name-Last: wei Author-Name: huarong gong Author-X-Name-First: huarong Author-X-Name-Last: gong Author-Name: Jinjun Feng Author-X-Name-First: Jinjun Author-X-Name-Last: Feng Title: Design of a two-stage, two-sheet-beam 220-GHz, 70-kW planar relativistic traveling-wave tube Abstract: In order to alleviate the problem of achieving large powers beyond 10 kW at frequencies as high as 220 GHz, a two-stage, two-sheet-beam relativistic TWT (SBRTWT) was proposed. For one-stage SBRTWT, there exists instability phenomenon as the effect of electron noise will become large enough compared with the small input power. To avoid the effect, the gain of the first-stage tube was decreased, and its output power was employed to drive the second-stage tube. A large-width branch-guide energy coupler was proposed, analyzed and designed, which can solve the difficult problem to couple the amplified microwave from a wide waveguide to another wide waveguide. A two-beam SBRTWT of 70 kW output with a gain of 28.5 dB was predicted. The findings establish that the two-stage configuration provides larger output powers than the single-stage configuration of SBRTWT and call for further research in two-stage SBRTWT. Journal: Journal of Electromagnetic Waves and Applications Pages: 1858-1868 Issue: 14 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1217797 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1217797 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:14:p:1858-1868 Template-Type: ReDIF-Article 1.0 Author-Name: Biswarup Rana Author-X-Name-First: Biswarup Author-X-Name-Last: Rana Author-Name: Susanta Kumar Parui Author-X-Name-First: Susanta Kumar Author-X-Name-Last: Parui Title: H-plane horn antenna using corrugated substrate integrated waveguide Abstract: In this paper, a novel corrugated substrate integrated waveguide (CSIW)-based H-plane horn antenna has been proposed for X-band applications. Quarter-wavelength open-circuited microstrip stubs are used in CSIW structures to achieve the TE10-like boundary condition. This structure does not require any conducting vias such as conventional substrate integrated waveguide (SIW). The antenna is fed by taper microstrip line followed by a section of CSIW operating in TE10 mode. The last section is flared section which is responsible for radiation from the structure. The structure is simulated with ANSYS made HFSS software, and a prototype is fabricated. The measurement results show an impedance bandwidth of 17.2% covering from 8.4 to 10.1 GHz. The radiation pattern is stable over the entire band of operation and has a peak gain of 12.5 dBi. The simulation results are in good agreement with the measured values. Journal: Journal of Electromagnetic Waves and Applications Pages: 1869-1876 Issue: 14 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1218799 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1218799 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:14:p:1869-1876 Template-Type: ReDIF-Article 1.0 Author-Name: Le Wang Author-X-Name-First: Le Author-X-Name-Last: Wang Author-Name: Wenbin Lin Author-X-Name-First: Wenbin Author-X-Name-Last: Lin Author-Name: Chenglong Wu Author-X-Name-First: Chenglong Author-X-Name-Last: Wu Author-Name: Peidong Yang Author-X-Name-First: Peidong Author-X-Name-Last: Yang Author-Name: Feibiao Dong Author-X-Name-First: Feibiao Author-X-Name-Last: Dong Title: The steady-state thermal blooming of the high-power laser propagation in the rain Abstract: We study the propagation of high-power laser in the rain. The effective permittivity of the rain is incorporated into the propagation model to study energy loss and further the steady-state thermal blooming of the high-power laser. With the help of simulations, we obtain the contour distribution of the laser beam at different propagation distance for different rain rates. Journal: Journal of Electromagnetic Waves and Applications Pages: 1877-1884 Issue: 14 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1219276 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1219276 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:14:p:1877-1884 Template-Type: ReDIF-Article 1.0 Author-Name: D. Liu Author-X-Name-First: D. Author-X-Name-Last: Liu Author-Name: K. A. Michalski Author-X-Name-First: K. A. Author-X-Name-Last: Michalski Title: Comparative study of bio-inspired optimization algorithms and their application to dielectric function fitting Abstract: A comparative study is presented for the latest bio-inspired optimization algorithms, known as bacterial foraging, firefly, cuckoo search, krill herd, and cuttlefish algorithms. This study also included the more established genetic and particle swarm optimization methods. These algorithms are then applied to a partial-fraction model fitting of tabulated measured dielectric function data for noble metals at optical wavelengths. Journal: Journal of Electromagnetic Waves and Applications Pages: 1885-1894 Issue: 14 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1219277 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1219277 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:14:p:1885-1894 Template-Type: ReDIF-Article 1.0 Author-Name: Behbod Ghalamkari Author-X-Name-First: Behbod Author-X-Name-Last: Ghalamkari Author-Name: Ahad Tavakoli Author-X-Name-First: Ahad Author-X-Name-Last: Tavakoli Title: A fast solution of TM wave scattering by a coated 2D partially filled rectangular crack Abstract: An analytical technique of kobayashi potential (KP) method is applied to study the TM plane wave scattering by a coated 2D partially filled rectangular crack in a ground plane. Initially, by expanding a summation of waveguide modal eigenfunctions, the electric field inside the coating layer is found. Then, the crack contribution is taken into account by addition of the Bessel eigenfunctions in both the coating layer and the semi-infinite half space. By applying the KP method and utilizing the Weber–Schafheitlin discontinuous integrals, the governing equations of an infinite summations with unknown coefficients are derived. Then, by imposing the boundary conditions, the unknown coefficients are determined. The proposed method is validated by comparisons made with the finite element method results. Finally, the effect of a progressively filling crack and the dielectric layer height increase on the far-field scattered field is investigated. The permittivities and permeabilities of the coating and the filling dielectric could be lossy or lossless. The proposed method is applicable to both narrow and wide cracks and is accurate and computationally efficient. Journal: Journal of Electromagnetic Waves and Applications Pages: 1895-1908 Issue: 14 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1220333 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1220333 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:14:p:1895-1908 Template-Type: ReDIF-Article 1.0 Author-Name: Abdul-Majid Wazwaz Author-X-Name-First: Abdul-Majid Author-X-Name-Last: Wazwaz Author-Name: S. A. El-Tantawy Author-X-Name-First: S. A. Author-X-Name-Last: El-Tantawy Title: Gaussian soliton solutions to a variety of nonlinear logarithmic Schrödinger equation Abstract: This work addresses a variety of Schrödinger equations with logarithmic nonlinearity, with and without an attenuation term. We show that the stationary and the time-dependent logarithmic models give Gaussian soliton solutions, or simply Gaussons, which are characterized by no soliton radiation, and propagate through dispersion-managed optical fibers. We examine the physical structures, especially the amplitude and width of the Gaussons which we will derive. Journal: Journal of Electromagnetic Waves and Applications Pages: 1909-1917 Issue: 14 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1222312 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1222312 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:14:p:1909-1917 Template-Type: ReDIF-Article 1.0 Author-Name: Meenu Kaushik Author-X-Name-First: Meenu Author-X-Name-Last: Kaushik Author-Name: Ayan Kumar Bandyopadhyay Author-X-Name-First: Ayan Kumar Author-X-Name-Last: Bandyopadhyay Author-Name: L. M. Joshi Author-X-Name-First: L. M. Author-X-Name-Last: Joshi Title: Theoretical design of the gun-cum-input cavity and focusing structure envisaged for a 350 MHz, 100 kW (CW) inductive output tube Abstract: The paper reports the theoretical approach and computer-aided design results for a 350 MHz, 100 kW (CW) inductive output tube. The design considerations and methodologies employed for electromagnetic simulation of individual electron gun and RF cavity assemblies and that of their combined assembly were presented. The electron gun parameters namely the beam radius, perveance and electrodes dimensions were optimized. The input cavity was designed and the parameters, namely the resonant frequency, radius and length of the cavity with respect to the desired propagating mode were characterized. The combined integrated model demonstrates the RF input cavity placed onto the gun structure. The interaction of electron beam (40 kV, 3.5 A) and applied input RF signal of 400 W produces an RF current of ~ 85 A in the interaction gap (i.e. cathode-grid spacing). The focusing structure of the device necessary for getting the efficient amplification has also been designed and optimized. The simulations presented in the paper are carried out using CST, MAGIC2D and TRAK codes. Journal: Journal of Electromagnetic Waves and Applications Pages: 1918-1928 Issue: 14 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1223557 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1223557 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:14:p:1918-1928 Template-Type: ReDIF-Article 1.0 Author-Name: Chie-In Lee Author-X-Name-First: Chie-In Author-X-Name-Last: Lee Author-Name: Yan-Ting Lin Author-X-Name-First: Yan-Ting Author-X-Name-Last: Lin Author-Name: Wei-Cheng Lin Author-X-Name-First: Wei-Cheng Author-X-Name-Last: Lin Title: Small-signal modeling for p-n junctions in the breakdown region at different temperatures using artificial neural networks Abstract: In this paper, an artificial neural network (ANN) approach is applied to efficiently and accurately determine small-signal parameters of a breakdown model for silicon p-n junctions operating in the impact ionization region at different temperatures for the first time. A feed-forward back propagation neural network program with a Levenberg Marquardt optimization algorithm is employed to implement this ANN-based parameter determination approach. Measured S-parameters at different temperatures which are regarded as a training data-set are fitted by this program to determine small-signal parameters of the breakdown equivalent circuit model at different temperatures. Multiplication factors of p-n junctions at different temperatures are also extracted. This simple and accurate breakdown characterization method based on the ANNs can be applicable to automatic parameter determination for devices operating in the breakdown region. Journal: Journal of Electromagnetic Waves and Applications Pages: 1929-1936 Issue: 14 Volume: 30 Year: 2016 Month: 9 X-DOI: 10.1080/09205071.2016.1224206 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1224206 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:14:p:1929-1936 Template-Type: ReDIF-Article 1.0 Author-Name: J. F. Gómez-Aguilar Author-X-Name-First: J. F. Author-X-Name-Last: Gómez-Aguilar Author-Name: R. F. Escobar-Jiménez Author-X-Name-First: R. F. Author-X-Name-Last: Escobar-Jiménez Author-Name: M. G. López-López Author-X-Name-First: M. G. Author-X-Name-Last: López-López Author-Name: V. M. Alvarado-Martínez Author-X-Name-First: V. M. Author-X-Name-Last: Alvarado-Martínez Title: Atangana-Baleanu fractional derivative applied to electromagnetic waves in dielectric media Abstract: This work presents alternative solutions of the fractional waves in dielectric media using the Atangana–Baleanu fractional operator in Liouville-Caputo and Riemann–Liouville sense, the order considered is 0<β,γ⩽1$ 0<\beta ,\gamma \leqslant 1 $ for the space-time domain. We solved analytically the fractional equation using the properties of Laplace transform operator together with the convolution theorem. New results are presented and the analytical solutions are given in terms of the multivariate Mittag-Leffler functions preserving the physical units of the system studied. Numerical simulations were performed for different values of fractional order. Journal: Journal of Electromagnetic Waves and Applications Pages: 1937-1952 Issue: 15 Volume: 30 Year: 2016 Month: 10 X-DOI: 10.1080/09205071.2016.1225521 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1225521 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:15:p:1937-1952 Template-Type: ReDIF-Article 1.0 Author-Name: Dengyao Tian Author-X-Name-First: Dengyao Author-X-Name-Last: Tian Author-Name: Quanyuan Feng Author-X-Name-First: Quanyuan Author-X-Name-Last: Feng Author-Name: Qianyin Xiang Author-X-Name-First: Qianyin Author-X-Name-Last: Xiang Title: A constant absolute bandwidth tunable band-pass filter based on magnetic dominated mixed coupling and source–load electric coupling Abstract: In this paper, a constant absolute bandwidth (CABW) band-pass filter based on magnetic dominated mixed coupling and source–load electric coupling is proposed. Specially, a novel mixed electric and magnetic coupling structure is presented to control the coupling coefficient variation and thus realize a narrow CABW width. Two transmission zeros are added to the filter response using a source–load coupling technique, leading to a better selectivity. The measurement shows that the –1 dB absolute and fractional bandwidth is 29 ± 3 MHz and 1.8–2.6%, respectively, while the central frequency of the passband varies from 1.11 to 1.51 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1953-1963 Issue: 15 Volume: 30 Year: 2016 Month: 10 X-DOI: 10.1080/09205071.2016.1226965 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1226965 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:15:p:1953-1963 Template-Type: ReDIF-Article 1.0 Author-Name: Hui Chen Author-X-Name-First: Hui Author-X-Name-Last: Chen Author-Name: Ke-song Chen Author-X-Name-First: Ke-song Author-X-Name-Last: Chen Author-Name: Xu Chen Author-X-Name-First: Xu Author-X-Name-Last: Chen Title: Planar dual-mode dual-band bandpass filter using a modified rectangular split-loop resonator loaded by an open-circuited stub Abstract: A compact planar dual-band bandpass filter using a new microstrip dual-mode resonator has been proposed in this article, which is based on a modified rectangular split-loop resonator loaded by an open-circuited stub. The implemented filter with two passbands has shown an excellent performance, including three transmission zeros disturbed nearby the two passband edges and between the passbands, by which a high selectivity is obtained for the proposed filter. Also, the measured results agree well with the simulated ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 1964-1973 Issue: 15 Volume: 30 Year: 2016 Month: 10 X-DOI: 10.1080/09205071.2016.1227279 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1227279 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:15:p:1964-1973 Template-Type: ReDIF-Article 1.0 Author-Name: Tatjana Gric Author-X-Name-First: Tatjana Author-X-Name-Last: Gric Title: Analysis of spoof surface plasmons in spoof-insulator-spoof waveguides Abstract: Herein, we present a detailed analysis of the propagation of surface waves along spoof-insulator-spoof (SIS) waveguides. Analytical dispersion equations are derived for the geometry under investigation, in view of the presence of the semiconductor and transparent conducting oxide (TCO) corrugations. More importantly, the proposed formulation reveals a fundamental connection between surface plasmons found in corrugated semiconductors as well as TCO and SIS structures. We envision that the proposed SIS structure may serve as a building block for optical resonators, waveguide bends, and splitters. Journal: Journal of Electromagnetic Waves and Applications Pages: 1974-1979 Issue: 15 Volume: 30 Year: 2016 Month: 10 X-DOI: 10.1080/09205071.2016.1229638 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1229638 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:15:p:1974-1979 Template-Type: ReDIF-Article 1.0 Author-Name: Juin Acharjee Author-X-Name-First: Juin Author-X-Name-Last: Acharjee Author-Name: Kaushik Mandal Author-X-Name-First: Kaushik Author-X-Name-Last: Mandal Author-Name: Sujit Kumar Mandal Author-X-Name-First: Sujit Kumar Author-X-Name-Last: Mandal Author-Name: Partha Pratim Sarkar Author-X-Name-First: Partha Pratim Author-X-Name-Last: Sarkar Title: A compact printed monopole antenna with enhanced bandwidth and variable dual band notch for UWB applications Abstract: This article presents a compact, enhanced bandwidth, and variable dual band notched printed monopole antenna for ultra wideband (UWB) applications. By inserting a simple inverted L-shaped slot in the ground plane and modifying the lower edge of the patch, wider bandwidth with usable fractional bandwidth of 139.2% (3.1–17.3 GHz) is achieved whereas two inverted U-shaped slots in the corner modified patch are embedded to realize two notch bands exactly at WiMAX (3.25–3.75 GHz) and WLAN (5.1–5.9 GHz). A precise design formula is also proposed to calculate the length of the slots. The proposed simple antenna structure with a 50 Ω feed line has been obtained within a small size of 0.11λ × 0.19λ. The simulated results are validated using measured results to show potentiality of the proposed antenna structure in UWB applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1980-1992 Issue: 15 Volume: 30 Year: 2016 Month: 10 X-DOI: 10.1080/09205071.2016.1234419 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1234419 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:15:p:1980-1992 Template-Type: ReDIF-Article 1.0 Author-Name: Song Wu Author-X-Name-First: Song Author-X-Name-Last: Wu Author-Name: Yuanyuan Yi Author-X-Name-First: Yuanyuan Author-X-Name-Last: Yi Author-Name: Zetai Yu Author-X-Name-First: Zetai Author-X-Name-Last: Yu Author-Name: Xiaojun Huang Author-X-Name-First: Xiaojun Author-X-Name-Last: Huang Author-Name: Helin Yang Author-X-Name-First: Helin Author-X-Name-Last: Yang Title: A zero-index metamaterial for gain and directivity enhancement of tapered slot antenna Abstract: This paper presents a zero metamaterial (ZIM) structure for the gain and directivity reinforcement of the TSA. The designed ZIM cell, which consists of resonant metal structure and inductor component, can operate at low frequencies with one component of permittivity tensor reaching zero. By changing the inductance value of the inductor component, the zero point of permittivity tensor of the ZIM will shift correspondingly. We embed ZIM cells in the typical TSA to improve the gain and directivity of TSA, making the overall structure compact, and the embedded ZIM cells have no effect on the operating frequency band of the TSA. The simulated results indicate that the gain of the TSA loaded with the ZIM cells has been enhanced by 0.9–2.48 dB, and the half-power beam width has been decreased by least 10° in the frequency range of 0.575–0.590 GHz compared with typical TSA. The measured results are well consistent with the simulated ones. The new designed antenna can be applied in the grounded-penetrating radar systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 1993-2002 Issue: 15 Volume: 30 Year: 2016 Month: 10 X-DOI: 10.1080/09205071.2016.1236705 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1236705 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:15:p:1993-2002 Template-Type: ReDIF-Article 1.0 Author-Name: Yuli Hu Author-X-Name-First: Yuli Author-X-Name-Last: Hu Author-Name: Le Kang Author-X-Name-First: Le Author-X-Name-Last: Kang Author-Name: Wei Zheng Author-X-Name-First: Wei Author-X-Name-Last: Zheng Author-Name: Jie Bai Author-X-Name-First: Jie Author-X-Name-Last: Bai Title: Impedance matching control method for an underwater magnetic resonance-based wireless power transfer system with metamaterials Abstract: In this paper, a new method of improving the efficiency of the underwater magnetic resonance-based wireless power transfer (MRWPT) system is proposed. A kind of the negative permeability (MNG) metamaterials with low megahertz frequency is designed, which can be adjusted to work well in the system. The S-parameters, resonant frequency, and permeability of metamaterials are worked out for analysis. A new impedance matching control method was also proposed for reducing the reflection loss in a way to help the sea water MRWPT system to achieve the maximum efficiency. This method is also able to reduce the unnecessary power loss caused by power fluctuation. The measured results show that the performance of the proposed metamaterials and the proposed control method are perfect in improving its efficiency in sea water. Journal: Journal of Electromagnetic Waves and Applications Pages: 2003-2019 Issue: 15 Volume: 30 Year: 2016 Month: 10 X-DOI: 10.1080/09205071.2016.1236706 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1236706 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:15:p:2003-2019 Template-Type: ReDIF-Article 1.0 Author-Name: Fan Wang Author-X-Name-First: Fan Author-X-Name-Last: Wang Author-Name: Yufeng Nie Author-X-Name-First: Yufeng Author-X-Name-Last: Nie Author-Name: Weiwei Zhang Author-X-Name-First: Weiwei Author-X-Name-Last: Zhang Author-Name: Wei Guo Author-X-Name-First: Wei Author-X-Name-Last: Guo Title: NPBS-based adaptive finite element method for static electromagnetic problems Abstract: To solve electromagnetic field problems by the finite element method (FEM), it is necessary for users to generate mesh in preprocessing. The quality of mesh, which depends on the quality of set of nodes, strongly affects the accuracy of the analysis result. In this paper, a novel NPBS (node placement method by bubble simulation)-based adaptive finite element method (NPBS-AFEM) was proposed to solve the static electromagnetic problems. The advantages of the NPBS-based AFEM, compared with other known methods, are given as follows: the NPBS-based AFEM not only generates a high-quality nodes set which can be connected to be high-quality meshes, but also uses less DOFs to achieve the required accuracy; this adaptive mesh refinement method can be combined with other a posteriori error estimators to conduct finite element computing; this AFEM can coarsen and refine the mesh in the same framework without manual intervention; it is very suitable to develop the NPBS method in parallel environments due to the short-range force between bubbles; it can be also used to deal with anisotropic problems where the bubbles are replaced by elliptical bubbles. It is shown that the mesh of high quality and higher accuracy than a highly optimized BM (bisection method)-based h-AFEM or uniform refinement method is obtained in three static electromagnetic field problems using the NPBS-AFEM. Journal: Journal of Electromagnetic Waves and Applications Pages: 2020-2038 Issue: 15 Volume: 30 Year: 2016 Month: 10 X-DOI: 10.1080/09205071.2016.1237896 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1237896 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:15:p:2020-2038 Template-Type: ReDIF-Article 1.0 Author-Name: Junghoon Ko Author-X-Name-First: Junghoon Author-X-Name-Last: Ko Author-Name: Sung Uk Lee Author-X-Name-First: Sung Uk Author-X-Name-Last: Lee Author-Name: Young Seok Kim Author-X-Name-First: Young Seok Author-X-Name-Last: Kim Author-Name: Dong-Jo Park Author-X-Name-First: Dong-Jo Author-X-Name-Last: Park Title: Measurements and analyses of 28 GHz indoor channel propagation based on a synchronized channel sounder using directional antennas Abstract: This paper presents measurements and analyses of channel propagation to investigate the channel characteristics of the millimeter wave for the indoor mobile communication system. The candidate for the promising carrier frequency is 28 GHz. We conducted the measurements considering conditions for the line of sight and the obstructed line of sight. The measurement points are located in a typical office room that is one of the main scenarios for the channel model. For channel propagation analysis, a novel channel sounder with a time synchronization scheme is introduced to combine channel measurements from different directions using an automatic scanning measurement system. With this system, omni-like power delay profiles of 28 GHz communication was successfully obtained. Furthermore, we analyze the spatial-temporal channel characteristics of an indoor environment such as path loss, delay and angular distributions, delay and angular spreads, and cross-correlation between the large-scale channel parameters. Journal: Journal of Electromagnetic Waves and Applications Pages: 2039-2054 Issue: 15 Volume: 30 Year: 2016 Month: 10 X-DOI: 10.1080/09205071.2016.1239552 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1239552 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:15:p:2039-2054 Template-Type: ReDIF-Article 1.0 Author-Name: M. D. Malykh Author-X-Name-First: M. D. Author-X-Name-Last: Malykh Author-Name: N. E. Nikolaev Author-X-Name-First: N. E. Author-X-Name-Last: Nikolaev Author-Name: L. A. Sevastianov Author-X-Name-First: L. A. Author-X-Name-Last: Sevastianov Title: The geometrical description of electromagnetic radiation Abstract: The paper describes the relationship between the solutions of Maxwell’s equations which can be considered at least locally as plane waves and the curvilinear coordinates of geometrical optics; it generalizes the results achieved by Lüneburg, concerning the evolution of surfaces of electromagnetic fields discontinuities. If vectors E→$ \vec{E} $ and H→$ \vec{H} $ are orthogonal to each other and their directions do not change with time t, but may vary from point to point in the domain G, then under some conditions there is an orthogonal coordinate system x1,x2,x3$ x_1,x_2,x_3 $ in which x1$ x_1 $-lines represent rays of geometrical optics, x2$ x_2 $-lines point out E→$ \vec{E} $-direction and, x3$ x_3 $-lines point out H→$ \vec{H} $-direction. This coordinate system will be called phase-ray coordinate system. In the article, it will be proved that field under study can be represented by two scalar functions. The article will also specify the necessary and sufficient conditions for the existence of a coordinate system, generated by the solution of Maxwell’s equations with the holonomic field of the Poynting vector. It is shown that the class of solutions of Maxwell’s equations, as described in this work, includes monochromatic polarized waves, and the Hilbert–Courant solutions and their generalizations. Journal: Journal of Electromagnetic Waves and Applications Pages: 2055-2066 Issue: 15 Volume: 30 Year: 2016 Month: 10 X-DOI: 10.1080/09205071.2016.1240632 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1240632 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:15:p:2055-2066 Template-Type: ReDIF-Article 1.0 Author-Name: Piotr Kurgan Author-X-Name-First: Piotr Author-X-Name-Last: Kurgan Author-Name: Sławomir Kozieł Author-X-Name-First: Sławomir Author-X-Name-Last: Kozieł Title: Surrogate-assisted multi-objective optimization of compact microwave couplers Abstract: This work presents a rigorous methodology for expedited simulation-driven multi-objective design of microwave couplers with compact footprints. The proposed approach is a viable alternative for computationally expensive population-based metaheuristics and exploits a surrogate-assisted point-by-point Pareto set determination scheme that utilizes – for the sake of computational efficiency – space-mapping-corrected equivalent circuit models. The technique is showcased using a complex design example of a compact rat-race coupler, for which a set of nine alternative design solutions is efficiently identified. The latter design solutions illustrate the best possible trade-offs between conflicting design objectives for the structure at hand, that is, its operational bandwidth and the layout area. The overall design cost corresponds to approximately 20 high-fidelity electromagnetic simulations of the miniaturized coupler. Several selected trade-off designs have been manufactured and measured for the purpose of method validation. Journal: Journal of Electromagnetic Waves and Applications Pages: 2067-2075 Issue: 15 Volume: 30 Year: 2016 Month: 10 X-DOI: 10.1080/09205071.2016.1230523 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1230523 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:15:p:2067-2075 Template-Type: ReDIF-Article 1.0 Author-Name: Mehdi Hamidkhani Author-X-Name-First: Mehdi Author-X-Name-Last: Hamidkhani Author-Name: Farzad Mohajeri Author-X-Name-First: Farzad Author-X-Name-Last: Mohajeri Title: A low phase noise microwave oscillator based on a high Q SIW cavity CSRR band-pass filter Abstract: This study designed, developed and put empirically into test a low phase noise oscillator using a complementary split ring resonator filter of high Q factor as a frequency stabilization and selection element. This oscillator is of parallel feedback type. The oscillator was designed at the group-delay-peak frequency of the filter to achieve a dramatic reduction in the phase noise of the oscillator. At the oscillation frequency 5.36 GHz, the phase noise was measured −128 dBcHz$ \frac{\text{dBc}}{\text{Hz}} $ at 100 kHz offset frequency and −145 dBcHz$ \frac{\text{dBc}}{\text{Hz}} $ at 1 MHz offset frequency. The designed oscillator revealed the output power 7 dBm. According to the scientific literature, the proposed oscillator was found to enjoy the best performance at low phase noise for planar microwave oscillators. Journal: Journal of Electromagnetic Waves and Applications Pages: 2077-2087 Issue: 16 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1231088 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1231088 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:16:p:2077-2087 Template-Type: ReDIF-Article 1.0 Author-Name: Mohammad Habibur Rahaman Author-X-Name-First: Mohammad Habibur Author-X-Name-Last: Rahaman Author-Name: Brandon A. Kemp Author-X-Name-First: Brandon A. Author-X-Name-Last: Kemp Title: Revisiting Mie’s scattering theory for the analysis of the plasmonic resonance of metal nanospheres Abstract: An alternate correction of Mie scattering theory for the analysis of plasmonics resonance of metal nanospheres is proposed. The analysis is based on the correction of Mie scattering theory originally developed for left-handed media or negative index media, which employs a solution using the Ricatti–Bessel functions in the calculation of Mie coefficients. It provides validation that the Mie solution for negative index media of spherical particles is also valid for resonance metal nanospheres. Therefore, the viewpoint of a time-reversal problem for the scattered fields in previous correction is not a necessary, fundamental correction to the Mie scattering theory for spherical metal particles. Our analytical solution is also verified by using finite element method. Journal: Journal of Electromagnetic Waves and Applications Pages: 2088-2098 Issue: 16 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1231089 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1231089 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:16:p:2088-2098 Template-Type: ReDIF-Article 1.0 Author-Name: Alina Caddemi Author-X-Name-First: Alina Author-X-Name-Last: Caddemi Author-Name: Emanuele Cardillo Author-X-Name-First: Emanuele Author-X-Name-Last: Cardillo Title: A straight-line equation for the notch tailoring of a microwave extra wideband filter Abstract: This paper deals with a flexible CAD methodology for the design of a microwave extra wideband filter introducing a notch at a desired frequency. The structure, designed in a cost-effective planar microstrip technology to operate in the 5–20 GHz frequency band, is capable of covering up to 120% of fractional bandwidth. It shows good performance in terms of in-band and out-of-band insertion loss and group delay. Furthermore, a simple relationship between the notch frequency and a single geometrical parameter of the structure has been extracted, thus making the component highly flexible to design. The procedure steps and the relevant design results are reported, including the electromagnetic analysis of the port connectors. Finally, different samples of the filter have been realized and measured to test the procedure. The experimental results have shown a good agreement with the expected performance thus confirming the effectiveness of the proposed methodology. Journal: Journal of Electromagnetic Waves and Applications Pages: 2099-2109 Issue: 16 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1231090 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1231090 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:16:p:2099-2109 Template-Type: ReDIF-Article 1.0 Author-Name: Farzad Khajeh-Khalili Author-X-Name-First: Farzad Author-X-Name-Last: Khajeh-Khalili Author-Name: M. Amin Honarvar Author-X-Name-First: M. Amin Author-X-Name-Last: Honarvar Title: A design of triple lines Wilkinson power divider for application in wireless communication systems Abstract: In this article, a novel microstrip Wilkinson power divider (WPD) has been analyzed, simulated, and fabricated, using the proposed triple lines (TLs) in place of the common quarter-wavelength transmission-line. The proposed structure has the high ability of selectivity for designing dimensions. In this direction with the use of PSO algorithm, optimized options will be obtained for the electrical lengths of the TLs. The characteristic admittances, with the intention of fabricating a structure with compact dimensions are also obtained. Besides, three coupled lines theory is used to reach a wideband performance. The proposed triple lines Wilkinson power divider (TLWPD) operates from 0.5 to 4.5 GHz with S11 < −10 dB, which include several wireless communication standards such as GSM, GPS, DCS, PCS, UMTS, WLAN, and WiMAX. The overall size of the TLWPD is 23.5 × 8.3 mm2 or 0.23 λg × 0.08 λg. The results of investigations taken in this article show the fact that the TLWPD, in addition to the small structure dimensions will be a wideband WPD. Journal: Journal of Electromagnetic Waves and Applications Pages: 2110-2124 Issue: 16 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1236704 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1236704 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:16:p:2110-2124 Template-Type: ReDIF-Article 1.0 Author-Name: Z. Menachem Author-X-Name-First: Z. Author-X-Name-Last: Menachem Author-Name: S. Tapuchi Author-X-Name-First: S. Author-X-Name-Last: Tapuchi Title: Straight hollow waveguide with three dielectric layers in the cross section Abstract: The main objective is to understand the influence of the three dielectric layers (and not only with one dielectric layer) and a metallic layer (Ag) in the cross section of the straight hollow waveguide on the output fields, output power density and output power transmission. The simplest and most efficient multilayer structure is a three dielectric layers that deposited on a metal layer. The contribution of the proposed technique to calculate the refractive indices and the transverse derivative of the dielectric profile for three dielectric layers is important to reduce the transmission losses of the dielectric-coated metal waveguides. This contribution is very important to improve the method that based on the mode model. This mode model can be a useful tool to predict the relevant parameters in the case of the hollow waveguide with three dielectric layers and a metallic layer (Ag) for practical applications (output fields, output power density and output power transmission), before carrying out experiments in the laboratory. Journal: Journal of Electromagnetic Waves and Applications Pages: 2125-2137 Issue: 16 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1246212 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1246212 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:16:p:2125-2137 Template-Type: ReDIF-Article 1.0 Author-Name: Lan-Wei Guo Author-X-Name-First: Lan-Wei Author-X-Name-Last: Guo Author-Name: Yongpin Chen Author-X-Name-First: Yongpin Author-X-Name-Last: Chen Author-Name: Jun Hu Author-X-Name-First: Jun Author-X-Name-Last: Hu Author-Name: Joshua Le-Wei Li Author-X-Name-First: Joshua Le-Wei Author-X-Name-Last: Li Author-Name: ZaiPing Nie Author-X-Name-First: ZaiPing Author-X-Name-Last: Nie Title: IE-DDM with a novel multiple-grid p-FFT for analyzing multiscale structures in half space Abstract: We present an integral equation domain decomposition method accelerated by a novel multiple-grid precorrected fast Fourier transform (MG-p-FFT) for the efficient analysis of multiscale structures in a half space. Based on the philosophy of DDM, the original computational domain is partitioned into several non-overlapping sub-domains. By employing non-conformal discretizations to each domain boundaries, combined field integral equation with half-space dyadic Green’s function is proposed for each individual sub-domain. Subsequently, the MG-p-FFT with auxiliary Cartesian grids with different size, order, location, and spacing, is adopted in each sub-domain independently to account for the self-interactions. Here, the proposed MG-p-FFT scheme outperforms the existing single-grid p-FFT scheme for multiscale problems by reducing the computational time and memory consumption. The proposed method can also be viewed as an effective preconditioning scheme for multiscale problems in a half space. The validity and advantages of the proposed method are illustrated by several representative numerical examples. Journal: Journal of Electromagnetic Waves and Applications Pages: 2138-2152 Issue: 16 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1247752 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1247752 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:16:p:2138-2152 Template-Type: ReDIF-Article 1.0 Author-Name: Borui Bian Author-X-Name-First: Borui Author-X-Name-Last: Bian Author-Name: Shaobin Liu Author-X-Name-First: Shaobin Author-X-Name-Last: Liu Author-Name: Xiangkun Kong Author-X-Name-First: Xiangkun Author-X-Name-Last: Kong Title: Three-dimensional microwave broadband metamaterial absorber with broad transmission window based on the coupled symmetric split ring resonators Abstract: A novel three-dimensional (3-D) microwave metamaterial absorber (MA) is presented, which exhibits the characteristics of broadband absorption with broad low insertion-loss transmission window. The proposed absorber is constructed by fabricating a 3-D backplane-less periodic interlocking lattice array consisting of resistors-loading symmetrical split ring resonators. By optimizing the geometry parameters and the resistance values, a broad absorption band with the relative bandwidth of 40.8% is achieved at lower frequencies, together with a low insertion-loss (<1 dB) transmission window with a relative bandwidth of 60% at upper frequencies. The design is polarization insensitive and the absorption peaks remain high level with large angles of oblique incidence for both transverse electric (TE) and transverse magnetic (TM) polarizations. The effective constitutive parameters are derived and the physical mechanisms are also investigated. The measurements on the metamaterial absorber (MA) prototype show good agreement with the simulated results, which further prove the validity of the design. It is expected that the proposed MA may improve the flexibilities for the designs of MA with transmission window and be favorable for some potential applications such as electromagnetic interference and stealth radome technologies. Journal: Journal of Electromagnetic Waves and Applications Pages: 2153-2164 Issue: 16 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1249417 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1249417 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:16:p:2153-2164 Template-Type: ReDIF-Article 1.0 Author-Name: Michele Spanu Author-X-Name-First: Michele Author-X-Name-Last: Spanu Author-Name: Alessandro Fanti Author-X-Name-First: Alessandro Author-X-Name-Last: Fanti Author-Name: Matteo Bruno Lodi Author-X-Name-First: Matteo Author-X-Name-Last: Bruno Lodi Author-Name: Sergio Casu Author-X-Name-First: Sergio Author-X-Name-Last: Casu Author-Name: Francesco Desogus Author-X-Name-First: Francesco Author-X-Name-Last: Desogus Author-Name: Bruno Bisceglia Author-X-Name-First: Bruno Author-X-Name-Last: Bisceglia Author-Name: Giuseppe Mazzarella Author-X-Name-First: Giuseppe Author-X-Name-Last: Mazzarella Title: Microwaves disinfection of farmland Abstract: This work focuses on the heat transfer dynamics in agricultural soils when exposed to microwave fields, in order to disinfect them and to eliminate dangerous organisms without using pesticides. The work manages with the use of a horn antenna to irradiate the superficial layer of soils and so to eliminate harmful bio-agents within a fixed depth. The soil was approximated using a transmission line model. Considering the dielectric constant of the ground as a function of the soil water content, it was possible to evaluate the power absorbed by the irradiated ground and the temperature increase and its profile depending on the irradiation time. Since the latter information is strictly connected to the heat transfer process occurring in the system, we demonstrated the feasibility of the methodology here proposed to achieve difficult conditions for microbial and pathogens life, leading to an effective disinfection of the treated farmland. Journal: Journal of Electromagnetic Waves and Applications Pages: 2165-2173 Issue: 16 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1249802 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1249802 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:16:p:2165-2173 Template-Type: ReDIF-Article 1.0 Author-Name: Omar A. Saraereh Author-X-Name-First: Omar A. Author-X-Name-Last: Saraereh Author-Name: Amjad Iqbal Author-X-Name-First: Amjad Author-X-Name-Last: Iqbal Title: Design of compact and miniaturize asymmetric SIR-DRA filter-antenna subsystem Abstract: The proposed work presents a compact filter–antenna subsystem design using asymmetric stepped impedance resonator filter and cylindrical dielectric resonator antenna. A cylindrical dielectric resonator antenna is excited from stepped impedance resonator through slot. The DRA is excited for HEM11 mode. Rather than utilizing customary 50 Ω interfaces, some intermediate impedance between filter and antenna is optimized to get the desired results. The assembly of both filter and antenna into one module leads to compactness in the RF front-end. The designed filter antenna subsystem has efficiency of 93%. Journal: Journal of Electromagnetic Waves and Applications Pages: 2174-2184 Issue: 16 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1249803 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1249803 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:16:p:2174-2184 Template-Type: ReDIF-Article 1.0 Author-Name: Adil Qayyum Author-X-Name-First: Adil Author-X-Name-Last: Qayyum Author-Name: Farhat Abbas Author-X-Name-First: Farhat Author-X-Name-Last: Abbas Author-Name: Qaisar A. Naqvi Author-X-Name-First: Qaisar A. Author-X-Name-Last: Naqvi Title: Quasi-static analysis of scattering from a radially uniaxial sphere with dispersive coating in chiral medium Abstract: The presented manuscript addresses the quasi-static analysis of a dispersive coated radially uniaxial (RU) sphere placed in an unbounded chiral medium. Dispersion has been included through Lorentz–Drude model. RU medium is defined as having dyadic permittivity and/ or permeability. In this manuscript only permittivity of the sphere has been taken to be dyadic. Expressions for the internal fields of sphere have been calculated and discussed. The scattered fields response in terms of polarizability have been studied for different coated materials. Results of the given geometry compared with the results of special cases, dielectric sphere placed in free space and layered dielectric spheres placed in chiral medium for validation of results. Journal: Journal of Electromagnetic Waves and Applications Pages: 2185-2205 Issue: 16 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1251340 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1251340 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:16:p:2185-2205 Template-Type: ReDIF-Article 1.0 Author-Name: Jun Tao Author-X-Name-First: Jun Author-X-Name-Last: Tao Author-Name: Quan yuan Feng Author-X-Name-First: Quan yuan Author-X-Name-Last: Feng Title: Compact isolation-enhanced UWB MIMO antenna with band-notch character Abstract: In this paper, a compact multiple-input multiple-output antenna with band-notched characteristic is presented for Ultra-Wideband (UWB) applications. Two orthogonally placed radiator elements excite the same open slot which consists of two connected T-shaped slots on the ground plane. Such orthogonal structure easily achieves good diversity performance. To enhance isolation of the lower band, a fork-shaped slot is notched on the ground between two radiators, and the mutual coupling reduces to −20 dB below for the entire UWB frequency band. By slitting open-ended quarter-wavelength L slots on the radiator elements, the rejection bands are achieved. The compact size of the antenna is only 30 × 30 mm2, and the antenna prototype is fabricated and measured. Measured results indicate that a wide-impedance bandwidth, which is from 2.85 to 11.9 GHz with rejection band of 5.1–6 GHz, is achieved, and the envelope correlation coefficient is below 0.008, which are competitive for portable UWB devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 2206-2214 Issue: 16 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1217173 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1217173 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:16:p:2206-2214 Template-Type: ReDIF-Article 1.0 Author-Name: Guo-cheng Wu Author-X-Name-First: Guo-cheng Author-X-Name-Last: Wu Author-Name: Guang-ming Wang Author-X-Name-First: Guang-ming Author-X-Name-Last: Wang Author-Name: Li Zhu Author-X-Name-First: Li Author-X-Name-Last: Zhu Author-Name: Xiang-jun Gao Author-X-Name-First: Xiang-jun Author-X-Name-Last: Gao Title: Novel improved metamaterial transmission line and its application in wideband leaky-wave antenna with wide beam-scanning angle range and low cross-polarization Abstract: In this paper, a novel-improved metamaterial transmission line (MTM TL) is investigated and applied to design periodic leaky-wave antenna (LWA) with wide beam-scanning angle range and low cross-polarization. The improved MTM TL consists of metallic holes and interdigital fingers (which embedded in the main microstrip line). By introducing the metallic holes loaded in the interdigital fingers, the parasitic resonant modes of conventional MTM TL can be eliminated effectively. Considering the continuous phase constants changing from negative to positive values of the improved MTM TL under the balanced condition, a continuous beam-scanning property from backward to forward directions of the resultant periodic LWA can be obtained. For verification, a periodic LWA, which consists of 20 unit cells of the improved MTM TL, is fabricated and measured. The measured and simulated results are in good agreements with each other in all condition. According to the measured results, the fabricated periodic LWA operates from 3.38 to 4.60 GHz with a bandwidth of 30.57%, and achieves a continuous beam-scanning property from backward –65° to forward +71° (including broadside radiation) over the operating frequency band. Moreover, the measured cross-polarization remains at a level of more than 30 dB below the co-polarization across the entire radiation region. The presented LWA should find promising applications in modern wireless communication systems due to these wonderful electromagnetic performances. Journal: Journal of Electromagnetic Waves and Applications Pages: 2215-2226 Issue: 17 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1242436 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1242436 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:17:p:2215-2226 Template-Type: ReDIF-Article 1.0 Author-Name: Danai Torrungrueng Author-X-Name-First: Danai Author-X-Name-Last: Torrungrueng Author-Name: Supakit Kawdungta Author-X-Name-First: Supakit Author-X-Name-Last: Kawdungta Author-Name: Prayoot Akkaraekthalin Author-X-Name-First: Prayoot Author-X-Name-Last: Akkaraekthalin Title: An efficient analysis of the far-field radiation of an electric/magnetic Hertzian dipole embedded in electromagnetic bandgap structures of periodic lossless multilayers using the equivalent CCITL model Abstract: In this paper, the far-field radiation of a Hertzian dipole embedded in electromagnetic bandgap structures of periodic lossless multilayers is studied analytically and numerically. To simplify the analysis of this radiation problem, the equivalent transmission line (TL) model based on conjugately characteristic-impedance TLs (CCITLs) is employed to efficiently compute the far-field radiation of the Hertzian dipole due to the periodic nature of the problem, where associated reflection coefficients, which are useful in computing far fields, can be determined effectively. It is found that numerical results based on the equivalent CCITL model are in very good agreement with those obtained from a commercial electromagnetic software. Journal: Journal of Electromagnetic Waves and Applications Pages: 2227-2240 Issue: 17 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1243490 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1243490 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:17:p:2227-2240 Template-Type: ReDIF-Article 1.0 Author-Name: Cheen Sean Oon Author-X-Name-First: Cheen Sean Author-X-Name-Last: Oon Author-Name: Muhammad Ateeq Author-X-Name-First: Muhammad Author-X-Name-Last: Ateeq Author-Name: Andy Shaw Author-X-Name-First: Andy Author-X-Name-Last: Shaw Author-Name: Stephen Wylie Author-X-Name-First: Stephen Author-X-Name-Last: Wylie Author-Name: Ahmed Al-Shamma’a Author-X-Name-First: Ahmed Author-X-Name-Last: Al-Shamma’a Author-Name: Salim Newaz Kazi Author-X-Name-First: Salim Newaz Author-X-Name-Last: Kazi Title: Detection of the gas–liquid two-phase flow regimes using non-intrusive microwave cylindrical cavity sensor Abstract: Gas–liquid two-phase flow phenomenon occurs in various engineering applications and the measurement of it is important. A microwave sensor in the form of a cylindrical cavity has been designed to operate between 5 and 5.7 GHz. The aim is to analyse a two phase gas–liquid flow regime in a pipeline. LabVIEW software is utilised to capture the data, process them and display the results in real time. The results have shown that the microwave sensor has successfully detected the two-phase flow regimes in both the static and dynamic flow environments with reasonable accuracy. The study has also shown the independence of the technique and its accuracy to the temperature change (28–83 °C). Several flow regimes of the gas–liquid two-phase flow have been discussed. The system is also able to detect the stratified, wavy, elongated bubbles and homogeneous flow regimes. Journal: Journal of Electromagnetic Waves and Applications Pages: 2241-2255 Issue: 17 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1244019 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1244019 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:17:p:2241-2255 Template-Type: ReDIF-Article 1.0 Author-Name: Pravin R. Prajapati Author-X-Name-First: Pravin R. Author-X-Name-Last: Prajapati Title: Multilayered circularly polarized microstrip antenna integrated with defected ground structure for wide impedance and axial ratio bandwidth Abstract: In planar antennas, the bandwidth enhancement can be obtained by multi-layered structure and using the parasitic patch along with proximity coupling. In this paper, further enhancement of the bandwidth demonstrated by integrating specific shape of the defected ground structure (DGS) in the ground layer of multi-layered circular polarized planar antenna. Enhancement of 64% in return loss bandwidth and 25% in axial ratio bandwidth obtained after integrating ring shape DGS. Two Laboratory prototype of antennas, one with and another without DGS are fabricated and tested. Details of the proposed antenna designs and role of DGS in performance enhancement of planar antenna are described, and typical experimental results are presented and discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 2256-2267 Issue: 17 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1245160 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1245160 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:17:p:2256-2267 Template-Type: ReDIF-Article 1.0 Author-Name: Li Liu Author-X-Name-First: Li Author-X-Name-Last: Liu Author-Name: Ruixia Ma Author-X-Name-First: Ruixia Author-X-Name-Last: Ma Author-Name: Jingxia Li Author-X-Name-First: Jingxia Author-X-Name-Last: Li Author-Name: Jianguo Zhang Author-X-Name-First: Jianguo Author-X-Name-Last: Zhang Author-Name: Bingjie Wang Author-X-Name-First: Bingjie Author-X-Name-Last: Wang Title: Anti-jamming property of Colpitts-based direct chaotic through-wall imaging radar Abstract: A direct chaotic through-wall imaging (TWI) radar using chaotic signal generated by improved Colpitts oscillator is proposed, and its good anti-jamming performance is investigated theoretically and experimentally. Compared with conventional TWI radar, the proposed radar has the advantages of very high range resolution, low probability of intercept, and immunity from jamming and interference. The characteristics of the chaotic signal are presented. According to the delta function-like autocorrelation of the chaotic signal, the range resolution of the radar is 6 cm. The cross-ambiguity functions with no discernible peaks are used to theoretically certify its interference immunity performance, and then the anti-jamming properties in the Colpitts jamming, linear frequency modulated chirp jamming, and noise jamming environments are demonstrated by numerical electromagnetic simulations using finite difference time domain, and the corresponding experiments. The simulation and experimental results show that the chaotic waveform possesses excellent jamming immunity to the noise and radio frequency interference. This feature makes the chaotic signal perform superbly in multi-radar environments. Journal: Journal of Electromagnetic Waves and Applications Pages: 2268-2279 Issue: 17 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1246207 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1246207 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:17:p:2268-2279 Template-Type: ReDIF-Article 1.0 Author-Name: Slawomir Koziel Author-X-Name-First: Slawomir Author-X-Name-Last: Koziel Author-Name: Adrian Bekasiewicz Author-X-Name-First: Adrian Author-X-Name-Last: Bekasiewicz Title: Rapid dimension scaling for notch frequency redesign of UWB band-notch antennas Abstract: One of important issues in the design of ultra-wideband (UWB) antennas is implementation of band-notch capability, critical to avoid interference with other standards such as WLAN. At the same time, appropriate dimension adjustment of antenna geometry parameters for precise frequency allocation of the notch and to ensure sufficient reflection level in the UWB band is quite challenging. For the sake of reliability it has to be based on full-wave electromagnetic (EM) simulations of the structure at hand. In this letter a simple technique for dimension scaling of UWB antennas is proposed that allows for rapid reallocation of the band-notch to a required frequency. Our methodology exploits a fast inverse model established using several reference designs obtained for coarse-discretization EM model of the antenna of interest as well as appropriate correction techniques that allows us to apply the model for antenna scaling at high-fidelity EM simulation level. The proposed procedure is demonstrated using a compact UWB monopole with the band-notch scaling range from 5 to 8 GHz. Simulation results are validated using physical measurements of the fabricated antenna prototypes. Journal: Journal of Electromagnetic Waves and Applications Pages: 2280-2292 Issue: 17 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1246208 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1246208 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:17:p:2280-2292 Template-Type: ReDIF-Article 1.0 Author-Name: Bezalel Finkelstein Author-X-Name-First: Bezalel Author-X-Name-Last: Finkelstein Author-Name: Raphael Kastner Author-X-Name-First: Raphael Author-X-Name-Last: Kastner Title: Constructing nonstandard and high order FDTD schemes in cylindrical coordinates using spectral domain and modified equation methodologies – 1-D case Abstract: One of the major drawbacks of the original Yee’s algorithm is “staircasing.” In an attempt to overcome this flaw, especially when trying to solve electromagnetic problems involving cylindrical geometries, an FDTD scheme was formulated in cylindrical coordinates. The vast majority of works published describe an algorithm with a (2, 2) order of accuracy. In this work, we use a recently introduced methodology, that of constructing finite difference schemes in the spectral domain, combined with the well-established one known as the “modified equation” to analyze existing cylindrical FDTD schemes and synthesize new nonstandard and high-order ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 2293-2310 Issue: 17 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1246209 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1246209 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:17:p:2293-2310 Template-Type: ReDIF-Article 1.0 Author-Name: Nooshin Valizade Shahmirzadi Author-X-Name-First: Nooshin Author-X-Name-Last: Valizade Shahmirzadi Author-Name: H. Oraizi Author-X-Name-First: H. Author-X-Name-Last: Oraizi Title: Frequency- and time-domain analysis of a novel reconfigurable microstrip antenna for UWB applications Abstract: A new design of ultra-wide band reconfigurable microstrip slot antenna with switchable single and dual band filtering functions is presented and its time- and frequency-domain results are discussed. Two filtering functions are added to the performance of the antenna by means of etching a meander slot on the radiating patch and introducing a pair of hook-shaped coupling parasitic elements on the ground plane. Embedding PIN diode switches into the antenna structure has added an additional merit to the antenna as a switchable single/dual band filtering operation. The designed antenna has a simple structure with a very small size of 20 × 20 mm2. Suitable agreement exists between its time- and frequency-domain results. The measured impedance bandwidth for VSWR < 2 extends in the frequency range of 3.1–10.6 GHz with fractional bandwidth of 109%, while filtering the interference with C-band and X-Band satellite communication systems at 3.7–4.35 and 7.7–8.9 GHz, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 2311-2324 Issue: 17 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1246210 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1246210 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:17:p:2311-2324 Template-Type: ReDIF-Article 1.0 Author-Name: Xinyan Ling Author-X-Name-First: Xinyan Author-X-Name-Last: Ling Author-Name: Zhongyin Xiao Author-X-Name-First: Zhongyin Author-X-Name-Last: Xiao Author-Name: Xiaoxia Zheng Author-X-Name-First: Xiaoxia Author-X-Name-Last: Zheng Author-Name: Jingyao Tang Author-X-Name-First: Jingyao Author-X-Name-Last: Tang Author-Name: Kaikai Xu Author-X-Name-First: Kaikai Author-X-Name-Last: Xu Title: Ultra-broadband metamaterial absorber based on the structure of resistive films Abstract: This paper presents a three-dimensional structure of metamaterial absorber, and the unit of the absorber is composed of six different size resistive films which are placed on the metal plane ground. The simulated results show that the absorber can realize ultra-broadband absorption, which is from 38 to 142 GHz when the absorption is larger than 90%. And the relative absorption bandwidth can achieve 115.5%. In addition, the proposed metamaterial absorber is polarization-insensitive, which has the same absorption spectra for TE and TM polarization waves. And the absorber has large incident and polarization angles. In the end, the power loss density is analyzed. Through observing the distribution of power loss density, a polarization-controlled metamaterial absorber can be implemented if subtract the resistance film of the horizontal direction or the vertical direction subtracted. And the polarization-controlled metamaterial absorber also has ultra-broadband absorption effect. We believe that the absorber will have many potential applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 2325-2333 Issue: 17 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1246211 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1246211 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:17:p:2325-2333 Template-Type: ReDIF-Article 1.0 Author-Name: Elizabeth Cruz-Pérez Author-X-Name-First: Elizabeth Author-X-Name-Last: Cruz-Pérez Author-Name: José L. Olvera-Cervantes Author-X-Name-First: José L. Author-X-Name-Last: Olvera-Cervantes Author-Name: Alonso Corona-Chávez Author-X-Name-First: Alonso Author-X-Name-Last: Corona-Chávez Title: Analysis and procedure to design differential wideband filters with high-selectivity and high common-mode suppression Abstract: This paper proposes a new structure to design differential wideband bandpass filters by cascading two different types of wideband bandpass filters. Detailed analysis to obtain the equations for designing differential filters with high selectivity and fractional bandwidths between 20 and 55% is presented. To complement the equations a design methodology is proposed and two prototypes with different bandwidth are designed, simulated, and fabricated. The measurement results under differential mode show that the designed filters present two transmission zeros, constant insertion losses, return losses greater than -11$ -11 $ dB and a stop band of at least 2.5f0$ f_0 $. On the other hand, the common-mode signals are suppressed below -25$ -25 $ dB in the whole passband. Journal: Journal of Electromagnetic Waves and Applications Pages: 2334-2343 Issue: 17 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1246979 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1246979 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:17:p:2334-2343 Template-Type: ReDIF-Article 1.0 Author-Name: Tomas Muñoz-Rodero Author-X-Name-First: Tomas Author-X-Name-Last: Muñoz-Rodero Author-Name: Pablo Padilla Author-X-Name-First: Pablo Author-X-Name-Last: Padilla Author-Name: José Manuel Fernández-González Author-X-Name-First: José Manuel Author-X-Name-Last: Fernández-González Author-Name: José Luis Padilla Author-X-Name-First: José Luis Author-X-Name-Last: Padilla Author-Name: Juan Francisco Valenzuela-Valdés Author-X-Name-First: Juan Francisco Author-X-Name-Last: Valenzuela-Valdés Title: Broadband planar multilayered reflectarray based on circular stacked patches and reflective printed circuits for microwave communication systems Abstract: This document provides the complete design of a broadband planar multilayered reflectarray based on circular stacked patches and reflective printed lines. These devices are conceived for their use in satellite communications at microwave and millimeter frequencies. The working principle of the reflectarray is based on the reception and front wave correction by means of printed phase shifters embedded in a phased array structure. Our approach is based on an array of circular stacked patches connected to reflective line shifters. Each reflective shifter at each array cell introduces a phase variation that can be modified due to the line length. The work implies the selection and design of the unitary radiating element and reflective lines of the array, along with the complete reflectarray definition and building up based on this constituting array cell. This work provides the initial specifications and constraints, a complete design, and a manufactured prototype with its performance results. Journal: Journal of Electromagnetic Waves and Applications Pages: 2344-2353 Issue: 17 Volume: 30 Year: 2016 Month: 11 X-DOI: 10.1080/09205071.2016.1249418 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1249418 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:17:p:2344-2353 Template-Type: ReDIF-Article 1.0 Author-Name: Yufei Pan Author-X-Name-First: Yufei Author-X-Name-Last: Pan Author-Name: Shaoyong Zheng Author-X-Name-First: Shaoyong Author-X-Name-Last: Zheng Author-Name: Yunliang Long Author-X-Name-First: Yunliang Author-X-Name-Last: Long Title: Simultaneous frequency- and coupling coefficient-reconfigurable quadrature coupler Abstract: A simultaneous frequency- and coupling coefficient-reconfigurable quadrature coupler is presented in this letter for the first time. Owe to the simplicity of patch element, the operating frequency and coupling coefficient can be easily controlled by the effective capacitances between the patch sector and ground plane with other parameters fixed. Two pairs of varactor diodes are loaded on the patch to achieve this reconfigurability. To demonstrate the proposed structure, a quadrature coupler was designed and measured to operate over a frequency range of 20% for equal power division and provide a reconfigurable coupling coefficients ranging from 4.7 to 10 dB at 5.2 GHz simultaneously. Journal: Journal of Electromagnetic Waves and Applications Pages: 2355-2364 Issue: 18 Volume: 30 Year: 2016 Month: 12 X-DOI: 10.1080/09205071.2016.1243489 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1243489 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:18:p:2355-2364 Template-Type: ReDIF-Article 1.0 Author-Name: Chryssoula A. Kyriazidou Author-X-Name-First: Chryssoula A. Author-X-Name-Last: Kyriazidou Author-Name: Harry Contopanagos Author-X-Name-First: Harry Author-X-Name-Last: Contopanagos Author-Name: Seunghwan Yoon Author-X-Name-First: Seunghwan Author-X-Name-Last: Yoon Author-Name: Anna Papió Toda Author-X-Name-First: Anna Author-X-Name-Last: Papió Toda Author-Name: Franco De Flaviis Author-X-Name-First: Franco Author-X-Name-Last: De Flaviis Author-Name: Jesus A. Castaneda Author-X-Name-First: Jesus A. Author-X-Name-Last: Castaneda Author-Name: Nicolaos G. Alexopoulos Author-X-Name-First: Nicolaos G. Author-X-Name-Last: Alexopoulos Title: 3D package-integrated artificial magnetic conductor antenna arrays for 60 GHz transceivers Abstract: We present a low-profile design of dipole antenna arrays integrated on a planar artificial magnetic conductor (AMC) based on spiral unit cells. The whole system is designed and manufactured on a multi-layer organic laminate packaging technology and can be integrated with a single-chip 60-GHz radio transceiver die. We analyze two fabricated arrays of different total area both of which contain 16 elements fed through a combiner network exciting the array elements either in phase or for 45° scan angle. The integrated antenna-AMC array element presented has twice the impedance bandwidth necessary to cover all international 60-GHz radio bands, small form factor suitable for on-package integration, and 5 dBi gain including all losses. The larger 16-element array, occupying 11 × 11 mm2 package area, has a measured gain of 17 dBi at broadside and 15 dBi at 45° scan angle, while the smaller array, occupying a 6.6 × 11 mm2 package area, has a gain of 15 dBi at broadside and 14 dBi at a 45° scan angle. These arrays are an ideal 3D-integrated package solution for 60 GHz radio transceivers. Journal: Journal of Electromagnetic Waves and Applications Pages: 2365-2389 Issue: 18 Volume: 30 Year: 2016 Month: 12 X-DOI: 10.1080/09205071.2016.1250679 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1250679 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:18:p:2365-2389 Template-Type: ReDIF-Article 1.0 Author-Name: Fanji Meng Author-X-Name-First: Fanji Author-X-Name-Last: Meng Author-Name: Satish Sharma Author-X-Name-First: Satish Author-X-Name-Last: Sharma Title: A single feed dual-band (2.4 GHz/5 GHz) miniaturized patch antenna for wireless local area network (WLAN) communications Abstract: A single feed dual-band miniaturized microstrip patch antenna for Wireless Local Area Network (WLAN) communications has been proposed. The outer rectangular loop patch and inner modified E-shaped patch were used to resonate at 2.4 and 5 GHz, respectively. In order to separate the effect between two frequency bands, a shorting pin was set between two resonance cells. The simulated results show that it can operate at 2.4 and 5 GHz bands with 0.072 GHz (2.407–2.479 GHz) and 0.715 GHz (5.137–5.853 GHz) fractional bandwidth, respectively, which can cover the whole frequency band of WLAN. In addition, the antenna is miniaturized by 31% compared to the conventional rectangular patch without a slot. At last, the proposed microstrip patch antenna has been fabricated and measured for both impedance matching and radiation patterns. A comparison of the measurement and simulation results is given, which show reasonable good agreement. Journal: Journal of Electromagnetic Waves and Applications Pages: 2390-2401 Issue: 18 Volume: 30 Year: 2016 Month: 12 X-DOI: 10.1080/09205071.2016.1251854 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1251854 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:18:p:2390-2401 Template-Type: ReDIF-Article 1.0 Author-Name: Rahima Bendjelloul Author-X-Name-First: Rahima Author-X-Name-Last: Bendjelloul Author-Name: Touraya Bouchemat Author-X-Name-First: Touraya Author-X-Name-Last: Bouchemat Author-Name: Mohamed Bouchemat Author-X-Name-First: Mohamed Author-X-Name-Last: Bouchemat Title: An optical channel drop filter based on 2D photonic crystal ring resonator Abstract: In this paper, we investigate an optical channel drop filter based on a new configuration of photonic crystal ring resonator in a two-dimensional square lattice of silicon rods. The numerical simulation results by the finite difference time domain method show that close to 100% dropping efficiency with quality factor of 1011 is achievable at wavelength λ = 1.55 μm, which is an important wavelength for optical communication systems. Also, we investigate the effect of different parameters on the filtering behavior of the structure and show that changing the refractive index, the lattice constant, and the radius of the rods in the structure affect the resonant wavelength, the dropping efficiency, and the quality factor of the filter. The simplicity of the design, its high dropping efficiency, and its high quality factor are the most significant advantages of our filter. Journal: Journal of Electromagnetic Waves and Applications Pages: 2402-2410 Issue: 18 Volume: 30 Year: 2016 Month: 12 X-DOI: 10.1080/09205071.2016.1253508 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1253508 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:18:p:2402-2410 Template-Type: ReDIF-Article 1.0 Author-Name: Mstislav E. Kaliberda Author-X-Name-First: Mstislav E. Author-X-Name-Last: Kaliberda Author-Name: Leonid M. Lytvynenko Author-X-Name-First: Leonid M. Author-X-Name-Last: Lytvynenko Author-Name: Sergey A. Pogarsky Author-X-Name-First: Sergey A. Author-X-Name-Last: Pogarsky Title: Singular integral equations in diffraction problem by an infinite periodic strip grating with one strip removed Abstract: The H-polarized plane wave diffraction by the infinite periodic grating with removed strip is considered. In the formulation, the current induced on each strip is divided into two currents, the current on the infinite periodic strip grating and the correction current induced by the removal of a strip. The scattered field is inducted by these currents. The problem is reduced to the dual integral equations with respect to the unknown spectral function of the correction field, and then to the singular integral equation with additional conditions. The singular integral equation of infinite periodic grating is also presented. The near and far fields scattered by the grating are analyzed. Journal: Journal of Electromagnetic Waves and Applications Pages: 2411-2426 Issue: 18 Volume: 30 Year: 2016 Month: 12 X-DOI: 10.1080/09205071.2016.1254071 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1254071 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:18:p:2411-2426 Template-Type: ReDIF-Article 1.0 Author-Name: Quan Zhao Author-X-Name-First: Quan Author-X-Name-Last: Zhao Author-Name: Yu Tian Author-X-Name-First: Yu Author-X-Name-Last: Tian Author-Name: Ling Tong Author-X-Name-First: Ling Author-X-Name-Last: Tong Author-Name: Bo Gao Author-X-Name-First: Bo Author-X-Name-Last: Gao Title: Improved physical model in layered media for via structures Abstract: In this paper, the physical model is extended for vias embedded in layered media between two parallel-plate pairs. The effect of this inhomogeneity on signal integrity analysis is crucial, but is rarely studied especially by using the equivalent circuit model. The model presented in this paper is constituted by upper and lower via-to-plane capacitances which are different from each other due to the inhomogeneous dielectrics and equivalent impedance matrix of the parallel-plate cavity with equivalent wave number. The via-to-plate capacitance with layered media is calculated by using cascaded Green’s function with image theory and integral equation method based on partial capacitance, which is the main contribution in this paper. The parallel-plate impedance is calculated by using the cavity resonator method. Transverse resonance method as well as an equivalent approximation method is used for wave number evaluation. For the first time, the circuit model presented in this paper is used for the issue of layered media, which is much simpler with sufficient accuracy up to 20 GHz when compared with analytical method. The model is validated with full-wave simulations. Journal: Journal of Electromagnetic Waves and Applications Pages: 2427-2443 Issue: 18 Volume: 30 Year: 2016 Month: 12 X-DOI: 10.1080/09205071.2016.1254572 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1254572 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:18:p:2427-2443 Template-Type: ReDIF-Article 1.0 Author-Name: Slawomir Koziel Author-X-Name-First: Slawomir Author-X-Name-Last: Koziel Author-Name: Adrian Bekasiewicz Author-X-Name-First: Adrian Author-X-Name-Last: Bekasiewicz Title: Low-fidelity model considerations for EM-driven design of antenna structures Abstract: Surrogate-based optimization (SBO) exploiting variable-fidelity EM models belongs to one of the most promising approaches to expedited simulation-driven antenna design. In SBO, the optimization burden is shifted to a coarsely discretized EM representation of the structure, whereas the high-fidelity model evaluations are carried out only to acquire data necessary for correction of the simplified model or verification of the obtained results. An important issue of variable-fidelity SBO schemes is determination of appropriate low-fidelity model, understood as finding an acceptable compromise between its evaluation time and accuracy. On one hand, unreliable responses of the model that is too coarse may lead to a failure (e.g. divergence) of the optimization algorithm. On the other hand, numerical cost of the design process significantly grows with discretization density of the computational model. Hence, adjustment of the latter should be done carefully so as to control the design cost. Normally, the trade-off between the cost and reliability of the low-fidelity model is determined manually based on the designer’s experience, mostly by checking for discrepancies between the responses for various discretization levels. In this work, the mesh setup is determined automatically through statistical analysis of correlations between the models of various fidelities. The method allows for selecting the discretization level of the low-fidelity model so that it provides acceptable trade-off between the speed and reliability of the design process. The proposed technique is verified using two structures: a dielectric resonator antenna and a slot-ring-coupled patch antenna. Journal: Journal of Electromagnetic Waves and Applications Pages: 2444-2458 Issue: 18 Volume: 30 Year: 2016 Month: 12 X-DOI: 10.1080/09205071.2016.1255567 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1255567 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:18:p:2444-2458 Template-Type: ReDIF-Article 1.0 Author-Name: J. C. Sales Author-X-Name-First: J. C. Author-X-Name-Last: Sales Author-Name: T. M. Pessoa Author-X-Name-First: T. M. Author-X-Name-Last: Pessoa Author-Name: A. C. Ferreira Author-X-Name-First: A. C. Author-X-Name-Last: Ferreira Author-Name: D. G. Correia Author-X-Name-First: D. G. Author-X-Name-Last: Correia Author-Name: C. S. Sobrinho Author-X-Name-First: C. S. Author-X-Name-Last: Sobrinho Author-Name: J. S. de Almeida Author-X-Name-First: J. S. Author-X-Name-Last: de Almeida Author-Name: J. W. M. Menezes Author-X-Name-First: J. W. M. Author-X-Name-Last: Menezes Author-Name: G. F. Guimarães Author-X-Name-First: G. F. Author-X-Name-Last: Guimarães Author-Name: A. S. B. Sombra Author-X-Name-First: A. S. B. Author-X-Name-Last: Sombra Title: High quality of logic gates from the return arm of a Sagnac fiber interferometer Abstract: In this paper, we analyze the characteristics of obtaining logic functions and logic gates in the reflected output of the Sagnac interferometer by unbalancing the interferometer through the effects of group velocity dispersion and self-phase modulation, mapped by the influence of the extinction ratio (XR) and also analyze the logic gates of better quality by proposing accuracy precision ratio (PR) defined. We studied the phase variation in the phase inserted to the input and we analyzed the related parameters of modulation. We investigated intrinsic features of reflection of the Sagnac interferometer and obtained the logic gates AND, OR, and XOR, and the logical functions ZERO, ONE, A·B¯$ A\cdot \bar{B} $ and A¯·B$ \bar{A}\cdot B $. A specific situation happens when ρ = 0.3 and |ε|=0.059W1/2$ |\varepsilon | = 0.059 \, {\text{W}}^{1/2} $, where we find the logic gates AND, OR, and XOR. Of all results, the XOR logic gate was obtained in a greater phase variation interval. The XR had the highest contrast when ρ = 0.2 and |ɛ| = 0.028 W1/2. The proposed reconfigurable theoretical set-up gives a contribution to the design of optical networks by the analysis of the obtained logic gates and logic functions in an all-optical environment. The best quality logic gate is the AND gate presenting the |PRTOTAL| = 34.99 when Δϕ=0.798π,ρ=0.3andε=0.059W1/2$ \Delta \phi = 0.798\pi ,\ \rho = 0.3 {\text{and}} \ \left| \varepsilon \right| = 0.059\, {\text{W}}^{1/2} $. Journal: Journal of Electromagnetic Waves and Applications Pages: 2459-2483 Issue: 18 Volume: 30 Year: 2016 Month: 12 X-DOI: 10.1080/09205071.2016.1257396 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1257396 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:18:p:2459-2483 Template-Type: ReDIF-Article 1.0 Author-Name: Çiğdem Seçkin Gürel Author-X-Name-First: Çiğdem Seçkin Author-X-Name-Last: Gürel Author-Name: Özkan Kılıç Author-X-Name-First: Özkan Author-X-Name-Last: Kılıç Title: Band-blocking optical filter including ultrathin metallic film Abstract: A new multilayered optical filter is designed using high- and low-index materials and ultrathin metallic film providing band-blocking characteristic. Power absorption, reflection and transmission characteristics of the structure depending on the high/low index values of the layers and stack numbers of layers are investigated. Overall results indicate that band-blocking filter in visible region is realized with quasi-periodically settled layers in the form of Fibonacci Series and proper adjustment of the structural parameters. Designed structure is useful for the absorbtion of special wavelengths in the visible region in 670–730 nm band by eliminating reflection and transmission. Journal: Journal of Electromagnetic Waves and Applications Pages: 2484-2491 Issue: 18 Volume: 30 Year: 2016 Month: 12 X-DOI: 10.1080/09205071.2016.1262792 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1262792 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:18:p:2484-2491 Template-Type: ReDIF-Article 1.0 Author-Name: Hai-Lin Dong Author-X-Name-First: Hai-Lin Author-X-Name-Last: Dong Author-Name: Shu-Xi Gong Author-X-Name-First: Shu-Xi Author-X-Name-Last: Gong Author-Name: Hui Xue Author-X-Name-First: Hui Author-X-Name-Last: Xue Author-Name: Xing Wang Author-X-Name-First: Xing Author-X-Name-Last: Wang Author-Name: Bo Zhao Author-X-Name-First: Bo Author-X-Name-Last: Zhao Author-Name: Peng-Fei Zhang Author-X-Name-First: Peng-Fei Author-X-Name-Last: Zhang Title: A hybrid broadband analysis approach for surface-wire junctions structures by applying AIM and asymptotic waveform evaluation technique Abstract: The asymptotic waveform evaluation (AWE) technique is utilized to deal with broadband electromagnetic problems of surface–wire junction geometries in this paper. To ensure the current continuity, triangles-to-segments junction model is used and the Rao–Wilton–Glisson (RWG) and triangular basis functions are used to solve the distributions of current on perfect electric conductor and wire, respectively. Then, the current on surface conductor, wire, and junctions are expanded in a rational function via Padé approximation. The AWE technique needs to store the high-order derivatives of the self-impedance and mutual-impedance matrices of surface–wire, which increase the memory requirements. Thus, the adaptive integral method is employed to reduce memory requirements and to accelerate the matrix-vector multiplications in an iterative solver. Finally, some numerical examples are shown to demonstrate the efficiency and accuracy of the proposed method Journal: Journal of Electromagnetic Waves and Applications Pages: 141-153 Issue: 2 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1048835 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1048835 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:2:p:141-153 Template-Type: ReDIF-Article 1.0 Author-Name: Lin Peng Author-X-Name-First: Lin Author-X-Name-Last: Peng Author-Name: Ji-yang Xie Author-X-Name-First: Ji-yang Author-X-Name-Last: Xie Author-Name: Xing Jiang Author-X-Name-First: Xing Author-X-Name-Last: Jiang Author-Name: Si-min Li Author-X-Name-First: Si-min Author-X-Name-Last: Li Title: Wideband microstrip antenna loaded by elliptical rings Abstract: The paper presents elliptical ring-loaded microstrip antennas for wideband applications. The parasitic stack elliptical rings bring in new resonances to enhance antenna bandwidth while maintaining the characteristics of compact size, low profile, and reasonable good polarization of microstrip antenna. By utilizing one or two elliptical rings upon a reference microstrip antenna (RMA) as parasitic, more resonances appeared as the rings operated as half-wavelength resonators. Thus, two and three resonances are observed for the one ring-loaded microstrip antenna (ORLMA) and dual ring-loaded microstrip antenna (DRLMA), respectively. The antennas maintain compact size and low-profile characteristics, and the volumes of RMA, ORLMA, and DRLMA compared to their corresponding low edge free space wavelength are 0.345 λ × 0.285 λ × 0.020 λ, 0.330 λ × 0.273 λ × 0.038 λ, and 0.392 λ × 0.287 λ × 0.037 λ, respectively, while their measured bandwidth increased from 2.8 to 6.3 and 7.0%. Reasonable good polarization and radiation patterns are also obtained for the antennas. Journal: Journal of Electromagnetic Waves and Applications Pages: 154-166 Issue: 2 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1096837 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1096837 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:2:p:154-166 Template-Type: ReDIF-Article 1.0 Author-Name: Peng-fei Sun Author-X-Name-First: Peng-fei Author-X-Name-Last: Sun Author-Name: Wei Shen Author-X-Name-First: Wei Author-X-Name-Last: Shen Author-Name: Liang Wu Author-X-Name-First: Liang Author-X-Name-Last: Wu Author-Name: Rong Qian Author-X-Name-First: Rong Author-X-Name-Last: Qian Author-Name: Xiao-wei Sun Author-X-Name-First: Xiao-wei Author-X-Name-Last: Sun Title: Compact substrate integrated waveguide transversal filter with mixed source–load coupling Abstract: This study proposes a compact implementation of substrate integrated waveguide (SIW) transversal filter with mixed source and load coupling. One dual-mode microstrip resonator, etched on the top metal layer of SIW cavity, is utilized to achieve transversal topology. Therefore, four transmission zeros can be obtained by introducing mixed sourced and load coupling, which is realized by inter-digital slot structure. A third-order SIW transversal filter sample is fabricated using printed circuit board technology, and its measured S-parameters have good agreements with the simulated ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 167-174 Issue: 2 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1096840 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1096840 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:2:p:167-174 Template-Type: ReDIF-Article 1.0 Author-Name: Chi-Jung Kuo Author-X-Name-First: Chi-Jung Author-X-Name-Last: Kuo Author-Name: Chong-Yi Liou Author-X-Name-First: Chong-Yi Author-X-Name-Last: Liou Author-Name: Jen-Chun Yeh Author-X-Name-First: Jen-Chun Author-X-Name-Last: Yeh Author-Name: Shau-Gang Mao Author-X-Name-First: Shau-Gang Author-X-Name-Last: Mao Title: A novel wideband circularly polarized dual-fed slot antenna with microstrip feeding network Abstract: This study presents the design of novel dual-fed circularly polarized (CP) antenna. This antenna consists of a tapered slot, a backside metal plate and a microstrip-fed delay line phase shifter. Based on the analysis of the radiation mechanism of antenna ground plane, the edge shape is optimized as a half-circle type to enhance the bandwidth of antenna gain and CP purity. The proposed antenna possesses a wideband return loss better than 10 dB in the range of 4.18–7.57 GHz, covering the bandwidth of axial ratio lower than 3 dB from 4.25 to 6.75 GHz. The measured antenna gain is approximately 9–10.5 dBic and the radiation patterns are broadside and consistent within the CP operating bandwidth. Journal: Journal of Electromagnetic Waves and Applications Pages: 175-187 Issue: 2 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1098574 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1098574 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:2:p:175-187 Template-Type: ReDIF-Article 1.0 Author-Name: HaiYan Tian Author-X-Name-First: HaiYan Author-X-Name-Last: Tian Author-Name: Jinchun Gao Author-X-Name-First: Jinchun Author-X-Name-Last: Gao Author-Name: Ming Su Author-X-Name-First: Ming Author-X-Name-Last: Su Author-Name: Yuanan Liu Author-X-Name-First: Yuanan Author-X-Name-Last: Liu Title: Super-miniaturized Wilkinson power divider using cross-connect meander microstrip lines and conductive vias Abstract: A novel three-dimensional (3-D) folded two-way microstrip lines (ML) is proposed for realizing the super-miniaturization of electron devices. The 3-D structure realized with two-way folded ML, which consists of several groups of cross-connected ML and conductive vias, has the potential to have an advanced performance than the corresponding conventional, meandering, and 3-D one-way ML. It can be arranged longer ML in limited spaces. Physical size reduction of the transmission line segments is from λ/4 to λ/32. The Wilkinson power divider (WPD) is designed to operate at the frequency of 433 MHz, has a return loss better than −29 dB, an insertion loss less than 0.28 dB, and isolation larger than +30 dB. The physical size has been reduced by 98.39% when compared with the conventional WPD. Design method about the folded two-way ML is presented for the first time. Journal: Journal of Electromagnetic Waves and Applications Pages: 188-194 Issue: 2 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1098575 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1098575 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:2:p:188-194 Template-Type: ReDIF-Article 1.0 Author-Name: H.-H. Chou Author-X-Name-First: H.-H. Author-X-Name-Last: Chou Author-Name: Y.-S. Lee Author-X-Name-First: Y.-S. Author-X-Name-Last: Lee Title: Experimental investigation and analysis of EMI in stacked I/O connectors of PCB Abstract: The electromagnetic interference (EMI) caused by the noise resulting from a common mode of stacked I/O connectors is analyzed using both numerical simulation and experimental measurements. The use of stacked connectors exists on the PCBs of today’s information technology equipment in order to reduce size; however, size reductions will cause increased severe EMI. After diagnosis and analysis, a strategy is presented to suppress the EMI noise level, as well as its emissions, and is found to be very effective as shown by our experiments. Journal: Journal of Electromagnetic Waves and Applications Pages: 195-206 Issue: 2 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1099477 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1099477 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:2:p:195-206 Template-Type: ReDIF-Article 1.0 Author-Name: Alfred Davletbaev Author-X-Name-First: Alfred Author-X-Name-Last: Davletbaev Author-Name: Liana Kovaleva Author-X-Name-First: Liana Author-X-Name-Last: Kovaleva Author-Name: Tayfun Babadagli Author-X-Name-First: Tayfun Author-X-Name-Last: Babadagli Title: Combining solvent injection, electromagnetic heating, and hydraulic fracturing for multistage heavy oil recovery Abstract: To model the combined multistage technologies of radio-frequency electromagnetic heating (RF-EM), solvent injection, and hydraulic fracturing, a mathematical model was developed. It was assumed that the well was previously hydraulically fractured and then the solvent was injected through it with simultaneous RF electromagnetic irradiation. The radiator of RF-EM waves was located at the bottom of the injection well. When the electromagnetic waves were irradiated into the reservoir, the temperature rises and the viscosity of the liquid decreases around the fractured well. While “cold” solvent was injected, it was heated at the bottom of the well so that the heat was transferred into the fracture and reservoir by convection. This leads to an increase of reservoir coverage by heating. The area of the thermal effect was determined by the length of fracture, duration of solvent injection, reduction in oil viscosity, increasing injectivity due to rising temperature, and solvent–heavy oil mixing around the bottomhole. Multistage process of reservoir stimulation was considered: (1) «Cold» production of heavy oil through the fractured well, (2) shut (shutdown) of the well without treatment, (3) solvent injection into the fractured production well with simultaneous RF-EM heating, (4) well was suspended to “soak” without any treatment, and (5) production of heavy oil with solvent without heating. The most efficient scenario was the combined RF-EM heating/fracturing multistage production technology. Recurring stages of solvent injection/RF-EM heating allowed maximum use of thermal energy and achieved the most efficient production growth. Journal: Journal of Electromagnetic Waves and Applications Pages: 207-224 Issue: 2 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1102093 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1102093 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:2:p:207-224 Template-Type: ReDIF-Article 1.0 Author-Name: Jonghun Jung Author-X-Name-First: Jonghun Author-X-Name-Last: Jung Author-Name: Geunyong Lee Author-X-Name-First: Geunyong Author-X-Name-Last: Lee Author-Name: Jong-In Song Author-X-Name-First: Jong-In Author-X-Name-Last: Song Title: A directional coupler with suppressed Tx leakage for UHF RFID reader applications Abstract: A directional coupler with a high isolation characteristic for radio frequency identification reader systems is presented. Compensation capacitors are used to improve the inherently poor isolation of a microstrip directional coupler due to unequal even- and odd-mode phase velocities. The transmitter leakage signal, which is reflected by the mismatch of the antenna impedance, is substantially reduced by optimization of the compensation capacitor values and the value of an additional resistor attached to the coupling port. The proposed directional coupler exhibits an isolation of 76.8 dB, a coupling factor of 16.6 dB, and an insertion loss of 0.28 dB for a matched antenna impedance at 910 MHz. It also has an isolation of more than 60 dB for mismatched antenna load impedances corresponding to a reflection coefficient of 0.33 at 910 MHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 225-231 Issue: 2 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1105154 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1105154 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:2:p:225-231 Template-Type: ReDIF-Article 1.0 Author-Name: O. Karabayir Author-X-Name-First: O. Author-X-Name-Last: Karabayir Author-Name: A.F. Coskun Author-X-Name-First: A.F. Author-X-Name-Last: Coskun Author-Name: O.M. Yucedag Author-X-Name-First: O.M. Author-X-Name-Last: Yucedag Author-Name: S. Makal Yucedag Author-X-Name-First: S. Author-X-Name-Last: Makal Yucedag Author-Name: H.A. Serim Author-X-Name-First: H.A. Author-X-Name-Last: Serim Author-Name: S. Kent Author-X-Name-First: S. Author-X-Name-Last: Kent Title: Investigation of wind farm effects on radar multiple target tracking Abstract: The increasing demand on wind farm (WF) installations has been raising the necessity and significance of performance assessment of electronic systems in the vicinity of WFs. Using a signal model for WF scattering, the interaction between the wind turbines (WTs) and pulse-Doppler radars (PDRs), the effects of WTs on the PDRs’ detection and tracking processes are investigated in this study. The extensive examination in this study provides insightful perspectives on the tracking performance of PDRs that are employing global nearest neighbor or probabilistic data association methods for the multiple target tracking operation under WF scatterings by exhibiting statistical metrics related to the track losses, false tracks depending on several system parameters, and WF configurations. Additionally, a novel WF design approach that is focused on minimizing WF effects on radar tracking performance is proposed in this study. The signal and tracking model employed in the examination provides a baseline for the analysis for WF-radar interactions, and the proposed WF design approach is promising to minimize the deteriorating effects of WFs on radar tracking performance. Journal: Journal of Electromagnetic Waves and Applications Pages: 232-250 Issue: 2 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1105155 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1105155 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:2:p:232-250 Template-Type: ReDIF-Article 1.0 Author-Name: Yalin Ma Author-X-Name-First: Yalin Author-X-Name-Last: Ma Author-Name: Wenjie Feng Author-X-Name-First: Wenjie Author-X-Name-Last: Feng Author-Name: Wenquan Che Author-X-Name-First: Wenquan Author-X-Name-Last: Che Author-Name: Jianxin Chen Author-X-Name-First: Jianxin Author-X-Name-Last: Chen Title: Low-loss tunable tri-pole band-pass filter using crossed resonator Abstract: A low-loss tunable tri-pole band-pass filter is presented in this study. To achieve tri-pole response, the tri-mode crossed resonator is adopted in the design. Resonant property is analyzed based on the transmission line theory. Analysis reveals that the first three resonant frequencies and two inherent transmission zeros (TZs) of the proposed resonator can be tuned by the suitable loading capacitances. To decrease the passband insertion loss, the varactor diodes and dc block capacitors are in series connected between the feeds and resonator. Furthermore, to achieve high skirt selectivity, source-load coupling is also introduced to create a TZ near the lower edge of the passband. A demonstration tunable tri-pole filter is designed, fabricated, and measured. The measured results show that the new filter has the wide passband frequency tuning range of 33.3%, low insertion loss of less than 1.6 dB, and high selectivity. Journal: Journal of Electromagnetic Waves and Applications Pages: 251-258 Issue: 2 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1105156 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1105156 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:2:p:251-258 Template-Type: ReDIF-Article 1.0 Author-Name: J.F. Gómez-Aguilar Author-X-Name-First: J.F. Author-X-Name-Last: Gómez-Aguilar Author-Name: H. Yépez-Martínez Author-X-Name-First: H. Author-X-Name-Last: Yépez-Martínez Author-Name: C. Calderón-Ramón Author-X-Name-First: C. Author-X-Name-Last: Calderón-Ramón Author-Name: M. Benavidez-Cruz Author-X-Name-First: M. Author-X-Name-Last: Benavidez-Cruz Author-Name: L.J. Morales-Mendoza Author-X-Name-First: L.J. Author-X-Name-Last: Morales-Mendoza Title: Fractional electromagnetic waves in conducting media Abstract: We present the fractional wave equation in a conducting material. We used a Maxwell’s equations with the assumptions that the charge density ρ$ \rho $ and current density J were zero, and that the permeability μ$ \mu $ and permittivity ϵ$ \epsilon $ were constants. The fractional wave equation will be examined separately; with fractional spatial derivative and fractional temporal derivative, finally, consider a Dirichlet conditions, the Fourier method was used to find the full solution of the fractional equation in analytic way. Two auxiliary parameters σx$ \sigma _x $ and σt$ \sigma _t $ are introduced; these parameters characterize consistently the existence of the fractional space-time derivatives into the fractional wave equation. A physical relation between these parameters is reported. The fractional derivative of Caputo type is considered and the corresponding solutions are given in terms of the Mittag-Leffler function show fractal space-time geometry different from the classical integer-order model. Journal: Journal of Electromagnetic Waves and Applications Pages: 259-271 Issue: 2 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1105761 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1105761 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:2:p:259-271 Template-Type: ReDIF-Article 1.0 Author-Name: Raúl Fernández-García Author-X-Name-First: Raúl Author-X-Name-Last: Fernández-García Author-Name: Ignacio Gil Author-X-Name-First: Ignacio Author-X-Name-Last: Gil Author-Name: Francesc Cano Author-X-Name-First: Francesc Author-X-Name-Last: Cano Title: Experimental evaluation of electrical properties of fabrics elaborated with conductive yarns Abstract: In this paper, the electrical characterization of two different fabric structures elaborated with conductive yarns and several pick densities are investigated in order to evaluate their electrical properties as conductive media of digital electrical signals. The real and imaginary impedance and the signal integrity have been measured for each e-textile. The results show that the impedance depends on the fabric structures and pick density. The eye diagram measurements experimentally demonstrate the functionality of these fabrics to transmit digital electric signals to communicate sensors with microcontrollers in wearable applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 272-279 Issue: 2 Volume: 30 Year: 2016 Month: 1 X-DOI: 10.1080/09205071.2015.1106987 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1106987 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:2:p:272-279 Template-Type: ReDIF-Article 1.0 Author-Name: R.A. Fenner Author-X-Name-First: R.A. Author-X-Name-Last: Fenner Author-Name: E.J. Rothwell Author-X-Name-First: E.J. Author-X-Name-Last: Rothwell Author-Name: L.L. Frasch Author-X-Name-First: L.L. Author-X-Name-Last: Frasch Title: The dual polarization method for characterization of dielectric materials Abstract: The nondestructive characterization of in situ conductor-backed media is an important task for many commercial and military applications. These and similar applications may require completely nondestructive and noncontact free space material characterization methods. Free space methods which fit these characteristics are at premium. One such of these methods is the dual polarization method. The dual polarization method utilizes the measurement of the reflection coefficient at both parallel and perpendicular polarization to determine the permittivity and permeability of an unknown material sample. This paper presents an overview of the dual polarization method to characterize conductor-backed media and two additional implementations of the method specific only to dielectric materials. These additional implementations include the characterization of conductor-backed dielectrics with either known or unknown sample thickness. All three implementations of the dual polarization method presented are demonstrated with measured reflection data from a conductor-backed Plexiglas sample and are shown with accompanying sensitivity analysis. Journal: Journal of Electromagnetic Waves and Applications Pages: 318-330 Issue: 3 Volume: 30 Year: 2016 Month: 2 X-DOI: 10.1080/09205071.2015.1109005 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1109005 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:3:p:318-330 Template-Type: ReDIF-Article 1.0 Author-Name: Anand Sharma Author-X-Name-First: Anand Author-X-Name-Last: Sharma Author-Name: Ravi Kumar Gangwar Author-X-Name-First: Ravi Kumar Author-X-Name-Last: Gangwar Title: Compact triband cylindrical dielectric resonator antenna with circular slots for wireless application Abstract: In this article, low-profile and compact cylindrical dielectric resonator antenna along with circular slots and filtering structure for wireless application is reported. Proposed antenna is excited by annular-shaped microstrip line. Two ring-shaped resonators placed on opposite sides of feed line are working as a band-pass filter. These resonators are unified with wideband cylindrical dielectric resonator antenna and make it suitable for triple band operations with better isolation level. Dual ring-shaped parasitic slots on a partial ground plane are used to make CDRA more compact. The proposed triple band antenna has been analyzed, studied and optimized using Ansoft HFSS simulation software. Prototype of proposed geometry has been fabricated and tested. There is a better accord between simulated and measured results. The proposed design engenders three frequency bands i.e. 2.35–2.55 GHz; 3.35–3.65 GHz; and 5.1–5.42 GHz with a resonant frequency of 2.45, 3.55, and 5.35 GHz, respectively. Proposed antenna design may find suitable applications for WLAN (2.4/5.2 GHz) and WiMAX (3.5 GHz) bands. The proposed design shows an average measured gain of 4.71 dB in the three desired bands. Journal: Journal of Electromagnetic Waves and Applications Pages: 331-340 Issue: 3 Volume: 30 Year: 2016 Month: 2 X-DOI: 10.1080/09205071.2015.1114430 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1114430 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:3:p:331-340 Template-Type: ReDIF-Article 1.0 Author-Name: Chang-Bin Ha Author-X-Name-First: Chang-Bin Author-X-Name-Last: Ha Author-Name: Seongjoo Lee Author-X-Name-First: Seongjoo Author-X-Name-Last: Lee Author-Name: Hyoung-Kyu Song Author-X-Name-First: Hyoung-Kyu Author-X-Name-Last: Song Title: Phase adjustment signaling based on packet structure for Wi-Fi backscatter system Abstract: This paper proposes the phase adjustment signaling based on packet structure for the Wi-Fi backscatter system. The Wi-Fi backscatter system has very low data rate due to the transmission method by unit of packet. In addition, because the Wi-Fi backscatter system uses simple energy detection method for identification of request information from the reader, the system has very low reliability. In order to solve these problems, the signaling that adjusts transmission power in according to transmitting information is proposed. For improvement of data rate of the system, the proposed signaling uses the transmission method by unit of OFDM symbol in Wi-Fi packet. Also, for improvement of reliability of the system, the proposed signaling uses the iterative transmission method in Wi-Fi packet. The simulations show that the proposed signaling improves performance of the Wi-Fi backscatter system. Also, because the proposed signaling can easily achieve diverse data rate or reliability in according to the parameters, it is useful to meet the demands of IoT application for specific data rate or reliability. Journal: Journal of Electromagnetic Waves and Applications Pages: 341-350 Issue: 3 Volume: 30 Year: 2016 Month: 2 X-DOI: 10.1080/09205071.2015.1114431 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1114431 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:3:p:341-350 Template-Type: ReDIF-Article 1.0 Author-Name: Abdurrahim Toktas Author-X-Name-First: Abdurrahim Author-X-Name-Last: Toktas Title: Log-periodic dipole array-based MIMO antenna for the mobile handsets Abstract: A novel design of multiple input–multiple output (MIMO) antenna based on the log-periodic dipole array (LPDA) for the mobile handsets is presented. The antenna operates in a wide frequency range of 1.86–3.84 GHz compatible with GSM, LTE, WLAN, and WiMAX. The MIMO design consists of two symmetrical and orthogonal radiating elements and a neutralization line (NL). The radiating element comprises a LPDA having a series of printed dipoles connected together with a microstrip line. Triangular and rectangular cuts on ground plane are carried out in accordance with the LPDAs so as to increase the impedance bandwidth and isolation. The antenna elements are linked with the NL to further enhance the isolation between the radiating elements. The performance of the MIMO antenna is analyzed in terms of S-parameters, radiation pattern, gain, total efficiency, envelope correlation coefficient, mean effective gain, multiplexing efficiency; and then it is verified through the measurements. The results demonstrate that the proposed MIMO antenna has good characteristics of wideband, gain, radiation pattern, isolation, and diversity. Journal: Journal of Electromagnetic Waves and Applications Pages: 351-365 Issue: 3 Volume: 30 Year: 2016 Month: 2 X-DOI: 10.1080/09205071.2015.1114432 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1114432 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:3:p:351-365 Template-Type: ReDIF-Article 1.0 Author-Name: M. Murugan Author-X-Name-First: M. Author-X-Name-Last: Murugan Author-Name: Malini S. Bapat Author-X-Name-First: Malini S. Author-X-Name-Last: Bapat Author-Name: V.K. Kokate Author-X-Name-First: V.K. Author-X-Name-Last: Kokate Title: Composites of nanosized strontium titanate epoxy resin as microwave absorber Abstract: Anechoic chambers are responsible for testing electromagnetic interference and make use of absorption materials that absorb RF radiation. In this paper, nanocrystalline strontium titanate (ST) (SrTiO3 or ST) powder was synthesized by hydrothermal method and the fibrillar composites of ST/epoxy resin were then fabricated into thin slabs of four different weight ratios. The composite materials were analyzed by XRD, SEM, and TEM. The reflectivity of the composite materials was measured by the transmission/reflection method using a vector network analyzer R&S: ZVA40, in the X and Ku bands (8–18 GHz) and the investigation of the microwave-absorbing properties of the composites reveal that ST with higher percolation threshold in ST/epoxy resin provides up to 48 dB absorption. Moreover, it also provides a wideband response of 7.1 GHz out of the total band of 10 GHz (i.e. 8.0–18.0 GHz) below −10 dB or less. Journal: Journal of Electromagnetic Waves and Applications Pages: 366-374 Issue: 3 Volume: 30 Year: 2016 Month: 2 X-DOI: 10.1080/09205071.2015.1114907 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1114907 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:3:p:366-374 Template-Type: ReDIF-Article 1.0 Author-Name: G. Tarabrin Author-X-Name-First: G. Author-X-Name-Last: Tarabrin Title: Radiated and reflected Doppler effects Abstract: Till now was known only one Doppler effect. In the article, we have named it classical. By the exact solution of correct mathematical problems with initial and boundary conditions which in mathematics are named as Cauchy’s problems adequate to physical processes which are described by Maxwell’s equations forming system of the partial differential equations of hyperbolic type of the problems of mathematical physics, existence of two Doppler effect was discovered. They differ from each other quantitatively and on physical sense. Classical Doppler effect, according to its physical sense, we have named radiated Doppler effect. Other effect, earlier completely unknown, according to physical sense, we have named reflected Doppler effect. The second new physical phenomenon derived as a result of research in this article, we have named deviation of radiated (classical) Doppler effect. The sense of opening is that the quantitative value of radiated Doppler effect measured by the receiver depends on an angle between the direction of a radiator movement and the direction from a radiator to the receiver. Existence of this effect is known to physics long ago. However, strictly reasonable mathematical model is offered for the first time. Journal: Journal of Electromagnetic Waves and Applications Pages: 375-389 Issue: 3 Volume: 30 Year: 2016 Month: 2 X-DOI: 10.1080/09205071.2015.1119069 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1119069 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:3:p:375-389 Template-Type: ReDIF-Article 1.0 Author-Name: Wei Shi Author-X-Name-First: Wei Author-X-Name-Last: Shi Author-Name: Zuping Qian Author-X-Name-First: Zuping Author-X-Name-Last: Qian Author-Name: Weiming Ni Author-X-Name-First: Weiming Author-X-Name-Last: Ni Title: A planar omnidirectional antenna with dual polarizations for base station applications Abstract: A new planar omnidirectional antenna with vertical polarization (VP) and horizontal polarization (HP) suitable for base stations is presented and discussed. The proposed antenna is a collinear printed structure, which is designed using the combination of folded microstrip patch array for VP and the modified slot array loaded by metal sheets for HP. This omnidirectional antenna has the advantages of simple structure, low profile, low cost and dual polarizations. An antenna prototype for demonstration is fabricated on a FR4 board with the size of 30 mm (width) × 350 mm (length) × 26 mm (height). The measured 10-dB impedance bandwidths for VP and HP are 445 MHz (2.4–2.845 GHz) and 230 MHz (2.51–2.74 GHz) respectively. The measured gain variation of less than 4 and 2.6 dB in the horizontal plane can be obtained for VP and HP at 2.5 GHz. The measured isolation between the two feeding ports for VP and HP is better than 40 dB over the whole bandwidth. Good agreement between the measured and simulated results can be observed. Journal: Journal of Electromagnetic Waves and Applications Pages: 390-403 Issue: 3 Volume: 30 Year: 2016 Month: 2 X-DOI: 10.1080/09205071.2015.1123654 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1123654 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:3:p:390-403 Template-Type: ReDIF-Article 1.0 Author-Name: Krzysztof A. Michalski Author-X-Name-First: Krzysztof A. Author-X-Name-Last: Michalski Author-Name: Juan R. Mosig Author-X-Name-First: Juan R. Author-X-Name-Last: Mosig Title: Efficient computation of Sommerfeld integral tails – methods and algorithms Abstract: A review is presented of the most effective methods for the computation of Sommerfeld integral tails. Such integrals, which are often oscillatory, singular and divergent, commonly arise in layered media Green functions. The mathematical foundations of various pertinent methods are discussed in detail and their performance is illustrated by relevant numerical examples. The associated algorithms are given in pseudocode for their easy computer implementation. Journal: Journal of Electromagnetic Waves and Applications Pages: 281-317 Issue: 3 Volume: 30 Year: 2016 Month: 2 X-DOI: 10.1080/09205071.2015.1129915 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1129915 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:3:p:281-317 Template-Type: ReDIF-Article 1.0 Author-Name: M. Salucci Author-X-Name-First: M. Author-X-Name-Last: Salucci Author-Name: L. Poli Author-X-Name-First: L. Author-X-Name-Last: Poli Author-Name: A.F. Morabito Author-X-Name-First: A.F. Author-X-Name-Last: Morabito Author-Name: P. Rocca Author-X-Name-First: P. Author-X-Name-Last: Rocca Title: Adaptive nulling through subarray switching in planar antenna arrays Abstract: The suppression of undesired signals impinging on a planar antenna array from unknown directions is addressed by adaptively connecting and disconnecting subarrays of elements from the beamforming network. The subarrays, periodically arranged on the array aperture, are equipped with radio-frequency switches that are controlled to maximize the ratio between the power of the desired signal, whose direction of arrival is supposed to be known, and the total power received by the antenna. A set of numerical results concerning different subarray layouts and interfering configurations is reported and discussed to show the effectiveness of the nulling method and the behavior of the considered array architectures. Journal: Journal of Electromagnetic Waves and Applications Pages: 404-414 Issue: 3 Volume: 30 Year: 2016 Month: 2 X-DOI: 10.1080/09205071.2015.1130662 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1130662 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:3:p:404-414 Template-Type: ReDIF-Article 1.0 Author-Name: P. López-Iturri Author-X-Name-First: P. Author-X-Name-Last: López-Iturri Author-Name: P. Rodríguez-Ulibarri Author-X-Name-First: P. Author-X-Name-Last: Rodríguez-Ulibarri Author-Name: E. Aguirre Author-X-Name-First: E. Author-X-Name-Last: Aguirre Author-Name: L. Azpilicueta Author-X-Name-First: L. Author-X-Name-Last: Azpilicueta Author-Name: M. Beruete Author-X-Name-First: M. Author-X-Name-Last: Beruete Author-Name: F. Falcone Author-X-Name-First: F. Author-X-Name-Last: Falcone Title: Hybrid equivalent source – 3D ray-launching simulation technique for deterministic estimation of radiated emissions of electrical appliances Abstract: In this work, a method for modeling the leaked radiofrequency radiation from electrical appliances is presented, with the aim of obtaining a model for a 3D ray-launching algorithm. The domestic microwave oven is the appliance under analysis, as it radiates a substantial amount of power and it is spread worldwide. The method uses numerical electromagnetic field simulations to obtain the exterior oven radiation. Due to the complexity of the metallic mesh of the oven door, a retrieval process has been implemented in order to accelerate the electromagnetic field simulation. This result is incorporated to a proprietary 3D ray-launching algorithm by obtaining equivalent radiation sources. Finally, the microwave oven leakage is obtained for the complete volume of an indoor scenario. The numerical results are then compared with experimental measurements, with good agreement. The proposed model is useful to predict accurately the leakage of the domestic microwave oven within a complete complex indoor scenario, aiding in further radioplanning considerations. Journal: Journal of Electromagnetic Waves and Applications Pages: 415-430 Issue: 4 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2015.1052571 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1052571 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:4:p:415-430 Template-Type: ReDIF-Article 1.0 Author-Name: Huang-Cheng Zhou Author-X-Name-First: Huang-Cheng Author-X-Name-Last: Zhou Author-Name: Yen-Sheng Chen Author-X-Name-First: Yen-Sheng Author-X-Name-Last: Chen Title: A quad-element LTE MIMO antenna on a finite ground plane for femtocell base stations Abstract: A quad-element multiple-input–multiple-output (MIMO) antenna for compact long term evolution (LTE) base stations is proposed. While most of the literature on LTE base station antennas concerns only the upper frequency bands (1710−2690 MHz), this work not only focuses on the wideband performance enhancement of LTE700/850/900 (698−960 MHz), but it also employs four-unit antenna elements, which are the maximum number to date for compact base stations aiming at LTE700/850/900. A pentagonal conductor wall is established on the ground plane; accordingly, not only does isolation improve, but the electromagnetic interference (EMI) between the antenna and other electronic components is reduced. Although the design space exhibits a highly truncated ground plane, we design a top-loading meandered monopole with dual sleeves attached to each side of the radiating body, optimizing the characteristics of impedance bandwidth and radiation efficiency concurrently. The experimental results show that the impedance characteristics, radiation performances, and signal correlation are highly desired for femtocell base stations. Journal: Journal of Electromagnetic Waves and Applications Pages: 431-443 Issue: 4 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2015.1117024 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1117024 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:4:p:431-443 Template-Type: ReDIF-Article 1.0 Author-Name: Rajib Ahmed Author-X-Name-First: Rajib Author-X-Name-Last: Ahmed Author-Name: Ahmmed A. Rifat Author-X-Name-First: Ahmmed A. Author-X-Name-Last: Rifat Author-Name: Ali K. Yetisen Author-X-Name-First: Ali K. Author-X-Name-Last: Yetisen Author-Name: Seok Hyun Yun Author-X-Name-First: Seok Hyun Author-X-Name-Last: Yun Author-Name: Safyan Khan Author-X-Name-First: Safyan Author-X-Name-Last: Khan Author-Name: Haider Butt Author-X-Name-First: Haider Author-X-Name-Last: Butt Title: Mode-multiplexed waveguide sensor Abstract: Optical sensors enable quantification of analyte concentrations non-invasively without being affected from electromagnetic fields. The development of single-mode waveguides (WGs) is simple approach; however, limitations in the spatial distribution of the refractive index and the inability to sense multiple samples at the same time. Here, we demonstrate a multi-mode WG model and matrix inversion method (MIM) to improve spatial information in at least one dimension. This method is used to optimize and estimate three external stimulus properties in TE00, TE01 and TM00 multiplexed modes for a semi-triangular ring resonator configuration. The multi-mode WG and MIM may have applications in the development of biosensors for multi-analyte detection. Journal: Journal of Electromagnetic Waves and Applications Pages: 444-455 Issue: 4 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2015.1117025 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1117025 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:4:p:444-455 Template-Type: ReDIF-Article 1.0 Author-Name: H. Gómez-Sousa Author-X-Name-First: H. Author-X-Name-Last: Gómez-Sousa Author-Name: Ó. Rubiños-López Author-X-Name-First: Ó. Author-X-Name-Last: Rubiños-López Author-Name: J.Á. Martínez-Lorenzo Author-X-Name-First: J.Á. Author-X-Name-Last: Martínez-Lorenzo Title: Comparison of iterative solvers for electromagnetic analysis of plasmonic nanostructures using multiple surface integral equation formulations Abstract: The electromagnetic behavior of plasmonic structures can be predicted after discretizing and solving a linear system of equations, derived from a continuous surface integral equation (SIE) and the appropriate boundary conditions, using a method of moments (MoM) methodology. In realistic large-scale optical problems, a direct inversion of the SIE–MoM matrix cannot be performed due to its large size, and an iterative solver must be used instead. This paper investigates the performance of four iterative solvers (GMRES, TFQMR, CGS, and BICGSTAB) for five different SIE–MoM formulations (PMCHWT, JMCFIE, CTF, CNF, and MNMF). Moreover, under this plasmonic context, a set of suggested guidelines are provided to choose a suitable SIE formulation and iterative solver depending on the desired simulation error and available runtime resources. Journal: Journal of Electromagnetic Waves and Applications Pages: 456-472 Issue: 4 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2015.1120165 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1120165 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:4:p:456-472 Template-Type: ReDIF-Article 1.0 Author-Name: L. Chen Author-X-Name-First: L. Author-X-Name-Last: Chen Author-Name: Z. Huang Author-X-Name-First: Z. Author-X-Name-Last: Huang Author-Name: K. Wang Author-X-Name-First: K. Author-X-Name-Last: Wang Author-Name: W. Li Author-X-Name-First: W. Author-X-Name-Last: Li Author-Name: S. Wang Author-X-Name-First: S. Author-X-Name-Last: Wang Title: Simulation and validation of radio frequency heating with conveyor movement Abstract: Computer simulation is widely used as a valuable tool to systematically study radio frequency (RF) heating with time-saving and effective cost. A computer simulation model using finite element-based commercial software, COMSOL, was developed to simulate temperature distributions in wheat samples packed in a rectangular plastic container and treated in a 6 kW, 27.12 MHz RF system under stationary and moving conditions. Both simulated and experimental results showed similar heating patterns in RF-treated wheat samples, in which corners and edges were more heated and the temperatures were higher in the lower sections of the container. The simulation results demonstrated that the RF heating uniformity could be improved by conveyor movement and selecting the top electrode area similar to the sample size. The validated model can be further applied to optimize parameters of conveyor movement and top electrode configuration to improve RF heating uniformity. Journal: Journal of Electromagnetic Waves and Applications Pages: 473-491 Issue: 4 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2015.1121841 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1121841 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:4:p:473-491 Template-Type: ReDIF-Article 1.0 Author-Name: F. Frezza Author-X-Name-First: F. Author-X-Name-Last: Frezza Author-Name: F. Mangini Author-X-Name-First: F. Author-X-Name-Last: Mangini Title: Electromagnetic scattering of an inhomogeneous elliptically polarized plane wave by a multilayered sphere Abstract: In this paper, a rigorous method in order to analyze the electromagnetic scattering by a multilayered sphere of an inhomogeneous elliptically polarized plane wave, is presented. One has to do with inhomogeneous plane waves when the scatterer is immersed in a medium generally dispersive and dissipative. The expression of the vectorial spherical harmonics expansion of an inhomogeneous elliptically polarized plane wave has been derived using the Legendre functions generalized via hypergeometric and gamma functions. The problem of the stratified sphere has been solved using the transfer-matrix approach, applied to each spherical surface, obtaining the coefficients of the scattered field and the internal field to the sphere system. In order to validate the presented method, a Matlab code and a numerical model based on the finite element method has been implemented. The comparison between the two methods is shown. Journal: Journal of Electromagnetic Waves and Applications Pages: 492-504 Issue: 4 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2015.1121842 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1121842 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:4:p:492-504 Template-Type: ReDIF-Article 1.0 Author-Name: Melek Usal Author-X-Name-First: Melek Author-X-Name-Last: Usal Author-Name: Mustafa Reşit Usal Author-X-Name-First: Mustafa Reşit Author-X-Name-Last: Usal Author-Name: Ergün Korkmaz Author-X-Name-First: Ergün Author-X-Name-Last: Korkmaz Title: Determination of constitutive equations dependent on temperature changes for dielectric materials having micro-voids Abstract: A damage constitutive model based on continuum damage mechanics (CDM) is proposed to investigate the electro-thermomechanical behavior of a thermoelastic dielectric structure in the present paper. The solid medium is assumed to be dielectric, incompressible, homogeneous, dependent on temperature gradient, having micro-voids, and showing linear elastic behavior. The matrix material made of elastic material involving an artificial anisotropy due to the existence of micro-voids has been assumed as an isotropic medium. Damage is incorporated by two symmetric, second-rank, tensor-valued, internal state variables which represent the total areas of “active” and “passive” voids contained within a representative volume element. Using fundamental concepts of continuum electrodynamics, CDMs and irreversible thermodynamics, the constitutive functionals have been obtained. It has been detected as a result of the thermodynamic constraints that stress potential function depends on two symmetric tensors and a vector, whereas the heat flux vector function depends on two symmetric tensors and two vectors. Since the matrix material has been assumed as an isotropic medium, the constitutive equations based on the constitutive functionals, which are stress potential and heat flux vector, have been obtained using the theory of invariants. Finally, the constitutive equations belonging to symmetric stress, polarization field, asymmetric stress, heat flux vector, and strain energy density release rate have been written in terms of material coordinate description. Journal: Journal of Electromagnetic Waves and Applications Pages: 505-522 Issue: 4 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2015.1125807 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1125807 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:4:p:505-522 Template-Type: ReDIF-Article 1.0 Author-Name: Kepeng Qiu Author-X-Name-First: Kepeng Author-X-Name-Last: Qiu Author-Name: Shuqi Feng Author-X-Name-First: Shuqi Author-X-Name-Last: Feng Title: A novel metamaterial absorber with perfect wave absorption obtained by layout design Abstract: In this work, a novel metamaterial absorber (MMA) with perfect wave absorption is designed through the layout optimization. The rotationally symmetrical design domain is determined by considering polarization insensitivity. The symmetrical design variables are related with each other. The optimization objective is to maximize the absorption index which is described by the reflection and transmission coefficients in the frequency range of 8–12 GHz with the constraint of volume fraction. The maximum absorptivity of the optimized MMA reaches 99.89%. And it has the polarization insensitivity, the wide range of oblique incident angles and the ideal impedance matching with the free space. Furthermore, the absorption frequencies exhibit regular variations while changing the sizes of unit cell and the thickness of dielectric substrate. Inspired by these analysis results and the existing researches, the multilayer MMA is designed in order to broaden the absorption band efficiently. The absorption frequency band reaches 1.1 GHz while the absorptivity is more than 85%. Journal: Journal of Electromagnetic Waves and Applications Pages: 523-535 Issue: 4 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2015.1134358 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1134358 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:4:p:523-535 Template-Type: ReDIF-Article 1.0 Author-Name: Zion Menachem Author-X-Name-First: Zion Author-X-Name-Last: Menachem Author-Name: Saad Tapuchi Author-X-Name-First: Saad Author-X-Name-Last: Tapuchi Title: Influence of rectangular and periodic rectangular profiles in the cross section of the straight waveguide on the output field Abstract: The first and the main objective of this research is to understand the influence of the rectangular and periodic rectangular profiles in the cross section along the straight waveguide on the output field. The second objective is to develop the technique to calculate the rectangular and periodic rectangular profiles in the cross section. The contribution of the technique and the particular application are important to improve the method that based on Laplace and Fourier transforms and the inverse Laplace and Fourier transforms also for the discontinuous rectangular and periodic rectangular profiles in the cross section (and not only for the continuous profiles). All the graphical results will be demonstrated as a response to a half-sine (TE10$ TE_{10} $) input-wave profile and the rectangular and periodic rectangular profiles in the cross section of the straight rectangular waveguide. The application is useful for straight waveguides in the microwave and the millimeter-wave regimes, with rectangular and periodic rectangular profiles in the cross section. Journal: Journal of Electromagnetic Waves and Applications Pages: 536-552 Issue: 4 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2015.1135761 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1135761 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:4:p:536-552 Template-Type: ReDIF-Article 1.0 Author-Name: The Editors Title: Corrigendum Journal: Journal of Electromagnetic Waves and Applications Pages: i-i Issue: 4 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2016.1138626 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1138626 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:4:p:i-i Template-Type: ReDIF-Article 1.0 Author-Name: Yulin Huang Author-X-Name-First: Yulin Author-X-Name-Last: Huang Author-Name: Xinyi Li Author-X-Name-First: Xinyi Author-X-Name-Last: Li Author-Name: Jingfu Bao Author-X-Name-First: Jingfu Author-X-Name-Last: Bao Author-Name: Di Deng Author-X-Name-First: Di Author-X-Name-Last: Deng Author-Name: Yiling Wang Author-X-Name-First: Yiling Author-X-Name-Last: Wang Author-Name: Yijia Du Author-X-Name-First: Yijia Author-X-Name-Last: Du Title: A 1.7–2.7-GHz 4-bit Phase shifter based on packaged RF MEMS switches Abstract: This study presents a 4-bit phase shifter with a maximum phase shift degree of 75° based on packaged metal-contact single-pole double-throw (SPDT) radio frequency microelectromechanical system (RF MEMS) switches mounted on a 20 mil RO4350 substrate and assembled with its driver module on a 4-layer printed circuit board (PCB) board. Electric length of 10° and characteristic impedance of 61.7 Ω are selected for T-stub matching. Standard PCB processing makes it easy to develop and suitable for taking place of mechanical tilt employed in recent base station. Measurements indicate a maximum insertion loss of 1.37 dB at 2.7 GHz and a minimum return loss of 11.71 dB. The phase accuracy is within 1.75° at 2.7 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 553-565 Issue: 5 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2015.1090347 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1090347 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:5:p:553-565 Template-Type: ReDIF-Article 1.0 Author-Name: Amit K. Varshney Author-X-Name-First: Amit K. Author-X-Name-Last: Varshney Author-Name: Raktim Guha Author-X-Name-First: Raktim Author-X-Name-Last: Guha Author-Name: Sanjay K. Ghosh Author-X-Name-First: Sanjay K. Author-X-Name-Last: Ghosh Author-Name: B. N. Basu Author-X-Name-First: B. N. Author-X-Name-Last: Basu Title: Gain-frequency response of a helix traveling-wave tube with T-shaped dielectric support rods in a metal envelope Abstract: The slow-wave structure parameters of a traveling-wave tube with T-shaped dielectric rods in a metal envelope were optimized for flat-to-negative dispersion characteristics obtained by the sheath-helix model of analysis. The analytical results were validated against those obtained by the tape-helix model of analysis and CST Microwave Studio. Such optimized structure parameters also gave wideband gain–frequency response of the device as predicted by Pierce’s small-signal theory. The electron beam voltage was also identified as an additional parameter for widening the device bandwidth. Journal: Journal of Electromagnetic Waves and Applications Pages: 566-578 Issue: 5 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2015.1132639 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1132639 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:5:p:566-578 Template-Type: ReDIF-Article 1.0 Author-Name: L. Pazin Author-X-Name-First: L. Author-X-Name-Last: Pazin Author-Name: Y. Leviatan Author-X-Name-First: Y. Author-X-Name-Last: Leviatan Title: On the matching characteristics of a rectangular slot located near the edge of a finite-size ground plane Abstract: We study the matching characteristics of a rectangular slot located in the farthest upper part of a ground plane. First, we investigate the effect of geometrical parameters including the length and width of the slot, the ground plane height, and feed point position on the input impedance. In turn, we consider the matching between the slot and a 50Ω$ 50~\Omega $ feed and examine impedance-matched frequencies and bandwidths. An approximate closed-form expression for the impedance-matched wavelength of the slot in terms of its length, width, and feed-point position is given. The results can aid in the design of application-specific slot antennas for handheld devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 579-588 Issue: 5 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2015.1133329 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1133329 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:5:p:579-588 Template-Type: ReDIF-Article 1.0 Author-Name: Sujitha Puthukodan Author-X-Name-First: Sujitha Author-X-Name-Last: Puthukodan Author-Name: Ehsan Dadrasnia Author-X-Name-First: Ehsan Author-X-Name-Last: Dadrasnia Author-Name: Vinod V. K. Thalakkatukalathil Author-X-Name-First: Vinod V. K. Author-X-Name-Last: Thalakkatukalathil Author-Name: Horacio Lamela Rivera Author-X-Name-First: Horacio Lamela Author-X-Name-Last: Rivera Author-Name: Guillaume Ducournau Author-X-Name-First: Guillaume Author-X-Name-Last: Ducournau Author-Name: Jean-Francois Lampin Author-X-Name-First: Jean-Francois Author-X-Name-Last: Lampin Title: Free space material characterization of carbon nanotube thin films at sub-terahertz frequencies Abstract: A free space, non-destructive, vectorial continuous wave terahertz analysis method is employed to study the material properties of single-walled and multi-walled carbon nanotube thin films deposited on substrates of fused quartz and silicon. The electrical and optical properties of the thin films have been investigated using a vector network analyzer, in the frequency range of 220–325 GHz (WR 3.4) and 325–500 GHz (WR 2.2). The Nicolson–Ross–Weir method is used to extract the material parameters. The refractive index, absorption coefficient, and the complex conductivity of the single-walled and multi-walled carbon nanotube thin films are extracted and studied. Journal: Journal of Electromagnetic Waves and Applications Pages: 589-598 Issue: 5 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2016.1138898 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1138898 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:5:p:589-598 Template-Type: ReDIF-Article 1.0 Author-Name: Zubaida Yusoff Author-X-Name-First: Zubaida Author-X-Name-Last: Yusoff Author-Name: Jonathan Lees Author-X-Name-First: Jonathan Author-X-Name-Last: Lees Author-Name: Muhammad Akmal Chaudhary Author-X-Name-First: Muhammad Akmal Author-X-Name-Last: Chaudhary Author-Name: Steve C. Cripps Author-X-Name-First: Steve C. Author-X-Name-Last: Cripps Title: Ferrite toroidal core with a trifilar wound RF broadband transformer design for tracking generators in wideband code division multiple access envelope tracking RFPA systems Abstract: In this paper, the design of an RF broadband transformer for wideband code division multiple access (WCDMA) tracking generators to be used in envelope tracking RF power amplifiers systems is presented. A ferrite toroidal core with a trifilar wound RF broadband transformer has been chosen to satisfy the (WCDMA) bandwidth requirement and also the power amplifier performance criteria that include the efficiency, electrical isolation, size and power consumption. The design components investigated comprises ferrite materials, number of turns on core windings and size. Journal: Journal of Electromagnetic Waves and Applications Pages: 599-611 Issue: 5 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2016.1138899 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1138899 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:5:p:599-611 Template-Type: ReDIF-Article 1.0 Author-Name: B. T. Venkatesh Murthy Author-X-Name-First: B. T. Author-X-Name-Last: Venkatesh Murthy Author-Name: I. Srinivasa Rao Author-X-Name-First: I. Author-X-Name-Last: Srinivasa Rao Title: Highly linear dual capacitive feedback LNA for L-band atmospheric radars Abstract: This paper presents the design of ultra-low noise amplifier (LNA) with dual capacitive shunt feedback in conjunction with source degenerated inductance methodology to simultaneously improve gain, noise figure (NF), and linearity. Addition of two feedback capacitors from drain to gate of the two transistors will relieve the trade-off between NF and linearity and the cascode design will increase the gain. To demonstrate this methodology, a single stage LNA is designed for UHF atmospheric radar application at 1.3 GHz and pHEMT technology is used for the design of LNA and fabricated on low-loss dielectric substrate. Measured results show that LNA has a gain of 24.1 dB and a very low NF of 0.38 dB. The input and output return losses are less than 11 dB and the third-order input intercept point is 48 dBm. Journal: Journal of Electromagnetic Waves and Applications Pages: 612-625 Issue: 5 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2016.1140087 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1140087 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:5:p:612-625 Template-Type: ReDIF-Article 1.0 Author-Name: Seyed Mostafa Mousavi Author-X-Name-First: Seyed Mostafa Author-X-Name-Last: Mousavi Author-Name: Seyed Abdullah Mirtaheri Author-X-Name-First: Seyed Abdullah Author-X-Name-Last: Mirtaheri Title: Design, implementation and test of a broadband isoflux beam reflectarray antenna for GEO satellites Abstract: The feasibility of deploying reflectarray antennas on synchronous satellites with the aim of achieving isoflux beam for optimum earth coverage is investigated. Due to the difference in free space loss from the satellite to different points on the earth, a conventional collimated beam pointing to the Earth centre is not efficient. So, there is a need for a radiation pattern whose gain increases at the line of sight angles to the horizon and diminishes towards the centre. Accordingly, a single-layer reflectarray antenna composed of loaded square patches is fabricated and tested. In this regard, the dimensions of reflectarray elements are adjusted using a robust optimization technique that minimizes the adverse effects of frequency dispersion in the intended frequency bandwidth. Experimental results demonstrate a stable radiation pattern with a relative bandwidth of about 11% at 14.25 GHz centre frequency. Journal: Journal of Electromagnetic Waves and Applications Pages: 626-636 Issue: 5 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2016.1141716 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1141716 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:5:p:626-636 Template-Type: ReDIF-Article 1.0 Author-Name: Soumen Banerjee Author-X-Name-First: Soumen Author-X-Name-Last: Banerjee Author-Name: Biswarup Rana Author-X-Name-First: Biswarup Author-X-Name-Last: Rana Author-Name: Susanta Kumar Parui Author-X-Name-First: Susanta Kumar Author-X-Name-Last: Parui Title: SIW based compact and dual-band equilateral triangular antennas Abstract: In this paper, a substrate integrated waveguide (SIW)-based equilateral compact and dual band triangular antennas have been proposed. A SIW-based coaxial fed equilateral triangular antenna has been initially considered. The antenna is found to resonate at 5.28 GHz corresponding to U-NII-2 WLAN band. Two sides of the said antenna are made perfect electrical conductor wall with array of metallic vias and the third side is kept open which acts like a perfect magnetic conductor (PMC) wall. A single slit has been introduced on the PMC wall of the initial antenna which causes a decrease in resonating frequency from 5.28 to 4.29 GHz. The antenna has been further miniaturized by introducing another parallel extra slit on the PMC wall which leads to a decrease in the resonating frequency to 3.3 GHz. The former antenna with single slit is found to exhibit 33% miniaturization while the latter with double slits reflects 56% miniaturization. By changing the coaxial feed location of the initial antenna at off-axis position, a dual band antenna has been realized. The dual band antenna is found to excite both TE101 and TE202 modes efficiently with corresponding resonating frequencies at 4.18 and 8.85 GHz. The prototypes have been fabricated on Arlon AD270 substrate and simulated results are compared with the measured ones. A good agreement has been observed between the simulated and measured results. Journal: Journal of Electromagnetic Waves and Applications Pages: 637-650 Issue: 5 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2016.1142395 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1142395 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:5:p:637-650 Template-Type: ReDIF-Article 1.0 Author-Name: Zijian Xing Author-X-Name-First: Zijian Author-X-Name-Last: Xing Author-Name: Ling Wang Author-X-Name-First: Ling Author-X-Name-Last: Wang Author-Name: Kun Wei Author-X-Name-First: Kun Author-X-Name-Last: Wei Author-Name: Rugui Yao Author-X-Name-First: Rugui Author-X-Name-Last: Yao Author-Name: Zhaolin Zhang Author-X-Name-First: Zhaolin Author-X-Name-Last: Zhang Author-Name: James Kweku Nkrumah Nyarko Author-X-Name-First: James Kweku Nkrumah Author-X-Name-Last: Nyarko Title: Study of novel antenna radome for circular polarizer and director Abstract: This study presents the use of contiguous rectangle-patches radome as a method of generating circularly polarized signals from linearly polarized antenna or antenna array that are covered by the structure. Experiment results of the novel structure with 2 × 2 antenna array are demonstrated for L-band operation. It is shown that left hand circular polarization of antenna array can be achieved with appropriate parameters design of radome. In addition, the structure is also built as a director that can greatly improve the gain of the antenna. Journal: Journal of Electromagnetic Waves and Applications Pages: 651-660 Issue: 5 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2016.1142909 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1142909 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:5:p:651-660 Template-Type: ReDIF-Article 1.0 Author-Name: Amany M. Saleh Author-X-Name-First: Amany M. Author-X-Name-Last: Saleh Author-Name: K.R. Mahmoud Author-X-Name-First: K.R. Author-X-Name-Last: Mahmoud Author-Name: Ibrahim I. Ibrahim Author-X-Name-First: Ibrahim I. Author-X-Name-Last: Ibrahim Author-Name: Ahmed M. Attiya Author-X-Name-First: Ahmed M. Author-X-Name-Last: Attiya Title: Analysis of anisotropic metasurfaces using generalized sheet transition condition Abstract: This paper presents an analysis of anisotropic metasurfaces using generalized sheet transition condition (GSTC). Unlike previously studied GSTC, the present analysis takes into consideration the coupling between transverse field components. Based on the shape of the metasurface element, coupling between transverse fields can be obtained. This coupling between transverse field components introduces polarization rotation in reflected and transmitted fields. This property can be used to control the wave polarization. Using anisotropic metasurfaces as superstrate for a printed antenna can control the resulting radiation pattern as well as the polarization of the radiated field. Journal: Journal of Electromagnetic Waves and Applications Pages: 661-676 Issue: 5 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2016.1143407 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1143407 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:5:p:661-676 Template-Type: ReDIF-Article 1.0 Author-Name: E. B. Manoukian Author-X-Name-First: E. B. Author-X-Name-Last: Manoukian Title: Electromagnetic propagation across a metal: the causal propagator Abstract: The very general expression of the Schwinger–Feynman causal propagator is explicitly derived for the transmission of a photon through a metal from air, as a generalization of our earlier work dealing with dielectrics. In a very general context, the corresponding transition amplitudes for crossing through the metal of a polarized or unpolarized photon are obtained. Inspired by Feynman’s intuitive and well-publicized non-technical treatment, we consider, from a quantum viewpoint, the fate of a red and a blue photon in determining their transmission probabilities, as an application, through a thin layer of silver whose complex dielectric function, in particular, has been experimentally carefully determined in recent years. Particular emphasis is also put in assessing the accuracy of the phenomenological expression of exponential damping used in considering transmissions through metals in comparison to the exact expressions obtained in the bulk of the paper. Journal: Journal of Electromagnetic Waves and Applications Pages: 677-688 Issue: 5 Volume: 30 Year: 2016 Month: 3 X-DOI: 10.1080/09205071.2016.1145075 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1145075 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:5:p:677-688 Template-Type: ReDIF-Article 1.0 Author-Name: H. Gómez-Sousa Author-X-Name-First: H. Author-X-Name-Last: Gómez-Sousa Author-Name: Ó. Rubiños-López Author-X-Name-First: Ó. Author-X-Name-Last: Rubiños-López Author-Name: J. Á. Martínez-Lorenzo Author-X-Name-First: J. Á. Author-X-Name-Last: Martínez-Lorenzo Author-Name: M. Arias-Acuña Author-X-Name-First: M. Author-X-Name-Last: Arias-Acuña Title: A computational method for modeling arbitrary junctions employing different surface integral equation formulations for three-dimensional scattering and radiation problems Abstract: This paper presents a new method, based on the well-known method of moments (MoM), for the numerical electromagnetic analysis of scattering and radiation from metallic or dielectric structures, or both structure types in the same simulation, that are in contact with other metallic or dielectric structures. The proposed method for solving the MoM junction problem consists of two separate algorithms, one of which comprises a generalization for bodies in contact of the surface integral equation (SIE) formulations. Unlike some other published SIE generalizations in the field of computational electromagnetics, this generalization does not require duplicating unknowns on the dielectric separation surfaces, except duplications for a very small fraction of unknowns corresponding to junction edges, which introduces a negligible computational cost. Additionally, this generalization is applicable to any ordinary single-scatterer SIE formulations employed as baseline. The other algorithm deals with enforcing boundary conditions and Kirchhoff’s Law, relating the surface current flow across a junction edge. Two important features inherent to this latter algorithm consist of a mathematically compact description in matrix form, and importantly, from a software engineering point of view, an easy implementation in existing MoM codes which makes the debugging process more comprehensible. A practical example involving a real grounded monopole antenna for airplane-satellite communication is analyzed for validation purposes by comparing with precise measurements covering different electrical sizes. Journal: Journal of Electromagnetic Waves and Applications Pages: 689-713 Issue: 6 Volume: 30 Year: 2016 Month: 4 X-DOI: 10.1080/09205071.2016.1140596 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1140596 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:6:p:689-713 Template-Type: ReDIF-Article 1.0 Author-Name: Jin Xu Author-X-Name-First: Jin Author-X-Name-Last: Xu Title: Compact tunable wideband bandpass filter using mixed coupling lumped dual-mode resonator Abstract: In this paper, a compact microstrip varactor-tuned wideband bandpass filter (BPF) is proposed by using mixed coupling lumped dual-mode resonator. The proposed tunable wideband BPF has a pair of transmission zeros around the passband, resulting in high passband selectivity. The measured results show that the passband can be tuned in a frequency range from 1.01 to 2.04 GHz with an almost 3 dB constant fractional bandwidth of 28 ± 1%. Within the tuning range, the insertion loss varies from 2.1 to 1.65 dB and the return loss is better than 10 dB. In addition, the tunability of 3 dB fractional bandwidth at 1.5 GHz is from 23 to 43%. Journal: Journal of Electromagnetic Waves and Applications Pages: 714-720 Issue: 6 Volume: 30 Year: 2016 Month: 4 X-DOI: 10.1080/09205071.2016.1145074 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1145074 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:6:p:714-720 Template-Type: ReDIF-Article 1.0 Author-Name: T. Gric Author-X-Name-First: T. Author-X-Name-Last: Gric Title: Spoof plasmons in corrugated transparent conducting oxides Abstract: Nowadays, there is a need to search for better materials aimed for plasmonic and metamaterial applications. Transparent conducting oxides (TCOs) are known as low-loss plasmonic materials in the near-infrared wavelength range. The further design of the lower loss materials would be available by fulfilling a more sophisticated theoretical study. In this work, we address the spoof plasmons on a periodically corrugated surface made of the TCOs. We assumed the Drude–Lorentz’s permittivity model of the semiconductor, which accurately describes the loss of these spoof surface plasmon polaritons (SPPs). In the THz frequency range, the properties of the dispersion and loss of spoof SPPs on corrugated ZnO and indium tin oxide surfaces are studied. A low-loss propagation of spoof SPPs can be achieved by an optimum design of the surface structure. Moreover, it was found that the low guiding attenuation can be achieved by employing the TCOs. Journal: Journal of Electromagnetic Waves and Applications Pages: 721-727 Issue: 6 Volume: 30 Year: 2016 Month: 4 X-DOI: 10.1080/09205071.2016.1145076 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1145076 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:6:p:721-727 Template-Type: ReDIF-Article 1.0 Author-Name: Doojung Kim Author-X-Name-First: Doojung Author-X-Name-Last: Kim Author-Name: Byung-Wook Min Author-X-Name-First: Byung-Wook Author-X-Name-Last: Min Title: High Power Ku-Band T/R and SP4T Switches in SOI CMOS Abstract: This paper presents silicon-on-insulation (SOI) CMOS T/R and SP4T switches with high-power handling capability. The CMOS transistors are stacked and their sources and drains are biased for the high-power handling capability. The TQ trench of 0.18-μ$ \upmu $m SOI CMOS process is properly placed to improve the substrate isolation between transistors. For the T/R switch, the measured insertion loss of Tx and Rx modes are <$ < $1.1 and <$ < $1.7 dB, respectively, in Ku-band (12–18 GHz). The measured isolation between Tx and Rx ports is >$ > $24 dB in the same frequency band. To author’s knowledge, this T/R switch shows the highest input 1-dB compression point of 34 dBm in Ku-band CMOS switches. The SP4T switch operates in DC-18 GHz, and the measured insertion loss and isolation are <$ < $2.4 and >$ > $19.5 dB, respectively, with the return loss of <-$ <\!\!- $9.3 dB. This chip sizes are 0.11 mm2$ ^2 $ for the T/R switch and 0.12 mm2$ ^2 $ for the SP4T switch. Journal: Journal of Electromagnetic Waves and Applications Pages: 728-739 Issue: 6 Volume: 30 Year: 2016 Month: 4 X-DOI: 10.1080/09205071.2016.1145077 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1145077 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:6:p:728-739 Template-Type: ReDIF-Article 1.0 Author-Name: L. Kavitha Author-X-Name-First: L. Author-X-Name-Last: Kavitha Author-Name: E. Parasuraman Author-X-Name-First: E. Author-X-Name-Last: Parasuraman Author-Name: D. Gopi Author-X-Name-First: D. Author-X-Name-Last: Gopi Author-Name: S. Bhuvaneswari Author-X-Name-First: S. Author-X-Name-Last: Bhuvaneswari Title: Propagation of electromagnetic solitons in an antiferromagnetic spinladder medium Abstract: The interplay of bilinear ferromagnetic coupling with antiferromagnetic rung and diagonal coupling along with the magnetic field component of the electromagnetic wave (EMW) has been studied by solving the Maxwell’s equation together with the two coupled Landau–Lifshitz nonlinear spin equations for the magnetization of the medium. The magnetization dynamics of the spin ladder under the influence of EMW is governed by a two coupled generalized derivative non-linear Schrödinger (CGDNLS) equations. We invoke the Jacobi elliptic function method to solve the CGDNLS equations and the EMW propagation assumes the forms of kink, antikink, soliton, and breather excitations. We perform numerical analysis on the static spin configurations and explored the typical chaotic spatial structures. Journal: Journal of Electromagnetic Waves and Applications Pages: 740-766 Issue: 6 Volume: 30 Year: 2016 Month: 4 X-DOI: 10.1080/09205071.2015.1137500 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1137500 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:6:p:740-766 Template-Type: ReDIF-Article 1.0 Author-Name: Stanislav Ogurtsov Author-X-Name-First: Stanislav Author-X-Name-Last: Ogurtsov Author-Name: Slawomir Koziel Author-X-Name-First: Slawomir Author-X-Name-Last: Koziel Title: Enhancement of circular polarization quality of single-patch two-input microstrip antennas Abstract: A novel approach to improving a circular polarization (CP) quality of single-patch microstrip antennas excited with dual-point feeds is presented. It is applicable to microstrip antennas with square as well as circular patches which are excited though two feeding inputs which have a 90° angular separation. An analytical model is formulated using a concept of superposition of far fields. This model provides novel closed-form formulas to calculate proper amplitude and phase excitation, which should be applied to the antenna inputs at the operating frequency, resulting in the enhanced axial ratio. The model processes the simulated far field of the antenna with only one input active at a time. The computed complex excitation makes the axial ratio exactly equal to one in the broadside direction at the operating frequency. Two numerical examples demonstrate this approach for microstrip patch antennas excited with through-substrate probes of coaxial connectors. It is also demonstrated through the examples that a certain excitation, referred to as the “amplitude only” excitation, may be sufficient – from practical point of view – to ensure high-quality CP for a particular patch antenna. Journal: Journal of Electromagnetic Waves and Applications Pages: 767-779 Issue: 6 Volume: 30 Year: 2016 Month: 4 X-DOI: 10.1080/09205071.2016.1147383 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1147383 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:6:p:767-779 Template-Type: ReDIF-Article 1.0 Author-Name: Wei-Jun Chen Author-X-Name-First: Wei-Jun Author-X-Name-Last: Chen Author-Name: Wei Shao Author-X-Name-First: Wei Author-X-Name-Last: Shao Author-Name: Jun Quan Author-X-Name-First: Jun Author-X-Name-Last: Quan Author-Name: Shi-Yu Long Author-X-Name-First: Shi-Yu Author-X-Name-Last: Long Title: Modeling of wave propagation in thin graphene sheets with WLP-FDTD method Abstract: In this paper, an efficient finite-difference time-domain (FDTD) method with weighted Laguerre polynomials is proposed to model electromagnetic wave propagation in thin graphene sheets accurately. The proposed method incorporates the intraband terms of the surface conductivity of graphene and introduces an auxiliary differential equation technique to establish the relationship between the electric field intensity and conduct electric current in graphene. Two numerical examples with wave propagation in thin graphene sheet are calculated. Compared with the FDTD method, the results from the proposed method show its accuracy and efficiency. Journal: Journal of Electromagnetic Waves and Applications Pages: 780-787 Issue: 6 Volume: 30 Year: 2016 Month: 4 X-DOI: 10.1080/09205071.2016.1150210 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1150210 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:6:p:780-787 Template-Type: ReDIF-Article 1.0 Author-Name: Houria Triki Author-X-Name-First: Houria Author-X-Name-Last: Triki Author-Name: Abdul-Majid Wazwaz Author-X-Name-First: Abdul-Majid Author-X-Name-Last: Wazwaz Title: New solitons and periodic wave solutions for the (2+1)-dimensional Heisenberg ferromagnetic spin chain equation Abstract: We consider a nonlinear Schrödinger type equation in (2+1) dimensions. The proposed equation describes the nonlinear spin dynamics of (2+1)-dimensional Heisenberg ferromagnetic spin chains with bilinear and anisotropic interactions in the semiclassical limit. We first construct three families of exact periodic solutions expressed in terms of Jacobi’s elliptic functions cn,  sn and dn. We second consider the limit where the elliptic modulus approaches 1 to obtain bright and dark soliton solutions. Furthermore, we find a new type of soliton-like solution, illustrating the potentially rich set of wave solutions of the (2+1)-dimensional Heisenberg ferromagnetic spin chain equation. Parametric conditions for the existence and uniqueness of exact solutions are presented. The derived structures of the obtained solutions offer a rich platform to study the nonlinear spin dynamics in magnetic materials. Journal: Journal of Electromagnetic Waves and Applications Pages: 788-794 Issue: 6 Volume: 30 Year: 2016 Month: 4 X-DOI: 10.1080/09205071.2016.1153986 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1153986 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:6:p:788-794 Template-Type: ReDIF-Article 1.0 Author-Name: Pengcheng Zhao Author-X-Name-First: Pengcheng Author-X-Name-Last: Zhao Author-Name: Lixin Guo Author-X-Name-First: Lixin Author-X-Name-Last: Guo Title: Effect of air breakdown in near-field region on maximum power radiated from aperture antenna Abstract: The high-power microwave easily causes the air breakdown in the near-field region of an antenna that is one of major factors to limit the enhancement of the radiation power at present. We study the maximum radiation power of a circular aperture antenna at which the maximum electric field in the near-field region equals the breakdown electric field in air, by using the field equivalent principle along with the global model. Results show that, with the pulse width increasing, the maximum radiation power decreases. The larger the antenna radius, the higher power can be radiated. The field distribution on the aperture has an obvious impact on the maximum radiation power. Journal: Journal of Electromagnetic Waves and Applications Pages: 795-804 Issue: 6 Volume: 30 Year: 2016 Month: 4 X-DOI: 10.1080/09205071.2016.1154484 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1154484 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:6:p:795-804 Template-Type: ReDIF-Article 1.0 Author-Name: Pitchanun Wongsiritorn Author-X-Name-First: Pitchanun Author-X-Name-Last: Wongsiritorn Author-Name: Chuwong Phongcharoenpanich Author-X-Name-First: Chuwong Author-X-Name-Last: Phongcharoenpanich Author-Name: Tajchai Pumpoung Author-X-Name-First: Tajchai Author-X-Name-Last: Pumpoung Author-Name: Kittisak Phaebua Author-X-Name-First: Kittisak Author-X-Name-Last: Phaebua Author-Name: Titipong Lertwiriyaprapa Author-X-Name-First: Titipong Author-X-Name-Last: Lertwiriyaprapa Title: Modified UTD-based UHF RFID tag antenna with two-pronged fork slot for coated metallic cylindrical surface Abstract: This research has proposed a modified uniform geometrical theory of diffraction (UTD) for radiation to investigate the radiation pattern on the coated metallic curved surface. The modified UTD, which accounts for the existence of the impedance surface (coating), is applied to the development of a compact UHF RFID passive tag antenna with a two-pronged fork slot to be mounted on the coated metallic cylindrical drum. In the calculation, the UHF RFID tag was initially represented by electric tangential (Ez-source) and equivalent magnetic tangential to the surface (Mz-source). The results indicated that the Mz-source could achieve a greater communication area, and thus the design of the tag antenna is of equivalent magnetic source. Simulations were then carried out to determine the optimal antenna parameters, and an antenna prototype was fabricated and tested. The simulation and measured results are in agreement. The research findings validate the effectiveness of the modified UTD-based UHF RFID tag for application on the coated metallic curved surface. Journal: Journal of Electromagnetic Waves and Applications Pages: 805-823 Issue: 6 Volume: 30 Year: 2016 Month: 4 X-DOI: 10.1080/09205071.2016.1172518 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1172518 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:6:p:805-823 Template-Type: ReDIF-Article 1.0 Author-Name: Xiang Li Author-X-Name-First: Xiang Author-X-Name-Last: Li Author-Name: Zhenhai Shao Author-X-Name-First: Zhenhai Author-X-Name-Last: Shao Author-Name: Mengkui Shen Author-X-Name-First: Mengkui Author-X-Name-Last: Shen Author-Name: Zhaosheng He Author-X-Name-First: Zhaosheng Author-X-Name-Last: He Title: High selectivity tunable filtering power divider based on liquid crystal technology for microwave applications Abstract: A novel electrically tunable filtering power divider, based on liquid crystal (LC) technology, is designed and experimentally demonstrated in this paper. Using low-cost T-shaped inverted-microstrip structures integrated with two dual-mode open-loop resonators, the tunable power divider possesses bandpass-filtering frequency response. Moreover, transitions between inverted-microstrip and microstrip structures are specifically designed at the I/O ports for the self-packaged. The experimental results indicate that the central frequency can be tuned from 5.75 to 6.25 GHz, i.e. a relative tuning range of 8.3%, the 3-dB bandwidth is 6.8 ± 0.2% over the whole tuning range, and the maximum amplitude and phase imbalance are less than 0.8 dB and 2.5°, respectively. In addition, the proposed filtering power divider has three transmission zeros to improve the frequency selectivity. Journal: Journal of Electromagnetic Waves and Applications Pages: 825-833 Issue: 7 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1155500 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1155500 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:7:p:825-833 Template-Type: ReDIF-Article 1.0 Author-Name: Behbod Ghalamkari Author-X-Name-First: Behbod Author-X-Name-Last: Ghalamkari Author-Name: Ahad Tavakoli Author-X-Name-First: Ahad Author-X-Name-Last: Tavakoli Title: A fast solution of TE wave scattering by a 2D partially dielectric filled and coated rectangular crack Abstract: A two-dimensional transverse-electric Electromagnetic (EM) plane-wave scattering by a partially filled rectangular crack in a ground plane that is coated by a dielectric layer is presented here by Kobayashi Potential (KP) method. First, the EM field inside the coating layer is expanded by a summation of waveguide modal eigenfunctions. Consequently, the crack contribution in terms of the Bessel eigenfunctions is added as a perturbation to the coating layer and the semi-infinite half-space fields. Then, using the Weber–Schafheitlin discontinuous integrals and applying the KP method, the governing equations of infinite summations with unknown coefficients are derived. Next, by imposing the boundary conditions, the unknown coefficients are determined. Besides validating the method with the finite element method, an extensive comparative analysis with other methods is also provided. Finally, the effect of a progressively filling of the coated crack on the far-field scattering is investigated. Both lossy and lossless permittivities and permeabilities are considered for the coating and the filling. The method is extremely accurate and computationally efficient, and could be applied to both narrow and wide cracks. Journal: Journal of Electromagnetic Waves and Applications Pages: 834-848 Issue: 7 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1157047 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1157047 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:7:p:834-848 Template-Type: ReDIF-Article 1.0 Author-Name: Jiangang Liu Author-X-Name-First: Jiangang Author-X-Name-Last: Liu Author-Name: Yong Jia Author-X-Name-First: Yong Author-X-Name-Last: Jia Author-Name: Lingjiang Kong Author-X-Name-First: Lingjiang Author-X-Name-Last: Kong Author-Name: Xiaobo Yang Author-X-Name-First: Xiaobo Author-X-Name-Last: Yang Author-Name: Qing Huo Liu Author-X-Name-First: Qing Huo Author-X-Name-Last: Liu Title: MIMO through-wall radar 3-D imaging of a human body in different postures Abstract: This paper focuses on three-dimensional (3-D) imaging for the human body with different postures to enhance the situation awareness ability of through-wall radar. First, we design a two-dimensional MIMO array where the receiving antennas are uniformly and sparsely arranged in horizontal and vertical directions and four time-division multiplexing transmitting elements are placed at the four array corners. As a result, the equivalent aperture is closed to four times the size of the physical array. Second, an identical time-delay wall compensation algorithm attached to back-projection algorithm is presented to easily and approximately correct the image distortion caused by wall penetration, which employs an identical time-delay offset in the whole 3-D pixel-to-pixel imaging process to partially balance out multiple different focusing time-delay errors corresponding to multiple transmit-receive channels in each pixel. Finally, we develop a human body model with three typical postures in the FDTD simulation. Based on the MIMO array and the time-delay compensation algorithm, the simulated images created via the back-projection algorithm clearly provide the identifiable posture characteristics. Journal: Journal of Electromagnetic Waves and Applications Pages: 849-859 Issue: 7 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1159996 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1159996 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:7:p:849-859 Template-Type: ReDIF-Article 1.0 Author-Name: Chaoying Zhao Author-X-Name-First: Chaoying Author-X-Name-Last: Zhao Author-Name: Wenjie Feng Author-X-Name-First: Wenjie Author-X-Name-Last: Feng Author-Name: Wenquan Che Author-X-Name-First: Wenquan Author-X-Name-Last: Che Title: High selectivity wideband filtering crossovers using stub-loaded ring resonators Abstract: Two high selectivity wideband filtering crossovers using stub-loaded ring resonators are proposed in this paper. Cascaded coupled lines and open stubs are used to generate two/four transmission zeros each near the crossover passbands. In addition, patterned grounded conductor in the ground plane can enlarge the coupling coefficient for the coupled lines with increasing the even-mode characteristic impedance, and the isolated conductor placed inside the slot can decrease the odd-mode characteristic impedance. Two filtering crossovers operated at 2.2 GHz with bandwidths of 27.5% from 1.945 to 2.55 GHz are designed and fabricated. They show good return loss more than 20 dB and nice insertion loss less than 1.7 dB in passband. Journal: Journal of Electromagnetic Waves and Applications Pages: 860-870 Issue: 7 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1159997 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1159997 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:7:p:860-870 Template-Type: ReDIF-Article 1.0 Author-Name: Bulent Kilic Author-X-Name-First: Bulent Author-X-Name-Last: Kilic Author-Name: Mustafa Inc Author-X-Name-First: Mustafa Author-X-Name-Last: Inc Title: Soliton solutions for the Kundu–Eckhaus equation with the aid of unified algebraic and auxiliary equation expansion methods Abstract: The modified unified algebraic (MUA) and auxiliary equation expansion (AEE) methods are applied to reach the different type soliton solutions of Kundu–Eckhaus (K–E) equation. It is illustrated that MUA and AEE are very effective methods to reach the various types of the solutions of nonlinear evolution equations. Journal: Journal of Electromagnetic Waves and Applications Pages: 871-879 Issue: 7 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1161563 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1161563 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:7:p:871-879 Template-Type: ReDIF-Article 1.0 Author-Name: Shuai Ding Author-X-Name-First: Shuai Author-X-Name-Last: Ding Author-Name: Rui Zang Author-X-Name-First: Rui Author-X-Name-Last: Zang Author-Name: Hong-Cheng Zhou Author-X-Name-First: Hong-Cheng Author-X-Name-Last: Zhou Author-Name: Bing-Zhong Wang Author-X-Name-First: Bing-Zhong Author-X-Name-Last: Wang Title: Impact of magnetic field distribution on performance of 18-vane 5.8 GHz magnetron Abstract: Impact of magnetic field distribution on the performance of an 18-vane 5.8 GHz magnetron is studied in this paper. The magnetic field distribution of the magnetron is calculated for the ideal and the real cases. Different from the ideal case, the real magnetic field is non-uniformly distributed in the interaction space. Based on the calculation results, the impacts of the non-uniform magnetic field distribution on the output power, oscillation time, and efficiency of the magnetron are studied by cavity hot-test simulation. The obtained simulation results are verified by experiment. The study provides reference basis for further improving the performance of the magnetron. Journal: Journal of Electromagnetic Waves and Applications Pages: 880-888 Issue: 7 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1164089 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1164089 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:7:p:880-888 Template-Type: ReDIF-Article 1.0 Author-Name: Huy Hung Tran Author-X-Name-First: Huy Hung Author-X-Name-Last: Tran Author-Name: Ikmo Park Author-X-Name-First: Ikmo Author-X-Name-Last: Park Title: Wideband circularly polarized low-profile antenna using artificial magnetic conductor Abstract: A wideband circularly polarized (CP) antenna with an artificial magnetic conductor (AMC) reflector is presented. Its primary radiation elements are composed of two bowtie dipoles which are arranged orthogonally through double-printed rings to allow easy impedance matching and produce good CP radiation. Planar periodic square metallic plates, which behave as AMC surfaces when placed on a grounded dielectric substrate, are appropriately incorporated with crossed bowtie dipoles to achieve the desired unidirectional radiation, low profile, as well as wideband features. The final design with an overall size of 0.75λo × 0.75λo × 0.11λo (λo is the free space wavelength at 5 GHz) resulted in a measured –10 dB |S11| bandwidth of 54.2% (4.3–7.5 GHz) and a 3-dB axial ratio bandwidth of 33.3% (5–7 GHz). The antenna yields right-hand circular polarization and broadside gain of approximately 7.9 dBic across the CP operating bandwidth. Journal: Journal of Electromagnetic Waves and Applications Pages: 889-897 Issue: 7 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1164629 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1164629 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:7:p:889-897 Template-Type: ReDIF-Article 1.0 Author-Name: Kutlu Karayahşi Author-X-Name-First: Kutlu Author-X-Name-Last: Karayahşi Author-Name: Ismail H. Tayyar Author-X-Name-First: Ismail H. Author-X-Name-Last: Tayyar Author-Name: Arif Dolma Author-X-Name-First: Arif Author-X-Name-Last: Dolma Title: Radiation from a coaxial waveguide formed by a semi-infinite cylindrical outer conductor and an infinite two-part impedance inner cylinder Abstract: In the present work, the scattering of a wave radiating inside a waveguide consisting of two coaxial cylinders the inner of which is infinite and has piecewise surface impedance, while the outer cylinder is infinitely thin, semi-infinite and perfect electrical conductor is analyzed using Wiener–Hopf technique. The problem is defined as a Wiener–Hopf equation by applying Fourier transformation to the scattered field and the boundary conditions. The scattered field inside the waveguide is expanded to series in terms of waveguide modes and the solution is obtained using the continuity conditions for the electromagnetic fields and transforming the problem into three sets of infinite algebraic equations containing three sets of infinite constants. In the numerical results section, the effects of the geometrical parameters and the impedances of the waveguide to the radiated field and the reflection coefficient is observed. Obtained results are compared to a previously solved problem. Journal: Journal of Electromagnetic Waves and Applications Pages: 898-914 Issue: 7 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1164630 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1164630 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:7:p:898-914 Template-Type: ReDIF-Article 1.0 Author-Name: Bilal Babayigit Author-X-Name-First: Bilal Author-X-Name-Last: Babayigit Author-Name: Ercan Senyigit Author-X-Name-First: Ercan Author-X-Name-Last: Senyigit Author-Name: Gokhan Mumcu Author-X-Name-First: Gokhan Author-X-Name-Last: Mumcu Title: Optimum broadband E-patch antenna design with Taguchi method Abstract: This paper describes the design of a broadband E-patch antenna using Taguchi method. Although this optimization method exhibits a fast convergence speed, its application to the antenna design has so far been very limited as compared to the particle swarm optimization and differential evolution. Different than the prior work on optimization-based design of E-patch antennas, the presented design is carried out by satisfying multiple objectives: the minimum antenna footprint area and |S11| < −10 dB bandwidth across 5–6 GHz band. The performance of this E-patch antenna design is compared with that of an E-patch antenna designed with the differential evolution algorithm to meet the same |S11| < −10 dB bandwidth criteria. It is shown that a two-level Taguchi method applied to E-patch design problem with 6 degrees of freedom can complete the design with 8 full-wave simulations as compared to the entire 26 = 64 possibilities. This is also considerably faster than the differential evolution algorithm that may require >300 full-wave simulations. In addition, it is shown that the presented design can meet the bandwidth criteria with a smaller footprint, hence demonstrates that minimization of the footprint must also be a part of the design process to achieve the best antenna solution. Furthermore, the E-patch antenna is fabricated and measured to confirm the validity of the proposed design. Journal: Journal of Electromagnetic Waves and Applications Pages: 915-927 Issue: 7 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1164631 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1164631 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:7:p:915-927 Template-Type: ReDIF-Article 1.0 Author-Name: Muhammad Ateeq Author-X-Name-First: Muhammad Author-X-Name-Last: Ateeq Author-Name: Andy Shaw Author-X-Name-First: Andy Author-X-Name-Last: Shaw Author-Name: Rob Garrett Author-X-Name-First: Rob Author-X-Name-Last: Garrett Author-Name: Paul Dickson Author-X-Name-First: Paul Author-X-Name-Last: Dickson Title: Feasibility study on using microwave sensing technique to analyse silver-based products Abstract: This paper reports on the feasibility of using a novel and robust microwave sensing technology to detect and analyse various silver-based products such as silver nitrate and silver oxide. The focus of the investigation is to differentiate between the two products, identify the contamination and change in the sample size. A microwave sensor designed previously in house has been utilised to carry out this initial study to analyse the capability of microwave sensing technique to carry out the analysis. The change in the microwave spectra are used as an indicator of the difference in the silver products and any contamination they may have. The results and their detailed repeatability confirm the viability of using microwave sensing technique as a potential method to analyse various silver products. The curves obtained from the material response to microwaves are distinguishable and can be related to the materials’ properties. The study suggests a design and development of a bespoke unit as a dedicated analysis tool and to address any anomalies arising from the current feasibility. This will have a huge industrial benefit in terms of cost reduction and time associated with the industrial analysis. Journal: Journal of Electromagnetic Waves and Applications Pages: 928-944 Issue: 7 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1172516 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1172516 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:7:p:928-944 Template-Type: ReDIF-Article 1.0 Author-Name: Shobhit K. Patel Author-X-Name-First: Shobhit K. Author-X-Name-Last: Patel Author-Name: Christos Argyropoulos Author-X-Name-First: Christos Author-X-Name-Last: Argyropoulos Title: Enhanced bandwidth and gain of compact microstrip antennas loaded with multiple corrugated split ring resonators Abstract: We present microstrip-based radiating structures loaded with multiple corrugated and non-corrugated split-ring resonator (SRR) metamaterials. We analyze how the change in gap spacing between multiple corrugated and non-corrugated SRRs can improve the bandwidth and gain performance compared to conventional SRR antenna designs. Regarding the corrugated designs, square teeth have been added to the outer edges of SRR rings. The microstrip antenna performance loaded with eight different SRR loads is analyzed. By changing the gap between the multiple SRR rings, the radiating response of the proposed antenna designs can be improved. Corrugated SRRs are also found to strongly improve the performance of conventional non-corrugated SRR-loaded antenna designs. The reflection coefficient, bandwidth, and radiation pattern results are presented and compared to previous relevant metamaterial microstrip antenna works. The highest obtained bandwidth is 420 MHz, which is achieved by three square teeth SRRs. The highest calculated gain is 7 dB and is achieved by loading two square teeth SRRs. The proposed antenna design can be tuned to different frequency bands by embedding microelectromechanical system switches in SRRs’ gaps. The proposed antennas have compact size combined with high bandwidth and gain performance. Journal: Journal of Electromagnetic Waves and Applications Pages: 945-961 Issue: 7 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1167633 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1167633 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:7:p:945-961 Template-Type: ReDIF-Article 1.0 Author-Name: Dong-Hyun Ha Author-X-Name-First: Dong-Hyun Author-X-Name-Last: Ha Author-Name: Ki-Ro Kim Author-X-Name-First: Ki-Ro Author-X-Name-Last: Kim Author-Name: Young-Hwan You Author-X-Name-First: Young-Hwan Author-X-Name-Last: You Author-Name: Ki-Won Kwon Author-X-Name-First: Ki-Won Author-X-Name-Last: Kwon Author-Name: Hyoung-Kyu Song Author-X-Name-First: Hyoung-Kyu Author-X-Name-Last: Song Title: Cooperative diversity scheme using virtual MIMO antenna array in a LTE-A uplink system Abstract: This paper proposes an effective cooperative communication scheme to obtain high reliability in a long-term evolution-advanced (LTE-A) uplink system. The proposed scheme constitutes the virtual multiple input multiple output antenna array by the cooperative communication scheme and suggests the transmission signal configuration applying spatial phase coding (SPC) with the modified hierarchical modulation. In the proposed transmission signal configuration, high diversity gain is provided by the SPC scheme and the data rate is improved by modified hierarchical modulation. The modified hierarchical modulation transforms the constellation of the conventional hierarchical-modulated signal in order to minimize the influence by noise in the proposed scheme. In the LTE-A uplink system, the proposed scheme is effective to a user equipment (UE) based on single carrier-frequency division multiple access because UE using only single antenna can obtain high reliability without additional antennas. Journal: Journal of Electromagnetic Waves and Applications Pages: 963-977 Issue: 8 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2015.1092895 File-URL: http://hdl.handle.net/10.1080/09205071.2015.1092895 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:8:p:963-977 Template-Type: ReDIF-Article 1.0 Author-Name: W. S. Yeoh Author-X-Name-First: W. S. Author-X-Name-Last: Yeoh Author-Name: W. S. T. Rowe Author-X-Name-First: W. S. T. Author-X-Name-Last: Rowe Title: Technique in miniaturization and bandwidth expansion of printed monopole antenna for WLAN and UWB applications Abstract: A novel miniaturized printed monopole is presented for ultra-wideband and multiple wireless services. The proposed antenna is compatible with many wireless standards, including Wi-Fi (2.4 GHz), Bluetooth (v1.0–v4.0), WiMAX (~2.5–5.5 GHz), Bluetooth 4.0 or Wireless USB (3.1–10.6 GHz), close range radar and satellite communication in the X band (~8–12 GHz), and Ku band (~12–14 GHz) applications. The proposed design is approximately 0.26λ in length with respect to the lowest frequency boundary at 2.36 GHz. The structure consists of two main parts, which are the nonlinear stepping grounded coplanar waveguide and the serial stepping monopoles. Miniaturization is achieved without any discrete component. It displays a fractional bandwidth of 6.2:1. The radiation patterns are reasonably omnidirectional for a small antenna with the gain ranges from 1 to 4 dBi across the impedance bandwidth. Journal: Journal of Electromagnetic Waves and Applications Pages: 978-984 Issue: 8 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1158128 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1158128 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:8:p:978-984 Template-Type: ReDIF-Article 1.0 Author-Name: H. Krraoui Author-X-Name-First: H. Author-X-Name-Last: Krraoui Author-Name: F. Mejri Author-X-Name-First: F. Author-X-Name-Last: Mejri Author-Name: T. Aguili Author-X-Name-First: T. Author-X-Name-Last: Aguili Title: Electromagnetic diffraction modeling of the finite multi-dielectric thickness in metallic wave-guides using GEC method: application to the characterization of vegetation leaves Abstract: In this paper, a new approach for electromagnetic modeling of the diffraction of finite multi-dielectric thickness in metallic wave-guides is presented. The proposed model, based on the method of moments combined to the generalized equivalent circuit, can concern several applications such as the investigation of vegetation leaves properties. Hence, in this work, we are interested in studying a corn leaf which is assumed as a superposition of rectangular dielectric slabs. We develop an electromagnetic analysis of a rectangular wave-guide loaded with a dielectric model that is composed of a leaf plant with a finite thickness. Interest has been focused on the influence of the wave diffraction according to the geometrical intern of the corn leaves. In this paper, we are particularly interested in studying these parameters against the dielectrics widths and the distances separating them. To validate this work, the obtained results are compared with those previously measured and published. A good agreement with literature is shown. Journal: Journal of Electromagnetic Waves and Applications Pages: 985-1004 Issue: 8 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1159146 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1159146 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:8:p:985-1004 Template-Type: ReDIF-Article 1.0 Author-Name: Xiao-Min Zhai Author-X-Name-First: Xiao-Min Author-X-Name-Last: Zhai Author-Name: Xia Zhou Author-X-Name-First: Xia Author-X-Name-Last: Zhou Author-Name: Li-Fang Yao Author-X-Name-First: Li-Fang Author-X-Name-Last: Yao Author-Name: Hui-Bo Wang Author-X-Name-First: Hui-Bo Author-X-Name-Last: Wang Author-Name: Jian-Feng Dong Author-X-Name-First: Jian-Feng Author-X-Name-Last: Dong Title: Complementary chiral metamaterial with multi-band asymmetric transmission and mutual conversion Abstract: In this paper, we propose a special chiral metamaterial (CMM) structure with a unit cell lacking mirror symmetry, which exhibits asymmetric transmission (AT) of terahertz radiation (1.4–2.3 THz) propagating through it in opposite directions. It is constructed by double-layered four complementary U-shaped resonators on both sides of a dielectric substrate, and the front and back layers are the same that are rotated by 90º with respect to each other. Numerical simulation results demonstrate that our scheme can realize large multi-band AT in terahertz band with a mutual conversion (x-to-y, and y-to-x) of linearly polarized electromagnetic waves only. The large cross-coupling reveals that the linear polarization of the incident wave is converted to its orthogonal polarization when the wave propagates through the designed structure. The surface current densities and electric field distributions of bi-layered CMM at the resonant frequencies are presented to interpret the multi-band AT with mutual conversion. The AT effect and resonant frequencies can be adjusted by geometric parameters of the unit cell. Journal: Journal of Electromagnetic Waves and Applications Pages: 1005-1020 Issue: 8 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1168322 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1168322 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:8:p:1005-1020 Template-Type: ReDIF-Article 1.0 Author-Name: Y.-H. Ren Author-X-Name-First: Y.-H. Author-X-Name-Last: Ren Author-Name: J. Ding Author-X-Name-First: J. Author-X-Name-Last: Ding Author-Name: C.-J. Guo Author-X-Name-First: C.-J. Author-X-Name-Last: Guo Author-Name: Y.-C. Song Author-X-Name-First: Y.-C. Author-X-Name-Last: Song Author-Name: Y. Qu Author-X-Name-First: Y. Author-X-Name-Last: Qu Title: A wideband gain-enhanced dual-polarized printed antenna based on log-periodic parasitic directors (LPPDs) Abstract: A novel wideband and high gain dual-polarized antenna with log-periodic parasitic directors is presented in this paper. The antenna is composed of two cross printed dipole antennas vertically fixed on an aluminum plate as ground plane, which are excited by two similar micro-strip baluns. In order to further improve the gain with a broad bandwidth, the log-periodic parasitic directors are loaded on the printed dipole antennas innovatively. Measured results show that the proposed antenna achieves a –10 dB return loss with bandwidth of 1–2.1 GHz (71%), and its port isolation is higher than –20 dB within that band. Furthermore, the average gain of antenna is improved by 3 dB because of LPPDs. Journal: Journal of Electromagnetic Waves and Applications Pages: 1021-1031 Issue: 8 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1168751 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1168751 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:8:p:1021-1031 Template-Type: ReDIF-Article 1.0 Author-Name: M. Aidi Author-X-Name-First: M. Author-X-Name-Last: Aidi Author-Name: M. Hajji Author-X-Name-First: M. Author-X-Name-Last: Hajji Author-Name: A. Ben Ammar Author-X-Name-First: A. Author-X-Name-Last: Ben Ammar Author-Name: T. Aguili Author-X-Name-First: T. Author-X-Name-Last: Aguili Title: Graphene nanoribbon antenna modeling based on MoM-GEC method for electromagnetic nanocommunications in the terahertz range Abstract: In this paper, we present a graphene nanoribbon (GNR)-based terahertz antenna array modeling using the MoM-GEC method (the moments method combined with the generalized equivalent circuit). The quantum mechanical conductivity of graphene is used to introduce the graphene’s effect in the mathematical formulation. The GNR is excited by a gap source with unit voltage localized in its center. The antenna structure is shielded in a rectangular waveguide with electric boundary walls. The proposed formulation is firstly validated and it yields efficient and accurate solutions. The obtained input impedance, current density distribution, and radiated electric field are presented to discuss the antenna performance in cases of single and antennas array. It is demonstrated that all results verify the boundary conditions and behave correctly corresponding to the physical laws. Furthermore, we showed that the antenna array leads to enhance the far-field communications for lower distances compared to conventional antenna. Journal: Journal of Electromagnetic Waves and Applications Pages: 1032-1048 Issue: 8 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1168752 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1168752 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:8:p:1032-1048 Template-Type: ReDIF-Article 1.0 Author-Name: Edward Bormashenko Author-X-Name-First: Edward Author-X-Name-Last: Bormashenko Title: Obstructions imposed by the Poincaré–Brouwer (“hairy ball”) theorem on the propagation of electromagnetic waves Abstract: The Poincaré–Brouwer (“hairy ball”) theorem is applied for the analysis of the propagation of electromagnetic waves, in the case when the wavefront forms a surface, topologically equivalent to a sphere (the surface possessing the Euler characteristic χ = 2). At least one point on the surface at which vectors of electric and magnetic fields equal zero will appear. The Poynting vector in this point is also zero. Restrictions imposed by the Poincaré–Brouwer theorem on the reflection and refraction of electromagnetic waves are discussed, in the case when the media are separated by the interface topologically equivalent to a sphere. Journal: Journal of Electromagnetic Waves and Applications Pages: 1049-1053 Issue: 8 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1169226 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1169226 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:8:p:1049-1053 Template-Type: ReDIF-Article 1.0 Author-Name: Izabela Slomian Author-X-Name-First: Izabela Author-X-Name-Last: Slomian Author-Name: Jakub Sorocki Author-X-Name-First: Jakub Author-X-Name-Last: Sorocki Author-Name: Slawomir Gruszczynski Author-X-Name-First: Slawomir Author-X-Name-Last: Gruszczynski Author-Name: Krzysztof Wincza Author-X-Name-First: Krzysztof Author-X-Name-Last: Wincza Title: Composite right/left-handed leaky-wave antenna with adjustable radiation bandwidth Abstract: A novel approach to the design of a 1-D CRLH leaky-wave antenna has been proposed in which the frequency range of beam scanning can be adjusted without the change of unit cell’s physical length. The presented antenna is based on a unit cell composed of series capacitor connected in cascade with four sections of transmission lines and two symmetrically located transmission-line stubs. The unique feature of such a unit cell is that the phase constant’s slope vs. frequency and the resulting scanning bandwidth can be adjusted by controlling the characteristic impedance and the electrical length of the open-ended transmission-line stubs while all other parameters are fixed. The theoretical investigation as well as experimental results of the developed antenna operating at 2.5 GHz are shown, proving the correctness of the described design technique. Journal: Journal of Electromagnetic Waves and Applications Pages: 1054-1063 Issue: 8 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1169950 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1169950 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:8:p:1054-1063 Template-Type: ReDIF-Article 1.0 Author-Name: Sen Wang Author-X-Name-First: Sen Author-X-Name-Last: Wang Author-Name: Yi-Huei Chen Author-X-Name-First: Yi-Huei Author-X-Name-Last: Chen Author-Name: Ren-Hua Chang Author-X-Name-First: Ren-Hua Author-X-Name-Last: Chang Title: A 2.4-GHz vital-sign sensor for noncontact healthcare monitoring Abstract: This paper presents a 2.4-GHz vital-sign sensor for noncontact healthcare monitoring applications. The sensor consists of one VCO, two circulators, three Wilkinson power dividers, one 90° hybrid, two mixers, and two active band-pass filters. The sensor with the injection-locked VCO and the I/Q demodulator reduces system complexity and avoids the null detection points, respectively. Moreover, the sensor achieves a long sensing distance without the need of a low-noise amplifier or a power amplifier. Under total power consumption of 17.8 mW, experimental results demonstrate that vital-sign signals including respiration and heartbeat can be identified and detected correctly up to 80 cm away from the subject. Moreover, the errors of heartbeats are less than 4.9% compared to a contact device. Journal: Journal of Electromagnetic Waves and Applications Pages: 1064-1074 Issue: 8 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1172517 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1172517 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:8:p:1064-1074 Template-Type: ReDIF-Article 1.0 Author-Name: M. A. Baqir Author-X-Name-First: M. A. Author-X-Name-Last: Baqir Author-Name: P. K. Choudhury Author-X-Name-First: P. K. Author-X-Name-Last: Choudhury Title: On the bimetallic 1D photonic crystals under angular incidence excitation Abstract: Ternary layer-based one-dimensional photonic crystal (1D PC) kind of optical filter is discussed that operates in the visible and near-infrared regimes of the electromagnetic spectrum. The 1D PC filter is comprised of bimetallic structure having three periodic nanolayers of gold, flint glass (SiO2), and silver. Dispersion and reflection characteristics of the proposed filter are analyzed by implementing the concept of transfer matrix and taking into account the incidence excitations under different angles. It is found that the structure exhibits behavior similarly to notch, comb, and Fabry–Pérot types of filter. It is expected that such filters would be useful in integrated optic as well as in sensing applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1075-1085 Issue: 8 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1172519 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1172519 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:8:p:1075-1085 Template-Type: ReDIF-Article 1.0 Author-Name: M. Yu. Medvedik Author-X-Name-First: M. Yu. Author-X-Name-Last: Medvedik Author-Name: Yu. G. Smirnov Author-X-Name-First: Yu. G. Author-X-Name-Last: Smirnov Author-Name: A. A. Tsupak Author-X-Name-First: A. A. Author-X-Name-Last: Tsupak Author-Name: D. V. Valovik Author-X-Name-First: D. V. Author-X-Name-Last: Valovik Title: Vector problem of electromagnetic wave diffraction by a system of inhomogeneous volume bodies, thin screens, and wire antennas Abstract: The vector problem of time-harmonic electromagnetic wave diffraction by a system of non-intersecting solid inhomogeneous bodies, infinitely thin perfectly conducting screens and wire antennas in the semi-classical formulation is considered. The original boundary value problem for Maxwell’s equations is reduced to a new system of singular integral equations over the volume domains, the screen surfaces and antennas, that is, over compact domains of dimension 3, 2, and 1. To obtain the equations, the fields scattererd by the bodies and the screens were represented via volume and surface potentials, respectively. To solve the integral equations approximately, the Galerkin method is applied; basis functions on the body, the screens and antennas are introduced as well as formulas for matrix elements in Galerkin method. Combining potential theory and pseudodifferential calculus allowed to obtain results on solvability of new system of integro-differential equations, as well as to theoretically justify the Galerkin method. To solve the problem of diffraction by obstacles of complex shape, novel subhierarchical approach is applied. Journal: Journal of Electromagnetic Waves and Applications Pages: 1086-1100 Issue: 8 Volume: 30 Year: 2016 Month: 5 X-DOI: 10.1080/09205071.2016.1172990 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1172990 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:8:p:1086-1100 Template-Type: ReDIF-Article 1.0 Author-Name: Annamaria Paljanos Author-X-Name-First: Annamaria Author-X-Name-Last: Paljanos Author-Name: Simona Miclăuș Author-X-Name-First: Simona Author-X-Name-Last: Miclăuș Author-Name: Paul Bechet Author-X-Name-First: Paul Author-X-Name-Last: Bechet Author-Name: Călin Munteanu Author-X-Name-First: Călin Author-X-Name-Last: Munteanu Title: Assessment of mobile phone user exposure to UMTS and LTE signals: comparative near-field radiated power levels for various data and voice application services Abstract: The aim of present research was the experimental characterization of the radiated power and its dynamics in the near-field of mobile terminal during its use in various voice and data application services belonging to either Universal Mobile Telecommunications System (UMTS) or Long-term Evolution (LTE) communication technologies. The quantification of the realistic electromagnetic exposure of human user was done by offering a complementary, non-standardized method that enables a comprehensive dosimetric understanding of radiation impact. Statistical analysis was applied over the radiated power levels measured in different wireless communication situations followed by average and worst case exposure highlighting. Highest power levels were measured for uploading-type applications running under both UMTS and LTE networks. Among UMTS voice application services, VoIP-radiated power levels were on average 1.4 higher than those for VoCS services. The multiplication factor of the radiated power in LTE vs. UMTS was in average 15.3, ranging from 9.3 up to 31.6, depending on the considered application service. Present results demonstrate that highest exposure is expected for the same application type when running under LTE rather than under UMTS standard. Journal: Journal of Electromagnetic Waves and Applications Pages: 1101-1115 Issue: 9 Volume: 30 Year: 2016 Month: 6 X-DOI: 10.1080/09205071.2016.1167634 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1167634 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:30:y:2016:i:9:p:1101-1115 Template-Type: ReDIF-Article 1.0 Author-Name: Tariq Rahim Author-X-Name-First: Tariq Author-X-Name-Last: Rahim Author-Name: Jiadong Xu Author-X-Name-First: Jiadong Author-X-Name-Last: Xu Title: Elliptical reflector in strong chiral medium supporting PPV and NPV simultaneously Abstract: The high-frequency electromagnetic waves reflected from a perfect electric conductor (PEC) elliptical surface placed in homogeneous, reciprocal, and isotropic medium with high value of chirality parameter kβ$ k\beta $ are analyzed. Negative phase velocity (NPV) and positive phase velocity (PPV) can be obtained by properly adjusting the value of chirality parameter. For the value of -113 dB) and low (<0.8 dB) in pass band. Measured results correlate with the simulated results and thus ensure that the proposed filter is a suitable candidate to mitigate interference caused by the co-existing and emerging wireless technologies. Journal: Journal of Electromagnetic Waves and Applications Pages: 57-71 Issue: 1 Volume: 31 Year: 2017 Month: 1 X-DOI: 10.1080/09205071.2016.1260063 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1260063 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:1:p:57-71 Template-Type: ReDIF-Article 1.0 Author-Name: Richard Obermeier Author-X-Name-First: Richard Author-X-Name-Last: Obermeier Author-Name: Jose Angel Martinez-Lorenzo Author-X-Name-First: Jose Angel Author-X-Name-Last: Martinez-Lorenzo Title: A compressive sensing approach for enhancing breast cancer detection using a hybrid DBT/NRI configuration Abstract: This work presents a novel breast cancer imaging approach that uses compressive sensing in a hybrid digital breast tomosynthesis (DBT)/nearfield radar imaging (NRI) system configuration. The non-homogeneous tissue distribution of the breast, described in terms of dielectric constant and conductivity, is extracted from the DBT image, and it is used by a full-wave finite difference in the frequency domain method to build a linearized model of the non-linear NRI imaging problem. The inversion of the linear problem is solved using compressive sensing imaging techniques, which lead to a reduction on the required number of sensing antennas and operational bandwidth without loss of performance. Journal: Journal of Electromagnetic Waves and Applications Pages: 72-81 Issue: 1 Volume: 31 Year: 2017 Month: 1 X-DOI: 10.1080/09205071.2016.1260064 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1260064 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:1:p:72-81 Template-Type: ReDIF-Article 1.0 Author-Name: Yao Zhang Author-X-Name-First: Yao Author-X-Name-Last: Zhang Author-Name: Xiao-Lan Zhao Author-X-Name-First: Xiao-Lan Author-X-Name-Last: Zhao Title: Compact tri-band bandpass filter with two closely frequency spaced passbands Abstract: A compact tri-band bandpass filter based on a novel six-mode resonator is proposed. The filter has three passbands centered at 2.45, 5.2, and 5.8 GHz for WLAN applications. Among them, two closely frequency-spaced passbands with a small center frequency ratio (1/1.11) are realized. The 3 dB bandwidth of the two passbands are 5.8 and 5.2%, which means they have equal absolute bandwidth. Source-load-coupling structure is adopted to enhance the high-isolation performance. And the filter has six transmission zeros, resulting in high-frequency selectivity. The passband frequencies and bandwidths of the filter can be controlled. The measured results are in good agreement with electromagnetic simulation. Its circuit only occupies 0.14 λg × 0.09 λg (11.2 mm × 7.1 mm), where λg is the guided wavelength at the lowest passband center frequency. Journal: Journal of Electromagnetic Waves and Applications Pages: 82-90 Issue: 1 Volume: 31 Year: 2017 Month: 1 X-DOI: 10.1080/09205071.2016.1270231 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1270231 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:1:p:82-90 Template-Type: ReDIF-Article 1.0 Author-Name: Xunjun He Author-X-Name-First: Xunjun Author-X-Name-Last: He Author-Name: Shaopeng Li Author-X-Name-First: Shaopeng Author-X-Name-Last: Li Author-Name: Xingyu Yang Author-X-Name-First: Xingyu Author-X-Name-Last: Yang Author-Name: Shuang Shi Author-X-Name-First: Shuang Author-X-Name-Last: Shi Author-Name: Fengmin Wu Author-X-Name-First: Fengmin Author-X-Name-Last: Wu Author-Name: Jiuxing Jiang Author-X-Name-First: Jiuxing Author-X-Name-Last: Jiang Title: High-sensitive dual-band sensor based on microsize circular ring complementary terahertz metamaterial Abstract: Recently, resonance sensing based on the terahertz metamaterials has attracted considerable attentions due to the enhancement and confinement of local fields in microsize gap of resonant structures. Here, a high-sensitive dual-band sensor based on the complementary terahertz metamaterial composed of microsize circular ring gap array is proposed to detect the thickness and refractive index of thin film. The structure of this sensor is polarization insensitive dual-band operating mode and can be easily filled by the biomolecules. Simulation results demonstrate that the dual-band resonances are very sensitive to the dielectric variation, and the sensitivity levels of 99 GHz/refractive index unit (RIU) for mode f1 and 242 GHz/RIU for mode f2 are obtained and further enhanced by optimizing structures. Therefore, this structure can exhibit promising application for monitoring thin film thickness. Journal: Journal of Electromagnetic Waves and Applications Pages: 91-100 Issue: 1 Volume: 31 Year: 2017 Month: 1 X-DOI: 10.1080/09205071.2016.1270232 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1270232 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:1:p:91-100 Template-Type: ReDIF-Article 1.0 Author-Name: Jianxing Li Author-X-Name-First: Jianxing Author-X-Name-Last: Li Author-Name: Changqing Wang Author-X-Name-First: Changqing Author-X-Name-Last: Wang Author-Name: Anxue Zhang Author-X-Name-First: Anxue Author-X-Name-Last: Zhang Author-Name: William T. Joines Author-X-Name-First: William T. Author-X-Name-Last: Joines Author-Name: Qing Huo Liu Author-X-Name-First: Qing Huo Author-X-Name-Last: Liu Title: Microstrip-line-fed reactively loaded circularly polarized annular-ring slot antenna Abstract: A simple and novel reactively loaded annular-ring slot antenna (ARSA) fed by a microstrip line is proposed and investigated for circularly polarized (CP) radiation. An appropriate reactive component, i.e. lumped capacitor/inductor, is introduced across the annular-ring slot at a proper position to achieve CP radiation. To validate the design concept, a capacitively loaded ARSA (CL-ARSA) and an inductively loaded ARSA (IL-ARSA) were implemented and measured, showing that good CP characteristics have been attained. The measured 3-dB axial ratio (AR) bandwidths for the CL-ARSA and IL-ARSA are 5.5 and 6.7%, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 101-110 Issue: 1 Volume: 31 Year: 2017 Month: 1 X-DOI: 10.1080/09205071.2016.1277790 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1277790 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:1:p:101-110 Template-Type: ReDIF-Article 1.0 Author-Name: Wen-quan Cao Author-X-Name-First: Wen-quan Author-X-Name-Last: Cao Author-Name: Bangning Zhang Author-X-Name-First: Bangning Author-X-Name-Last: Zhang Author-Name: Wei Hong Author-X-Name-First: Wei Author-X-Name-Last: Hong Author-Name: Jun Jin Author-X-Name-First: Jun Author-X-Name-Last: Jin Title: L-shaped slot coupling-fed low-profile broadband circularly polarized patch antenna with metasurface Abstract: Metasurface-based circularly polarized (CP) patch antenna with broadband property is proposed and analyzed in this paper. L-shaped slot coupling method is adopted to feed a 4 × 4 equally divided patch antenna (EDPA). By optimizing the geometry of the feeding structure, broad CP bandwidth is achieved which is much wider than the patch-truncated type. One prototype is fabricated for verification and the results show that the proposed antenna has a wide impedance bandwidth, which is 55.4% ranging from 4.66 to 8.23 GHz (S11 < −10 dB). The 3-dB AR bandwidth is 23.6% from 5.6 to 7.1 GHz, among which a good right-handed circularly polarized radiation is obtained. Furthermore, the gain variation is small (7.3–8.1 dBic). Journal: Journal of Electromagnetic Waves and Applications Pages: 111-120 Issue: 1 Volume: 31 Year: 2017 Month: 1 X-DOI: 10.1080/09205071.2016.1278185 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1278185 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:1:p:111-120 Template-Type: ReDIF-Article 1.0 Author-Name: Yang Su Author-X-Name-First: Yang Author-X-Name-Last: Su Author-Name: Raj Mittra Author-X-Name-First: Raj Author-X-Name-Last: Mittra Author-Name: Weixing Sheng Author-X-Name-First: Weixing Author-X-Name-Last: Sheng Title: Analysis of scattering from multi-scale and multiple targets using characteristic basis function (CBFM) and integral equation discontinuous Galerkin (IEDG) methods Abstract: In this paper, the characteristic basis function method is adapted to analyze the problem of scattering from multiple and multi-scale impenetrable targets in conjunction with the discontinuous Galerkin method, and the monopolar RWG functions are chosen as the basis functions. This method enables us to analyze multiple and multi-scale targets using nonconforming discretizations. The use of the CBFs helps reduce the size of the impedance matrix of the associated method of moment significantly, enabling us to employ direct solvers as opposed to iterative solvers. The process of generating the reduced matrix is naturally parallel, and the reduced matrix is well conditioned, which obviates the need for pre-conditioning. In addition, the adaptive cross-approximation algorithm is implemented to reduce the complexity of the computation. Numerical results are included to demonstrate the accuracy and efficiency of the present approach when analyzing scattering from multiple and multi-scale targets using nonconforming discretizations. Journal: Journal of Electromagnetic Waves and Applications Pages: 969-980 Issue: 10 Volume: 31 Year: 2017 Month: 7 X-DOI: 10.1080/09205071.2017.1311237 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1311237 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:10:p:969-980 Template-Type: ReDIF-Article 1.0 Author-Name: Jiao Liu Author-X-Name-First: Jiao Author-X-Name-Last: Liu Author-Name: Lixin Guo Author-X-Name-First: Lixin Author-X-Name-Last: Guo Title: Analysis of terahertz scattering from electrically large scatterer with NURBS modeling Abstract: A novel expression based on conventional Non-Uniform Rational B-Splines surfaces is proposed to model a scatterer, which can be used to overcome the deficiencies of conventional modeling method and can also be combined perfectly with the stationary phase method (SPM). Furthermore, we propose a fast and accurate algorithm to locate inner critical points and boundary critical points of physical optics (PO) integrals, as well as to locate stationary points of edge-diffracted integrals. The terahertz (THz) scattering field from an electrically large scatterer is evaluated by the physical theory of diffraction and SPM (PTD-SPM), which consists of four parts, including the PO scattering field from inner critical points, boundary critical points, corner points of PO integrals, and edge-diffracted field from the stationary points of edge-diffracted integral. Moreover, the order of magnitude of each part contribution is derived. Numerical results demonstrate that PTD-SPM is a valid and efficient algorithm for analyzing THz scattering from an electrically large scatterer. Journal: Journal of Electromagnetic Waves and Applications Pages: 981-996 Issue: 10 Volume: 31 Year: 2017 Month: 7 X-DOI: 10.1080/09205071.2017.1317037 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1317037 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:10:p:981-996 Template-Type: ReDIF-Article 1.0 Author-Name: Su Sheng Author-X-Name-First: Su Author-X-Name-Last: Sheng Author-Name: Yi Wang Author-X-Name-First: Yi Author-X-Name-Last: Wang Title: Closed-form analysis of high-resistivity thin-film electrode in the hybrid varactor structure Abstract: Hybrid ferroelectric thin-film varactor device architecture is presented that allows for integrating the features of both structures of coplanar and parallel-plate varactors. In this structure, a high-resistivity oxide thin film is used as dc bias bottom electrode, while the existence of the high-resistivity oxide thin-film electrode is considered as disturbance to the original electric field in the coplanar varactor. Using analytic solution of electromagnetic field, the disturbance caused by high-resistivity thin film in microwave TEM wave is derived. The result shows that this disturbance could be modeled as serial or shunt resistance in the transmission line equivalent circuit and the magnitude of it is proportional to the conductivity and thickness of the conductor thin film. With conductivity and thickness low enough, the conductor film will be “transparent” to microwave field. Using high-resistance dc bias electrode “transparent” to microwave is expected to be able to bring much more flexibility in the developing of microwave ferroelectric tunable devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 997-1006 Issue: 10 Volume: 31 Year: 2017 Month: 7 X-DOI: 10.1080/09205071.2017.1317607 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1317607 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:10:p:997-1006 Template-Type: ReDIF-Article 1.0 Author-Name: Mayank Agarwal Author-X-Name-First: Mayank Author-X-Name-Last: Agarwal Author-Name: Ashis Kumar Behera Author-X-Name-First: Ashis Author-X-Name-Last: Kumar Behera Author-Name: Manoj Kumar Meshram Author-X-Name-First: Manoj Author-X-Name-Last: Kumar Meshram Title: MIMO-configured WLAN access point antenna with high port isolation Abstract: A four-element MIMO (multiple-input multiple-output) antenna system utilizing planar inverted-F antenna for 5 GHz WLAN (wireless local area network, band 1: 5.15–5.35 GHz, band 2: 5.725–5.825 GHz) access point applications is presented in this paper. The detrimental effects of practical device environment on the antenna isolation performance are compensated using an array of metasurface-based isolator between the antenna elements. The proposed isolator partially absorbs the fields responsible for coupling and rotates the polarization of rest of the coupled fields. The working mechanism of the proposed isolator is explained with the surface current distribution. The proposed antenna also exhibits spatial/pattern diversity and thus, the lower values of envelope correlation coefficient make it suitable for the MIMO application. Journal: Journal of Electromagnetic Waves and Applications Pages: 1007-1019 Issue: 10 Volume: 31 Year: 2017 Month: 7 X-DOI: 10.1080/09205071.2017.1319300 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1319300 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:10:p:1007-1019 Template-Type: ReDIF-Article 1.0 Author-Name: Seung-Jae Lee Author-X-Name-First: Seung-Jae Author-X-Name-Last: Lee Author-Name: In-Sik Choi Author-X-Name-First: In-Sik Author-X-Name-Last: Choi Author-Name: Dae-Young Chae Author-X-Name-First: Dae-Young Author-X-Name-Last: Chae Title: A novel feature extraction method for radar target classification using fusion of early-time and late-time regions Abstract: This paper proposes a feature vector fusion of early-time and late-time regions, which improves the performance of radar target classification. For verifying the performance of the proposed method, we use the calculated radar cross section (RCS) of four full-scale targets and measured the RCS of three scale model targets. Then, we extract a feature vector from a waveform structure in the early-time region. The resonance frequencies are extracted using an evolutionary programming (EP)-based CLEAN algorithm in the late-time region. The extracted feature vectors are passed through the feature fusion process and then used as inputs for a neural network classifier. The results show that the proposed method exhibits better performance than those that use either early-time or late-time features. Journal: Journal of Electromagnetic Waves and Applications Pages: 1020-1033 Issue: 10 Volume: 31 Year: 2017 Month: 7 X-DOI: 10.1080/09205071.2017.1324324 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1324324 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:10:p:1020-1033 Template-Type: ReDIF-Article 1.0 Author-Name: Lijun Zhou Author-X-Name-First: Lijun Author-X-Name-Last: Zhou Author-Name: Shan Ouyang Author-X-Name-First: Shan Author-X-Name-Last: Ouyang Author-Name: Guisheng Liao Author-X-Name-First: Guisheng Author-X-Name-Last: Liao Author-Name: Liangnian Jin Author-X-Name-First: Liangnian Author-X-Name-Last: Jin Title: Width estimation of a subsurface water-filled crack using internal multiple reflections from electromagnetic scattering model of a cylinder Abstract: A width estimation method for a subsurface water-filled crack using internal multiple reflections is proposed. The energy transport and path length of internal multiple reflections are analyzed from electromagnetic scattering model of a dielectric cylinder using the extended ray theory. The energy transport shows that some multiple rays transport along the surface of the cylinder to the receiver, which form the creeping waves, and some multiple rays refract toward the receiver, focusing on the radial direction. The conclusion that the path lengths are multiples of a diameter distance is utilized to estimate the width of the cylinder. In order to distinguish the adjacent reflections with small time interval, wavefronts and resonances of internal multiple reflections are also analyzed, based on the fact that the creeping waves and refracted waves at the radial direction show different resonances in the time-frequency domain. In order to verify the proposed method, experiments both in free space and subsurface scene are given to estimate the width of water-filled cracks. Journal: Journal of Electromagnetic Waves and Applications Pages: 1034-1048 Issue: 10 Volume: 31 Year: 2017 Month: 7 X-DOI: 10.1080/09205071.2017.1324325 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1324325 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:10:p:1034-1048 Template-Type: ReDIF-Article 1.0 Author-Name: Ankita Verma Author-X-Name-First: Ankita Author-X-Name-Last: Verma Author-Name: Sushmita Bhushan Author-X-Name-First: Sushmita Author-X-Name-Last: Bhushan Author-Name: Pramod Narayan Tripathi Author-X-Name-First: Pramod Narayan Author-X-Name-Last: Tripathi Author-Name: Manish Goswami Author-X-Name-First: Manish Author-X-Name-Last: Goswami Author-Name: B. R. Singh Author-X-Name-First: B. R. Author-X-Name-Last: Singh Title: A defected ground split ring resonator for an ultra-fast, selective sensing of glucose content in blood plasma Abstract: Compact antenna-coupled split-ring resonator-based sensors have been designed, fabricated, and tested for sensing glucose concentration in blood plasma. Both circular and square type metallic ring is integrated along with two monopole antennas upon a dielectric substrate, which exhibits a resonance frequency of 1.9 GHz and 8.3 GHz, respectively. The effect of defected ground plane is also investigated which is observed to produce a deep rejection frequency band with sharp cutoff resonant frequency. The SRRs exhibit a shift in resonant frequency with change in reflection coefficient when subjected to blood plasma with different concentration of glucose. Journal: Journal of Electromagnetic Waves and Applications Pages: 1049-1061 Issue: 10 Volume: 31 Year: 2017 Month: 7 X-DOI: 10.1080/09205071.2017.1325011 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1325011 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:10:p:1049-1061 Template-Type: ReDIF-Article 1.0 Author-Name: Abdullah G. Al-Sehemi Author-X-Name-First: Abdullah G. Author-X-Name-Last: Al-Sehemi Author-Name: Ahmed A. Al-Ghamdi Author-X-Name-First: Ahmed A. Author-X-Name-Last: Al-Ghamdi Author-Name: Nikolay T. Dishovsky Author-X-Name-First: Nikolay T. Author-X-Name-Last: Dishovsky Author-Name: Nikolay T. Atanasov Author-X-Name-First: Nikolay T. Author-X-Name-Last: Atanasov Author-Name: Gabriela L. Atanasova Author-X-Name-First: Gabriela L. Author-X-Name-Last: Atanasova Title: Flexible and small wearable antenna for wireless body area network applications Abstract: In this paper, we present design and simulation of the compact planar dipole antenna on fully flexible nitrile butadiene rubber polymer composite for body area network applications. A three-layer human tissue model is used to numerically analyse the performance of the antenna, including the human body effect. The proposed antenna achieves stable on-body performance: |S11| varies from −19.45 dB (in free space) at 2.46 GHz resonant frequency to −20.62 dB (on the skin) at 2.44 GHz resonant frequency. Additionally, the specific absorption rate (SAR) of the proposed antenna is evaluated. It was found that the maximum 1 g average SAR value is only 0.20 W/kg for an input power of 100 mW at a distance 2 mm away from tissue model. Simulated and measured results are presented to demonstrate the validity of the proposed antenna. Furthermore, the proposed antenna offer advantages of being compact, of low profile, cheap and easy to fabricate. Journal: Journal of Electromagnetic Waves and Applications Pages: 1063-1082 Issue: 11-12 Volume: 31 Year: 2017 Month: 8 X-DOI: 10.1080/09205071.2017.1336492 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1336492 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:11-12:p:1063-1082 Template-Type: ReDIF-Article 1.0 Author-Name: Lihang Du Author-X-Name-First: Lihang Author-X-Name-Last: Du Author-Name: Cheng Gao Author-X-Name-First: Cheng Author-X-Name-Last: Gao Author-Name: Qi Zhang Author-X-Name-First: Qi Author-X-Name-Last: Zhang Title: Numerical analysis on electromagnetic radiation environment of the bounded-wave simulator with a metal plate Abstract: This paper presents a detailed analysis of the propagation characteristics of the magnetic field around bounded-wave simulator excited by high-altitude nuclear electromagnetic pulse (HEMP), meanwhile, the effects of thickness, size, electrical conductivity, and magnetic permeability on the magnetic field are discussed. Furthermore, at the basis of the energy spectrum distribution of excitation source, the exposure value of the radiation field is calculated according to GB8702. The results suggest that whether with protective measures or not, the magnetic field derived from HEMP is not harmful to human body in a single test. Journal: Journal of Electromagnetic Waves and Applications Pages: 1083-1092 Issue: 11-12 Volume: 31 Year: 2017 Month: 8 X-DOI: 10.1080/09205071.2017.1336493 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1336493 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:11-12:p:1083-1092 Template-Type: ReDIF-Article 1.0 Author-Name: Ping Du Author-X-Name-First: Ping Author-X-Name-Last: Du Author-Name: Yu Shao Author-X-Name-First: Yu Author-X-Name-Last: Shao Author-Name: Cheng Wang Author-X-Name-First: Cheng Author-X-Name-Last: Wang Title: Fast frequency sweep of metallic antennas using frequency-independent reaction and enhanced gap source model Abstract: In this paper, the enhanced gap source model is combined with the frequency-independent reaction(FIR)-MoM to analyze the input impedance of the metallic antenna over a wide frequency band. The enhanced gap source model is a simple feeding model, which can overcome the instability of the gap source model. Thus, the stable results can be obtained. In the FIR-MoM, the exponential of the Green’s function is expanded as Taylor series in terms of the distance between the centers of the testing and source functions. The impedance matrix is expressed as the summation, in which each term is the multiplication of the frequency-independent matrix and the frequency-dependent phase term. The frequency-independent matrices are computed before the frequency sweep. Thus, the efficiency of the FIR is very high. The impedance matrix can be efficiently generated when the FIR is used for frequency sweep. The FIR-MoM is suitable for the whole frequency range. Moreover, the precision can be dynamically improved. By combining these two techniques, the stable results over a wide frequency range can be efficiently obtained. To test the accuracy and efficiency of the proposed method, two numerical examples are implemented. Numerical results validate the accuracy and the efficiency. Journal: Journal of Electromagnetic Waves and Applications Pages: 1093-1100 Issue: 11-12 Volume: 31 Year: 2017 Month: 8 X-DOI: 10.1080/09205071.2017.1336494 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1336494 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:11-12:p:1093-1100 Template-Type: ReDIF-Article 1.0 Author-Name: Jia-Kun Wang Author-X-Name-First: Jia-Kun Author-X-Name-Last: Wang Author-Name: Min Zhang Author-X-Name-First: Min Author-X-Name-Last: Zhang Author-Name: Zhao-Hui Cai Author-X-Name-First: Zhao-Hui Author-X-Name-Last: Cai Author-Name: Jun-Long Chen Author-X-Name-First: Jun-Long Author-X-Name-Last: Chen Title: SAR imaging simulation of ship-generated internal wave wake in stratified ocean Abstract: Simulation of synthetic aperture radar (SAR) imaging of ship-generated internal wave wake in stratified ocean is conducted through the combination of scattering and modulation effects under the background of wind waves. With the derived surface velocity of internal wave wake from the velocity potential, a reconstruction of the wave elevation is implemented by means of the frequency decomposition technique. Based on the hydrodynamic model, the facet scattering model is presented for the fully polarimetric backscattering and the velocity bunching imaging model is applied to the SAR image simulation of surface waves with an embedded internal wave wake. Numerical simulations show that the wave patterns of internal wave wake, which modulates the distribution of Bragg waves on sea surface, are closely dependent on ship speed. And the conditions are classified for a good visibility of internal wave wake in SAR image. Besides, the great agreement with measurement strongly verifies the validity of the simulation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1101-1114 Issue: 11-12 Volume: 31 Year: 2017 Month: 8 X-DOI: 10.1080/09205071.2017.1337527 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1337527 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:11-12:p:1101-1114 Template-Type: ReDIF-Article 1.0 Author-Name: Jianhong Hao Author-X-Name-First: Jianhong Author-X-Name-Last: Hao Author-Name: Luhang Jiang Author-X-Name-First: Luhang Author-X-Name-Last: Jiang Author-Name: Yanfei Gong Author-X-Name-First: Yanfei Author-X-Name-Last: Gong Author-Name: Jieqing Fan Author-X-Name-First: Jieqing Author-X-Name-Last: Fan Title: Analytical method for load response of a transmission line in a double-enclosure with multiple covered apertures Abstract: An efficient analytical model has been developed for predicting the load response of a lossless transmission line (TL) in a rectangular double-enclosure with multiple apertures covered by conductive sheets, excited by an external plane wave of oblique incidence. First, the electromagnetic field in the enclosure is calculated using the enclosure dyadic Green’s function and the transfer impedance of the sheets against the plane wave. Then, the electric current induced at the termination loads of the TL is computed in combination of the equivalent lumped-pi circuit model of the line and the Agrawal’s model. The analytical model has been successfully verified by the full-wave software CST (Computer Simulation Technology) over a wide frequency band, and it is employed to analyze the effect of various parameters on the induced current, including the sheet conductivity, the load impedance, and the position of the line. This model consumes less time compared with numerical methods, and it can also deal with covered aperture arrays on multiple sides of the enclosure. Journal: Journal of Electromagnetic Waves and Applications Pages: 1115-1133 Issue: 11-12 Volume: 31 Year: 2017 Month: 8 X-DOI: 10.1080/09205071.2017.1338165 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1338165 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:11-12:p:1115-1133 Template-Type: ReDIF-Article 1.0 Author-Name: Shanjun Chen Author-X-Name-First: Shanjun Author-X-Name-Last: Chen Author-Name: Haibin Duan Author-X-Name-First: Haibin Author-X-Name-Last: Duan Author-Name: Guozhi Zhao Author-X-Name-First: Guozhi Author-X-Name-Last: Zhao Title: Multi-objective optimization design of induction magnetometer based on improved chemical reaction algorithm Abstract: The optimal design of Induction Magnetometer (IM) is a prevalent and practical issue. A major combinatorial optimization problem is to design an IM so that it operates optimally in the sense of producing minimal equivalent input magnetic noise level and having the minimal total weight. In this paper, we constructed a desirability function that combines the above two conflicting criteria and proposed a novel Adaptive Chemical Reaction Optimization based on Stimulating Strategy (SE-ACRO) to address this multi-objective optimization problem. CRO is a newly developed evolutionary algorithm inspired by the interactions between molecules in chemical reactions. In the proposed SE-ACRO, on the basis of the original CRO, we further introduced probability selection mechanism and stimulating strategy to improve the performance of the algorithm. In addition, the adaptive mechanism was used for the adjustment of some parameters in CRO. Simulation results demonstrate that the proposed SE-ACRO algorithm is highly competitive and outperforms many other state-of-the-art evolutionary algorithms in the aspects of searching ability, robustness, and convergence rate. At the same time, the optimal trade-offs between the equivalent input magnetic noise level and the total weight of IM is achieved. Journal: Journal of Electromagnetic Waves and Applications Pages: 1134-1150 Issue: 11-12 Volume: 31 Year: 2017 Month: 8 X-DOI: 10.1080/09205071.2017.1331145 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1331145 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:11-12:p:1134-1150 Template-Type: ReDIF-Article 1.0 Author-Name: S. Ramsey Author-X-Name-First: S. Author-X-Name-Last: Ramsey Author-Name: T. Mayo Author-X-Name-First: T. Author-X-Name-Last: Mayo Author-Name: S. G. Lambrakos Author-X-Name-First: S. G. Author-X-Name-Last: Lambrakos Title: Estimated permittivity functions for NIR and SWIR absorbing dyes by inverse analysis of transmission spectra Abstract: An inverse analysis of transmission spectra for near-infrared (NIR, 0.7–0.9 μm) and shortwave infrared (SWIR, 0.9–1.7 μm) absorbing dyes in solution is presented. This analysis employs a parametric model of transmission through a sample of finite thickness, where the permittivity function is represented parametrically by a linear combination of Lorentz oscillator models. The results of this analysis provide estimates of permittivity functions, which can be adopted as input data to other types of models, such as those for prediction of transmission and reflectivity spectra for composites containing mixtures of dyes and other materials. In addition, the results of this analysis should contribute to a database of estimated permittivity functions for practical analysis of spectra. Journal: Journal of Electromagnetic Waves and Applications Pages: 1151-1159 Issue: 11-12 Volume: 31 Year: 2017 Month: 8 X-DOI: 10.1080/09205071.2017.1335621 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1335621 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:11-12:p:1151-1159 Template-Type: ReDIF-Article 1.0 Author-Name: Chie-In Lee Author-X-Name-First: Chie-In Author-X-Name-Last: Lee Author-Name: Yan-Ting Lin Author-X-Name-First: Yan-Ting Author-X-Name-Last: Lin Author-Name: Wei-Cheng Lin Author-X-Name-First: Wei-Cheng Author-X-Name-Last: Lin Title: An improved large-signal model by artificial neural network for the MOSFETs operating in the breakdown region Abstract: An improved large-signal breakdown model establishment applying an artificial neural network (ANN) approach is presented for metal-oxide-semiconductor field-effect transistors (MOSFETs) operating in the breakdown regime for the first time. A neural network program with the feed-forward back propagation algorithm and Levenberg Marquardt optimization is utilized to obtain the MOSFET large-signal model for breakdown operation. When compared with the conventional model without the breakdown effects considered, more accurate large-signal characteristics in the breakdown regime can be obtained by incorporating the avalanche network using the ANN approach. The breakdown network is demonstrated to be significant for large-signal characterization at high bias according to the analysis of minimum acceptable error. Besides, the divergence problem due to the neglected avalanche network can be avoided during ANN training in the avalanche regime. The accuracy of the presented model can keep about 2% error. The presented ANN approach can be applied to device large-signal modeling in the impact ionization regime. Journal: Journal of Electromagnetic Waves and Applications Pages: 1160-1166 Issue: 11-12 Volume: 31 Year: 2017 Month: 8 X-DOI: 10.1080/09205071.2017.1338166 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1338166 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:11-12:p:1160-1166 Template-Type: ReDIF-Article 1.0 Author-Name: Guirong Feng Author-X-Name-First: Guirong Author-X-Name-Last: Feng Author-Name: Xiaowei Shi Author-X-Name-First: Xiaowei Author-X-Name-Last: Shi Author-Name: Lei Chen Author-X-Name-First: Lei Author-X-Name-Last: Chen Author-Name: Hao Yue Author-X-Name-First: Hao Author-X-Name-Last: Yue Author-Name: Yaozhou Yang Author-X-Name-First: Yaozhou Author-X-Name-Last: Yang Title: A metasurfaced surface-wave antenna with performance enhancement Abstract: A wideband and high gain Metasurface (MTS)-based surface-wave antenna with a monopole-like radiation pattern for wireless communication system is presented in this paper. The proposed antenna consists of a centre-fed circular patch antenna, an air substrate layer and a MTS-loaded superstrate. By the use of the slow-wave structure of the MTS, surface waves can effectively launch on the top surface of the superstrate. The diffraction of surface waves forms a monopole-like radiation pattern. With the introduction of a single ring of truncated MTS surrounding the circular patch, the radiating field of the circular patch antenna is constructively transformed to diffraction fields of surface waves, yielding an enhancement on bandwidth and gain. The proposed antenna with a low profile of 0.075 free-space wavelength achieves a 19.4% (4.69–5.7 GHz) bandwidth centred at 5.2 GHz and an average gain of 7.32 dBi. Journal: Journal of Electromagnetic Waves and Applications Pages: 1167-1176 Issue: 11-12 Volume: 31 Year: 2017 Month: 8 X-DOI: 10.1080/09205071.2017.1338623 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1338623 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:11-12:p:1167-1176 Template-Type: ReDIF-Article 1.0 Author-Name: Krzysztof A. Michalski Author-X-Name-First: Krzysztof A. Author-X-Name-Last: Michalski Author-Name: Donald R. Wilton Author-X-Name-First: Donald R. Author-X-Name-Last: Wilton Title: On the computation of plane-wave impressed fields and far-zone fields of arbitrary current sources in planar multilayer dielectric and plasmonic media Abstract: A unified and succinct transmission line formulation is presented for the computation of the plane-wave impressed fields and far-zone radiation fields due to arbitrary electric and magnetic current source distributions embedded in planar layered media. The equivalence principle and the spectral-domain transmission-line network analogue of the multilayer medium are used to express the fields in terms of the voltage and current transmission-line Green functions. The new formulation is applied to sample problems involving both dielectric and plasmonic multilayer media. Journal: Journal of Electromagnetic Waves and Applications Pages: 1177-1193 Issue: 11-12 Volume: 31 Year: 2017 Month: 8 X-DOI: 10.1080/09205071.2017.1341345 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1341345 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:11-12:p:1177-1193 Template-Type: ReDIF-Article 1.0 Author-Name: I. Gil Author-X-Name-First: I. Author-X-Name-Last: Gil Author-Name: R. Fernández-García Author-X-Name-First: R. Author-X-Name-Last: Fernández-García Title: Wearable PIFA antenna implemented on jean substrate for wireless body area network Abstract: A novel wearable PIFA antenna jeans substrate topology have been designed, simulated and tested. This paper investigates the impact of introducing an additional substrate in order to improve the antenna performance, shielding effect in terms of SAR and degree of wearability, in comparison with the standard topology. The proposed embroidered PIFA involves a ground plane sandwiched by two jeans substrates and requires a 50 × 16 mm area. It operates at 2.45 GHz presenting a 1.98 dBi gain with a 29.1% efficiency in contact with the human body. On-voxel analysis reveals that SAR standards are satisfied for occupational sector in any case and for public exposure at 1 cm from the body. Journal: Journal of Electromagnetic Waves and Applications Pages: 1194-1204 Issue: 11-12 Volume: 31 Year: 2017 Month: 8 X-DOI: 10.1080/09205071.2017.1341854 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1341854 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:11-12:p:1194-1204 Template-Type: ReDIF-Article 1.0 Author-Name: Chandan Kumar Ghosh Author-X-Name-First: Chandan Kumar Author-X-Name-Last: Ghosh Author-Name: Amrita Medda Author-X-Name-First: Amrita Author-X-Name-Last: Medda Title: Harmonic suppression of a dual-polarized microstrip array by using microstrip stubs Abstract: A compact dual-polarized two-element microstrip antenna array has been designed at 3.5 GHz frequency band and the higher order modes up to second harmonics have been successfully suppressed for two orthogonal modes. Two pairs of microstrip stubs of electrical lengths λg1/4 (λg1 = wavelength of 1st harmonic signal) and λg2/8 (λg2 = wavelength of 2nd harmonic signal) respectively have been integrated with the microstrip feed line and two harmonics and a sub-harmonic of the fundamental mode have been reduced. The design offers a port isolation of more than 23 dB over the operating band and the measured bandwidths of the two polarizations of 250 and 275 MHz, respectively, are reported. Simulated and measured results show that the harmonic components exist at 7.05 GHz (1st harmonic, TM20), 10.45 GHz (2nd harmonic, TM30) and also a sub-harmonics at 5.5 GHz (TM12 of the fundamental frequency have been successfully suppressed. The harmonic properties of microstrip antenna with and without stubs have been studied and the result indicates that the harmonic components of the array for two orthogonal polarizations have been well eliminated because of the effect of the tuning stubs. To validate the concept the prototypes were fabricated, tested and compared with the simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1205-1215 Issue: 13 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1292153 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1292153 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:13:p:1205-1215 Template-Type: ReDIF-Article 1.0 Author-Name: Ling-ling Wang Author-X-Name-First: Ling-ling Author-X-Name-Last: Wang Author-Name: Shao-bin Liu Author-X-Name-First: Shao-bin Author-X-Name-Last: Liu Author-Name: Hai-feng Zhang Author-X-Name-First: Hai-feng Author-X-Name-Last: Zhang Author-Name: Xiang-kun Kong Author-X-Name-First: Xiang-kun Author-X-Name-Last: Kong Author-Name: Lu-lu Liu Author-X-Name-First: Lu-lu Author-X-Name-Last: Liu Title: High-impedance surface-based flexible broadband absorber Abstract: In this paper, a novel broadband flexible metamaterial absorber, which is based on high impedance surface (HIS), has been investigated. The polarization-insensitive absorber can suppress the backward RCS by about 10 dBm2. Numerically simulated results indicate that the HIS metamaterial absorber (HIS-MA) obtains 11.14 GHz wide absorption from 6.86 to 18 GHz with the absorption over 90%. The results of experiment coincide with simulations, which prove the feasibility of HIS-MA. The flexibility and absorption performance of the HIS-MA is demonstrated by simulating and measuring the absorptivity as the absorber is bended on cylinders, which can obtain some novel properties. The simulated results of bistatic RCS showed that the bistatic RCS of HIS-MA bended on a cylindrical object is reduced by nearly 10 dBm2 compared with the conventional planar HIS-MA. The proposed absorber has more advantages in conformal applications than ordinary rigid absorber in its stealth property. Journal: Journal of Electromagnetic Waves and Applications Pages: 1216-1231 Issue: 13 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1326850 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1326850 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:13:p:1216-1231 Template-Type: ReDIF-Article 1.0 Author-Name: Mathieu Gendron Author-X-Name-First: Mathieu Author-X-Name-Last: Gendron Author-Name: Bruce Hazel Author-X-Name-First: Bruce Author-X-Name-Last: Hazel Author-Name: Eric Boudreault Author-X-Name-First: Eric Author-X-Name-Last: Boudreault Author-Name: Henri Champliaud Author-X-Name-First: Henri Author-X-Name-Last: Champliaud Author-Name: Xuan-Tan Pham Author-X-Name-First: Xuan-Tan Author-X-Name-Last: Pham Title: Modeling circular inductors coupled to a semi-infinite magnetic medium considering the proximity effect Abstract: This paper presents a simple 2D electromagnetic model that solves the high-frequency current distribution, considering the proximity effect, in a planar spiral coil above a linear conductive or non-conductive semi-infinite magnetic medium. The conductive regions are divided into axisymmetric elements in which the current is assumed constant. The current flowing in each element depends on its complex impedance and is computed by Kirchhoff’s circuit law. To take the effect of the magnetic medium into account, a new set of mutual inductance formulas are presented. Those formulas are expressed in terms of elliptic integrals and the fast-converging arithmetic–geometric mean iteration of Gauss. The geometric mean distance method is used to deal with elements of arbitrarily shaped cross-section. Elliptic integrals are also used to express the magnetic flux density. The current distribution, the magnetic field and the equivalent impedance computed with the multifilament model agree well with the results obtained using commercial finite element software. Journal: Journal of Electromagnetic Waves and Applications Pages: 1232-1254 Issue: 13 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1336491 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1336491 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:13:p:1232-1254 Template-Type: ReDIF-Article 1.0 Author-Name: Li Gao Author-X-Name-First: Li Author-X-Name-Last: Gao Author-Name: Yao Zhang Author-X-Name-First: Yao Author-X-Name-Last: Zhang Author-Name: Jin-Xu Xu Author-X-Name-First: Jin-Xu Author-X-Name-Last: Xu Author-Name: Xiao-Lan Zhao Author-X-Name-First: Xiao-Lan Author-X-Name-Last: Zhao Title: Quad-band bandpass filter with controllable frequencies using asymmetric stub-loaded resonators Abstract: In this paper, we present a compact quad-band bandpass filter (BPF) using asymmetric stub-loaded resonators. The resonator consists of a main transmission line with a short stub and two pairs of open stubs with different lengths. The whole resonator can be regarded as two different half-wavelength resonators and a simple stub-loaded resonator. Therefore, the resonator consists of four controllable modes, which are utilized to realize a quad-band response. Meanwhile, by using hook shape feed lines and source-load coupling structure, transmission zeros are generated near the passband, resulting in high selectivity. For demonstration, a compact quad-band BPF with operating frequencies of 1.57/2.45/3.5/5.15 GHz is implemented. Good agreement between the measured and simulated results is presented to verify the theoretical prediction. Journal: Journal of Electromagnetic Waves and Applications Pages: 1255-1264 Issue: 13 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1341347 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1341347 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:13:p:1255-1264 Template-Type: ReDIF-Article 1.0 Author-Name: Volodymyr I. Fesenko Author-X-Name-First: Volodymyr I. Author-X-Name-Last: Fesenko Author-Name: Vladimir R. Tuz Author-X-Name-First: Vladimir R. Author-X-Name-Last: Tuz Author-Name: Illia V. Fedorin Author-X-Name-First: Illia V. Author-X-Name-Last: Fedorin Author-Name: Hong-Bo Sun Author-X-Name-First: Hong-Bo Author-X-Name-Last: Sun Author-Name: Valeriy M. Shulga Author-X-Name-First: Valeriy M. Author-X-Name-Last: Shulga Author-Name: Wei Han Author-X-Name-First: Wei Author-X-Name-Last: Han Title: Control of single-mode operation in a circular waveguide filled by a longitudinally magnetized gyroelectromagnetic medium Abstract: A substantial control of dispersion features of the hybrid EH01$ _{01} $ and HE11$ _{11} $ modes of a circular waveguide which is completely filled by a longitudinally magnetized composite finely-stratified ferrite-semiconductor structure is discussed. A relation between the resonant conditions of such a composite gyroelectromagnetic filling of the circular waveguide and dispersion features of the supported modes are studied. Three distinct frequency bands with the single-mode operation under normal as well as anomalous dispersion conditions of the EH01$ _{01} $ mode are identified by solving an optimization problem with respect to the filling factors of the composite medium. The possibility of achieving isolated propagation of the HE11$ _{11} $ mode is revealed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1265-1276 Issue: 13 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1346486 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1346486 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:13:p:1265-1276 Template-Type: ReDIF-Article 1.0 Author-Name: Omar Elizarraras Author-X-Name-First: Omar Author-X-Name-Last: Elizarraras Author-Name: Marco A. Panduro Author-X-Name-First: Marco A. Author-X-Name-Last: Panduro Author-Name: Aldo Mendez Author-X-Name-First: Aldo Author-X-Name-Last: Mendez Author-Name: Alberto Reyna Author-X-Name-First: Alberto Author-X-Name-Last: Reyna Author-Name: David H. Covarrubias Author-X-Name-First: David H. Author-X-Name-Last: Covarrubias Title: Design of circular antenna arrays of circular subarrays exploiting rotational symmetry Abstract: This paper presents a design of fractal antenna arrays based on circular arrays of circular subarrays for scannable pattern using rotational symmetry properties of the complex feeding excitations for a maximum performance in terms of side lobe level (SLL) and directivity (DIR). This fractal array design considers the optimization of the amplitude and phase excitations exploiting the fractal characteristics of the geometry (rotational symmetry) in order to generate a scannable pattern. The synthesis process is carried out by the method of Differential Evolution (DE). The main advantages of using rotational symmetry are that the optimal excitations for a particular beam steering angle could be applied to other beam steering angles remaining in the same array factor characteristics (SLL and directivity) for every beam steering angle. This design of fractal antenna arrays provides a complete scanning of the azimuth plane with optimal characteristics of the radiation pattern using just one optimal design vector of amplitude and phase excitations. Furthermore, the performance of the fractal antenna array optimized with DE is compared with respect to the cases of Genetic Algorithms (GA), Particle Swarm Optimization (PSO), and the conventional progressive phase for the same array geometry. Journal: Journal of Electromagnetic Waves and Applications Pages: 1277-1288 Issue: 13 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1347529 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1347529 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:13:p:1277-1288 Template-Type: ReDIF-Article 1.0 Author-Name: Süleyman İlker Mıstık Author-X-Name-First: Süleyman İlker Author-X-Name-Last: Mıstık Author-Name: Erhan Sancak Author-X-Name-First: Erhan Author-X-Name-Last: Sancak Author-Name: Sabih Ovalı Author-X-Name-First: Sabih Author-X-Name-Last: Ovalı Author-Name: Mehmet Akalın Author-X-Name-First: Mehmet Author-X-Name-Last: Akalın Title: Investigation of electromagnetic shielding properties of boron, carbon and boron–carbon fibre hybrid woven fabrics and their polymer composites Abstract: The growth of the electronic industry and the widespread use of electronic equipment in communications, computations, automations, biomedicine, space and other purposes have led to many electromagnetic interference (EMI) problems as systems operate in close proximity. It is likely to become more severe in the future, unless proper EMI control methodology and techniques are used to meet the electromagnetic compatibility requirements. In recent years, electromagnetic (EM) waves in the 1–10 GHz range are broadly used in wireless communication tools and local area networks. In the future, the usable range of EM waves will tend to shift further to higher frequency regions with the development of information technology as well as electronic devices. As a consequence, the seriousness of problems such as EMI of electronic devices and health issues is ever rising. In this study, electromagnetic shielding effectiveness, absorbance and reflectance properties of the boron, carbon and boron–carbon plain woven fabrics and boron/polyester, carbon/polyester, and boron–carbon/polyester hybrid composites were investigated. Using a coaxial transmission line holder set-up, the (EMSE), reflectance and absorbance of various fabrics and composites were carried out in the frequency range from 15 to 3000 MHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1289-1303 Issue: 13 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1348257 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1348257 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:13:p:1289-1303 Template-Type: ReDIF-Article 1.0 Author-Name: Haibo Song Author-X-Name-First: Haibo Author-X-Name-Last: Song Author-Name: Kefeng Ji Author-X-Name-First: Kefeng Author-X-Name-Last: Ji Author-Name: Kai Yang Author-X-Name-First: Kai Author-X-Name-Last: Yang Author-Name: Huanxin Zou Author-X-Name-First: Huanxin Author-X-Name-Last: Zou Author-Name: Jinjun Mo Author-X-Name-First: Jinjun Author-X-Name-Last: Mo Title: Extension of analytic physical optics to calculate bistatic 3D scattering from obtuse dihedral Abstract: As a canonical shape, dihedral’s scattering mechanism can be found in a variety of scenes and has been intensively studied in the past. The state-of-the-art analytic physical optics (APO), as a typical analytic solution, utilizes few physically relevant parameters to calculate the bistatic 3D scattering of dihedral accurately and efficiently. However, the original APO solution is only for right-angle dihedral case, in this paper, the APO is extended to calculate the bistatic 3D scattering of obtuse dihedral by introducing a parameter α (α ≥ 90°) which corresponding to the interior angle of dihedral. Then, with the general term α taking into account, like the right-angle dihedral case (i.e. α = 90°), the first- and second-order scatterings of obtuse dihedral are derived. Especially, for the computation of second-order scattering, the incident field and illuminated area of each plate are analyzed and derived in depth for the more complex and general obtuse dihedral geometry. Then, the total scattering solutions of obtuse dihedral composed of first- and second-order scatterings are presented. From the extension process, it is obvious that right-angle dihedral and rectangular plate are only the specific cases of the extended model. The experiments by comparing the extended model with shooting and bouncing rays and method of moments validate the effectiveness of the extension. Journal: Journal of Electromagnetic Waves and Applications Pages: 1304-1324 Issue: 13 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1348258 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1348258 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:13:p:1304-1324 Template-Type: ReDIF-Article 1.0 Author-Name: Aleksei P. Kiselev Author-X-Name-First: Aleksei P. Author-X-Name-Last: Kiselev Author-Name: Alexandr B. Plachenov Author-X-Name-First: Alexandr B. Author-X-Name-Last: Plachenov Author-Name: Galina N. Dyakova Author-X-Name-First: Galina N. Author-X-Name-Last: Dyakova Title: On the analyticity of waveforms in complexified relatively undistorted progressing waves Abstract: We consider two classes of exact solutions of the wave equation, which play an important role in the linear theory of localized wave propagation. These are the complexified spherical wave, known as the “complex source wavefield”, and the complexified Bateman solution. Both involve an arbitrary analytic function of a complex argument, known as the waveform. We explore a possibility of considering non-analytical waveforms and establish that in the both cases the analyticity is unavoidable. Journal: Journal of Electromagnetic Waves and Applications Pages: 1325-1332 Issue: 13 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1348259 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1348259 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:13:p:1325-1332 Template-Type: ReDIF-Article 1.0 Author-Name: Anupam R. Chandran Author-X-Name-First: Anupam R. Author-X-Name-Last: Chandran Author-Name: Senan Morris Author-X-Name-First: Senan Author-X-Name-Last: Morris Author-Name: Sujith Raman Author-X-Name-First: Sujith Author-X-Name-Last: Raman Author-Name: Nick Timmons Author-X-Name-First: Nick Author-X-Name-Last: Timmons Author-Name: Jim Morrison Author-X-Name-First: Jim Author-X-Name-Last: Morrison Title: Microstrip patch based switched beam antenna at 2.45 GHz for wireless sensor network applications Abstract: The design and development of a switched beam antenna at 2.45 GHz industrial, scientific and medical band for wireless sensor network applications is presented in this paper. The antenna is capable of switching the beam pattern in directions such as in the boresight direction 0°, ±63° and as a bidirectional endfire radiator (±85°). The directive gain of the antenna is 3.9, 5.8 and 5.8 dBi in respect to those angles. The shift in the resonance frequency is found to be negligible irrespective of the direction of the switched beam. The realized gain of the proposed antenna in the steering direction is found to be better than a standard microstrip patch antenna on the same size of the substrate and ground plane. The antenna was designed and optimized through simulations using CST microwave studio and the prototype was experimentally tested using R&S ZVB8 network analyser. Journal: Journal of Electromagnetic Waves and Applications Pages: 1333-1341 Issue: 13 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1348260 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1348260 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:13:p:1333-1341 Template-Type: ReDIF-Article 1.0 Author-Name: Yassine Nioua Author-X-Name-First: Yassine Author-X-Name-Last: Nioua Author-Name: Salahddine El Bouazzaoui Author-X-Name-First: Salahddine Author-X-Name-Last: El Bouazzaoui Author-Name: Mohammed Essaid Achour Author-X-Name-First: Mohammed Essaid Author-X-Name-Last: Achour Author-Name: Luis Cadillon Costa Author-X-Name-First: Luis Cadillon Author-X-Name-Last: Costa Title: Modeling microwave dielectric properties of polymer composites using the interphase approach Abstract: The electrical properties of heterogeneous materials are closely related to the composition of its constituents. Several theoretical approaches have been developed to predict the complex permittivity of composites materials, such as the mixture laws and the effective medium theories. However, these laws fail to interpret experimental data at high concentrations of filler, because the morphological parameters such as particle size, their distribution, and mostly the interphase region between the components are not taken into account. A new model for predicting the complex permittivity of composite materials is presented, taking into account the interaction between the filler and the matrix. We report a study on the dielectric properties of the epoxy polymer/carbon black nanocomposites, with different concentrations of the dispersed conducting particles, at 35 GHz, using the interphase model. The experimental results of the complex permittivity are compared to those obtained by the proposed theoretical model. Journal: Journal of Electromagnetic Waves and Applications Pages: 1343-1352 Issue: 14 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1348261 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1348261 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:14:p:1343-1352 Template-Type: ReDIF-Article 1.0 Author-Name: Aly R. Seadawy Author-X-Name-First: Aly R. Author-X-Name-Last: Seadawy Title: Modulation instability analysis for the generalized derivative higher order nonlinear Schrödinger equation and its the bright and dark soliton solutions Abstract: The generalized derivative higher order non-linear Schrödinger (DNLS) equation describes pluses propagation in optical fibers and can be regarded as a special case of the generalized higher order non-linear Schrödinger equation. We derive a Lagrangian and the invariant variational principle for DNLS equation. Using the amplitude ansatz method, we obtain the different cases of the exact bright, dark and bright–dark solitary wave soliton solutions of the generalized higher order DNLS equation. By implementing the modulation instability analysis and stability analysis solutions, the stability analysis of the obtained solutions and the movement role of the waves are analyzed. All solutions are analytic and stable. Journal: Journal of Electromagnetic Waves and Applications Pages: 1353-1362 Issue: 14 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1348262 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1348262 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:14:p:1353-1362 Template-Type: ReDIF-Article 1.0 Author-Name: Jun Chai Author-X-Name-First: Jun Author-X-Name-Last: Chai Author-Name: Bo Tian Author-X-Name-First: Bo Author-X-Name-Last: Tian Author-Name: Han-Peng Chai Author-X-Name-First: Han-Peng Author-X-Name-Last: Chai Author-Name: Yu-Qiang Yuan Author-X-Name-First: Yu-Qiang Author-X-Name-Last: Yuan Title: Lax pair and vector solitons for a variable-coefficient coherently-coupled nonlinear Schrödinger system in the nonlinear birefringent optical fiber Abstract: Nowadays, with respect to the nonlinear birefringent optical fibers, efforts have been put into investigating the coupled nonlinear Schrödinger (NLS) systems. In this paper, symbolic computation on a variable-coefficient coherently-coupled NLS system with the alternate signs of nonlinearities is performed. Under a variable-coefficient constraint Ω(t)2=[lnγ(t)]t2-[lnγ(t)]tt$ \Omega (t)^{2}=[\ln \gamma (t)]_{t}^{2}-[\ln \gamma (t)]_{tt} $, the system is shown to be integrable in the Lax sense with a Lax pair constructed, where t is the normalized time, γ(t)$ \gamma (t) $ is the strength of the four wave mixing terms, and Ω(t)2$ \Omega (t)^{2} $ is the strength of the anti-trapping parabolic potential. With an auxiliary function, bilinear forms, vector one- and two-soliton solutions are obtained. Figures are displayed to help us study the vector solitons: When γ(t)$ \gamma (t) $ is a constant, vector soliton propagates stably with the amplitude and velocity unvarying (vector soliton’s amplitude changes with the change of that constant, while its velocity can not be affected by that constant); When γ(t)$ \gamma (t) $ is a t-varying function, i.e. Ω(t)2≠0$ \Omega (t)^{2}\ne 0 $, amplitude and velocity of the vector soliton both vary with t increasing, while Ω(t)2$ \Omega (t)^{2} $ affects the vector soliton’s amplitude and velocity. With the different γ(t)$ \gamma (t) $ or Ω(t)2$ \Omega (t)^{2} $, interactions between the amplitude- and velocity-unvarying vector two solitons and those between the amplitude- and velocity-varying vector two solitons are displayed, respectively. By virtue of the system and its complex-conjugate system, conservation laws for the vector solitons, including the total energy and momentum, are constructed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1363-1375 Issue: 14 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1348994 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1348994 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:14:p:1363-1375 Template-Type: ReDIF-Article 1.0 Author-Name: Yaru Wang Author-X-Name-First: Yaru Author-X-Name-Last: Wang Author-Name: Zhihui Geng Author-X-Name-First: Zhihui Author-X-Name-Last: Geng Author-Name: Hongsheng Wang Author-X-Name-First: Hongsheng Author-X-Name-Last: Wang Author-Name: Xiaowan Hou Author-X-Name-First: Xiaowan Author-X-Name-Last: Hou Author-Name: Shouxi Xu Author-X-Name-First: Shouxi Author-X-Name-Last: Xu Author-Name: Gaofeng Liu Author-X-Name-First: Gaofeng Author-X-Name-Last: Liu Author-Name: Dongping Gao Author-X-Name-First: Dongping Author-X-Name-Last: Gao Title: Simulation of transverse field sweeping system and thermal analysis of an undepreesed collector for a gyrotron Abstract: In this paper, the simulation of transverse sweeping system (TFSS) and thermal analysis of undepressed collector for a 94 GHz, 30 kW CW gyrotron are presented. A smooth power-density distribution profile on the collector is obtained through repeated comparison of the TFSS simulation results, which indicates the range of spent beam spread and the peak power density are about 370 mm and 130 W/cm2, respectively. The sensitivities of the TFSS’s parameters to the power distribution profile are also studied and analyzed. To avoid the melting of the collector, a cooling channel groove is designed and the thermal analysis with finite element software ANSYS is performed under the non-uniform heat flux. The maximum outer and inner surface temperatures are 94.3 and 102.4 °C with water temperature at 20 °C, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 1376-1385 Issue: 14 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1348996 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1348996 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:14:p:1376-1385 Template-Type: ReDIF-Article 1.0 Author-Name: Izabela Slomian Author-X-Name-First: Izabela Author-X-Name-Last: Slomian Author-Name: Krzysztof Wincza Author-X-Name-First: Krzysztof Author-X-Name-Last: Wincza Author-Name: Kamil Staszek Author-X-Name-First: Kamil Author-X-Name-Last: Staszek Author-Name: Slawomir Gruszczynski Author-X-Name-First: Slawomir Author-X-Name-Last: Gruszczynski Title: Folded single-layer 8 × 8 Butler matrix Abstract: A concept of an 8 × 8 Butler matrix realized in a single-layer structure folded to create a cylindrical surface has been proposed. With the use of such a structure it is possible to eliminate crossovers and to reduce losses within a circuit by maintaining connecting lines as short as possible. The proposed concept has been experimentally verified by simulations and measurements of an 8 × 8 Butler matrix operating at 2.5 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1386-1398 Issue: 14 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1348997 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1348997 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:14:p:1386-1398 Template-Type: ReDIF-Article 1.0 Author-Name: L. Poli Author-X-Name-First: L. Author-X-Name-Last: Poli Author-Name: G. Oliveri Author-X-Name-First: G. Author-X-Name-Last: Oliveri Author-Name: P. Rocca Author-X-Name-First: P. Author-X-Name-Last: Rocca Author-Name: M. Salucci Author-X-Name-First: M. Author-X-Name-Last: Salucci Author-Name: A. Massa Author-X-Name-First: A. Author-X-Name-Last: Massa Title: Long-distance WPT unconventional arrays synthesis Abstract: Two innovative array concepts are introduced for the design of long-distance Wireless Power Transfer (WPT) radiating systems. The achievable tradeoffs between complexity/cost mitigation and power focusing capabilities of unconventional WPT architectures with respect to state-of-the-art optimal WPT solutions are investigated. To this end, clustered or sparse WPT arrangements are introduced by formulating their syntheses either as excitation or as pattern matching problems then solved by ad-hoc versions of the Contiguous Partition Method and Compressive Sensing algorithms. Selected numerical examples are presented to assess the features and the potentialities of unconventional WPT designs also in comparison with traditional state-of-the-art optimal methods. Journal: Journal of Electromagnetic Waves and Applications Pages: 1399-1420 Issue: 14 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1348998 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1348998 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:14:p:1399-1420 Template-Type: ReDIF-Article 1.0 Author-Name: Emanuele Calabrò Author-X-Name-First: Emanuele Author-X-Name-Last: Calabrò Author-Name: Salvatore Magazù Author-X-Name-First: Salvatore Author-X-Name-Last: Magazù Title: Experimental verification of the far-field approximation for a mobile phone antenna Abstract: The aim of this study was to verify the validity of the far-field approximation for a mobile phone during a call. Typical models of mobile phones were used to measure the electromagnetic field emitted during a call at various distances from the mobile phone using a selective radiation meter Narda SRM 3000. The near-field and far-field theories were applied to obtained measurements. As a result, the far-field approximation could be applied also at a few centimeters from the mobile phone. Nevertheless, it resulted that the best accuracy of the application of the far-field approximation to mobile phones working is obtained at distances larger than 40 cm, in agreement with the theoretic formulations relative to the condition that the antenna dimension is lesser than the wavelength of microwave radiation used by mobile phone working. Journal: Journal of Electromagnetic Waves and Applications Pages: 1421-1433 Issue: 14 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1348999 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1348999 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:14:p:1421-1433 Template-Type: ReDIF-Article 1.0 Author-Name: Sungwoo Lee Author-X-Name-First: Sungwoo Author-X-Name-Last: Lee Author-Name: Youngoo Yang Author-X-Name-First: Youngoo Author-X-Name-Last: Yang Author-Name: Kang-Yoon Lee Author-X-Name-First: Kang-Yoon Author-X-Name-Last: Lee Author-Name: Keum Cheol Hwang Author-X-Name-First: Keum Cheol Author-X-Name-Last: Hwang Title: Circularly polarized CHANEL-logo antenna for GNSS applications Abstract: In this study, a wearable CHANEL-logo antenna with circular polarization for global navigation satellite system (GNSS) applications is proposed. A leather substrate and EM-271S silver paste are used to fabricate the proposed antenna. In order to produce circular polarization while maintaining the configuration of the CHANEL-logo, a circular slot is embedded on a ground plane and a coplanar waveguide feed scheme is used. As a result, the proposed antenna produces right-hand circular polarization. A prototype of the proposed antenna is fabricated and measured to assess its performance. The measured -10$ -10 $ dB reflection and 3 dB axial ratio bandwidths of the proposed antenna are approximately 4.4% (1.555–1.625 GHz) and 3.14% (1.565–1.615 GHz), respectively. The measured peak gain of the fabricated antenna is -4.02$ -4.02 $ dBic. Journal: Journal of Electromagnetic Waves and Applications Pages: 1434-1443 Issue: 14 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1349000 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1349000 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:14:p:1434-1443 Template-Type: ReDIF-Article 1.0 Author-Name: Ferdows B. Zarrabi Author-X-Name-First: Ferdows B. Author-X-Name-Last: Zarrabi Author-Name: Maryam Bazgir Author-X-Name-First: Maryam Author-X-Name-Last: Bazgir Author-Name: Sepideh Ebrahimi Author-X-Name-First: Sepideh Author-X-Name-Last: Ebrahimi Author-Name: Afsaneh Saee Arezoomand Author-X-Name-First: Afsaneh Author-X-Name-Last: Saee Arezoomand Title: Fano resonance for U-I nano-array independent to the polarization providing bio-sensing applications Abstract: Investigation of nanoparticles independent of the incident wave polarization and its effects on Fano resonance is noticed in this article. In various studies, achievements of Fano resonance have been noticed in both symmetric and asymmetric structures based on interaction between bright and dark mode. However, Fano resonance in symmetric particles is limited to some special shapes therefore, we have noticed the existence of Fano resonance in asymmetric U-I structures. On the other hand, for making independent the polarization and reducing the polarization effect on cross section, we have suggested special array of the particles. The results show that we have both dark and bright modes at the bonding resonance and both array models show the polarization independence to the incident wave for mid infrared applications. For bio-sensing applications, the FOM factor is studied and compared for each resonance and it is revealed that at the Fano resonance, the FOM factor shows highest value in comparison to plasmonic mode at U-array structures which makes the Fano resonances valuable for distinguishing materials in the optical regime with more resolution. Journal: Journal of Electromagnetic Waves and Applications Pages: 1444-1452 Issue: 14 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1351401 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1351401 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:14:p:1444-1452 Template-Type: ReDIF-Article 1.0 Author-Name: Arcesio Arbelaez-Nieto Author-X-Name-First: Arcesio Author-X-Name-Last: Arbelaez-Nieto Author-Name: Jose-Luis Olvera-Cervantes Author-X-Name-First: Jose-Luis Author-X-Name-Last: Olvera-Cervantes Author-Name: Carlos E. Saavedra Author-X-Name-First: Carlos E. Author-X-Name-Last: Saavedra Author-Name: Alonso Corona-Chavez Author-X-Name-First: Alonso Author-X-Name-Last: Corona-Chavez Title: Balanced liquid metal reconfigurable microstrip filter Abstract: A reconfigurable balanced resonator and a reconfigurable Balanced Band-Pass Filter (BBPF) are presented in this work. The resonator is based on closed-loop transmission lines, two parallel lines and two T-sections. Reconfigurability is achieved using Eutetic Galium–Indium (EGaIn) liquid metal. A third-order reconfigurable filter was designed, fabricated, and measured to work at 2 and 1.65 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1453-1466 Issue: 14 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1351402 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1351402 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:14:p:1453-1466 Template-Type: ReDIF-Article 1.0 Author-Name: Wenxing Li Author-X-Name-First: Wenxing Author-X-Name-Last: Li Author-Name: Yuanyuan Li Author-X-Name-First: Yuanyuan Author-X-Name-Last: Li Author-Name: Chongyi Yue Author-X-Name-First: Chongyi Author-X-Name-Last: Yue Title: An angular-stable miniaturized frequency selective surface with controllable frequency band ratio using lumped elements Abstract: A novel dual-band miniaturized-element frequency selective surface (MEFSS) using lumped elements is proposed to achieve angular-stable response and controllable frequency band ratio. The MEFSS consists of two metal layers of the same period for the unit cell. The operating principle and the synthesis procedure of the MEFSS are analyzed based on the equivalent circuit model. The prototype of the MEFSS is simulated, fabricated, and tested, and the simulation results have a good agreement with the measurement results. To further reduce the element size and achieve a controllable band ratio, inductors and capacitors are, respectively, loaded on the top layer and the bottom layer of interlayer substrate to decrease the resonant frequency. Choosing the values of loaded lumped components properly, the resonance frequencies and the band ratio can be controlled. The unit size of this modified MEFSS is consumedly miniaturized to 0.0015λ0×0.0015λ0$ 0.0015 \ \lambda_{0} \times 0.0015 \ \lambda_{0} $, where λ0$ \lambda_{0} $ represents the resonance wavelength in free space. Compared to the previous works, the proposed MEFSS has a better miniaturization performance. The results show that the modified dual-band MEFSS has a large band ratio and high stability in the scope of incidence angles of 80° for TE and TM polarization. Journal: Journal of Electromagnetic Waves and Applications Pages: 1467-1483 Issue: 14 Volume: 31 Year: 2017 Month: 9 X-DOI: 10.1080/09205071.2017.1352540 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1352540 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:14:p:1467-1483 Template-Type: ReDIF-Article 1.0 Author-Name: S. M. Abo-Dahab Author-X-Name-First: S. M. Author-X-Name-Last: Abo-Dahab Author-Name: Siddhartha Biswas Author-X-Name-First: Siddhartha Author-X-Name-Last: Biswas Title: Effect of rotation on Rayleigh waves in magneto-thermoelastic transversely isotropic medium with thermal relaxation times Abstract: The present article deals with the propagation of Rayleigh surface waves in homogeneous transversely isotropic medium. Effect of rotation on Rayleigh waves in thermoelastic half-space is studied under the purview of the three-phase-lag model in presence of magnetic field. The normal mode analysis is used to obtain the expressions for the displacement components, stresses, and temperature distribution. The frequency equations in the closed form are derived and the path of particles during Rayleigh wave propagation is found elliptical. In order to illustrate the analytical developments, the numerical solution is carried out and the computer-simulated results in respect of Rayleigh wave velocity, attenuation coefficient, and specific loss are presented graphically. Journal: Journal of Electromagnetic Waves and Applications Pages: 1485-1507 Issue: 15 Volume: 31 Year: 2017 Month: 10 X-DOI: 10.1080/09205071.2017.1351403 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1351403 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:15:p:1485-1507 Template-Type: ReDIF-Article 1.0 Author-Name: Scott Ramsey Author-X-Name-First: Scott Author-X-Name-Last: Ramsey Author-Name: Troy Mayo Author-X-Name-First: Troy Author-X-Name-Last: Mayo Author-Name: Samuel G. Lambrakos Author-X-Name-First: Samuel G. Author-X-Name-Last: Lambrakos Title: A parametric model of NIR and SWIR reflectance spectra for dyed fabrics Abstract: This study describes a parametric model of diffuse reflectance for the purpose of simulating the spectral response of near-infrared (NIR, 0.7–0.9 μm) and shortwave infrared (SWIR, 0.9–1.7 μm) absorbing dyes for minimizing NIR-SWIR reflectance of dyed fabrics. This model is purely phenomenological, but is optimal with respect to numbers of parameters. This model establishes ground-work for development of a prediction tool, which when given the constituent materials available, will enable rapid optimization of NIR/SWIR band contrast matching of composite systems, (e.g. uniforms and ancillary gear) for a given specification of NIR-SWIR reflectance. This model adopts absorption coefficients for NIR/SWIR absorbing dyes whose absorption spectra span the NIR/SWIR spectral range. Military camouflage fabric consisting of 50/50 nylon/cotton blend in a ripstop weave printed with four-color digital pattern was used as the test substrate for NIR/SWIR dye application. The results of this study provide validation of the parametric model within reasonable error, for practical applications including simulating NIR/SWIR spectral responses corresponding to fixed dye and dye blend concentrations in prototype camouflage fabrics. Journal: Journal of Electromagnetic Waves and Applications Pages: 1508-1519 Issue: 15 Volume: 31 Year: 2017 Month: 10 X-DOI: 10.1080/09205071.2017.1352541 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1352541 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:15:p:1508-1519 Template-Type: ReDIF-Article 1.0 Author-Name: Lin-Ping Song Author-X-Name-First: Lin-Ping Author-X-Name-Last: Song Author-Name: Leonard R. Pasion Author-X-Name-First: Leonard R. Author-X-Name-Last: Pasion Author-Name: Douglas W. Oldenburg Author-X-Name-First: Douglas W. Author-X-Name-Last: Oldenburg Title: Space-time MUSIC imaging of EMI sensing data and a subspace partition study Abstract: To localize sources in electromagnetic induction (EMI) sensing, we propose a space-time MUltiple SIgnal Classification (MUSIC) imaging approach. Under the EMI physical model, the approach is established upon a receiver array-based spatial and temporal response matrix. In contrast to the multi-static response matrix-based MUSIC imaging approach that requires a sufficient number of receivers and transmitters, the new imaging scheme relaxes the condition on a large number of transmitters and thus becomes applicable to a wide range of EMI sensing systems. We also investigate the issue of forming a noise subspace that is essential to the MUSIC performance. Our theoretic analysis indicates that the choice of an underestimated noise subspace is appropriate for the imaging. Thus it implies, when doing a subspace partition required in the MUSIC, that a difficult task of exactly distinguishing signal from noise eigenvalues can be eased greatly in a practical eigenvalue distribution map. The technique is evaluated through the synthetic and real data. The results show that the space-time MUSIC can be used to detect sources with an EMI system consisting of multiple receivers but a few transmitters. As predicted from the theoretical analysis, the tests show that the MUSIC-source locations are robust to under-estimates of the dimension of the noise subspace. Journal: Journal of Electromagnetic Waves and Applications Pages: 1520-1540 Issue: 15 Volume: 31 Year: 2017 Month: 10 X-DOI: 10.1080/09205071.2017.1353925 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1353925 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:15:p:1520-1540 Template-Type: ReDIF-Article 1.0 Author-Name: Jagdish Kumar Author-X-Name-First: Jagdish Author-X-Name-Last: Kumar Author-Name: Rajendra Kumar Verma Author-X-Name-First: Rajendra Kumar Author-X-Name-Last: Verma Author-Name: Mahesh Kumar Author-X-Name-First: Mahesh Author-X-Name-Last: Kumar Author-Name: N. Kanagraj Author-X-Name-First: N. Author-X-Name-Last: Kanagraj Author-Name: S. Maurya Author-X-Name-First: S. Author-X-Name-Last: Maurya Author-Name: V. V. P. Singh Author-X-Name-First: V. V. P. Author-X-Name-Last: Singh Title: Design considerations and experimental estimation of temperature coefficient of resistance of W-Re heater for high power pulse magnetrons Abstract: This paper deals with the design methodology of the heater for an indirectly-heated oxide-coated-cathode of a 3 MW S-Band Pulse Magnetron. The temperature coefficient of resistance of 97%Tungsten – 3%Rhenium (W97-Re3) wire has been experimentally estimated. A value in the range of 3.07 × 10−3 – 3.43 × 10−3 per °C has been estimated over the temperature range of 863–1439 °C. An approach to design the heater has been evolved in order to ensure quality, reliability, and long life of high power magnetrons. Journal: Journal of Electromagnetic Waves and Applications Pages: 1541-1549 Issue: 15 Volume: 31 Year: 2017 Month: 10 X-DOI: 10.1080/09205071.2017.1353926 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1353926 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:15:p:1541-1549 Template-Type: ReDIF-Article 1.0 Author-Name: Jeet Banerjee Author-X-Name-First: Jeet Author-X-Name-Last: Banerjee Author-Name: Anirban Karmakar Author-X-Name-First: Anirban Author-X-Name-Last: Karmakar Author-Name: Rowdra Ghatak Author-X-Name-First: Rowdra Author-X-Name-Last: Ghatak Author-Name: Dipak Ranjan Poddar Author-X-Name-First: Dipak Ranjan Author-X-Name-Last: Poddar Title: Compact CPW-fed UWB MIMO antenna with a novel modified Minkowski fractal defected ground structure (DGS) for high isolation and triple band-notch characteristic Abstract: A compact printed ultra-wideband (UWB) multiple input multiple output (MIMO) antenna with coplanar waveguide feed for portable UWB applications is presented. The radiator and ground plane of the antenna are etched with an overall size of 26.75 mm × 41.5 mm. The UWB MIMO antenna consists of two planar identical monopole antenna elements and a novel modified Minkowski fractal defect is introduced in the ground plane for enhancing the isolation of the MIMO system. The proposed antenna has an impedance bandwidth (for │S11│ < −10 dB) ranging from 3.1 to 11.5 GHz (VSWR ≤ 2) and an isolation of more than 15 dB is achieved between the adjacent planar monopoles. The band rejection phenomenon in wireless local area network band is achieved by etching rotated C-shaped slots from the respective patches. Also, two identical rectangular slots are etched on the respective ground planes which enhances the lower UWB bandwidth and cause interference suppression at Wi-Max and C-band (3.3–3.7 and 3.7–4.2 GHz), respectively. A further improvement in isolation from 14.71 to 21.81 dB is achieved by the addition of parallel rectangular strips at the back side of the antenna. Acceptable agreement is obtained between the simulated and measured antenna performance parameters. Journal: Journal of Electromagnetic Waves and Applications Pages: 1550-1565 Issue: 15 Volume: 31 Year: 2017 Month: 10 X-DOI: 10.1080/09205071.2017.1354727 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1354727 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:15:p:1550-1565 Template-Type: ReDIF-Article 1.0 Author-Name: B. J. Xiang Author-X-Name-First: B. J. Author-X-Name-Last: Xiang Author-Name: X. F. Ye Author-X-Name-First: X. F. Author-X-Name-Last: Ye Author-Name: Y. F. Pan Author-X-Name-First: Y. F. Author-X-Name-Last: Pan Author-Name: S. Y. Zheng Author-X-Name-First: S. Y. Author-X-Name-Last: Zheng Author-Name: Y. L. Long Author-X-Name-First: Y. L. Author-X-Name-Last: Long Title: Coupling coefficient reconfigurable quadrature coupler based on mechanical switches Abstract: The conventional reconfigurable quadrature coupler configuration usually requires an external supply voltage which reduces its robustness. A new quadrature coupler with reconfigurable coupling coefficient is implemented using a mechanical control approach to simultaneously satisfy high performance and reliability requirements. Two mechanical switches are firstly implemented on a circular patch to realize two states with different coupling coefficient. To further increase the flexibility in reconfigurability, two more mechanical switches are employed. For demonstration purposes, two patch quadrature couplers were designed, simulated, and measured. The coupling coefficient of coupler I can be switched between 9 dB and 3 dB from 4.9 GHz to 5.3 GHz. Coupler II gave a reconfigurable coupling coefficient, which can be switched between 4 dB, 6 dB, and 11 dB at 3.5 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1566-1582 Issue: 15 Volume: 31 Year: 2017 Month: 10 X-DOI: 10.1080/09205071.2017.1355267 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1355267 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:15:p:1566-1582 Template-Type: ReDIF-Article 1.0 Author-Name: Woong Kang Author-X-Name-First: Woong Author-X-Name-Last: Kang Author-Name: Kangwook Kim Author-X-Name-First: Kangwook Author-X-Name-Last: Kim Title: Design and implementation of complementary dipoles with continuous resistive loading Abstract: A complementary pair of antennas with continuous resistive loading was implemented on a printed circuit board (PCB) with a resistive layer, and the characteristics were investigated for pulse radiation. The antennas considered in this paper are the resistively loaded dipole and its complementary conductively loaded slot (CS). The continuous loading profile was realized by tapering the resistive layer of the PCB through etching processes. With the proposed method of implementation, precise realization of the profile is made possible, while at the same time, the resulting structures are mechanically stable. The feeding structures for the proposed antennas were investigated to achieve stable impedance matching over a broad frequency range. In addition, in the case of the CS, the resistive termination of the PCB was investigated to reduce late-time ringing. The fabricated antennas were then measured and analyzed in the time domain for use in broadband pulse radiation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1583-1595 Issue: 15 Volume: 31 Year: 2017 Month: 10 X-DOI: 10.1080/09205071.2017.1356245 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1356245 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:15:p:1583-1595 Template-Type: ReDIF-Article 1.0 Author-Name: M. Hajji Author-X-Name-First: M. Author-X-Name-Last: Hajji Author-Name: M. Aidi Author-X-Name-First: M. Author-X-Name-Last: Aidi Author-Name: T. Aguili Author-X-Name-First: T. Author-X-Name-Last: Aguili Title: A new hybridization of MS-GEC and PO methods for study of electromagnetic scattering in waveguides Abstract: This paper proposes a new hybrid method called MS-GEC/PO. This method is based on the coupling between the multi-scale combined to generalized equivalent circuit method (MS-GEC) and the hybrid approach MoM-GEC/PO (MoM-GEC method coupled to Physical Optic method). The MS-GEC method, in its new formulation based on local modal operators, can reduce considerably the requirements (CPU time and memory resources) especially when the number of scales increases. However, the MoM-GEC/PO can reduce these requirements because it is based on a single test function permitting an important reduction of the manipulated matrices size. Consequently, applying the new hybridization MS-GEC/PO, we can take the advantageous of both of these methods assuring a multiple gain in requirements. In this paper, we present the new considered hybridization and we validate it on an example of application. The obtained results are in agreement with the MoM-GEC method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1596-1608 Issue: 15 Volume: 31 Year: 2017 Month: 10 X-DOI: 10.1080/09205071.2017.1356752 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1356752 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:15:p:1596-1608 Template-Type: ReDIF-Article 1.0 Author-Name: Shu-Chuan Chen Author-X-Name-First: Shu-Chuan Author-X-Name-Last: Chen Author-Name: Chih-Chia Huang Author-X-Name-First: Chih-Chia Author-X-Name-Last: Huang Author-Name: Ming-Chan Hsu Author-X-Name-First: Ming-Chan Author-X-Name-Last: Hsu Title: Reconfigurable long-term evolution/wireless wide area network antennas integrated with the metal frame of tablet computers Abstract: This study proposed a reconfigurable antenna design integrated with the metal frame of tablet computers that can switch between long-term evolution (LTE) and wireless wide area network (WWAN) frequencies. The antenna is installed in a 75 × 5 mm clearance without the ground plane, and a 2 mm opening is created on the metal frame on the top right side of the clearance, which create an open-slot structure. Moreover, this antenna structure contains a switch element; switching between on and off forms two antenna structures that generate two resonant modes of the antenna structure, as well as excites other resonant modes of the open-slot structure. Therefore, the proposed antenna design can cover both the low-frequency (i.e. LTE700/GSM850/900) and high-frequency (i.e. GSM1800/1900/UMTS/LTE2300/2500) bands of LTE/WWAN frequencies. Specifically, without using matching circuits, the proposed antenna can cover the eight frequency bands required for LTE/WWAN within a profile height of 5 mm simply by incorporating a switch element in the structure; hence, the proposed design is highly suitable for application in tablet devices with a narrow border. In addition, this antenna can be closely integrated with its surrounding metal elements and the measured results revealed an antenna efficiency of ≥50%, exceeding the requirement for actual application. Journal: Journal of Electromagnetic Waves and Applications Pages: 1609-1623 Issue: 15 Volume: 31 Year: 2017 Month: 10 X-DOI: 10.1080/09205071.2017.1356753 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1356753 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:15:p:1609-1623 Template-Type: ReDIF-Article 1.0 Author-Name: Qaisar Abbas Naqvi Author-X-Name-First: Qaisar Abbas Author-X-Name-Last: Naqvi Author-Name: Muhammad Arshad Fiaz Author-X-Name-First: Muhammad Arshad Author-X-Name-Last: Fiaz Title: Electromagnetic behavior of a planar interface of non-integer dimensional spaces Abstract: Reflection and transmission properties of a planar interface of two non-integer dimensional (NID) half spaces are studied. It is assumed that dimensions of both half spaces normal to the interface are non-integer. Both half spaces are distinguished from each other by non integer dimensions rather than wavenumbers. A plane wave has been taken as source of excitation. It is observed that non integer dimensions are also the factors controlling the reflection and transmission properties of the interface. Special cases are also considered when one or neither of the two half-spaces are NID. Journal: Journal of Electromagnetic Waves and Applications Pages: 1625-1637 Issue: 16 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1358108 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1358108 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:16:p:1625-1637 Template-Type: ReDIF-Article 1.0 Author-Name: H. Krraoui Author-X-Name-First: H. Author-X-Name-Last: Krraoui Author-Name: F. Mejri Author-X-Name-First: F. Author-X-Name-Last: Mejri Author-Name: T. Aguili Author-X-Name-First: T. Author-X-Name-Last: Aguili Title: Nondestructive measurement of complex permittivity by a microwave technique: detection of contamination and food quality Abstract: In this paper, we interested of wideband measurement system that permits to characterize high- and low-loss materials according to physical and chemical properties of cheddar cheese and beef. The proposed measurements system, spanning a frequency range of 1–18 GHz, is constituted by one port junction of a small diameter (a=0.8$ a=0.8 $ mm, b=2.7$ b=2.7 $ mm) coaxial probe and a standard rectangular waveguide. Theoretical reflection coefficient is obtained using the generalized equivalent circuit method that takes into account most of the involved physical phenomena. Thus, the effect of higher order modes as well as the dominant modes is considered. The complex permittivity of material is extracted by minimizing the difference between the theoretical and measured reflection coefficient. The complexity of the electromagnetic analysis does not allow to find an analytical relation between these two parameters. A computer code based on genetic algorithm is developed to numerically solve the inverse problem. To validate this program, we perform measurements on standard materials of known permittivity as air and FR4 (Flame Resistant 4) in the 1–18 GHz range. Journal: Journal of Electromagnetic Waves and Applications Pages: 1638-1657 Issue: 16 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1359114 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1359114 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:16:p:1638-1657 Template-Type: ReDIF-Article 1.0 Author-Name: Jia Zhao Author-X-Name-First: Jia Author-X-Name-Last: Zhao Author-Name: Min Zhang Author-X-Name-First: Min Author-X-Name-Last: Zhang Author-Name: Xin Wang Author-X-Name-First: Xin Author-X-Name-Last: Wang Author-Name: Ding Nie Author-X-Name-First: Ding Author-X-Name-Last: Nie Title: Parameters estimation and ISAR imaging of multiple maneuvering targets based on an order reduction method for cubic chirps Abstract: Inverse synthetic aperture radar (ISAR) imaging is an efficient method for providing high resolution image of maneuvering target especially in many military applications. Practically, the received echoes of complex maneuvering target are always described as cubic phase signals (CPS). Then, migrations through resolution cells are inevitably induced. Additionally, for scenes in which multiple targets exist, the situations become even worse. In this paper, an algorithm for parameters estimation and ISAR imaging of multiple maneuvering targets is proposed, where adjacent cross correlation function (ACCF), modified keystone transform (MKT), fractional Fourier transform (FrFT) and Hough transform (HT) are employed. The algorithm firstly employs ACCF to obtain a reduced order of the original CPS. Then, MKT and FrFT are introduced to realize parameters estimation of multiple targets. Thirdly, motion compensations for each target are accomplished with the estimators. Noting that the radar echoes are not separated previously, compensation result for one target is certainly interfered by the signal components of the others. To resolve this problem, edge detection and HT are utilized to separate the corrected range profile history. Finally, focused ISAR images of each target are obtained after azimuth compression. Simulation results demonstrate the validity of the proposed algorithm. Journal: Journal of Electromagnetic Waves and Applications Pages: 1658-1675 Issue: 16 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1359682 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1359682 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:16:p:1658-1675 Template-Type: ReDIF-Article 1.0 Author-Name: Shunyong Hu Author-X-Name-First: Shunyong Author-X-Name-Last: Hu Author-Name: Kaijun Song Author-X-Name-First: Kaijun Author-X-Name-Last: Song Author-Name: Yong Fan Author-X-Name-First: Yong Author-X-Name-Last: Fan Title: Multilayer four-way power divider with improved isolation performance Abstract: A novel compact quasi-planar four-way high isolation power divider is presented in this paper. The CPW-microstrip transition structure is used to imply the isolation circuit. The equivalent circuits are given to analyse and design the proposed power divider. To improve the isolation performance and output impedance matching, the phase compensation technique is analysed and used. A four-way high isolation power divider centred at 1.9 GHz is designed and fabricated. The measured results of the four-way power divider agree with the simulated results closely. The total size of the fabricated four-way power divider is 0.18 λg × 0.21 λg. The measured results indicate that the proposed power dividers have a low insertion loss, excellent impedance matching at all ports, good amplitude and phase balance at the output ports, and high isolation among the output ports. Journal: Journal of Electromagnetic Waves and Applications Pages: 1676-1684 Issue: 16 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1359684 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1359684 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:16:p:1676-1684 Template-Type: ReDIF-Article 1.0 Author-Name: Giovanni A. Casula Author-X-Name-First: Giovanni A. Author-X-Name-Last: Casula Author-Name: Giorgio Montisci Author-X-Name-First: Giorgio Author-X-Name-Last: Montisci Author-Name: Andrea Michel Author-X-Name-First: Andrea Author-X-Name-Last: Michel Author-Name: Paolo Nepa Author-X-Name-First: Paolo Author-X-Name-Last: Nepa Title: Robustness of complementary wearable ungrounded antennas with respect to the human body Abstract: Several wearable antennas have been presented in the open scientific literature, showing a good robustness with respect to the body coupling effect, both on the input matching and on the antenna efficiency. In this work, we evaluate and compare the robustness with respect to the coupling with the human body of complementary structures. We focus on structures widely used as wearable antennas, namely the ungrounded meandered printed antennas (which are electric antennas), and the ungrounded meandered slot printed antennas (which are magnetic antennas). We will show that, although in non-wearable context these complementary structures are essentially equivalent, for wearable applications it is preferable to use magnetic antennas configurations, i.e. meandered slot printed antennas, because, by means of appropriate design choices, they can be far less sensitive to the proximity to the human body. Journal: Journal of Electromagnetic Waves and Applications Pages: 1685-1697 Issue: 16 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1359685 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1359685 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:16:p:1685-1697 Template-Type: ReDIF-Article 1.0 Author-Name: Adam Kusiek Author-X-Name-First: Adam Author-X-Name-Last: Kusiek Author-Name: Jerzy Mazur Author-X-Name-First: Jerzy Author-X-Name-Last: Mazur Title: Left-handed propagation characteristics of a dielectric and metal-loaded periodic circular waveguide Abstract: In this paper, a periodic dielectric/metallic rod is located in a circular waveguide to obtain left-handed operation. Two geometries of the dielectric/metallic rod are proposed and examined. The dispersion characteristics of the investigated waveguides are obtained using a surface impedance model. Moreover, equivalent circuit models are proposed allowing for calculation of the dispersion characteristics and scattering parameters of the considered waveguide structures. The numerical results are compared with those obtained from commercial software and from experiment. The obtained results prove the left-handed properties of the investigated structures. Journal: Journal of Electromagnetic Waves and Applications Pages: 1698-1710 Issue: 16 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1360802 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1360802 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:16:p:1698-1710 Template-Type: ReDIF-Article 1.0 Author-Name: Muhammad Arshad Author-X-Name-First: Muhammad Author-X-Name-Last: Arshad Author-Name: Aly R. Seadawy Author-X-Name-First: Aly R. Author-X-Name-Last: Seadawy Author-Name: Dianchen Lu Author-X-Name-First: Dianchen Author-X-Name-Last: Lu Title: Bright–dark solitary wave solutions of generalized higher-order nonlinear Schrödinger equation and its applications in optics Abstract: Analysis of short-pulse propagation in positive dispersion media for example in optical fibers and in shallow water, requires assorted high-order derivative terms. The different dynamical features underlying soliton interactions in the generalized higher-order nonlinear Schrödinger equation, which model multimode wave propagation under varied physical situations in nonlinear optics, are studied. In this paper, the new exact solitary solutions in generalized form of generalized higher-order nonlinear Schrödinger equation (NLSE) are constructed with the aid of symbolic computation by employing modified extended direct algebraic method. The complex physical phenomena of generalized higher-order NLSE can be understand from the obtained solutions. The computational work shows that the current method is simple, general, powerful, effective, and wider applicable. Moreover, several new complex higher-order NLSEs that arising in mathematical physics can also be solved by this efficient method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1711-1721 Issue: 16 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1362361 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1362361 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:16:p:1711-1721 Template-Type: ReDIF-Article 1.0 Author-Name: D. Yang Author-X-Name-First: D. Author-X-Name-Last: Yang Author-Name: B. Liang Author-X-Name-First: B. Author-X-Name-Last: Liang Author-Name: D. Zhao Author-X-Name-First: D. Author-X-Name-Last: Zhao Author-Name: W. Shi Author-X-Name-First: W. Author-X-Name-Last: Shi Title: MIMO-SAR orthogonal waveform set design based on random subcarriers OFDM signal Abstract: The orthogonal waveform set with excellent characteristics is one of the key technologies to realize the advantages of the MIMO-SAR radar system. Among them, the orthogonality and Doppler tolerance are the most urgent requirements. The waveform sets with approximate rational orthogonality can be generated using interleaved subcarriers OFDM (I-OFDM) technique while maintaining the same range resolution as the OFDM signal, which has been paid more attention in MIMO radar waveform design. However, the narrow orthogonal time-delay range limits the design and application of I-OFDM orthogonal waveform sets. In this paper, random subcarriers OFDM (R-OFDM) design method is proposed. First, the cost function is constructed based on the PSLR and ISLR value of the autocorrelation and cross-correlation ambiguity function. Then, the subcarriers frequency distribution structure and the weighted scheme are obtained by the optimization algorithm. At last, the performance of the proposed waveform sets is verified by computer simulation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1722-1738 Issue: 16 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1363002 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1363002 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:16:p:1722-1738 Template-Type: ReDIF-Article 1.0 Author-Name: Héctor Lorduy G. Author-X-Name-First: Héctor Author-X-Name-Last: Lorduy G. Author-Name: L. M. Castellanos Author-X-Name-First: L. M. Author-X-Name-Last: Castellanos Author-Name: Jose Jiménez M. Author-X-Name-First: Jose Author-X-Name-Last: Jiménez M. Author-Name: Jimena Restrepo P. Author-X-Name-First: Jimena Author-X-Name-Last: Restrepo P. Title: Selected frequencies to obtain transmission coefficients invariant under deformation on LHM materials: an application to the sensors design Abstract: The use of sensors with metamaterials cells has become a common use practice. The frequency of the prove wave determines the number and size of the sensor. We report the results of simulations for a particular size and geometry of a metamaterial cell, were a small range of frequencies for which the transmission coefficient is invariant under cell’s deformations and the frequencies that can be used for sensing are below this critical frequency. Since the dimensions and geometric of the resonators (SRR) and thin wires (TW) determines the frequency of the magnetic and plasmonic resonances, we use deformations of the cells as sensing strategy, we propose a specific left-handed metamaterial pressure sensor using a deformable dielectric substrate loaded with TW and SRRs. We analyzed the modification of the transmission coefficient when the cell dimensions are changed, and show how critical is the choice of the sensing frequency. Journal: Journal of Electromagnetic Waves and Applications Pages: 1739-1745 Issue: 16 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1363671 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1363671 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:16:p:1739-1745 Template-Type: ReDIF-Article 1.0 Author-Name: Xiaoping Huang Author-X-Name-First: Xiaoping Author-X-Name-Last: Huang Author-Name: Fengzhen Song Author-X-Name-First: Fengzhen Author-X-Name-Last: Song Author-Name: Tao Chen Author-X-Name-First: Tao Author-X-Name-Last: Chen Author-Name: Peifeng Zhang Author-X-Name-First: Peifeng Author-X-Name-Last: Zhang Author-Name: Huayang Li Author-X-Name-First: Huayang Author-X-Name-Last: Li Author-Name: Jianjian Huo Author-X-Name-First: Jianjian Author-X-Name-Last: Huo Author-Name: Qing Zhao Author-X-Name-First: Qing Author-X-Name-Last: Zhao Title: Fixed low-frequency electrical parameter measurement on rock cores with the coaxial probe method Abstract: In the borehole radar detection, the dielectric permittivity testing is crucial to the accuracy of the detection depth. Usually, the dielectric permittivity εr$ \varepsilon_{r} $ is a dynamic parameter even in the same medium with different structures, or in the different physical environments. Therefore, testing methods for the dielectric permittivity measurement of the sample should be adjusted to fit the local conditions. However, it is usually difficult to measure the dielectric permittivity directly so far. In this paper, we present the design and fabrication of a fixed low-frequency electrical parameter testing system with open-ended coaxial probe technique to meet the desired requirement in borehole radar detection. Using this testing system, the dielectric permittivity of the rock core samples and non-rock samples was tested directly. The measured results and simulation results by CST are in good agreement, which demonstrated the accuracy of the measuring technique and the significance for microwave remote sensing in the dielectric permittivity measurements. So, our method could be extended to the application in borehole radar detection. Journal: Journal of Electromagnetic Waves and Applications Pages: 1746-1754 Issue: 16 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1363669 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1363669 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:16:p:1746-1754 Template-Type: ReDIF-Article 1.0 Author-Name: Erik Fritz-Andrade Author-X-Name-First: Erik Author-X-Name-Last: Fritz-Andrade Author-Name: Jose Alfredo Tirado-Mendez Author-X-Name-First: Jose Alfredo Author-X-Name-Last: Tirado-Mendez Author-Name: Hildeberto Jardon-Aguilar Author-X-Name-First: Hildeberto Author-X-Name-Last: Jardon-Aguilar Author-Name: Ruben Flores-Leal Author-X-Name-First: Ruben Author-X-Name-Last: Flores-Leal Title: Application of complementary split ring resonators for size reduction in patch antenna arrays Abstract: In this paper, a novel technique for reducing the dimensions of patch antennas and their arrays is presented. The procedure uses complementary split ring resonators (CSRRs) for increasing the slow-wave effect on the radiator, and therefore augmenting its electrical length, which implicates the modified antenna gets a lower physical dimension than a conventional one for a given frequency. Led by the use of CSRRs, the patches may be closer to each other, without affecting the side lobes magnitude either the directivity of the array compared to a conventional one. As an example, a 4 × 1 patch array was designed and its total area was 40% smaller compared to a conventional one, considering the same design conditions with and without CSRRs. The gain, directivity, and coupling of the prototype were not affected. Journal: Journal of Electromagnetic Waves and Applications Pages: 1755-1768 Issue: 16 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1363668 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1363668 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:16:p:1755-1768 Template-Type: ReDIF-Article 1.0 Author-Name: P. K. Choudhury Author-X-Name-First: P. K. Author-X-Name-Last: Choudhury Author-Name: M. Abou El-Nasr Author-X-Name-First: M. Author-X-Name-Last: Abou El-Nasr Title: Whither vacuum tubes? Journal: Journal of Electromagnetic Waves and Applications Pages: 1769-1770 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1357374 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1357374 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1769-1770 Template-Type: ReDIF-Article 1.0 Author-Name: B. N. Basu Author-X-Name-First: B. N. Author-X-Name-Last: Basu Author-Name: S. K. Datta Author-X-Name-First: S. K. Author-X-Name-Last: Datta Title: Microwave tubes and applications Journal: Journal of Electromagnetic Waves and Applications Pages: 1771-1774 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1375646 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1375646 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1771-1774 Template-Type: ReDIF-Article 1.0 Author-Name: A. S. Gilmour Author-X-Name-First: A. S. Author-X-Name-Last: Gilmour Title: An overview of my efforts to bridge the gap in the microwave tube area between what universities provide and what the industry needs Abstract: My efforts to “bridge the gap” span a period of nearly 40 years and consist of over 100 courses on microwave tubes presented to well over 2000 scientists, engineers, and technicians. I developed the first five-day course for the US Navy. After several more courses, I wrote Microwave Tubes. In 1988, I developed the equivalent of a one-semester course on traveling wave tubes for the Navy and presented it several times each at Teledyne, Litton, Varian, and Hughes. In 1994, I wrote Principles of Traveling Wave Tubes, which was translated and published in Russia. I continued expanding and refining the courses and, in 2011, I wrote Klystrons, Traveling Wave Tubes, Magnetrons, Crossed-Field Amplifiers, and Gyrotrons, which was translated and published in China. Most recently, my courses have been attended by scientists and engineers from China, Sweden, Turkey, the United Kingdom, and Germany as well as the United States. Journal: Journal of Electromagnetic Waves and Applications Pages: 1775-1785 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1338624 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1338624 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1775-1785 Template-Type: ReDIF-Article 1.0 Author-Name: Brian L. Beaudoin Author-X-Name-First: Brian L. Author-X-Name-Last: Beaudoin Author-Name: Gregory S. Nusinovich Author-X-Name-First: Gregory S. Author-X-Name-Last: Nusinovich Author-Name: Gennady Milikh Author-X-Name-First: Gennady Author-X-Name-Last: Milikh Author-Name: Antonio Ting Author-X-Name-First: Antonio Author-X-Name-Last: Ting Author-Name: Steven Gold Author-X-Name-First: Steven Author-X-Name-Last: Gold Author-Name: Jayakrishnan A. Karakkad Author-X-Name-First: Jayakrishnan A. Author-X-Name-Last: Karakkad Author-Name: Amith H. Narayan Author-X-Name-First: Amith H. Author-X-Name-Last: Narayan Author-Name: David B. Matthew Author-X-Name-First: David B. Author-X-Name-Last: Matthew Author-Name: Dennis K. Papadopoulos Author-X-Name-First: Dennis K. Author-X-Name-Last: Papadopoulos Author-Name: Thomas M. Antonsen Author-X-Name-First: Thomas M. Author-X-Name-Last: Antonsen Title: Highly efficient, megawatt-class, radio frequency source for mobile ionospheric heaters Abstract: A mobile heater for ionospheric modification studies requires a new megawatt (MW) class radio frequency (RF) source operating with an antenna array 1/20 the area of the High-Frequency Active Auroral Research Program (HAARP). To deliver an effective power density comparable to HAARP, the total source power must be in the range of 16 MW, thus demanding highly efficient sources. While the development of a whole multi-megawatt system for mobile ionospheric heaters is a complex engineering problem, in the present paper we describe only the work of our group on studying main features of a prototype MW-class vacuum electronics RF source for such system. The source design we are currently pursuing assumes class D operation using a modified version of the inductive output tube. The electron beam is a thin annular beam, switched on and off by a mod-anode as opposed to a grid. The beam is then passed through a decelerating gap, and its kinetic energy is extracted using a tunable resonant circuit that presents a constant impedance in the range of 3–10 MHz. With this design the beam is almost completely decelerated at all frequencies, thus achieving high efficiency. Journal: Journal of Electromagnetic Waves and Applications Pages: 1786-1801 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1360214 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1360214 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1786-1801 Template-Type: ReDIF-Article 1.0 Author-Name: Girish Chandra Tripathi Author-X-Name-First: Girish Chandra Author-X-Name-Last: Tripathi Author-Name: Meenakshi Rawat Author-X-Name-First: Meenakshi Author-X-Name-Last: Rawat Author-Name: Sudhir Kamath Author-X-Name-First: Sudhir Author-X-Name-Last: Kamath Author-Name: M. V. Kartikeyan Author-X-Name-First: M. V. Author-X-Name-Last: Kartikeyan Title: Linearization of traveling-wave tube amplifiers using digitally supported signal injection technique Abstract: This paper presents a digitally supported signal injection technique for the intermodulation distortion terms (IMDs) resulting from the non-linearity of Traveling-wave tube amplifiers. It is shown that the state-of-the art analog techniques have inherent limitation due to the inaccuracy of analog components. The proposed technique provides more accurate cancellation of third-order IMD as compared to its analog counterpart. Moreover, it is shown that the presented technique can be easily extended to compensate for higher order IMDs simultaneously. Journal: Journal of Electromagnetic Waves and Applications Pages: 1802-1815 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1374884 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1374884 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1802-1815 Template-Type: ReDIF-Article 1.0 Author-Name: S. E. Rahaman Author-X-Name-First: S. E. Author-X-Name-Last: Rahaman Author-Name: R. K. Barik Author-X-Name-First: R. K. Author-X-Name-Last: Barik Author-Name: A. K. Singh Author-X-Name-First: A. K. Author-X-Name-Last: Singh Author-Name: S. K. Shukla Author-X-Name-First: S. K. Author-X-Name-Last: Shukla Author-Name: S.-H. Min Author-X-Name-First: S.-H. Author-X-Name-Last: Min Author-Name: G.-S. Park Author-X-Name-First: G.-S. Author-X-Name-Last: Park Title: Design of high efficiency and high thrust grid system for ion thruster Abstract: Ion thruster is the most efficient population system of satellite to control its orbits in deep space. Total efficiency, thrust, and specific impulse are the key characterization parameters of an ion thruster which define its performance. At present, total efficiency is limited within the range of 36–68%. In this paper, a new grid design is discussed to increase the total efficiency and thrust of ion thruster wherein screen grid has chamfered edges. The ion beam dynamics were simulated in OPERA14.0-3D. The simulated result is shown to have increased thrust and total efficiency from 0.196–0.364 mN and 41.29–74.66%, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 1816-1825 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1349002 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1349002 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1816-1825 Template-Type: ReDIF-Article 1.0 Author-Name: Haiyang Wang Author-X-Name-First: Haiyang Author-X-Name-Last: Wang Author-Name: Biao Hu Author-X-Name-First: Biao Author-X-Name-Last: Hu Author-Name: Yaqun Jiang Author-X-Name-First: Yaqun Author-X-Name-Last: Jiang Author-Name: Chaoxiong He Author-X-Name-First: Chaoxiong Author-X-Name-Last: He Author-Name: Tianming Li Author-X-Name-First: Tianming Author-X-Name-Last: Li Author-Name: Jiayin Li Author-X-Name-First: Jiayin Author-X-Name-Last: Li Author-Name: Xinhui Wu Author-X-Name-First: Xinhui Author-X-Name-Last: Wu Title: Electromagnetic and particle-in-cell simulation studies of megawatt asymmetrical resonant magnetron Abstract: The asymmetrical resonant magnetron has been theoretically analysed and thoroughly simulated in this paper. By introducing the strap breaks and asymmetrical resonant cavity, the weaken field of the interaction zone can increase the interaction efficiency and the enhanced field of the output coupling also can improve the output power. Through the PIC simulation, the electron dynamics theory can be validated, at the same time, the critical characteristics such as the mode competition, output power and the conversion efficiency have been also well examined. The result shows that a careful control of the operating parameters is important for the performance, and this magnetron can finally generate a pure frequency spectrum at 2.9938 GHz with 3.21 MW output power and 43.23% conversion efficiency, respectively. Finally, this megawatt asymmetrical resonant magnetron has been successfully applied in the medical linear accelerator. Journal: Journal of Electromagnetic Waves and Applications Pages: 1826-1834 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1335622 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1335622 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1826-1834 Template-Type: ReDIF-Article 1.0 Author-Name: Xiaojie Chen Author-X-Name-First: Xiaojie Author-X-Name-Last: Chen Author-Name: Heping Huang Author-X-Name-First: Heping Author-X-Name-Last: Huang Author-Name: Wan Jiang Author-X-Name-First: Wan Author-X-Name-Last: Jiang Author-Name: Changjun Liu Author-X-Name-First: Changjun Author-X-Name-Last: Liu Title: Study on microwave coherent power combining based on 20-kW S-band CW power-adjustable magnetrons Abstract: In order to meet the requirements of large-power capacity in microwave-energy industry, the microwave coherent power combining by multiple magnetrons is a valid method to gain a large-power and high efficiency microwave source. In microwave energy applications, microwave absorption of industrial materials is varying in the heating duration and dependent on the dynamic change of materials. It is the first time that a 20-kW continuously power-adjustable injection-locked magnetron source has been achieved, and according to the experiment results, the maximum microwave coherent power combining output reaches 33.1 kW, and the coherent power combining efficiency is higher than 93%. The experiments show that the unbalanced output power between the two magnetrons does not affect greatly on the microwave coherent power combining efficiency. It is a great progress to develop the microwave power source which satisfies the power capacity requirement of microwave energy industry with the real-time power adjustment for the microwave industrial applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1835-1842 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1363003 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1363003 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1835-1842 Template-Type: ReDIF-Article 1.0 Author-Name: Gabriele Costanza Author-X-Name-First: Gabriele Author-X-Name-Last: Costanza Author-Name: Anders Karlsson Author-X-Name-First: Anders Author-X-Name-Last: Karlsson Title: Time domain analysis of higher order modes induced power dissipation in accelerating cavities Abstract: We give a semi-analytical method for the calculation of the transient power and energy dissipated in the cavity walls of an accelerating structure due to the excitation of the higher order modes by a sequence of accelerating bunches. We treat the case where more than one bunch is present in the structure at the same time. The dissipated power is evaluated using the Lagrangian formalism and the dissipation function. Both the dissipated power from the transient fields, present when the bunch is inside the cavity, and from the time harmonic fields, present when the bunch has left the cavity, are included in the evaluations. This method is applied to the six-cell elliptic medium beta cavities for the LINAC of the European Spallation Source. The simulations constitute a thorough test of the dissipated power of the design. Journal: Journal of Electromagnetic Waves and Applications Pages: 1843-1863 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1364174 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1364174 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1843-1863 Template-Type: ReDIF-Article 1.0 Author-Name: V. Nallasamy Author-X-Name-First: V. Author-X-Name-Last: Nallasamy Author-Name: Subrata Kumar Datta Author-X-Name-First: Subrata Kumar Author-X-Name-Last: Datta Author-Name: S. Umamaheswara Reddy Author-X-Name-First: S. Umamaheswara Author-X-Name-Last: Reddy Author-Name: P. K. Jain Author-X-Name-First: P. K. Author-X-Name-Last: Jain Title: Advances and present trends in magnetically insulated line oscillator Abstract: The magnetically insulated line oscillator is an attractive high-power microwave (HPM) source. It is a compact lightweight gigawatt-class coaxial crossed-field device requiring no externally applied magnetic field to insulate the electron flow between the anode–cathode gap. This paper is aimed at reviewing the work carried out in the area with emphasis on performance enhancement of the device, and its future in the wake of rapid development of HPM sources. A brief outline of the research pursued in the country also has been presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 1864-1874 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1338622 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1338622 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1864-1874 Template-Type: ReDIF-Article 1.0 Author-Name: Sun-Hong Min Author-X-Name-First: Sun-Hong Author-X-Name-Last: Min Author-Name: Ohjoon Kwon Author-X-Name-First: Ohjoon Author-X-Name-Last: Kwon Author-Name: Matlabjon Sattorov Author-X-Name-First: Matlabjon Author-X-Name-Last: Sattorov Author-Name: Hoechun Jung Author-X-Name-First: Hoechun Author-X-Name-Last: Jung Author-Name: In-Keun Baek Author-X-Name-First: In-Keun Author-X-Name-Last: Baek Author-Name: Seontae Kim Author-X-Name-First: Seontae Author-X-Name-Last: Kim Author-Name: Jin-Young Jeong Author-X-Name-First: Jin-Young Author-X-Name-Last: Jeong Author-Name: Jungmin Jang Author-X-Name-First: Jungmin Author-X-Name-Last: Jang Author-Name: Dongpyo Hong Author-X-Name-First: Dongpyo Author-X-Name-Last: Hong Author-Name: Ranajoy Bhattacharya Author-X-Name-First: Ranajoy Author-X-Name-Last: Bhattacharya Author-Name: Ranjan Kumar Barik Author-X-Name-First: Ranjan Kumar Author-X-Name-Last: Barik Author-Name: Anirban Bera Author-X-Name-First: Anirban Author-X-Name-Last: Bera Author-Name: Seunghyuk Park Author-X-Name-First: Seunghyuk Author-X-Name-Last: Park Author-Name: Jihwan Ahn Author-X-Name-First: Jihwan Author-X-Name-Last: Ahn Author-Name: Sang Heun Lee Author-X-Name-First: Sang Heun Author-X-Name-Last: Lee Author-Name: Young Joong Yoon Author-X-Name-First: Young Joong Author-X-Name-Last: Yoon Author-Name: Gun-Sik Park Author-X-Name-First: Gun-Sik Author-X-Name-Last: Park Title: Effects on electronics exposed to high-power microwaves on the basis of a relativistic backward-wave oscillator operating on the X-band Abstract: An analysis of the effects of electromagnetic pulses from a high-power microwave (HPM) radiation technique is conducted using a relativistic backward-wave oscillator (RBWO) which uses relativistic electron beams in vacuum circuits. The application described here is based on a relativistic electron device and uses relativistic electron beams to generate high-power electromagnetic radiation. The RBWO was fabricated to operate in a relativistic region with a gamma factor (γ) of 2 at an acceleration voltage of 500 kV. A mode-converted relativistic back-wave oscillator with an antenna that converts TM01 to TE11 was designed and fabricated because the electric field of the center in the RBWO circuit is null. The effects on electronic devices by HPM radiation and exposure were assessed. The effects on electronic devices exposed to HPMs, the failure of information equipment, and modulation of and interference with the received signal through a theoretical model of the threshold power relative to the influence on the target were confirmed in a high-output microwave exposure environment. Particularly, information devices containing semiconductors can undergo serious failures and breakdowns due to the thermal secondary breakdown caused by the high-output transient electromagnetic waves, and it is a theoretical consideration that reverse voltage occurs due to the generation of surge current when caught in the PN-junction region. Finally, the range of power regarding the effectiveness of the electromagnetic coupling of electronics exposed to HPM radiation was estimated. Journal: Journal of Electromagnetic Waves and Applications Pages: 1875-1901 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1354728 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1354728 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1875-1901 Template-Type: ReDIF-Article 1.0 Author-Name: Robert Waring Author-X-Name-First: Robert Author-X-Name-Last: Waring Author-Name: Claudio Paoloni Author-X-Name-First: Claudio Author-X-Name-Last: Paoloni Title: Lagrangian simulator for millimetre wave TWT based on non-rotationally symmetric slow wave structure Abstract: A novel Lagrangian code for fast simulation of non-rotationally symmetric slow wave structure for millimetre wave Travelling wave tubes is proposed. Novel slow wave structures (SWS) suitable for fabrication at millimetre wave frequencies often have non-rotationally symmetric, differently from the helix that has a cylindrical symmetry. This prevents the use of conventional Lagrangian simulators valid for symmetric cylindrical symmetry. A modified Lagrangian simulator to simulate arbitrary symmetry SWS is proposed. The proposed simulator permits a very fast simulation of the large signal performance of the novel SWS, as the Double Corrugated Waveguide. Journal: Journal of Electromagnetic Waves and Applications Pages: 1902-1913 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1365629 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1365629 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1902-1913 Template-Type: ReDIF-Article 1.0 Author-Name: Zhanliang Wang Author-X-Name-First: Zhanliang Author-X-Name-Last: Wang Author-Name: Qing Zhou Author-X-Name-First: Qing Author-X-Name-Last: Zhou Author-Name: Huarong Gong Author-X-Name-First: Huarong Author-X-Name-Last: Gong Author-Name: Junpeng Liao Author-X-Name-First: Junpeng Author-X-Name-Last: Liao Author-Name: Yanyu Wei Author-X-Name-First: Yanyu Author-X-Name-Last: Wei Author-Name: Zhaoyun Duan Author-X-Name-First: Zhaoyun Author-X-Name-Last: Duan Author-Name: Hongwei Liu Author-X-Name-First: Hongwei Author-X-Name-Last: Liu Author-Name: Yubin Gong Author-X-Name-First: Yubin Author-X-Name-Last: Gong Title: Development of a 140-GHz folded-waveguide traveling-wave tube in a relatively larger circular electron beam tunnel Abstract: A 140-GHz folded-waveguide traveling wave tube (FWG-TWT) with a relatively larger circular electron beam tunnel was designed and developed. Using simulation software, the high frequency characteristics, the transfer characteristics, and the beam-wave interaction of the TWT were studied in detail. The simulation predicted up to 98 W output power and about 43 dB gain of FWG-TWT at the center frequency. The input and output couplers compatible with the FWG-SWS and the periodic permanent magnet focusing structure were designed. The FWG-TWT thus designed was fabricated and tested. The experimental result shows the output power exceeding 1.6 W and the gain exceeding 25 dB at 140 GHz when the input power is 5 mW. The reasons for the departure of the experimental from the simulated results have been explained. Journal: Journal of Electromagnetic Waves and Applications Pages: 1914-1923 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1341346 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1341346 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1914-1923 Template-Type: ReDIF-Article 1.0 Author-Name: Hongwei Liu Author-X-Name-First: Hongwei Author-X-Name-Last: Liu Author-Name: Zhanliang Wang Author-X-Name-First: Zhanliang Author-X-Name-Last: Wang Author-Name: Yubin Gong Author-X-Name-First: Yubin Author-X-Name-Last: Gong Author-Name: Yanyu Wei Author-X-Name-First: Yanyu Author-X-Name-Last: Wei Author-Name: Zhaoyun Duan Author-X-Name-First: Zhaoyun Author-X-Name-Last: Duan Author-Name: Huarong Gong Author-X-Name-First: Huarong Author-X-Name-Last: Gong Author-Name: Jinjun Feng Author-X-Name-First: Jinjun Author-X-Name-Last: Feng Title: Study on Ka-band sheet-beam, three-slot-staggered-ladder coupled-cavity traveling-wave tube in a small tunable periodic cusped magnet Abstract: A Ka-band sheet electron beam (SEB) traveling-wave tube (TWT) based on three-slot staggered-ladder (TSTL) coupled-cavity slow-wave structure (CC-SWS) is proposed. The high-frequency characteristics of TSTL SWS were analyzed in detail. A well-matched input/output coupling system that solves the problem of energy coupling between the SWS and the external circuit was designed. A new method of loading the distributed attenuator for TSTL SWS was investigated for suppressing backward wave oscillation effectively. In addition, a SEB gun which can produce the SEB conveniently was optimized. A small tunable periodic cusped magnet (STPCM) system was designed to focus the low voltage, high-current SEB, which decreases the whole dimension of the TWT sufficiently. Moreover, the special STPCM system is predicted to exhibit 100% beam transmission efficiency. Finally, the beam-wave interaction was studied. The results obtained by CST simulation show that the SEB TWT can produce output power over 5 kW within the bandwidth ranging from 31.5 to 35.5 GHz, and the maximum output power is 10.15 kW at 33 GHz, corresponding electron efficiency of 10.36%. The fabrication of the device is under way. Journal: Journal of Electromagnetic Waves and Applications Pages: 1924-1937 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1341855 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1341855 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1924-1937 Template-Type: ReDIF-Article 1.0 Author-Name: Ding Chong Author-X-Name-First: Ding Author-X-Name-Last: Chong Author-Name: Wei Yanyu Author-X-Name-First: Wei Author-X-Name-Last: Yanyu Author-Name: Li Qian Author-X-Name-First: Li Author-X-Name-Last: Qian Author-Name: Zhang Luqi Author-X-Name-First: Zhang Author-X-Name-Last: Luqi Author-Name: Guo Guo Author-X-Name-First: Guo Author-X-Name-Last: Guo Author-Name: Gong Yubin Author-X-Name-First: Gong Author-X-Name-Last: Yubin Title: A dielectric-embedded microstrip meander line slow-wave structure for miniaturized traveling wave tube Abstract: A modified microstrip meander line (MML) slow-wave structure (SWS) embedded with dielectric rod for miniaturized traveling wave tubes (TWTs) is presented in this paper. High-frequency characteristics, fabrication processes, and beam-wave interaction of the modified MML SWS are analyzed. Compared with conventional MML SWSs supported by dielectric substrate, the modified MML SWS possesses a wider cold bandwidth (about 53.5% increased) and larger interaction impedances (about 21.4% increased). Moreover, this modified MML has better connection with the dielectric, which may improve the slow-wave structure’s stability and reliability under thermal shock, stress impact, and electron bombardment. The beam-wave interaction simulation results indicate that TWTs using the modified MML SWS is capable of delivering 75.85 W saturated output power, corresponding a gain of 28.8 dB and an electron efficiency of 6.32% at the frequency of 35 GHz, with the sheet electron beam of 6000 V and 200 mA. Journal: Journal of Electromagnetic Waves and Applications Pages: 1938-1946 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1358109 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1358109 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1938-1946 Template-Type: ReDIF-Article 1.0 Author-Name: Nitin Kumar Author-X-Name-First: Nitin Author-X-Name-Last: Kumar Author-Name: Udaybir Singh Author-X-Name-First: Udaybir Author-X-Name-Last: Singh Author-Name: Anirban Bera Author-X-Name-First: Anirban Author-X-Name-Last: Bera Author-Name: A. K. Sinha Author-X-Name-First: A. K. Author-X-Name-Last: Sinha Title: A gyrating electron beam source for frequency tunable, 200 GHz gyrotron Abstract: Magnetron injection gun (MIG) is an important and critical part of any gyrotron. The overall performance of gyrotron deeply depends on the quality of gyrating electron beam. In this article, the design of triode type magnetron injection gun for 200 GHz frequency tunable gyrotron is discussed. It is planned to design and develop a 200 GHz gyrotron for 300 MHz DNP-NMR spectroscopy. The triode MIG is designed in such a way that it can be used in 200 GHz gyrotron of higher RF power for other applications also such as electron spin resonance, imaging. First, geometrical and electrical parameters of MIG are calculated using trade-off and scaling equations. Based on the calculated parameters, further, electron beam trajectory simulations are performed in EGUN. The geometry of electrodes are optimized through numerous simulation iterations to achieve the required beam parameters, such as, minimum spread in velocity and guiding center radius, an optimum value of velocity ratio (1.3–1.5), guiding center radius as per the maximum beam-wave coupling strength. The magnet system is designed to achieve the smooth Gaussian type of magnetic field profile with peak value of 7.35 T at cavity center. Further detail parametric analyses are performed which would be helpful in the frequency tuning and long-time stable operation of gyrotron device. Journal: Journal of Electromagnetic Waves and Applications Pages: 1947-1958 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1349001 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1349001 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1947-1958 Template-Type: ReDIF-Article 1.0 Author-Name: Shahana K. Author-X-Name-First: Shahana Author-X-Name-Last: K. Author-Name: Vishal Kesari Author-X-Name-First: Vishal Author-X-Name-Last: Kesari Author-Name: S. Karmakar Author-X-Name-First: S. Author-X-Name-Last: Karmakar Author-Name: R. Seshadri Author-X-Name-First: R. Author-X-Name-Last: Seshadri Title: Simulation of TE6,2-to-Gaussian mode launcher for a millimeter-wave gyrotron Abstract: The short-length TE6,2-to-Gaussian mode launcher for a millimeter-wave transverse output gyrotron was designed and simulated using two different software tools, namely Launcher Optimization Tool (LOT) and Surf3d. The geometrical parameters were calculated using geometric optics theory and the dimensions were optimized using the tools: LOT and Surf3d to achieve maximum possible (>95%) energy conversion and Gaussian fit. The launcher length to cut length ratio has been optimized as 4.15, taper angle 0.23° and the helical cut angle 70.6° for achieving energy conversion of 96 and 97%, and Gaussian fit of 98 and 97%, respectively, using LOT and Surf3d. Further, the radial variations in azimuth as well as in axial direction due to dimpled profiles obtained using the two tools were compared. Journal: Journal of Electromagnetic Waves and Applications Pages: 1959-1970 Issue: 17 Volume: 31 Year: 2017 Month: 11 X-DOI: 10.1080/09205071.2017.1360213 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1360213 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:17:p:1959-1970 Template-Type: ReDIF-Article 1.0 Author-Name: P. K. Choudhury Author-X-Name-First: P. K. Author-X-Name-Last: Choudhury Author-Name: M. Abou El-Nasr Author-X-Name-First: M. Author-X-Name-Last: Abou El-Nasr Title: Current trends of graphene technology Journal: Journal of Electromagnetic Waves and Applications Pages: 1971-1973 Issue: 18 Volume: 31 Year: 2017 Month: 12 X-DOI: 10.1080/09205071.2017.1388629 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1388629 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:18:p:1971-1973 Template-Type: ReDIF-Article 1.0 Author-Name: Sudin Ganguly Author-X-Name-First: Sudin Author-X-Name-Last: Ganguly Author-Name: Saurabh Basu Author-X-Name-First: Saurabh Author-X-Name-Last: Basu Title: Conductance properties of six terminal graphene nanoribbons in presence of a magnetic field: integer quantum Hall effect revisited Abstract: We study the behavior of charge and spin transport properties in the presence of magnetic field and Rashba spin-orbit interaction in a six-terminal graphene nanoribbon using the multi-terminal Landauer-Büttiker formula and Green’s function approach. We find that the Rashba spin-orbit coupling have detrimental effect on the quantum Hall plateaus in the sense that the width of the plateaus have drastically reduced in presence of the spin-orbit term. To assess whether presence of magnetic fields will have effects on the spintronic applications, we study the spin Hall conductance in presence of magnetic field. The spin Hall conductance features are also affected by the presence of a magnetic field where the antisymmetric nature with respect to zero of the Fermi energy, a prominent signature of the electron-hole symmetry, is destroyed. The local density of states data provides strong evidence of the above results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1974-1982 Issue: 18 Volume: 31 Year: 2017 Month: 12 X-DOI: 10.1080/09205071.2017.1369907 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1369907 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:18:p:1974-1982 Template-Type: ReDIF-Article 1.0 Author-Name: Jianying Guo Author-X-Name-First: Jianying Author-X-Name-Last: Guo Author-Name: Juan Chen Author-X-Name-First: Juan Author-X-Name-Last: Chen Author-Name: Jianguo Wang Author-X-Name-First: Jianguo Author-X-Name-Last: Wang Title: Using HIE-FDTD method to simulate graphene’s interband conductivity Abstract: A hybrid implicit–explicit-finite-difference time-domain (HIE-FDTD) method is modified to simulate the graphene. In this method, both the intraband and interband conductivity of grahene are considered. A simple Pade fit method is used to represent the interband conductivity which has complex relation with the angular frequency, and is incorporated into the HIE-FDTD method directly through an auxiliary difference equation. An infinite graphene sheet is simulated using presented technique and the result is compared with that of the conventional FDTD scheme and theoretical value. The results show that the HIE-FDTD method has excellent computational accuracy and considerably higher computational efficiency than FDTD scheme. Besides, the numerical example presents that the interband conductivity of the graphene has important effect on the numerical result at high frequency range, especially when the chemical potential is small. Journal: Journal of Electromagnetic Waves and Applications Pages: 1983-1993 Issue: 18 Volume: 31 Year: 2017 Month: 12 X-DOI: 10.1080/09205071.2017.1296789 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1296789 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:18:p:1983-1993 Template-Type: ReDIF-Article 1.0 Author-Name: Juan Chen Author-X-Name-First: Juan Author-X-Name-Last: Chen Author-Name: Jianying Guo Author-X-Name-First: Jianying Author-X-Name-Last: Guo Author-Name: Anxue Zhang Author-X-Name-First: Anxue Author-X-Name-Last: Zhang Title: Incorporating interband conductivity into ADI-FDTD method to simulate graphene Abstract: The interband conductivity of graphene approximated by using Pade fit method is incorporated into the alternating-direction implicit finite difference time domain (ADI-FDTD) method to simulate graphene. The accuracy of the Pade fit method is verified. The ADI-FDTD method is unconditionally stable, so its computational efficiency is greatly larger than that of FDTD method, which is validated by numerical example. Besides, it shows that the interband conductivity of graphene has important effect on numerical result at high frequency range, especially when chemical potential is small. Journal: Journal of Electromagnetic Waves and Applications Pages: 1994-2004 Issue: 18 Volume: 31 Year: 2017 Month: 12 X-DOI: 10.1080/09205071.2016.1264318 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1264318 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:18:p:1994-2004 Template-Type: ReDIF-Article 1.0 Author-Name: Ning Xu Author-X-Name-First: Ning Author-X-Name-Last: Xu Author-Name: Juan Chen Author-X-Name-First: Juan Author-X-Name-Last: Chen Author-Name: Jianguo Wang Author-X-Name-First: Jianguo Author-X-Name-Last: Wang Author-Name: Xijia Qin Author-X-Name-First: Xijia Author-X-Name-Last: Qin Title: A dispersive WCS-FDTD method for simulating graphene-based absorber Abstract: A dispersive weakly conditionally stable finite-difference time-domain (WCS-FDTD) method for the efficient simulations of the graphene-based absorbers with fine structures in two directions is proposed in this paper. It is based on the auxiliary differential equation technique and the hybrid implicit explicit difference technique. The maximum time step size of this method is only determined by the largest spatial discretization. The numerical results demonstrate that the dispersive WCS-FDTD method has high computational accuracy and the computational time is greatly reduced compared with the dispersive FDTD method and the dispersive HIE-FDTD method. Journal: Journal of Electromagnetic Waves and Applications Pages: 2005-2015 Issue: 18 Volume: 31 Year: 2017 Month: 12 X-DOI: 10.1080/09205071.2017.1330161 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1330161 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:18:p:2005-2015 Template-Type: ReDIF-Article 1.0 Author-Name: Guangsheng Deng Author-X-Name-First: Guangsheng Author-X-Name-Last: Deng Author-Name: Tianyu Xia Author-X-Name-First: Tianyu Author-X-Name-Last: Xia Author-Name: Jun Yang Author-X-Name-First: Jun Author-X-Name-Last: Yang Author-Name: Zhiping Yin Author-X-Name-First: Zhiping Author-X-Name-Last: Yin Title: A graphene-based broadband terahertz metamaterial modulator Abstract: A metamaterial (MM) structure composed of a graphene layer, a SiO2/Si substrate, and a metal pattern layer, which is dynamically tunable is numerically proposed at terahertz (THz) frequencies. This study shows that the modulation of the proposed structure mainly depends on the transmission band between two neighboring resonance dips. Based on this property, a fairly wide modulation bandwidth is realized. Moreover, by adjusting the Fermi level of the graphene layer, a modulation depth of the transmission can reach 91.63% for y-polarized wave and 78.66% for x-polarized wave, respectively. Most importantly, the fabrication of the proposed structure is much easier than reported graphene MM modulators as the graphene monolayer is directly deposited on a substrate. This work may provide a further step in the development of tunable devices, such as broadband transmission modulators and sensors. Journal: Journal of Electromagnetic Waves and Applications Pages: 2016-2024 Issue: 18 Volume: 31 Year: 2017 Month: 12 X-DOI: 10.1080/09205071.2016.1277960 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1277960 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:18:p:2016-2024 Template-Type: ReDIF-Article 1.0 Author-Name: Masoud Jabbari Author-X-Name-First: Masoud Author-X-Name-Last: Jabbari Title: Coherent and incoherent manipulation of optical bistability and group velocity in a dielectric slab with a monolayer of quantized graphene Abstract: A new model is suggested for controlling the optical bistability (OB) and group velocity of transmitted light via coherent and incoherent control of applied fields. Our proposed structure is studied theoretically based on quantum coherence and interference mechanism in a defect dielectric slab with a monolayer of quantized four-level graphene system. Our results show that the manipulation of OB by adjusting the controllable parameters can be possible at one or more points of the bistable spectrum. Moreover, our investigations on the transmitted and reflected pulses show that the subluminal and superluminal light propagation can be possible in a specific situation of parametric conditions. Journal: Journal of Electromagnetic Waves and Applications Pages: 2025-2035 Issue: 18 Volume: 31 Year: 2017 Month: 12 X-DOI: 10.1080/09205071.2017.1323016 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1323016 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:18:p:2025-2035 Template-Type: ReDIF-Article 1.0 Author-Name: Jeet Ghosh Author-X-Name-First: Jeet Author-X-Name-Last: Ghosh Author-Name: Debasis Mitra Author-X-Name-First: Debasis Author-X-Name-Last: Mitra Title: Mutual coupling reduction in planar antenna by graphene metasurface for THz application Abstract: This paper presents an effective approach to mitigate mutual coupling between two densely packed planar antenna operating at the lower THz frequency band by incorporating a graphene-based metasurface. The graphene metasurface has been designed using Electric inductive capacitive (ELC) resonator on the both sides of a silicon substrate. The metasurface is designed to provide band stop functionality in the operating bandwidth of the antenna. Here, surface impedance model of the graphene is used for analysing the metasurface layer. Throughout the operating band of the antenna, coupling suppression of 8–12 dB is obtained with element separation of less than λ0/12$ \lambda_{0} /12 $. Thus, this proposed approach can be utilized to mitigate mutual coupling between antennas in THz application. Journal: Journal of Electromagnetic Waves and Applications Pages: 2036-2045 Issue: 18 Volume: 31 Year: 2017 Month: 12 X-DOI: 10.1080/09205071.2016.1277959 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1277959 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:18:p:2036-2045 Template-Type: ReDIF-Article 1.0 Author-Name: J. Kumar Author-X-Name-First: J. Author-X-Name-Last: Kumar Author-Name: B. Basu Author-X-Name-First: B. Author-X-Name-Last: Basu Author-Name: F. A. Talukdar Author-X-Name-First: F. A. Author-X-Name-Last: Talukdar Author-Name: A. Nandi Author-X-Name-First: A. Author-X-Name-Last: Nandi Title: Graphene-based wideband antenna for aeronautical radio-navigation applications Abstract: In this paper, a conductive layer is developed by printing a graphene nanoparticles-based conductive ink on the silk fabric showing surface resistance of 2.3 Ω$ \Omega $S-1$ ^{-1} $ and conductivity of 0.435×105$ 0.435\times 10^5 $ Sm-1$ ^{-1} $, respectively. The printed silk fabric is utilized to fabricate TM02$ \text{ TM}_{02} $ mode wideband antenna for aeronautical radio-navigation applications centered at 4200 MHz. Excellent -6dB$ -6dB $ impedance bandwidth of 26.4% is obtained by incorporating a patch-ground shorting stub. The antenna has reasonable radiation efficiency above 74% including packaging losses and conical radiation pattern at higher order mode. The simulation and measurements are performed considering practical scenario showing excellent measured results. Journal: Journal of Electromagnetic Waves and Applications Pages: 2046-2054 Issue: 18 Volume: 31 Year: 2017 Month: 12 X-DOI: 10.1080/09205071.2017.1359686 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1359686 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:18:p:2046-2054 Template-Type: ReDIF-Article 1.0 Author-Name: M. A. Baqir Author-X-Name-First: M. A. Author-X-Name-Last: Baqir Author-Name: P. K. Choudhury Author-X-Name-First: P. K. Author-X-Name-Last: Choudhury Title: Graphene-based slab waveguide for slow-light propagation and mode filtering Abstract: The existence of broadband slow-waves through slab waveguide comprised of sub-wavelength-sized bulk gold and bounded with graphene and silica layers was investigated. A monolayer of graphene medium was taken to be interposed between the gold core and the silica cladding (of the guide). The dispersion behavior exhibits that the guide supports only the fundamental transverse magnetic (TM0) mode, whereas the transverse electric (TE) and the higher order TM modes are blocked. Furthermore, slow-waves can sustain in the guide in the entire visible region of the electromagnetic spectrum. Journal: Journal of Electromagnetic Waves and Applications Pages: 2055-2063 Issue: 18 Volume: 31 Year: 2017 Month: 12 X-DOI: 10.1080/09205071.2017.1280421 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1280421 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:18:p:2055-2063 Template-Type: ReDIF-Article 1.0 Author-Name: In-Keun Baek Author-X-Name-First: In-Keun Author-X-Name-Last: Baek Author-Name: Ranajoy Bhattacharya Author-X-Name-First: Ranajoy Author-X-Name-Last: Bhattacharya Author-Name: Jeong Seok Lee Author-X-Name-First: Jeong Seok Author-X-Name-Last: Lee Author-Name: Seontae Kim Author-X-Name-First: Seontae Author-X-Name-Last: Kim Author-Name: Dongpyo Hong Author-X-Name-First: Dongpyo Author-X-Name-Last: Hong Author-Name: Matlabjon A. Sattorov Author-X-Name-First: Matlabjon A. Author-X-Name-Last: Sattorov Author-Name: Sun-Hong Min Author-X-Name-First: Sun-Hong Author-X-Name-Last: Min Author-Name: Yong Hyup Kim Author-X-Name-First: Yong Hyup Author-X-Name-Last: Kim Author-Name: Gun-Sik Park Author-X-Name-First: Gun-Sik Author-X-Name-Last: Park Title: Uniform high current and current density field emission from the chiseled edge of a vertically aligned graphene-based thin film Abstract: The field emission properties of the controlled emission edge of a vertically aligned graphene-based thin film are presented. A current and current density of above 7 mA and 200 A/cm2, respectively, with uniform electron emission, are achieved. Uniform high current and current density emissions can be realized by the pre-mechanical shaping and post electrical conditioning of reduced graphene oxide (rGO) film emission, owing to the robustness, thinness (<1 μm), and well-defined uniform film thickness. Field emission luminance demonstrates uniform emission over the entire emission area with a high aspect ratio. Along with a high current emission, the rGO film exhibits excellent emission stability, long-term. This offers prospects for various applications in field emission displays, electron microscopy, and particularly for the realization of miniaturized terahertz vacuum electronic devices, which require electron sources with uniform high currents and current densities, such as long-lifetime cold cathodes. Journal: Journal of Electromagnetic Waves and Applications Pages: 2064-2073 Issue: 18 Volume: 31 Year: 2017 Month: 12 X-DOI: 10.1080/09205071.2017.1345658 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1345658 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:18:p:2064-2073 Template-Type: ReDIF-Article 1.0 Author-Name: A. K. Singh Author-X-Name-First: A. K. Author-X-Name-Last: Singh Author-Name: S. K. Shukla Author-X-Name-First: S. K. Author-X-Name-Last: Shukla Author-Name: M. S. Bisht Author-X-Name-First: M. S. Author-X-Name-Last: Bisht Author-Name: S. E. Rahaman Author-X-Name-First: S. E. Author-X-Name-Last: Rahaman Author-Name: J. Kalidoss Author-X-Name-First: J. Author-X-Name-Last: Kalidoss Author-Name: M. Debata Author-X-Name-First: M. Author-X-Name-Last: Debata Author-Name: R. K. Barik Author-X-Name-First: R. K. Author-X-Name-Last: Barik Title: Synthesis and characterization of nano-brazing alloy for thermionic dispenser cathode application Abstract: Development of thermionic cathode for use in vacuum electron devices is very much critical due to high-temperature operation. Brazing of the porous tungsten cathode button and molybdenum sleeve, puts the challenge of using a suitable braze material. The paper describes synthesis of a brazing alloy based on nano-composites of Mo–Ru–Ni. The synthesized powder was analyzed by Scanning Electron Microscopy coupled to Energy Dispersive Spectroscopy. The spreading/wettability, flowability, and melting characteristics of the synthesized nano-powder have been found superior to those of its mechanically mixed variant. Journal: Journal of Electromagnetic Waves and Applications Pages: 2074-2080 Issue: 18 Volume: 31 Year: 2017 Month: 12 X-DOI: 10.1080/09205071.2017.1357505 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1357505 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:18:p:2074-2080 Template-Type: ReDIF-Article 1.0 Author-Name: Krishnaswamy Sankaran Author-X-Name-First: Krishnaswamy Author-X-Name-Last: Sankaran Title: Beyond DIV, CURL and GRAD: modelling electromagnetic problems using algebraic topology Abstract: Have you ever questioned why do we almost always use vector calculus and differential equations in electromagnetics? Are these the only tools at our disposal for studying and modelling electromagnetic problems? Well, the answer is no and this paper is about an alternative approach to model electromagnetic problems using algebraic topology. This approach has a few advantages compared to the familiar differential formulation-based methods in modelling electromagnetic and multiphysics problems. In differential formulation we need one of the several numerical methods like finite difference, finite element, method of moments and spectral methods to obtain approximate solution to the electromagnetic problem. In contrast, algebraic topology-based method leads directly to discrete formulation using global quantities. Furthermore, in the case of electromagnetics, all underlying global quantities are scalars. Hence, there is no need for vector calculus. In addition, we also avoid interpolating local vector field quantities as required in several numerical methods. Though algebraic topology offers powerful and elegant tools for solving various engineering problems, many applied physicists and engineers are not familiar with this subject. This is partly due to the fact that most publications on this topic burden us with complicated mathematical analysis filled with convoluted jargons. If one can introduce the key ideas of algebraic topology using familiar concepts, computational and applied physics, and engineering community can appreciate and benefit from its advantages over methods based on differential formulation. With this goal, we present the main ideas of algebraic topology applied to electromagnetics problems. Journal: Journal of Electromagnetic Waves and Applications Pages: 121-149 Issue: 2 Volume: 31 Year: 2017 Month: 1 X-DOI: 10.1080/09205071.2016.1257397 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1257397 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:2:p:121-149 Template-Type: ReDIF-Article 1.0 Author-Name: Ding-Bing Lin Author-X-Name-First: Ding-Bing Author-X-Name-Last: Lin Author-Name: Chung-Pin Huang Author-X-Name-First: Chung-Pin Author-X-Name-Last: Huang Author-Name: Wen-Sheng Liu Author-X-Name-First: Wen-Sheng Author-X-Name-Last: Liu Author-Name: Hsin-Nan Ke Author-X-Name-First: Hsin-Nan Author-X-Name-Last: Ke Title: The analysis of transient waveform and common mode noise on differential broadside-coupled delay lines Abstract: In the past, conventional edge-coupled differential serpentine and spiral delay lines were widely employed to minimize the clock skew and to compensate the time skew between two differential pairs in high speed printed circuit boards application. Now, in order to minimize the circuit size in a miniaturized design, the spacing between two parallel adjacent unit lines of delay line will be closer and closer, but it is facing electromagnetic coupling and crosstalk noise from adjacent lines. Furthermore, the time skew between positive and negative lines of the edge-coupled differential delay lines results from the lines with non-symmetrical right-angle bended routing, the common mode noise will also get higher and higher. Thus, new differential routing schemes of serpentine and spiral delay lines with broadside-coupled geometry were proposed to reduce the common mode noise. Moreover, in order to validate the accuracy of presented inductive and capacitive circuit models applied to broadside-coupled geometry, the 3-D full wave simulation and measurement validations of near-end crosstalk noise, far-end crosstalk noise and eye diagram have been also implemented in this paper. It is shown that the measured results are in good agreements with the simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 150-165 Issue: 2 Volume: 31 Year: 2017 Month: 1 X-DOI: 10.1080/09205071.2016.1260497 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1260497 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:2:p:150-165 Template-Type: ReDIF-Article 1.0 Author-Name: Montree Saowadee Author-X-Name-First: Montree Author-X-Name-Last: Saowadee Author-Name: Titipong Lertwiriyaprapa Author-X-Name-First: Titipong Author-X-Name-Last: Lertwiriyaprapa Author-Name: Suramate Chalermwisutkul Author-X-Name-First: Suramate Author-X-Name-Last: Chalermwisutkul Author-Name: Prayoot Akkaraekthalin Author-X-Name-First: Prayoot Author-X-Name-Last: Akkaraekthalin Title: Novel approximate UTD ray solution for the radiation and scattering by antennas near a planar material junction on PEC ground plane Abstract: A novel approximate uniform geometrical theory of diffraction (UTD) for analyzing an electromagnetic wave diffracted by a planar material junction on PEC ground plane has been developed in this research. The proposed UTD solution is based on an ansatz obtained from the Weiner–Hopf (W–H) solution by approximating the W–H split functions. This makes the proposed UTD solution to be a relatively simple and closed form expression. Additionally, the proposed UTD solution can deal with both a planar material junction on PEC ground plane and a two-part problem with any types of wave illumination such as a plane wave, a cylindrical wave, and a spherical wave. The accuracy of the proposed UTD solution is compared with the W–H solution and finite different time domain (FDTD) which provides very good agreement. The proposed UTD solution has very small numerical errors. However, the accuracy of the proposed UTD solution is good enough for engineering applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 166-181 Issue: 2 Volume: 31 Year: 2017 Month: 1 X-DOI: 10.1080/09205071.2016.1266288 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1266288 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:2:p:166-181 Template-Type: ReDIF-Article 1.0 Author-Name: Sudipta Banerjee Author-X-Name-First: Sudipta Author-X-Name-Last: Banerjee Author-Name: Durbadal Mandal Author-X-Name-First: Durbadal Author-X-Name-Last: Mandal Title: Array pattern optimization for steerable linear isotropic antenna array using novel particle swarm optimization Abstract: In this paper, the beam steerable isotropic Linear Antenna Array is designed for reducing the side lobe level using evolutionary optimization technique. The optimization techniques particle swarm optimization (PSO) and Novel PSO are used to reduce the side lobe level (SLL) as well as to steer the main beam in specific direction. In this design of steerable Linear arrays, the amplitude excitations are optimized. Obtained results show that the maximum peak of SLL of the resultant patterns is as per requirement. This paper presents a good performance in the array factor response and suppressed SLL for different numbers of elements and different values of the steering angle of direction of the main beam with evolutionary optimization. Journal: Journal of Electromagnetic Waves and Applications Pages: 182-208 Issue: 2 Volume: 31 Year: 2017 Month: 1 X-DOI: 10.1080/09205071.2016.1268074 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1268074 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:2:p:182-208 Template-Type: ReDIF-Article 1.0 Author-Name: Salvatore Campione Author-X-Name-First: Salvatore Author-X-Name-Last: Campione Author-Name: Larry K. Warne Author-X-Name-First: Larry K. Author-X-Name-Last: Warne Author-Name: Lorena I. Basilio Author-X-Name-First: Lorena I. Author-X-Name-Last: Basilio Author-Name: C. David Turner Author-X-Name-First: C. David Author-X-Name-Last: Turner Author-Name: Keith L. Cartwright Author-X-Name-First: Keith L. Author-X-Name-Last: Cartwright Author-Name: Kenneth C. Chen Author-X-Name-First: Kenneth C. Author-X-Name-Last: Chen Title: Electromagnetic pulse excitation of finite- and infinitely-long lossy conductors over a lossy ground plane Abstract: This paper details a model for the response of a finite- or an infinite-length wire interacting with a conducting ground to an electromagnetic pulse excitation. We develop a frequency–domain method based on transmission line theory that we name ATLOG – Analytic Transmission Line Over Ground. This method is developed as an alternative to full-wave methods, as it delivers a fast and reliable solution. It allows for the treatment of finite or infinite lossy, coated wires, and lossy grounds. The cases of wire above ground, as well as resting on the ground and buried beneath the ground are treated. The reported method is general and the time response of the induced current is obtained using an inverse Fourier transform of the current in the frequency domain. The focus is on the characteristics and propagation of the transmission line mode. Comparisons with full-wave simulations strengthen the validity of the proposed method. Journal: Journal of Electromagnetic Waves and Applications Pages: 209-224 Issue: 2 Volume: 31 Year: 2017 Month: 1 X-DOI: 10.1080/09205071.2016.1270776 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1270776 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:2:p:209-224 Template-Type: ReDIF-Article 1.0 Author-Name: Hua Long Sun Author-X-Name-First: Hua Long Author-X-Name-Last: Sun Author-Name: Chuang Ming Tong Author-X-Name-First: Chuang Ming Author-X-Name-Last: Tong Title: Analysis of scattering from composite conductor and dielectric objects using single integral equation method and FG-FFT Abstract: A hybrid method of single integral equation and the electric/magnetic current combined field integral equation (JMCFIE) is proposed, abbreviated as SJMCFIE, for analyzing scattering from composite conductor and dielectric objects. Fitting Green’s function with fast Fourier transform (FG-FFT) is adopted to combine SJMCFIE to lastly formulate SJMCFIE-FG-FFT for reducing computation complexity of resultant matrix-vector multiplications further. Next, scattering from the composite hemisphere is computed to verify SJMCFIE-FG-FFT on memory storage, computation efficiency compared to SJMCFIE-MLFMA. Simultaneously, comparison of FG-FFT and the other FFT-based algorithms being combined with SJMCFIE shows that SJMCFIE-FG-FFT is insensitive to grid spacing, easy implementation, and high accuracy. Besides, SJMCFIE-FG-FFT also can be used for analyzing scattering from the coated structure. Journal: Journal of Electromagnetic Waves and Applications Pages: 225-240 Issue: 2 Volume: 31 Year: 2017 Month: 1 X-DOI: 10.1080/09205071.2016.1276481 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1276481 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:2:p:225-240 Template-Type: ReDIF-Article 1.0 Author-Name: The Editors Title: Correction to: The Sommerfeld half-space problem revisited: from radio frequencies and Zenneck waves to visible light and Fano modes Journal: Journal of Electromagnetic Waves and Applications Pages: 241-241 Issue: 2 Volume: 31 Year: 2017 Month: 1 X-DOI: 10.1080/09205071.2017.1278825 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1278825 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:2:p:241-241 Template-Type: ReDIF-Article 1.0 Author-Name: Wan-Li Zhan Author-X-Name-First: Wan-Li Author-X-Name-Last: Zhan Author-Name: Xiao-Lan Zhao Author-X-Name-First: Xiao-Lan Author-X-Name-Last: Zhao Title: Compact filtering power divider with harmonic suppression Abstract: This paper presents a compact power divider with wide-stopband bandpass responses. In the proposed circuit, two identical quarter-wavelength resonators are symmetrically coupled to a stub-loaded resonator to enable dual functions. Discriminating coupling is employed to suppress the third harmonic. By introducing series-connected two capacitors and one resistor, the isolation is enhanced to more than 20 dB. For demonstration, a filtering power divider operating at 2.4 GHz is designed and fabricated. Good agreement is observed between the measured and simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 243-249 Issue: 3 Volume: 31 Year: 2017 Month: 2 X-DOI: 10.1080/09205071.2016.1264317 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1264317 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:3:p:243-249 Template-Type: ReDIF-Article 1.0 Author-Name: Li Jiangting Author-X-Name-First: Li Author-X-Name-Last: Jiangting Author-Name: Yang Shaofei Author-X-Name-First: Yang Author-X-Name-Last: Shaofei Author-Name: Guo Lixin Author-X-Name-First: Guo Author-X-Name-Last: Lixin Title: Electromagnetic waves propagation in hypersonic turbulence using fractal phase screen method Abstract: The experimental fractal measurements of hypersonic turbulence are used to calculate the scaling exponent, spectral index, and power spectrum of hypersonic turbulence. The characteristics of electromagnetic wave propagation through hypersonic turbulence are studied using the fractal phase screen method based on the Weierstrass fractal function. The effects of the fractal dimension, inner scale, outer scale, variance of the refractive index fluctuation, and the wavelength of incident electromagnetic wave on the diffracted average-intensity distribution by a fractal phase screen are analyzed. Results show that the variance of the refractive index fluctuation determines the ratio of coherent to incoherent intensity. The fractal dimension, Reynolds number, and outer scale of hype- rsonic turbulence determine the incoherent field distribution. As the variance of the refractive index decreases, the coherent portion of the diffracted average intensity becomes clearer. With the increasing fractal dimension, the maximum diffracted average intensity decreases and the incoherent intensity becomes more evident. Journal: Journal of Electromagnetic Waves and Applications Pages: 250-262 Issue: 3 Volume: 31 Year: 2017 Month: 2 X-DOI: 10.1080/09205071.2016.1276858 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1276858 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:3:p:250-262 Template-Type: ReDIF-Article 1.0 Author-Name: Musarat Abbas Author-X-Name-First: Musarat Author-X-Name-Last: Abbas Author-Name: Azhar Abbas Rizvi Author-X-Name-First: Azhar Abbas Author-X-Name-Last: Rizvi Author-Name: Muhammad Arshad Fiaz Author-X-Name-First: Muhammad Arshad Author-X-Name-Last: Fiaz Author-Name: Qaisar Abbas Naqvi Author-X-Name-First: Qaisar Abbas Author-X-Name-Last: Naqvi Title: Scattering of electromagnetic plane wave from a low contrast circular cylinder buried in non-integer dimensional Half Space Abstract: The objective of this paper is to study ‘scattering of electromagnetic waves from a dielectric circular cylinder buried in non-integer dimensional dielectric half-space’. To achieve this objective first two auxiliary problems are solved. The problem of reflection and transmission of electromagnetic waves for an interface between two dielectric mediums is studied first. The dimension normal to the interface is non-integer. Secondly, radiated fields from a buried current carrying line source in an non-integer dimensional half-space have been derived. By using the results of these auxiliary problems, scattering from a low contrast dielectric cylinder buried in non-integer dimensional half-space is studied using perturbation technique. Special cases are also considered when one of the two or both half-spaces are taken to be of integer dimension Journal: Journal of Electromagnetic Waves and Applications Pages: 263-283 Issue: 3 Volume: 31 Year: 2017 Month: 2 X-DOI: 10.1080/09205071.2016.1276859 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1276859 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:3:p:263-283 Template-Type: ReDIF-Article 1.0 Author-Name: Mahmoud A. Abdalla Author-X-Name-First: Mahmoud A. Author-X-Name-Last: Abdalla Author-Name: Walaa W. Wahba Author-X-Name-First: Walaa W. Author-X-Name-Last: Wahba Author-Name: Abdelmegid M. Allam Author-X-Name-First: Abdelmegid M. Author-X-Name-Last: Allam Title: Asymmetric dual-band integrated compact CRLH SIW array antenna Abstract: In this paper, we introduce a compact dual-band two-element array antenna in a substrate integrated waveguide (SIW) configuration for C-band applications. A new geometry based on an asymmetric composite right–left-handed transmission line cells was suggested for the single antenna element. The proposed geometry has the advantage of having arbitrary dual-frequency design. The array elements are fed with a wideband SIW impedance transformer. The results indicate that the proposed antenna element size is only 15 × 12.8 mm2, which approximately represents up to 70% size reduction at similar frequencies. The radiation properties of the array antenna have broadside radiation pattern at the two bands. The detailed analytical design explanation, full wave simulations, and experimental measurements are introduced. Journal: Journal of Electromagnetic Waves and Applications Pages: 284-296 Issue: 3 Volume: 31 Year: 2017 Month: 2 X-DOI: 10.1080/09205071.2016.1276860 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1276860 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:3:p:284-296 Template-Type: ReDIF-Article 1.0 Author-Name: Slawomir Koziel Author-X-Name-First: Slawomir Author-X-Name-Last: Koziel Author-Name: Adrian Bekasiewicz Author-X-Name-First: Adrian Author-X-Name-Last: Bekasiewicz Title: Rapid dimension scaling of dual-band antennas using variable-fidelity EM models and inverse surrogates Abstract: Computationally, efficient scaling of geometry parameters that allows finding the structure dimensions for various operating frequencies is important to expedite the antenna design process. Unfortunately, the scaling problem is challenging, particularly for dual- and multi-band antennas because certain geometry parameters may influence several bands. Also, the relationship between the optimum dimensions and operating frequencies is normally nonlinear and cannot be accurately described using analytical models. In this work, we address the scaling problem for dual-band antennas so that optimum dimensions ensuring that the antenna operates at the two frequencies of choice can be obtained at minimum cost. The presented approach exploits inverse surrogate models where geometry parameters of the structure are represented through design surfaces. The latter are identified using a set of reference designs obtained for coarse-discretization electromagnetic (EM) simulation models and further corrected to be applicable at the high-fidelity EM model level. The proposed method is demonstrated using two examples of dual-band planar antennas. Simulation results are validated using experimental data. Journal: Journal of Electromagnetic Waves and Applications Pages: 297-308 Issue: 3 Volume: 31 Year: 2017 Month: 2 X-DOI: 10.1080/09205071.2016.1276861 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1276861 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:3:p:297-308 Template-Type: ReDIF-Article 1.0 Author-Name: Zhe Liu Author-X-Name-First: Zhe Author-X-Name-Last: Liu Author-Name: Yaping Li Author-X-Name-First: Yaping Author-X-Name-Last: Li Author-Name: Zhen Pan Author-X-Name-First: Zhen Author-X-Name-Last: Pan Author-Name: Ying Su Author-X-Name-First: Ying Author-X-Name-Last: Su Author-Name: Xiuchen Wang Author-X-Name-First: Xiuchen Author-X-Name-Last: Wang Title: FDTD computation of shielding effectiveness of electromagnetic shielding fabric based on weave region Abstract: Numerical computation of shielding effectiveness (SE) of electromagnetic shielding fabric (EMSF) is a research difficulty, making no a suitable model for it at present. This paper proposes a partition method based on the yarn diameter and fabric weave structure. The fabric is divided into overlapping region, lateral single yarn region, longitudinal single yarn region, and interstice region according to the weave feature. A fabric structure model for FDTD numerical computation of the SE is constructed. The electromagnetic parameters of each region are tested according to the transmission and reflection method. The Yee’s grid discretization method of the structure model is given, and the absorption boundary and the excitation parameters are set to determine the physical model of the fabric. The numerical computation of the physical model is done by the East FDTD electromagnetic computation software. The computation data are compared with the actual testing data, and the results show that the computation results of the SE of the EMSF with the proposed model are satisfied. The research in this paper provides an important reference value for the design, production, evaluation, and theoretical study of the EMSF. Journal: Journal of Electromagnetic Waves and Applications Pages: 309-322 Issue: 3 Volume: 31 Year: 2017 Month: 2 X-DOI: 10.1080/09205071.2016.1277957 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1277957 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:3:p:309-322 Template-Type: ReDIF-Article 1.0 Author-Name: Shu-Chuan Chen Author-X-Name-First: Shu-Chuan Author-X-Name-Last: Chen Author-Name: Jia-Yi Sze Author-X-Name-First: Jia-Yi Author-X-Name-Last: Sze Author-Name: Kai-Jen Chuang Author-X-Name-First: Kai-Jen Author-X-Name-Last: Chuang Title: Isolation enhancement of small-size WLAN MIMO antenna array for laptop computer application Abstract: This paper proposes a multiple-input multiple-output (MIMO) antenna array comprising two compact wireless local-area network (WLAN) antennas with high isolation in between. The two operating frequency bands are designed to completely enclose the 2.4/5.2/5.8 GHz WLAN bands. The MIMO antenna array having a small size, a low height, and a small thickness is especially suitable to be installed in ultra-thin notebook computers. The size of the designed antenna array has been reduced to about 40% than those of the MIMO arrays appearing in the recent literature. The designed isolation element between the two radiating antennas consists of two resonant slots, the lengths of which are individually a quarter-wavelength at 2.45 and 5.5 GHz. The isolation elements block the horizontal surface currents on the system ground plane, leading to mutualcoupling reduction between the two source antennas and hence excellent isolation between them. Results indicate that the proposed MIMO antenna array has good characteristics of antenna radiation efficiency, and impedance matching in the two bands of interest. Journal: Journal of Electromagnetic Waves and Applications Pages: 323-334 Issue: 3 Volume: 31 Year: 2017 Month: 2 X-DOI: 10.1080/09205071.2016.1277958 File-URL: http://hdl.handle.net/10.1080/09205071.2016.1277958 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:3:p:323-334 Template-Type: ReDIF-Article 1.0 Author-Name: Anumoy Ghosh Author-X-Name-First: Anumoy Author-X-Name-Last: Ghosh Author-Name: Tapan Mandal Author-X-Name-First: Tapan Author-X-Name-Last: Mandal Author-Name: Santanu Das Author-X-Name-First: Santanu Author-X-Name-Last: Das Title: Design and analysis of annular ring-based RIS and its use in dual-band patch antenna miniaturization for wireless applications Abstract: This paper proposes the design of a Reactive Impedance Surface (RIS) which comprises a 5 × 5 array of grounded unit cells. The unit cells have annular ring structures on their top surfaces. A detailed analysis of the unit cell leading to its impedance characteristic is presented and validated with simulated results. The RIS exhibits inductive impedance below 4.92 GHz. Next, the RIS is used as the ground of a dual-band patch antenna instead of a metallic ground for the purpose of miniaturization. As a result, the lower resonant frequency of the antenna is lowered from 3.36 to 2.4 GHz exhibiting 28.6% miniaturization. The higher resonant frequency is decreased from 4.77 to 3.43 GHz exhibiting 28.1% miniaturization. The theory of antenna miniaturization using RIS is also discussed. The lower and higher resonant frequencies of the miniaturized antenna correspond to the WiFi and WiMAX frequencies, respectively. The gain and efficiency at these two frequencies are significant and radiation patterns are stable with low cross- polarization level. Hence, the proposed structure can be used for practical wireless applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 335-349 Issue: 3 Volume: 31 Year: 2017 Month: 2 X-DOI: 10.1080/09205071.2017.1282329 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1282329 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:3:p:335-349 Template-Type: ReDIF-Article 1.0 Author-Name: Vladimir R. Tuz Author-X-Name-First: Vladimir R. Author-X-Name-Last: Tuz Author-Name: Illia V. Fedorin Author-X-Name-First: Illia V. Author-X-Name-Last: Fedorin Author-Name: Volodymyr I. Fesenko Author-X-Name-First: Volodymyr I. Author-X-Name-Last: Fesenko Author-Name: Hong-Bo Sun Author-X-Name-First: Hong-Bo Author-X-Name-Last: Sun Author-Name: Valeriy M. Shulga Author-X-Name-First: Valeriy M. Author-X-Name-Last: Shulga Author-Name: Wei Han Author-X-Name-First: Wei Author-X-Name-Last: Han Title: Dispersion peculiarities of hybrid modes in a circular waveguide filled by a composite gyroelectromagnetic medium Abstract: Extraordinary dispersion features of a circular waveguide filled by a longitudinally magnetized composite gyroelectromagnetic medium are studied. The composite medium is considered to be constructed by juxtaposition together of magnetic and semiconductor layers providing all characteristic dimensions of the resulting multilayered system are much smaller than the wavelength in the corresponding part of the composite medium. The waveguide dispersion equation and its eigenmodes are derived. The mode classification is made in a standard manner so that the guided modes are sorted into a class of hybrid HE and EH waves in terms of their unique dispersion characteristics. The numerical results are obtained in the band near the frequencies of corresponding resonances in constitutive materials of the composite medium, and they show that the modes behaviors become to be quite diverse due to manifestation of a strong combined geometrical and material dispersion related to the waveguide parameters and gyroelectromagnetic filling, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 350-362 Issue: 3 Volume: 31 Year: 2017 Month: 2 X-DOI: 10.1080/09205071.2017.1285726 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1285726 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:3:p:350-362 Template-Type: ReDIF-Article 1.0 Author-Name: E. Tahanian Author-X-Name-First: E. Author-X-Name-Last: Tahanian Author-Name: G. R. Dadashzadeh Author-X-Name-First: G. R. Author-X-Name-Last: Dadashzadeh Title: Gain analysis of the gap-groove folded-waveguide travelling-wave tube Abstract: In this paper, a Pierce-type analysis for the novel gap-groove folded-waveguide (GGFW) sheet electron beam traveling-wave tube is presented. The introduced analysis effectively reduces the required time for the initial design and optimization procedure of these kinds of tubes. Using equivalent circuit of the slow-wave structure, the one-dimensional linearized Pierce theory is applied to calculate the amplifier gain. Furthermore, the obtained results of the analysis are compared with those of PIC simulations. Good agreement between these results verifies the correctness and accuracy of the presented analysis. Journal: Journal of Electromagnetic Waves and Applications Pages: 363-374 Issue: 4 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1282328 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1282328 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:4:p:363-374 Template-Type: ReDIF-Article 1.0 Author-Name: V. Nallasamy Author-X-Name-First: V. Author-X-Name-Last: Nallasamy Author-Name: C. Narasimhamurthy Author-X-Name-First: C. Author-X-Name-Last: Narasimhamurthy Author-Name: B. Geetha Author-X-Name-First: B. Author-X-Name-Last: Geetha Author-Name: Sanjay Kumar Gupta Author-X-Name-First: Sanjay Kumar Author-X-Name-Last: Gupta Author-Name: Subrata Kumar Datta Author-X-Name-First: Subrata Kumar Author-X-Name-Last: Datta Author-Name: S. Umamaheshwara Reddy Author-X-Name-First: S. Author-X-Name-Last: Umamaheshwara Reddy Author-Name: P. K. Jain Author-X-Name-First: P. K. Author-X-Name-Last: Jain Title: Electromagnetic simulation and experimental characterization of RF interaction structure of an S-band magnetically insulated line oscillator Abstract: An S-band RF interaction structure of a magnetically insulated line oscillator operating at fundamental-mode was designed using analytical formulations, and simulated using 3-D electromagnetic code CST Microwave Studio for its dispersion characteristics and RF output performance. The slow-wave structure was fabricated using precision CNC machining and characterized for its dispersion characteristics. The measured value of pi-mode frequency was found to be in close agreement (2.6%) with that from the simulation. Journal: Journal of Electromagnetic Waves and Applications Pages: 375-382 Issue: 4 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1285255 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1285255 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:4:p:375-382 Template-Type: ReDIF-Article 1.0 Author-Name: Byung Moo Lee Author-X-Name-First: Byung Moo Author-X-Name-Last: Lee Author-Name: Youngok Kim Author-X-Name-First: Youngok Author-X-Name-Last: Kim Title: Optimal transmission power determination to increase energy efficiency of large-scale MIMO antenna systems Abstract: Large-scale (LS) MIMO antenna systems use excessive amount of TX antennas and serve limited number of users to make very high channel gain, and it is obvious that the channel gain increases spectral efficiency of the system. The transmission power of LS-MIMO systems also can be reduced from the increment of channel gain to increase energy efficiency (EE). In this situation, a determination of transmission power which is reduced from total available transmission power can be an important scheme to achieve high EE. This paper proposes a determination scheme of the EE optimum transmission power for LS-MIMO systems. The approximated optimum transmission power is derived analytically as a closed-form function based on various parameters, such as number of TX antennas, number of users, system bandwidth, interference, and so on. Using the closed-form function with the measurable parameters, we can easily get the optimum EE transmission power in real-time. The effectiveness of proposed scheme is validated with numerical simulations. According to the results, the proposed scheme can significantly increase the EE with fairly small loss of channel capacity, compared with ordinary LS-MIMO systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 383-393 Issue: 4 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1285727 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1285727 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:4:p:383-393 Template-Type: ReDIF-Article 1.0 Author-Name: Deepak Sood Author-X-Name-First: Deepak Author-X-Name-Last: Sood Author-Name: Chandra Charu Tripathi Author-X-Name-First: Chandra Charu Author-X-Name-Last: Tripathi Title: A polarization insensitive compact ultrathin wide-angle penta-band metamaterial absorber Abstract: In this paper, the design, fabrication, and measurements of a compact ultrathin five-band metamaterial absorber with wide-angle stability have been presented. The unit cell of the absorber consists of five concentric metallic circular rings printed as the top layer of a grounded dielectric substrate of thickness 1 mm. The radii and the intermediate gap between the rings are optimized such that the proposed absorber exhibits five distinct absorption peaks at frequencies of 5.28, 7.36, 9.52, 12.64, and 16.32 GHz with absorptivities of 92.03, 90.46, 95.10, 91.65, and 91.10%, respectively. The proposed absorber is polarization insensitive for both TE and TM incident wave and results high absorption for wide incidence angle up to 60°. The proposed structure is compact with its unit cell size of 0.54 λ0 and ultrathin with thickness of ~λ0/19 corresponding to the highest frequency of absorption. Surface current and field distributions are studied to understand the absorption mechanism. A prototype of the proposed absorber is fabricated and experimentally tested for different polarization and incident angles. The measured results are observed to be in agreement with the simulated ones. The proposed absorber is suitable for potential applications due to its multi-band absorption. Journal: Journal of Electromagnetic Waves and Applications Pages: 394-404 Issue: 4 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1288172 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1288172 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:4:p:394-404 Template-Type: ReDIF-Article 1.0 Author-Name: Mario Lucido Author-X-Name-First: Mario Author-X-Name-Last: Lucido Author-Name: Fulvio Schettino Author-X-Name-First: Fulvio Author-X-Name-Last: Schettino Author-Name: Marco Donald Migliore Author-X-Name-First: Marco Donald Author-X-Name-Last: Migliore Author-Name: Daniele Pinchera Author-X-Name-First: Daniele Author-X-Name-Last: Pinchera Author-Name: Francesca Di Murro Author-X-Name-First: Francesca Author-X-Name-Last: Di Murro Author-Name: Gaetano Panariello Author-X-Name-First: Gaetano Author-X-Name-Last: Panariello Title: Electromagnetic scattering by a zero-thickness PEC annular ring: a new highly efficient MoM solution Abstract: In this paper, a fast converging method for accurate and efficient analysis of the electromagnetic scattering by a zero-thickness perfectly electrically conducting annular ring is presented. An electric field integral equation in the vector Hankel transform domain is obtained by expanding the unknown surface current density in cylindrical harmonics. A fast convergence of exponential type is achieved by means of Galerkin’s method with expansion functions reconstructing the expected physical behaviour of the nth cylindrical harmonic at the edges of the annular ring with closed-form spectral domain counterparts. Moreover, the elements of the coefficient matrix are efficiently evaluated by means of algebraic manipulations and a suitable integration procedure in the complex plane. In order to verify the correctness of the presented method, comparisons with the commercial software CST Microwave Studio are performed. Journal: Journal of Electromagnetic Waves and Applications Pages: 405-416 Issue: 4 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1291364 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1291364 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:4:p:405-416 Template-Type: ReDIF-Article 1.0 Author-Name: Xiaotian Pan Author-X-Name-First: Xiaotian Author-X-Name-Last: Pan Author-Name: Dawei Liu Author-X-Name-First: Dawei Author-X-Name-Last: Liu Author-Name: He Liu Author-X-Name-First: He Author-X-Name-Last: Liu Author-Name: Bo Cheng Author-X-Name-First: Bo Author-X-Name-Last: Cheng Author-Name: Xinya Qiao Author-X-Name-First: Xinya Author-X-Name-Last: Qiao Title: The retrieval of dielectric constants for liquid crystals using open-ended waveguide method based on simulated annealing Abstract: In this paper, we present a retrieval method of the dielectric constants of electrically controllable unit cell based on liquid crystals (LCs) using open-ended waveguide by simulated annealing. The reflection coefficient is measured from unit cell based on LCs at the end of open-ended waveguide. This measurement setup is similar to the waveguide simulator, which makes the measurement result very suitable for the design of reflectarrays. The dielectric constants are reconstructed by minimizing iteratively a cost function related to the difference between the measurement and the estimation calculated from forward model that is repeatedly updated. And then, the dielectric constants of a mixed LC material TEB30A at six different voltages are obtained using this method. At last, the dielectric constant of TICONIC TLY-5 is retrieved to verify this method, and the result shows good agreement with the known value. Journal: Journal of Electromagnetic Waves and Applications Pages: 417-426 Issue: 4 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1291365 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1291365 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:4:p:417-426 Template-Type: ReDIF-Article 1.0 Author-Name: P. Padilla Author-X-Name-First: P. Author-X-Name-Last: Padilla Author-Name: J. F. Valenzuela-Valdés Author-X-Name-First: J. F. Author-X-Name-Last: Valenzuela-Valdés Author-Name: J. L. Padilla Author-X-Name-First: J. L. Author-X-Name-Last: Padilla Author-Name: J. M. Fernández-González Author-X-Name-First: J. M. Author-X-Name-Last: Fernández-González Author-Name: M. Sierra-Castañer Author-X-Name-First: M. Author-X-Name-Last: Sierra-Castañer Title: Further on ‘broadband electronically tunable reflection-based phase shifter for active-steering microwave reflectarray systems in Ku-Band’: prototype validation Abstract: This piece of work aims to be a complementary document extending our previous article ‘Broadband electronically tunable reflection-based phase shifter for active-steering microwave reflectarray systems in Ku-Band’, recently published in the Journal of Electromagnetic Waves and Applications. This document provides the experimental validation of the former work through prototypes of the designed phase shifter, detailing the shifter manufacturing process, and providing the prototype measurements for its characterization. The shifter characterization yields good performance results, thus validating our original design. Journal: Journal of Electromagnetic Waves and Applications Pages: 427-432 Issue: 4 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1291367 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1291367 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:4:p:427-432 Template-Type: ReDIF-Article 1.0 Author-Name: Enver Adas Author-X-Name-First: Enver Author-X-Name-Last: Adas Author-Name: Franco De Flaviis Author-X-Name-First: Franco Author-X-Name-Last: De Flaviis Author-Name: Nicolaos G. Alexopoulos Author-X-Name-First: Nicolaos G. Author-X-Name-Last: Alexopoulos Title: Mode-free electromagnetic bandgap materials with broadside radiation as phased array antenna elements Abstract: This paper presents a new class of electromagnetic bandgap material (EBG), which we define as the bandgap-antenna structure. It is a true EBG material, with both surface and leaky waves suppressed from the whole structure along all lateral directions, and it is also an antenna element simultaneously. The configuration has two metallization layers of sliced concentric rings between a square-shaped radiating top metal layer and a bottom ground plane. The lower rings are connected to the ground plane through vias and the patch of the top layer is fed with a probe. Eigenmode- and transmission-based full-wave modal analyses of the whole structure proved the presence of a mode-free bandgap region within which the proposed design radiates to broadside direction with 6.01 dBi gain. This structure is an ideal choice for phased array elements due to being modeless along the lateral directions while radiating to the broadside direction; phased array elements will be isolated if the proposed construction is used for array elements. Journal: Journal of Electromagnetic Waves and Applications Pages: 433-446 Issue: 4 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1291368 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1291368 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:4:p:433-446 Template-Type: ReDIF-Article 1.0 Author-Name: Huiqing Zhai Author-X-Name-First: Huiqing Author-X-Name-Last: Zhai Author-Name: Biao Zhang Author-X-Name-First: Biao Author-X-Name-Last: Zhang Author-Name: Kedi Zhang Author-X-Name-First: Kedi Author-X-Name-Last: Zhang Author-Name: Chuanhan Zhan Author-X-Name-First: Chuanhan Author-X-Name-Last: Zhan Title: A stub-loaded reconfigurable broadband metamaterial absorber with wide-angle and polarization stability Abstract: In this communication, a stub-loaded reconfigurable broadband metamaterial absorber (MMA) based on lumped components is proposed and experimentally verified. An absorption bandwidth of 6.3 GHz is realized with more than 90% absorptivity ranging from 8.3 to 14.6 GHz (the relative bandwidth reaches 55%) by selecting certain values of resistors and inductors. The parameter analysis of the loaded stubs illustrates their vital influence on enlarging the absorbing bandwidth. In addition, the designed absorber has good performances on polarization-insensitiveness and wide angles of incident waves for both TE and TM polarization. The waveguide measurement method is utilized to verify the simulated results of the reconfigurable broadband MMA. Journal: Journal of Electromagnetic Waves and Applications Pages: 447-459 Issue: 4 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1293567 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1293567 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:4:p:447-459 Template-Type: ReDIF-Article 1.0 Author-Name: Abhijyoti Ghosh Author-X-Name-First: Abhijyoti Author-X-Name-Last: Ghosh Author-Name: Sudipta Chattopadhyay Author-X-Name-First: Sudipta Author-X-Name-Last: Chattopadhyay Author-Name: Subhradeep Chakraborty Author-X-Name-First: Subhradeep Author-X-Name-Last: Chakraborty Author-Name: Banani Basu Author-X-Name-First: Banani Author-X-Name-Last: Basu Title: Cross type defected ground structure integrated microstrip antenna: a novel perspective for broad banding and augmenting polarization purity Abstract: A simple cross type defected ground structure (CDGS) integrated rectangular microstrip antenna (RMA) has been proposed to achieve broad bandwidth along with augmented (improved) co-polarized to cross-polarized radiation (CP-XP) isolation over principal and diagonal planes. In this design, a crucial emphasis is given for concurrent improvement of both bandwidth and polarization purity of microstrip antenna without hampering dominant mode fields. Around 25–28 dB CP-XP isolation is achieved over wide elevation angle with the proposed structure with 25% impedance bandwidth. The simulated and measured results show a close resemblance with each other. The proposed geometry is very simple, easy to fabricate and therefore helps in effortlessness manufacturing process. Therefore, the present structure appears to be ideal in numerous applications where polarization purity is the key issue over the wide bandwidth. Journal: Journal of Electromagnetic Waves and Applications Pages: 461-476 Issue: 5 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1284610 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1284610 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:5:p:461-476 Template-Type: ReDIF-Article 1.0 Author-Name: Maryam Hajisadeghi Esfahani Author-X-Name-First: Maryam Author-X-Name-Last: Hajisadeghi Esfahani Author-Name: Hadi Roohani Ghehsareh Author-X-Name-First: Hadi Author-X-Name-Last: Roohani Ghehsareh Author-Name: Seyed Kamal Etesami Author-X-Name-First: Seyed Kamal Author-X-Name-Last: Etesami Title: A meshless method for the investigation of electromagnetic scattering from arbitrary shaped anisotropic cylindrical objects Abstract: In the current work, an advanced computational technique is formulated and performed to investigate the wave scattering problem from an infinitely transversally large anisotropic cylinder with arbitrary cross section. A meshless local Petrov–Galerkin method is used to discretize the anisotropic interior (inside the scatterer) and isotropic exterior (outside the scatterer) problems. The total electric fields inside and outside the scatterer are approximated by linear combinations of the generalized multiquadric radial basis functions. The local Heavisde step function is employed as the test function in weak formulation. Moreover, a simple collocation scheme is used to impose the interface and radiation boundary conditions directly. The proposed numerical technique is an efficient instrument to deal with practical complex scatterers and also has a good advantage in treating the material discontinuity at the interface between two different media. The performance and efficiency of the method are demonstrated through some test problems. Journal: Journal of Electromagnetic Waves and Applications Pages: 477-494 Issue: 5 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1285254 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1285254 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:5:p:477-494 Template-Type: ReDIF-Article 1.0 Author-Name: Magdy A. Ezzat Author-X-Name-First: Magdy A. Author-X-Name-Last: Ezzat Author-Name: Alaa A. El-Bary Author-X-Name-First: Alaa A. Author-X-Name-Last: El-Bary Title: Fractional order theory to an infinite thermo-viscoelastic body with a cylindrical cavity in the presence of an axial uniform magnetic field Abstract: The model of fractional time-derivative of generalized magneto–thermo–viscoelasticity equations for isotropic media in the presence of a constant magnetic field is considered. Some essential theorems on the linear coupled and generalized theories of thermo-viscoelasticity can be easily obtained. This model is applied to solve a problem of an infinite body with a cylindrical cavity in the presence of an axial uniform magnetic field. The boundary of the cavity is subjected to a combination of thermal and mechanical shock acting for a finite period of time. Laplace transform techniques are used to derive the solution in the Laplace transform domain. The inversion process is carried out using a numerical method based on Fourier series expansions. Numerical computations for the temperature, the displacement and the stress distributions as well as for the induced magnetic and electric fields are carried out and represented graphically. Comparisons are made with the results predicted by the generalizations, Lord–Shulman theory, and Green–Lindsay theory as well as to the coupled theory. Journal: Journal of Electromagnetic Waves and Applications Pages: 495-513 Issue: 5 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1285728 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1285728 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:5:p:495-513 Template-Type: ReDIF-Article 1.0 Author-Name: Qian Zhou Author-X-Name-First: Qian Author-X-Name-Last: Zhou Author-Name: Yan Han Author-X-Name-First: Yan Author-X-Name-Last: Han Author-Name: Shifeng Zhang Author-X-Name-First: Shifeng Author-X-Name-Last: Zhang Author-Name: Xiaoxia Han Author-X-Name-First: Xiaoxia Author-X-Name-Last: Han Author-Name: Ray C. C. Cheung Author-X-Name-First: Ray C. C. Author-X-Name-Last: Cheung Author-Name: Guangtao Feng Author-X-Name-First: Guangtao Author-X-Name-Last: Feng Title: A V-band VCO with on-chip body bias voltage control technique using 40-nm CMOS process Abstract: This paper presents a V-band voltage-controlled oscillator (VCO) implemented in 40-nm CMOS Process. The on-chip body bias voltage control technique is adopted to improve phase noise and stability of the output signal and to design an LC tank and output buffer circuitry that compensates for the process, voltage, and temperature variations. The design was fabricated in RF Mixed-signal CMOS process with die size 0.078 mm2. Based on the silicon results, the proposed VCO achieve a phase noise of −86 dBc/Hz at 1 MHz offset. The VCO draws 17.8 mA current from a 1.2 V supply. Compared with the traditional structure VCO of the same batch, the measured figure of merit (FOM) is optimized from −165.4 to −169 dB. The novel VCO demonstrates better FOM performance compared to the traditional VCO structure. Moreover, the measured output signal power offset of novel VCO is reduced by 1.8 dBm, which will contribute to the improvement in the yield of chip manufacturing. Journal: Journal of Electromagnetic Waves and Applications Pages: 514-521 Issue: 5 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1291366 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1291366 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:5:p:514-521 Template-Type: ReDIF-Article 1.0 Author-Name: Ning Liu Author-X-Name-First: Ning Author-X-Name-Last: Liu Author-Name: Xianjun Sheng Author-X-Name-First: Xianjun Author-X-Name-Last: Sheng Author-Name: Chunbo Zhang Author-X-Name-First: Chunbo Author-X-Name-Last: Zhang Author-Name: Jingjing Fan Author-X-Name-First: Jingjing Author-X-Name-Last: Fan Author-Name: Dongming Guo Author-X-Name-First: Dongming Author-X-Name-Last: Guo Title: Design of FSS radome using binary particle swarm algorithm combined with pixel-overlap technique Abstract: An optimization method for designing frequency selective surface (FSS) radome using binary particle swarm optimization (BPSO) algorithm combined with pixel-overlap technique is proposed, in this paper. The proposed method takes the connectivity condition of adjacent conductors within FSS element into consideration. With the help of pixel-overlap technique, lattice points in FSS element are avoided by overlapping adjacent conductors, which improves the manufacturability of the FSS layers. Also, structure parameters of the FSS radome can be obtained according to the desired frequency selective property using the BPSO algorithm. To verify the validity of the proposed method, a sandwich-structured FSS radome is designed, fabricated, and measured. Good agreements between the simulation and measurement results can be observed, which demonstrate that the proposed method can be applied to design FSS radome. Journal: Journal of Electromagnetic Waves and Applications Pages: 522-531 Issue: 5 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1294506 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1294506 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:5:p:522-531 Template-Type: ReDIF-Article 1.0 Author-Name: Radu Mitran Author-X-Name-First: Radu Author-X-Name-Last: Mitran Author-Name: Paul Bechet Author-X-Name-First: Paul Author-X-Name-Last: Bechet Title: HF radio channels evaluation using passive sounding in the Black Sea area Abstract: The main challenge for high-frequency (HF) sky wave communication is the non-stationary behaviour of ionosphere parameters, which imposes constraints on choosing carrier frequency, signal bandwidth, modulation and receiver algorithms to overcome channel impairments. Short- to medium-range HF communication could be the most likely scenario for a European country due to the terrain and communication infrastructure spreading. The main aim of this work was to evaluate HF channels in Black Sea region for distances up to 600 km. Passive sounding and ray tracing were used in order to estimate attenuation and propagation modes. The measurement campaign lasted 9 months. The results proved that for evaluated channels, more than one propagation modes were recorded at the receiver site. Attenuation depends on frequency and time of the day. The outcomes of this research are useful for HF frequency management and HF waveform design. Journal: Journal of Electromagnetic Waves and Applications Pages: 532-543 Issue: 5 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1297256 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1297256 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:5:p:532-543 Template-Type: ReDIF-Article 1.0 Author-Name: Leyre Azpilicueta Author-X-Name-First: Leyre Author-X-Name-Last: Azpilicueta Author-Name: Peio López-Iturri Author-X-Name-First: Peio Author-X-Name-Last: López-Iturri Author-Name: Erik Aguirre Author-X-Name-First: Erik Author-X-Name-Last: Aguirre Author-Name: Cesar Vargas-Rosales Author-X-Name-First: Cesar Author-X-Name-Last: Vargas-Rosales Author-Name: Arancha León Author-X-Name-First: Arancha Author-X-Name-Last: León Author-Name: Francisco Falcone Author-X-Name-First: Francisco Author-X-Name-Last: Falcone Title: Influence of meshing adaption in convergence performance of deterministic ray launching estimation in indoor scenarios Abstract: In this paper, an adaptive meshing solution implemented in an in-house developed three-dimensional ray launching algorithm to model the radio wave propagation channel in large environments is presented. Results show that when large scenarios are analyzed, adaptive meshing is necessary to avoid algorithm divergence, leading to accurate results when comparing with real measurements. In addition, simulation results of an indoor large and complex scenario in terms of received power and power delay profile are presented, showing significant influence of multipath propagation in indoor radio channel behavior. The use of the adaptive meshing for the analysis of large and complex scenarios can aid in the adequate deployment of wireless communication systems for large, complex indoor scenarios. Journal: Journal of Electromagnetic Waves and Applications Pages: 544-559 Issue: 5 Volume: 31 Year: 2017 Month: 3 X-DOI: 10.1080/09205071.2017.1298476 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1298476 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:5:p:544-559 Template-Type: ReDIF-Article 1.0 Author-Name: Daniel Seseña-Martinez Author-X-Name-First: Daniel Author-X-Name-Last: Seseña-Martinez Author-Name: Jorge Rodriguez-Cuevas Author-X-Name-First: Jorge Author-X-Name-Last: Rodriguez-Cuevas Author-Name: Jose I. Martinez-Lopez Author-X-Name-First: Jose I. Author-X-Name-Last: Martinez-Lopez Author-Name: Alexander E. Martynyuk Author-X-Name-First: Alexander E. Author-X-Name-Last: Martynyuk Title: Spiraphase-type leaky-wave structure Abstract: A leaky-wave structure (LWS) based on two stacked spiraphase-type reflectarrays (RAs) is analysed in this paper. Each RA contains capacitively loaded ring slot elements arranged at the nodes of a square periodic grid. The proposed LWS performs frequency scanning of a conical beam by changing the cone aperture angle 2θ0. Furthermore, the reconfiguration of the radiation pattern can be achieved by rotating the RA elements. Four Ka-band LWSs with different angular positions of the capacitive loads at the top RA were designed, fabricated and tested to demonstrate the pattern reconfiguration capability. A full-wave mathematical model was used to optimize the reflectarray elements and a simplified mathematical model was developed to predict the radiation characteristics of the whole structure. It was experimentally proven that frequency sweep from 36.37 to 39.9 GHz leads to the change of the angle θ0 from 0° to 38°. The increment of θ0 from 0° to 23° at 36.4 GHz was observed, when the reactive loads of the ring-slot elements at the top RA were rotated on the angle 18°. Good agreement between theoretical predictions and measurements was observed. Journal: Journal of Electromagnetic Waves and Applications Pages: 561-576 Issue: 6 Volume: 31 Year: 2017 Month: 4 X-DOI: 10.1080/09205071.2017.1296788 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1296788 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:6:p:561-576 Template-Type: ReDIF-Article 1.0 Author-Name: Jinpil Tak Author-X-Name-First: Jinpil Author-X-Name-Last: Tak Author-Name: Eun Jeong Author-X-Name-First: Eun Author-X-Name-Last: Jeong Author-Name: Jaehoon Choi Author-X-Name-First: Jaehoon Author-X-Name-Last: Choi Title: Metamaterial absorbers for 24-GHz automotive radar applications Abstract: Absorbers for automotive radar applications must satisfy some requirements such as a wide incident angle, polarization insensitivity, flexibility, low-profile structure, and low cost. To satisfy these requirements, we propose two types of metamaterial absorber for a 24-GHz automotive radar system. The first absorber is composed of 60 × 60 equally spaced unit cells with an electric LC resonator, a substrate, and a ground sheet. It has a peak absorptivity of 99.7% at 24.1 GHz and total full-width at half-maximum (FWHM) of 1.0 GHz. To increase the FWHM, a bandwidth-enhanced absorber was designed by arranging the unit cells into an optimized offset sub-array structure. The proposed absorber exhibited peaks at 24.1 and 25.2 GHz with absorptivities of 97.8 and 74.5%, respectively. The FWHM improved by 900 MHz compared with that of an equally spaced absorber. The measured results of the fabricated absorbers agreed well with the simulated ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 577-593 Issue: 6 Volume: 31 Year: 2017 Month: 4 X-DOI: 10.1080/09205071.2017.1297257 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1297257 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:6:p:577-593 Template-Type: ReDIF-Article 1.0 Author-Name: Yong Wang Author-X-Name-First: Yong Author-X-Name-Last: Wang Author-Name: Wenbin Ye Author-X-Name-First: Wenbin Author-X-Name-Last: Ye Author-Name: Yan Hong Author-X-Name-First: Yan Author-X-Name-Last: Hong Author-Name: Yuan Cao Author-X-Name-First: Yuan Author-X-Name-Last: Cao Author-Name: Yuanjin Zheng Author-X-Name-First: Yuanjin Author-X-Name-Last: Zheng Title: Feasibility study: highly integrated chipset design for compact synthetic aperture radar payload on micro-satellite Abstract: Micro- and nano-satellites are attractive due to the low development and launching costs. Carried by micro- and nano-satellites, synthetic aperture radars (SARs) have great potential for urban, oceanography, land use, and agriculture usages. Different than conventional satellites, the payload of micro- and nano-satellites is limited. This imposes great challenges on the SAR system design. Traditional SARs adopt thousands of millimeter-wave integrated circuit (MMIC) components; they are bulky and power hungry. This paper investigates the feasibility to deploy the emerging technologies to shrink the volume, reduce the cost, and improve the power efficiency of the SAR system. Highly integrated radar transceiver integrated circuits (ICs) are reviewed, and an SAR transceiver IC is developed. Design technologies of low-noise amplifiers (LNAs) and high-power amplifiers (HPAs) are compared, and Gallium Nitride (GaN) technology is proposed. A novel microelectromechanical system-based delay line is also proposed for satellite SAR to reduce the system size. Existing issues and expected improvements of these technologies are also elaborated. This work shows a clear route map for the future shrinkage of SAR system, and would be a useful guideline to the development of compact SARs for micro-satellites. Journal: Journal of Electromagnetic Waves and Applications Pages: 594-603 Issue: 6 Volume: 31 Year: 2017 Month: 4 X-DOI: 10.1080/09205071.2017.1298477 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1298477 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:6:p:594-603 Template-Type: ReDIF-Article 1.0 Author-Name: İsmail Hakkı Tayyar Author-X-Name-First: İsmail Hakkı Author-X-Name-Last: Tayyar Author-Name: Bektaş Çolak Author-X-Name-First: Bektaş Author-X-Name-Last: Çolak Title: Plane wave scattering by a dielectric loaded slit in a thick impedance screen Abstract: The electromagnetic scattering of the plane wave by a slit loaded with dielectric in a thick impedance screen is considered for a rather general case where the surface impedances of the screen planes and vertical sides of the slit have different values. Because of the symmetry of the scattering structure, the image bisection principle is used and the original problem is splitted up into even and odd excitation cases. By introducing the Fourier transform for each case yields a modified Wiener–Hopf equation of the second kind for each excitation. After decoupling these equations by standard transformation, each modified Wiener–Hopf equation is reduced to a pair of coupled Fredholm integral equations of the second kind. The solution of each integral equation involves two sets of infinitely many constants satisfying two infinite systems of linear algebraic equations and Branch-cut integrals which are evaluated approximately. Numerical solutions of these systems are obtained for various values of the parameters such as the surface impedance of the screen, the vertical wall impedance of the slit, the width and the thickness of the slit and the permittivity of the filling material of the slit which permit one to study the effect of these parameters on the diffraction phenomenon. In order to validate the present Wiener–Hopf solution, experimental verification of the dielectric loaded thick metallic slit has been implemented in microwave frequencies with good agreements. Journal: Journal of Electromagnetic Waves and Applications Pages: 604-626 Issue: 6 Volume: 31 Year: 2017 Month: 4 X-DOI: 10.1080/09205071.2017.1300545 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1300545 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:6:p:604-626 Template-Type: ReDIF-Article 1.0 Author-Name: Stanislav Kovar Author-X-Name-First: Stanislav Author-X-Name-Last: Kovar Author-Name: Ivan Spano Author-X-Name-First: Ivan Author-X-Name-Last: Spano Author-Name: Gianluca Gatto Author-X-Name-First: Gianluca Author-X-Name-Last: Gatto Author-Name: Jan Valouch Author-X-Name-First: Jan Author-X-Name-Last: Valouch Author-Name: Milan Adamek Author-X-Name-First: Milan Author-X-Name-Last: Adamek Title: SAR evaluation of wireless antenna on implanted cardiac pacemaker Abstract: For many people, a pacemaker represents something scary because it is related to heart disease. However, that is not the main purpose of this paper, the object of the article is the technical aspect of pacemakers, in particular, their calculation of specific absorption rate values, to which the pacemaker is exposed. A pacemaker generates electrical discharges that are transferred into the heart via a lead wire and electrodes. Authors focus on the impact of Wi-Fi signal antennas on a pacemaker. A dipole antenna working in the frequency range around 5 GHz is chosen as a source of electromagnetic radiation because this kind of antennas is relatively new and it is not widely used yet. Nevertheless, it represents a potential for the future. The experiment is performed through electromagnetic simulation software called CST Microwave Studio that provides tools for SAR calculation and it allows to visualise the scatter of the resulting SAR values around the pacemaker or human torso. Journal: Journal of Electromagnetic Waves and Applications Pages: 627-635 Issue: 6 Volume: 31 Year: 2017 Month: 4 X-DOI: 10.1080/09205071.2017.1301831 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1301831 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:6:p:627-635 Template-Type: ReDIF-Article 1.0 Author-Name: Licinius Dimitri Sá de Alcantara Author-X-Name-First: Licinius Dimitri Sá Author-X-Name-Last: de Alcantara Author-Name: Kellen Diane Carvalho Gomes Author-X-Name-First: Kellen Diane Carvalho Author-X-Name-Last: Gomes Author-Name: Victor Alexandrovich Dmitriev Author-X-Name-First: Victor Alexandrovich Author-X-Name-Last: Dmitriev Author-Name: Rodrigo Melo e Silva de Oliveira Author-X-Name-First: Rodrigo Melo e Silva Author-X-Name-Last: de Oliveira Title: Modeling and analysis of lightning effects in OPGW cables using the ADI-FDTD method Abstract: Current density distribution in optical ground wire cables hit by lightning strokes is numerically calculated and studied in time domain. For this analysis, two models for current source were considered, since atmospheric discharge has two major components which usually damage more severely the cable: the long and short duration current components. The analysis is performed by employing the Alternating Direction Implicit Finite-Difference Time-Domain (ADI-FDTD) method, which the presented formulation was especially developed by the authors to analyze this phenomenon. The convolutional perfectly matched layer (CPML) technique adapted for the ADI method, called ADI-CPML, is also developed in this work for truncating the ADI-FDTD computational domain. Journal: Journal of Electromagnetic Waves and Applications Pages: 636-649 Issue: 6 Volume: 31 Year: 2017 Month: 4 X-DOI: 10.1080/09205071.2017.1297255 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1297255 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:6:p:636-649 Template-Type: ReDIF-Article 1.0 Author-Name: Dagang Liu Author-X-Name-First: Dagang Author-X-Name-Last: Liu Author-Name: Xinbing Tang Author-X-Name-First: Xinbing Author-X-Name-Last: Tang Author-Name: Yang Yan Author-X-Name-First: Yang Author-X-Name-Last: Yan Author-Name: Huihui Wang Author-X-Name-First: Huihui Author-X-Name-Last: Wang Author-Name: Lin Meng Author-X-Name-First: Lin Author-X-Name-Last: Meng Title: Design of confocal waveguide interaction structure for a 220 GHz gyro-TWT Abstract: The high frequency characteristics of confocal waveguide interaction structure are studied, by which the confocal radius and mirror width of the confocal 220 GHz gyro-traveling-wave tube (gyro-TWT) are obtained. The characteristics of coupled dispersion curve, absolute instability, and backward wave oscillation are analyzed. Based on such analysis, methods that are using two lossy severs to suppress backward wave oscillation in 220 GHz gyro-TWT are put forward. Moreover, the experiment and numerical simulation of interaction structure of gyro-TWT with one lossy sever and the full three-dimensional numerical simulation of interaction structure of 220 GHz gyro-TWT with two lossy severs are carried out. The simulation results with two lossy severs show a peak output power of 10.7 kW, a peak efficiency of 11.65%, a peak gain of 25.5 dB, and a 1 dB bandwidth of 2.3 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 650-662 Issue: 6 Volume: 31 Year: 2017 Month: 4 X-DOI: 10.1080/09205071.2017.1306463 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1306463 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:6:p:650-662 Template-Type: ReDIF-Article 1.0 Author-Name: Y. J. Yoo Author-X-Name-First: Y. J. Author-X-Name-Last: Yoo Author-Name: J. S. Hwang Author-X-Name-First: J. S. Author-X-Name-Last: Hwang Author-Name: Y. P. Lee Author-X-Name-First: Y. P. Author-X-Name-Last: Lee Title: Flexible perfect metamaterial absorbers for electromagnetic wave Abstract: The flexible metamaterials (MMs) provide a new field in controlling electromagnetic waves. This paper comprises the MMs made on flexible and elastic substrates, together with the relevant techniques and approaches. The perspective is also described, which includes the possible conversion of investigated MMs into practical devices. For an example of the research and development so far in this fascinating area, by using a planar and flexible MM, the low-frequency perfect absorption has been obtained even with very small unit-cell size in snake-shape structure. These shrunken, deep-sub-wavelength and thin MM absorbers were numerically and experimentally investigated by increasing the inductance. The absorbers are specially designed for absorption peaks around 2 GHz and 400 MHz, which can be used for depressing the EM noise from everyday electronic devices and mobile phones. It has been reported new concept of water droplet-based MM perfect absorber absorbing perfectly electromagnetic wave with water, an eco-friendly material which is very ordinary and plentiful on the earth. If arranging water droplets with particular height and diameter on material surface, meta-properties absorbing electromagnetic wave perfectly in GHz broadband were shown. It was possible to control absorption ratio and absorption wavelength band of electromagnetic wave according to the shape of water droplet and apply to various flexible and/or transparent substrates such as plastic, glass, and paper. These results can lead wide applications to variously civilian and military products in the future by providing perfect absorber of broadband in all products including bendable and transparent materials. Journal: Journal of Electromagnetic Waves and Applications Pages: 663-715 Issue: 7 Volume: 31 Year: 2017 Month: 5 X-DOI: 10.1080/09205071.2017.1312557 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1312557 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:7:p:663-715 Template-Type: ReDIF-Article 1.0 Author-Name: Mohammad Mahdi Honari Author-X-Name-First: Mohammad Mahdi Author-X-Name-Last: Honari Author-Name: Rashid Mirzavand Author-X-Name-First: Rashid Author-X-Name-Last: Mirzavand Author-Name: Pedram Mousavi Author-X-Name-First: Pedram Author-X-Name-Last: Mousavi Title: Design of wideband phase shifters with low phase error using parallel inductor and capacitor for wideband antenna applications Abstract: In this paper, a phase shifter with arbitrary phase shift is presented using a coupled-line section and lumped elements. The proposed structure which consists of coupled-line section and parallel inductor and capacitor takes advantage of being realizable for phase shifts more than 90° due to relaxing the requirement for tight coupling in coupled line. The analysis shows that it is possible to achieve an arbitrary phase shift on a wide band with a low phase error. To verify the concept, three 90°, 135° and 180° phase shifters are fabricated. Measured 10-dB impedance bandwidths of 73, 62 and 56% have been obtained for 90°, 135° and 180° phase shifters, respectively, with maximum phase error of ±3°. Finally, to avoid the problems of using discrete elements, the inductor and capacitor in180° phase shifter arte realized utilizing microstrip lines. The measurement results of both designs with discrete elements and microstrip lines are a match which indicates that the proposed structure is reliable for arbitrary phase shift for high frequencies. Journal: Journal of Electromagnetic Waves and Applications Pages: 716-726 Issue: 7 Volume: 31 Year: 2017 Month: 5 X-DOI: 10.1080/09205071.2017.1308838 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1308838 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:7:p:716-726 Template-Type: ReDIF-Article 1.0 Author-Name: Maria Denise Astorino Author-X-Name-First: Maria Denise Author-X-Name-Last: Astorino Author-Name: Fabrizio Frezza Author-X-Name-First: Fabrizio Author-X-Name-Last: Frezza Author-Name: Nicola Tedeschi Author-X-Name-First: Nicola Author-X-Name-Last: Tedeschi Title: Broad-band terahertz metamaterial absorber with stacked electric ring resonators Abstract: In this paper, we propose an ultra-thin broad-band metamaterial absorber composed of a periodic array of three-layered electric ring resonators (ERRs) within a dielectric spacer and backed by a metallic ground plane for THz applications. The overlapping of the resonance peaks relevant to the ERRs leads to a broad spectral absorption bandwidth over a wide range of incidence angles under both transverse electric and transverse magnetic polarizations. We analyze the effect of different physical properties on the absorption spectra in order to estimate the dielectric and Ohmic losses in the metamaterial structure. In addition, the Nicolson, Ross, and Weir algorithm is adopted as homogenization technique to retrieve the effective electromagnetic parameters, while the interference theory is employed to compare the simulated and analytical results for the multi-layered absorber. Journal: Journal of Electromagnetic Waves and Applications Pages: 727-739 Issue: 7 Volume: 31 Year: 2017 Month: 5 X-DOI: 10.1080/09205071.2017.1308839 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1308839 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:7:p:727-739 Template-Type: ReDIF-Article 1.0 Author-Name: You-Feng Cheng Author-X-Name-First: You-Feng Author-X-Name-Last: Cheng Author-Name: Wei Shao Author-X-Name-First: Wei Author-X-Name-Last: Shao Author-Name: Xiao Ding Author-X-Name-First: Xiao Author-X-Name-Last: Ding Author-Name: Mengxia Yu Author-X-Name-First: Mengxia Author-X-Name-Last: Yu Author-Name: Jing Ma Author-X-Name-First: Jing Author-X-Name-Last: Ma Author-Name: Congjun Jin Author-X-Name-First: Congjun Author-X-Name-Last: Jin Title: A novel beam steerable antenna based on dual-reconfiguration technique Abstract: In this paper, a novel beam-steerable antenna based on a dual-reconfiguration technique is presented. The proposed antenna with a double-layer structure operates at 3.65 GHz. On the lower layer, a coplanar parasitic structure whose operational principle is similar to a quasi-Yagi strip structure is used as the driven element to supply the first-level reconfiguration. The parasitic upper layer which adopts a pixel surface is implemented for the second-level reconfiguration. By switching four PIN diodes on the lower layer and changing the pixel surface of the upper layer, the proposed antenna is capable of realizing beam steering (θ = 0°, ±10°, ±20°, ±30°, ±40°, ±50°, and ±60°) with a gain fluctuation lower than 1 dB. A multi-objective genetic algorithm and a co-simulation strategy are used to optimize the operating state of the pixel surface. The antenna is optimized, fabricated and measured. The measured results agree well with the simulated ones, and they validate the powerful reconfigurable ability of the proposed antenna. Journal: Journal of Electromagnetic Waves and Applications Pages: 740-751 Issue: 7 Volume: 31 Year: 2017 Month: 5 X-DOI: 10.1080/09205071.2017.1311809 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1311809 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:7:p:740-751 Template-Type: ReDIF-Article 1.0 Author-Name: J. F. Gómez-Aguilar Author-X-Name-First: J. F. Author-X-Name-Last: Gómez-Aguilar Author-Name: Dumitru Baleanu Author-X-Name-First: Dumitru Author-X-Name-Last: Baleanu Title: Schrödinger equation involving fractional operators with non-singular kernel Abstract: An alternative model of fractional Schrödinger equation involving Caputo-Fabrizio fractional operator and the new fractional operator based on the Mittag–Leffler function is proposed. We obtain the eigenvalues and eigenfunctions for a free particle moving in the infinite potential well. Numerical simulations of alternative models are presented for evaluating the effectiveness of these representations. We showed that fractional Schrödinger equation via Caputo–Fabrizio operator is a particular case of fractional Schrödinger equation obtained with the new fractional operator based in the Mittag–Leffler function. Journal: Journal of Electromagnetic Waves and Applications Pages: 752-761 Issue: 7 Volume: 31 Year: 2017 Month: 5 X-DOI: 10.1080/09205071.2017.1312556 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1312556 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:7:p:752-761 Template-Type: ReDIF-Article 1.0 Author-Name: Xinhang Song Author-X-Name-First: Xinhang Author-X-Name-Last: Song Author-Name: Chunyu Yang Author-X-Name-First: Chunyu Author-X-Name-Last: Yang Author-Name: Weitian Yu Author-X-Name-First: Weitian Author-X-Name-Last: Yu Author-Name: Yujia Zhang Author-X-Name-First: Yujia Author-X-Name-Last: Zhang Author-Name: Mengli Liu Author-X-Name-First: Mengli Author-X-Name-Last: Liu Author-Name: Ming Lei Author-X-Name-First: Ming Author-X-Name-Last: Lei Author-Name: Wen-Jun Liu Author-X-Name-First: Wen-Jun Author-X-Name-Last: Liu Title: Inelastic interaction between dark solitons for fourth-order variable-coefficient nonlinear Schrödinger equation Abstract: Dark solitons have the advantages of high stability, long transmission distance, and low time jitter, they can be used in the field of high precision measurement, optical communication, and nonlinear optics. In this paper, inelastic interactions between dark solitons are investigated. With the analytic dark soliton solutions for the fourth-order variable-coefficient nonlinear Schrödinger equation, various types of inelastic interactions between dark solitons are presented. Influences of corresponding parameters are analyzed. Results may be applied in the optical switching devices and design of logic gates. Journal: Journal of Electromagnetic Waves and Applications Pages: 762-767 Issue: 7 Volume: 31 Year: 2017 Month: 5 X-DOI: 10.1080/09205071.2017.1319302 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1319302 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:7:p:762-767 Template-Type: ReDIF-Article 1.0 Author-Name: Tonko Garma Author-X-Name-First: Tonko Author-X-Name-Last: Garma Author-Name: Silvestar Šesnić Author-X-Name-First: Silvestar Author-X-Name-Last: Šesnić Author-Name: Dragan Poljak Author-X-Name-First: Dragan Author-X-Name-Last: Poljak Author-Name: Anđela Matković Author-X-Name-First: Anđela Author-X-Name-Last: Matković Title: Impulse impedance of the horizontal grounding electrode: comparison of the theoretical antenna model approach and experimental analysis Abstract: The paper deals with the comparison of two methods for the calculation of the impulse impedance of the horizontal grounding electrode defined as a ratio of maximum values of induced voltage and current at the injection point on the electrode. The current distribution along the electrode is calculated using the antenna theory based model featuring the thin-wire approximation and corresponding Pocklington integro-differential equation in the frequency domain. The equation is solved using analytical techniques with the exact solution of the integral over Green’s function. The scattered voltage is subsequently calculated from the Generalized Telegrapher’s equation. On the other hand, experimental technique based on direct in situ impulse impedance measurements is applied on the actual horizontal electrode based grounding system. The results obtained via different methods agree satisfactorily, proving that the proposed model can be used to estimate the impulse impedance and, furthermore, complement the understanding of the grounding electrode early time behavior by providing the transient impedance data. Journal: Journal of Electromagnetic Waves and Applications Pages: 769-780 Issue: 8 Volume: 31 Year: 2017 Month: 5 X-DOI: 10.1080/09205071.2017.1313133 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1313133 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:8:p:769-780 Template-Type: ReDIF-Article 1.0 Author-Name: Eugene Smolkin Author-X-Name-First: Eugene Author-X-Name-Last: Smolkin Author-Name: Yuri Shestopalov Author-X-Name-First: Yuri Author-X-Name-Last: Shestopalov Title: Nonlinear Goubau line: analytical–numerical approaches and new propagation regimes Abstract: We consider propagation of surface TE waves in the Goubau line (GL) assuming that the dielectric cover is non-linear and inhomogeneous. The problem at hand is reduced to a non-linear integral equation with a kernel in the form of the Green function of an auxiliary boundary value problem on an interval. The existence of propagating TE waves for the chosen nonlinearity (Kerr law) is proved by the method of contraction. Conditions under which several higher-order waves can propagate are obtained, and the intervals of the corresponding propagation constants are determined. For the numerical solution, a method based on solving an auxiliary Cauchy problem (a version of the shooting method) is proposed. In numerical experiment two types of nonlinearities are considered and compared: Kerr nonlinearity and nonlinearity with saturation. New propagation modes are found. Journal: Journal of Electromagnetic Waves and Applications Pages: 781-797 Issue: 8 Volume: 31 Year: 2017 Month: 5 X-DOI: 10.1080/09205071.2017.1317036 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1317036 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:8:p:781-797 Template-Type: ReDIF-Article 1.0 Author-Name: Muhammad Khalid Author-X-Name-First: Muhammad Author-X-Name-Last: Khalid Author-Name: Nicola Tedeschi Author-X-Name-First: Nicola Author-X-Name-Last: Tedeschi Author-Name: Fabrizio Frezza Author-X-Name-First: Fabrizio Author-X-Name-Last: Frezza Title: Analysis of reflection from a novel anisotropic lossy medium characterized by particular material properties Abstract: In this paper, we investigate the reflection characteristics of a novel electric–magnetic uniaxial lossy medium, characterized by extreme material properties and having optic axis in a generic direction. The novelty of the medium is specified by particular material parameters: very large transverse and very small axial components of permittivity and permeability with respect to the optic axis of the medium. To study the reflection, we consider an interface between a simple isotropic medium and the uniaxial medium defined by the complex permittivity and permeability tensors. Electromagnetic response of the medium is analyzed under different situations by considering various orientations of the plane of incidence and by arbitrarily choosing the direction of the optic axis. We emphasize the importance of direction of the optic axis and discuss its influence on electromagnetic reflection from the interface. It is noted that this novel material exhibits a very interesting property of behaving like a perfect absorber or a perfect reflector depending upon the orientation of the optic axis. Moreover, we also observe a Brewster’s angle like effect where the interface shows total transmission for the co-component of the incident wave while total reflection for the cross-component. An analytical relation for this Brewster-like angle is also presented. This property may enable the material to find applications in the realization of polarization inverters. Journal: Journal of Electromagnetic Waves and Applications Pages: 798-807 Issue: 8 Volume: 31 Year: 2017 Month: 5 X-DOI: 10.1080/09205071.2017.1317038 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1317038 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:8:p:798-807 Template-Type: ReDIF-Article 1.0 Author-Name: Chenlu Li Author-X-Name-First: Chenlu Author-X-Name-Last: Li Author-Name: Yufa Sun Author-X-Name-First: Yufa Author-X-Name-Last: Sun Author-Name: Guohua Wang Author-X-Name-First: Guohua Author-X-Name-Last: Wang Author-Name: Zhonggen Wang Author-X-Name-First: Zhonggen Author-X-Name-Last: Wang Title: Fast analysis for large-scale electromagnetic scattering problems by a hybrid approach Abstract: In this paper, a fast and accurate hybrid approach based on the multilevel characteristic basis function method (MLCBFM) is presented to analyze the electrically large scattering problems. First, a modified fast dipole method (MFDM) is proposed to improve the accuracy and efficiency of the conventional fast dipole method (FDM). Then, the MFDM is combined with the adaptive cross approximation (ACA) algorithm and the equivalent dipole method (EDM) to enhance the efficiency of the MLCBFM. In the proposed hybrid method, the use of MFDM makes the construction of secondary characteristic basis functions and reduced matrix of the MLCBFM more accurate and efficient. The impedance matrices representing the interactions of the middle-field pairs are efficiently compressed by using the ACA in order to enable the hybrid method to further reduce the time and the memory significantly when the criterion for the far-field pairs becomes stricter to obtain relatively high accurate solutions. The numerical results of one hundred PEC cubes have demonstrated that the MFDM is capable of effectively reducing the CPU time and the relative errors. Furthermore, another results have shown that the proposed hybrid method has reduced the CPU time and the memory requirement by 27 and 32%, respectively, when the same criterion for the far-field pairs are chosen. Journal: Journal of Electromagnetic Waves and Applications Pages: 808-819 Issue: 8 Volume: 31 Year: 2017 Month: 5 X-DOI: 10.1080/09205071.2017.1317608 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1317608 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:8:p:808-819 Template-Type: ReDIF-Article 1.0 Author-Name: Arnold Abramov Author-X-Name-First: Arnold Author-X-Name-Last: Abramov Author-Name: Alexander Kostikov Author-X-Name-First: Alexander Author-X-Name-Last: Kostikov Author-Name: Ruopeng Liu Author-X-Name-First: Ruopeng Author-X-Name-Last: Liu Author-Name: Chunlin Ji Author-X-Name-First: Chunlin Author-X-Name-Last: Ji Author-Name: Xue Li Author-X-Name-First: Xue Author-X-Name-Last: Li Author-Name: Juehui Zhou Author-X-Name-First: Juehui Author-X-Name-Last: Zhou Author-Name: Zexi Chen Author-X-Name-First: Zexi Author-X-Name-Last: Chen Title: Formation of the high electromagnetic waves intensity areas by multiple cylinders scattering: whispering gallery modes and photonic nanojet Abstract: Multiple-cylinder scattering of electromagnetic plane waves are considered. It is shown that the process can led to formation of two kinds of high intensity areas of electromagnetic waves. The first type arise inside cylinder due to so-called whispering gallery modes (WGM), while the second type represents itself a narrow, high-intensity beam of light generated at the shadow-side surface of illuminated dielectric cylinders. In our model, WGM can occur because of the presence of additional cylinder scatterers at specific location, while WGMs can only form in a single cylinder for specific cylinder radius and/or wavelength values. Also, presence of the additional cylinders increases a length of photonic nanojets (up to two times) compared to the case of a single cylinder. The results of calculation for different values of electric permittivity and radii of cylinders are presented and discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 820-827 Issue: 8 Volume: 31 Year: 2017 Month: 5 X-DOI: 10.1080/09205071.2017.1317609 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1317609 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:8:p:820-827 Template-Type: ReDIF-Article 1.0 Author-Name: Xia Zhou Author-X-Name-First: Xia Author-X-Name-Last: Zhou Author-Name: Min-Hua Li Author-X-Name-First: Min-Hua Author-X-Name-Last: Li Author-Name: Hui-Bo Wang Author-X-Name-First: Hui-Bo Author-X-Name-Last: Wang Author-Name: Chuan Wang Author-X-Name-First: Chuan Author-X-Name-Last: Wang Author-Name: Xiao-Min Zhai Author-X-Name-First: Xiao-Min Author-X-Name-Last: Zhai Author-Name: Jian-Feng Dong Author-X-Name-First: Jian-Feng Author-X-Name-Last: Dong Title: Mutual conversion and multi-band diode-like asymmetric transmission of linearly polarized waves in multi-layered metasurface Abstract: A metasurface consisting of three layer H-shaped arrayed structures is proposed. Numerical simulation and experiment results demonstrate that our scheme can realize mutual polarization conversion and multi-band diode-like asymmetric transmission for linearly polarized waves in the microwave region. This designed metasurface can achieve cross-polarization conversion with a high magnitude of 0.93 for y-to-x polarization and 0.92 for x-to-y polarization at 6.4 and 13.6 GHz, respectively. The polarization conversion between two orthogonal linearly polarized waves is also analyzed by the activity and ellipticity. We have found the structure has the multi-band 90° polarization rotation angle and almost zero ellipticity for both x- and y-polarized waves at two resonant frequencies. We believe our findings are beneficial in enriching the application in photonic devices such as polarization rotators and diode-like devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 828-836 Issue: 8 Volume: 31 Year: 2017 Month: 5 X-DOI: 10.1080/09205071.2017.1317610 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1317610 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:8:p:828-836 Template-Type: ReDIF-Article 1.0 Author-Name: Aşkın Altınoklu Author-X-Name-First: Aşkın Author-X-Name-Last: Altınoklu Author-Name: Barışcan Karaosmanoğlu Author-X-Name-First: Barışcan Author-X-Name-Last: Karaosmanoğlu Author-Name: Özgür Ergül Author-X-Name-First: Özgür Author-X-Name-Last: Ergül Title: Electromagnetic optimization of corrugated metallic sheets for maximum power focusing Abstract: We present full-wave electromagnetic optimization of corrugated metallic sheets to achieve maximum power focusing at desired locations when illuminated by plane waves. The corrugations are freely applied by moving the discretization nodes, leading to huge optimization spaces that are scanned by employing genetic algorithms. The required simulations are performed accurately and efficiently via the method of moments or the multilevel fast multipole algorithm. Hundreds of thousands of simulations are performed to demonstrate the feasibility of strong optical focusing, even with relatively small sheets in terms of wavelength. The corrugated sheets can be useful in various applications, such as energy harvesting, solar cells, imaging, and optical sensing. Journal: Journal of Electromagnetic Waves and Applications Pages: 837-849 Issue: 8 Volume: 31 Year: 2017 Month: 5 X-DOI: 10.1080/09205071.2017.1319299 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1319299 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:8:p:837-849 Template-Type: ReDIF-Article 1.0 Author-Name: M. I. Epov Author-X-Name-First: M. I. Author-X-Name-Last: Epov Author-Name: E. P. Kurochkina Author-X-Name-First: E. P. Author-X-Name-Last: Kurochkina Author-Name: O. N. Soboleva Author-X-Name-First: O. N. Author-X-Name-Last: Soboleva Title: Effective coefficients of quasi-steady Maxwell’s equations with multiscale isotropic log-stable conductivity Abstract: The effective coefficients in the quasi-steady Maxwell’s equations are calculated for a multiscale isotropic medium by using a subgrid modeling approach.The conductivity is mathematically represented by a Kolmogorov multiplicative cascade with a log-stable probability distribution. The skewness of the stable probability distribution β$ \beta $ is equal to one. The parameter α$ \alpha $ is such that 1<α<2$ 1 < \alpha < 2 $, where the situation α=2$ \alpha = 2 $ corresponds to the Gaussian distribution. Thus, the variance of the stable probability distribution is infinite, but the mean is finite. The scale of a solution domain is assumed to be large as compared with the scale of heterogeneities of the medium. The theoretical results obtained in the paper are compared with the results of a direct 3D numerical simulation. Journal: Journal of Electromagnetic Waves and Applications Pages: 850-866 Issue: 8 Volume: 31 Year: 2017 Month: 5 X-DOI: 10.1080/09205071.2017.1319301 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1319301 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:8:p:850-866 Template-Type: ReDIF-Article 1.0 Author-Name: Changqing Wang Author-X-Name-First: Changqing Author-X-Name-Last: Wang Author-Name: Jianxing Li Author-X-Name-First: Jianxing Author-X-Name-Last: Li Author-Name: Anxue Zhang Author-X-Name-First: Anxue Author-X-Name-Last: Zhang Author-Name: William T. Joines Author-X-Name-First: William T. Author-X-Name-Last: Joines Author-Name: Qing Huo Liu Author-X-Name-First: Qing Huo Author-X-Name-Last: Liu Title: Dual-band capacitively loaded annular-ring slot antenna for dual-sense circular polarization Abstract: This paper investigates a simplified and new capacitively loaded annular-ring slot antenna (ARSA) for dual-band and dual-sense circular polarization. The antenna is comprised of two concentric annular-ring slots coupled to a microstrip feed line to achieve dual-band operation. With introducing proper distributed capacitances fulfilled by two closely spaced T-shaped arc strips across the outer and inner annular-ring slots at opposite positions with respect to the microstrip feed line, the dual-sense circular polarization can hence be obtained. The antenna features that the impedance and circular polarization characteristic for the upper band can be independently adjusted. Numerical analysis and experimental validation have been carried out. The measured 10-dB return loss impedance bandwidths for both bands are greater than 22.0%. The measured 3-dB axial ratio (AR) bandwidths are 3.6 and 5.6%, respectively, for the lower and upper bands. Journal: Journal of Electromagnetic Waves and Applications Pages: 867-878 Issue: 9 Volume: 31 Year: 2017 Month: 6 X-DOI: 10.1080/09205071.2017.1326322 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1326322 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:9:p:867-878 Template-Type: ReDIF-Article 1.0 Author-Name: Siddhartha Biswas Author-X-Name-First: Siddhartha Author-X-Name-Last: Biswas Author-Name: Basudeb Mukhopadhyay Author-X-Name-First: Basudeb Author-X-Name-Last: Mukhopadhyay Author-Name: Soumen Shaw Author-X-Name-First: Soumen Author-X-Name-Last: Shaw Title: Thermal shock response in magneto-thermoelastic orthotropic medium with three-phase-lag model Abstract: This paper is dealing with the thermal shock response on the propagation of electro-magneto-thermoelastic disturbances in an orthotropic medium. In this context, three-phase-lag model of generalized thermoelasticity theory is considered. In presence of magnetic field as well as electric field, Maxwell’s equations are adopted to formulate the electro-magneto thermoelastic coupled governing equations. The considered formulation is applied to the half-space subjected to time-dependent thermal shock. The normal mode analysis is used to obtain the analytical expressions of the field variables. The variation of displacement, stress and temperature distribution with and without magnetic effect for various thermoelastic models are presented graphically. Finally, a comparison of the results with different models of thermoelasticity is made. Journal: Journal of Electromagnetic Waves and Applications Pages: 879-897 Issue: 9 Volume: 31 Year: 2017 Month: 6 X-DOI: 10.1080/09205071.2017.1326851 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1326851 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:9:p:879-897 Template-Type: ReDIF-Article 1.0 Author-Name: Ahmet Kizilay Author-X-Name-First: Ahmet Author-X-Name-Last: Kizilay Author-Name: Uğur Saynak Author-X-Name-First: Uğur Author-X-Name-Last: Saynak Author-Name: Gokhan Uygur Author-X-Name-First: Gokhan Author-X-Name-Last: Uygur Title: Scattering from an object behind multi-layer periodic gratings of cylindrical shapes Abstract: The problem of electromagnetic scattering from a perfect electric conductor (PEC) object of arbitrary cross-section behind multilayer of periodic gratings of circular cylinders is solved by a hybrid method combining the Method of Moments (MoM), decomposition, and the Physical Optics methods. The periodic grating’s periodic cell consists of multiple layers of lossy-dielectric scattering elements situated in free space. The PEC object under the periodic gratings assumed to be electrically large. A set of electric-field integral equations (EFIEs) for the perturbation currents both on the portion of the PEC object and the periodic gratings most strongly interacting with each other obtained using the surface equivalence principle and a decomposition method. Then, MoM is used to solve the EFIEs in the frequency domain to obtain the scattered electric field. Journal: Journal of Electromagnetic Waves and Applications Pages: 898-911 Issue: 9 Volume: 31 Year: 2017 Month: 6 X-DOI: 10.1080/09205071.2017.1326852 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1326852 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:9:p:898-911 Template-Type: ReDIF-Article 1.0 Author-Name: Muhammad Akhtar Author-X-Name-First: Muhammad Author-X-Name-Last: Akhtar Author-Name: Muhammad Arshad Fiaz Author-X-Name-First: Muhammad Author-X-Name-Last: Arshad Fiaz Author-Name: Muhammad Aqueel Ashraf Author-X-Name-First: Muhammad Author-X-Name-Last: Aqueel Ashraf Title: Gaussian beam scattering from a DNG chiral coated PEMC cylinder buried below slightly rough surface Abstract: Scattering from a perfect electromagnetic conducting (PEMC) cylinder coated with double negative (DNG) chiral material buried below a slightly rough Gaussian surface is studied. To limit the amount of reflected energy from the surface, the incident field is considered a Gaussian beam instead of a plane wave. Use of Small perturbation method (SPM) and spectral plane wave representation of fields (SPRF) has been done to calculate the scattered field above the rough surface. A sinusoidal and Gaussian rough surfaces are considered. Since the general case with PEMC core and DNG chiral coating is considered here. The earlier published results for perfect electric conductor (PEC) core with chiral coating are obtained by selecting proper parameters in this generalized solution for the validation of the formulation. Different scattering scenarios are simulated by varying the chirality and thickness of the coating layer. Effect of correlation length of rough surface on scattering pattern is also analyzed. Journal: Journal of Electromagnetic Waves and Applications Pages: 912-926 Issue: 9 Volume: 31 Year: 2017 Month: 6 X-DOI: 10.1080/09205071.2017.1326853 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1326853 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:9:p:912-926 Template-Type: ReDIF-Article 1.0 Author-Name: Sadiq Ullah Author-X-Name-First: Sadiq Author-X-Name-Last: Ullah Author-Name: Farooq Faisal Author-X-Name-First: Farooq Author-X-Name-Last: Faisal Author-Name: Ashfaq Ahmad Author-X-Name-First: Ashfaq Author-X-Name-Last: Ahmad Author-Name: Usman Ali Author-X-Name-First: Usman Author-X-Name-Last: Ali Author-Name: Farooq Ahmad Tahir Author-X-Name-First: Farooq Ahmad Author-X-Name-Last: Tahir Author-Name: James A. Flint Author-X-Name-First: James A. Author-X-Name-Last: Flint Title: Design and analysis of a novel tri-band flower-shaped planar antenna for GPS and WiMAX applications Abstract: This paper presents the design of a tri-band flower-shaped planar monopole antenna operating at three frequencies i.e. 1.576 (GPS), 2.668, and 3.636 GHz (Mobile WiMAX). The radiating element of the antenna is backed by a 1.6 mm thicker FR-4 substrate having a dielectric constant of 4.3. The substrate is backed by a truncated ground plane. The antenna is fed through a 50 Ω microstrip line. The flower shape of the radiating element is derived from the basic circular shape by introducing in it rounded slots of various radii. The upper part of the antenna is flower shaped while the lower part comprises a microstrip feed line and two branches, each having two “leaves” at the end. The leaves and branches contribute in the impedance matching of the lower (1.576 GHz) and middle (2.668 GHz) frequency bands. The antenna gives an acceptable simulated efficiency >70% in the three frequency bands. Suitable gains of 1.63, 2.59, and 3.23 dB are obtained at 1.576, 2.668, and 3.636 GHz, respectively. The antenna matched with a VSWR < 1.2 in the three frequency bands. The prototype of the antenna is fabricated and tested in the laboratory, and good agreement in simulated and measured results is achieved. The proposed design is a visually appealing and may find uses as an external antenna in GPS and WiMAX applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 927-940 Issue: 9 Volume: 31 Year: 2017 Month: 6 X-DOI: 10.1080/09205071.2017.1330160 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1330160 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:9:p:927-940 Template-Type: ReDIF-Article 1.0 Author-Name: Zarko Sakotic Author-X-Name-First: Zarko Author-X-Name-Last: Sakotic Author-Name: Vesna Crnojevic-Bengin Author-X-Name-First: Vesna Author-X-Name-Last: Crnojevic-Bengin Author-Name: Nikolina Jankovic Author-X-Name-First: Nikolina Author-X-Name-Last: Jankovic Title: Compact dual-band coupler with independent control of band positions and power-split ratios based on circular patch with DGS Abstract: In this paper, we propose a novel dual-band coupler based on circular patch structure perturbed with slits, shorting posts and defected ground structures. It is shown that the proposed perturbations allow size reduction and independent control of the operating bands in terms of their position and power-split ratio between the output ports. To demonstrate the potential of the proposed structure, two dual-band 3-dB couplers operating at 2.4/5.2 and 2.4/5.8 GHz have been designed, fabricated and measured. The couplers are characterized by excellent in-band performance and compact size of only 0.41λg × 0.41λg. Additionally, three couplers operating at 2.4/5.8 GHz with different combinations of coupling coefficients at the two operating bands have been designed and fabricated. Journal: Journal of Electromagnetic Waves and Applications Pages: 941-956 Issue: 9 Volume: 31 Year: 2017 Month: 6 X-DOI: 10.1080/09205071.2017.1330710 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1330710 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:9:p:941-956 Template-Type: ReDIF-Article 1.0 Author-Name: Jinxin Li Author-X-Name-First: Jinxin Author-X-Name-Last: Li Author-Name: Shiwen Yang Author-X-Name-First: Shiwen Author-X-Name-Last: Yang Author-Name: Zaiping Nie Author-X-Name-First: Zaiping Author-X-Name-Last: Nie Author-Name: William T. Joines Author-X-Name-First: William T. Author-X-Name-Last: Joines Author-Name: QingHuo Liu Author-X-Name-First: QingHuo Author-X-Name-Last: Liu Title: Dual-polarized metamaterial cavity-backed antennas for mutual coupling reduction Abstract: A novel metamaterial cavity for mutual coupling reduction of two closely positioned dual-polarized antennas is proposed in this paper. The metamaterial cavity is composed of four sets of meta-surfaces. Two sets are composed of double-layer complementary frequency selective surface and the other two are composed of double-layer complementary negative-index material. In comparison with those two antennas without the metamaterial cavity, measured results show that the isolation level of the same polarization ports (S13 and S24) and the cross-polarization ports (S14 and S23) for the proposed metamaterial cavity-backed antennas can be improved by at most 12.5 and 9.5 dB over the frequency band of 2.5–2.7 GHz, respectively. More importantly, the dual-polarized antenna array keeps other good performance such as VSWR <2 and a stable radiation pattern where the metamaterial cavity is loaded. Comparative analysis on the performance of the simulations and experiments are demonstrated. The proposed metamaterial cavity is easy to integrate with pico-base station antennas or relay antennas. Journal: Journal of Electromagnetic Waves and Applications Pages: 957-968 Issue: 9 Volume: 31 Year: 2017 Month: 6 X-DOI: 10.1080/09205071.2017.1331144 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1331144 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:9:p:957-968 Template-Type: ReDIF-Article 1.0 Author-Name: The Editors Title: Correction to: Thermal shock response in magneto-thermoelastic orthotropic medium with three-phase-lag model Journal: Journal of Electromagnetic Waves and Applications Pages: i-i Issue: 9 Volume: 31 Year: 2017 Month: 6 X-DOI: 10.1080/09205071.2017.1336324 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1336324 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:31:y:2017:i:9:p:i-i Template-Type: ReDIF-Article 1.0 Author-Name: Luděk Klimeš Author-X-Name-First: Luděk Author-X-Name-Last: Klimeš Title: Superposition of Gaussian packets in smoothly heterogeneous bianisotropic media Abstract: We derive the equations for the integral superposition of Gaussian packets in smoothly heterogeneous media. The superposition of Gaussian packets is especially useful in the vicinity of spatial caustics where the ray theory under consideration is singular. The equations are applicable to both the anisotropic ray theory and the coupling ray theory in bianisotropic media, or to the isotropic ray theory in isotropic media. The equations can be used in both Cartesian and curvilinear coordinates. The equations are applicable not only to electromagnetic waves in bianisotropic media, but also to other kinds of vectorial waves, e.g. to elastic waves in generally anisotropic media. Journal: Journal of Electromagnetic Waves and Applications Pages: 1-6 Issue: 1 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1356244 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1356244 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:1:p:1-6 Template-Type: ReDIF-Article 1.0 Author-Name: Abolfazl Mostaani Author-X-Name-First: Abolfazl Author-X-Name-Last: Mostaani Author-Name: S. Mohammed Hassan Javadzadeh Author-X-Name-First: S. Mohammed Hassan Author-X-Name-Last: Javadzadeh Title: Nonlinearity in superconducting CPW open-end and gap discontinuities Abstract: In this paper, non-linear circuit models of the superconducting CPW (SCOW) open-ends and gaps are presented. The model can be used to create a fast and accurate analysis of the nonlinearity in SCOW applications such as end-coupled filters, which have such gap and open-end discontinuities. The non-linear circuit is solved using harmonic balance (HOB) method to compute the third-order intermodulation (IMD3) distortion and fundamental outputs. As an example, we analyze the nonlinearity of an end-coupled SCOW band pass filter (BP) to validate the model. The model can be used to minimize the nonlinearity in such superconducting structures via optimizing the resonators of superconducting filters. The main difference between the proposed model and the one in the literatures is that there is no clear discussion or method about nonlinearity in discontinuous SCOW structures because of absence of closed-form formula for some equivalent circuit model of discontinuities. As an example, for determining the value of the equivalent gap capacitance of a SCOW structure, we can’t find any easy-use and direct equation. But in this paper, we also propose a closed-form equation for calculating the such capacitances. Journal: Journal of Electromagnetic Waves and Applications Pages: 7-18 Issue: 1 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1359683 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1359683 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:1:p:7-18 Template-Type: ReDIF-Article 1.0 Author-Name: François Bieth Author-X-Name-First: François Author-X-Name-Last: Bieth Author-Name: Philippe Delmote Author-X-Name-First: Philippe Author-X-Name-Last: Delmote Title: Measurement of high-power ultra wideband signal penetration through different types of walls Abstract: This paper presents the experimental results of transmission of ultra-wideband, high-power microwave signals through different types of walls which are used for structural systems in exterior construction. The study focuses on different real configurations: four walls (autoclaved cellular concrete, traditional concrete block, reinforced concrete and hollow brick) have been built outdoors to measure their transmission coefficients. A sub-nanosecond pulse generator has been used, allowing measurements over a frequency band from 100 MHz to 6 GHz. Further investigations have been carried out on the tested structures through numerical simulation, in order to compare the measurement results of walls made of complex elements and those of numerical models of the walls based on material permittivity parameters. The influence of moisture for different types of walls has also been quantified. Journal: Journal of Electromagnetic Waves and Applications Pages: 19-32 Issue: 1 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1361867 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1361867 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:1:p:19-32 Template-Type: ReDIF-Article 1.0 Author-Name: Pengyu Zhang Author-X-Name-First: Pengyu Author-X-Name-Last: Zhang Author-Name: Jiaran Qi Author-X-Name-First: Jiaran Author-X-Name-Last: Qi Author-Name: Jinghui Qiu Author-X-Name-First: Jinghui Author-X-Name-Last: Qiu Title: A generalized network method for the rigorous analysis of sub-reflector scattering problems Abstract: A generalized network method is proposed in this paper for rigorous analysis of the sub-reflector scattering problem in a dual-reflector antenna, by dividing it into two subdomains, i.e. a feed and a sub-reflector. The addition theorems of spherical waves help connect the independent subdomain scattering matrix representations, leading to a global generalized network. A numerical example in a single-displaced Cassegrain dual-reflector antenna is presented to validate our method. The numerical results are then compared against those by the method of moment. The excellent coincidence with respect to the reflection coefficient of the feed, and the amplitude and phase of the scattered field in a near-field region demonstrates the accuracy of the hybrid method. Besides, its computational efficiency promises our method great potentials to compute the scattered fields in a sub-reflector configuration. Further combination with physical optics leads to a complete numerical solution for dual-reflector antennas. Journal: Journal of Electromagnetic Waves and Applications Pages: 33-42 Issue: 1 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1363670 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1363670 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:1:p:33-42 Template-Type: ReDIF-Article 1.0 Author-Name: Dwipjoy Sarkar Author-X-Name-First: Dwipjoy Author-X-Name-Last: Sarkar Author-Name: Tamasi Moyra Author-X-Name-First: Tamasi Author-X-Name-Last: Moyra Author-Name: Priyansha Bhowmik Author-X-Name-First: Priyansha Author-X-Name-Last: Bhowmik Title: A low-cost 4.9 GHz balanced bandpass filter with good common mode isolation Abstract: This paper presents a compact and low-cost balanced bandpass filter (BPF) operating at 4.9 GHz with high selectivity using mixed coupled ‘U’ shaped resonators, parallel coupled feed line, open and centrally loaded short circuited stubs, respectively. The odd–even mode decoupling scheme and the weakly coupled resonator concepts are utilized for the analysis and validation of differential mode (DM) and common mode (CM) equivalent circuits of the proposed BPF. The passband CM response of the balanced BPF is suppressed above 30 dB by employing grounded stubs in the symmetry plane, which converts the CM response to an all stop characteristic. The second harmonics generated by the BPF is also suppressed using open stubs located near the feed lines. The proposed balanced BPF is fabricated on an FR4 substrate (εr = 4.4, h = 1.6 mm, tan δ = 0.02), which provides 10.7% measured 3 dB fractional bandwidth (FBW) and minimum 1.2 dB insertion loss in the passband (4.7–5.2 GHz). A good agreement is found between the simulated and measured results. Journal: Journal of Electromagnetic Waves and Applications Pages: 43-53 Issue: 1 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1365628 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1365628 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:1:p:43-53 Template-Type: ReDIF-Article 1.0 Author-Name: B. D. Nguyen Author-X-Name-First: B. D. Author-X-Name-Last: Nguyen Author-Name: Su Van Tran Author-X-Name-First: Su Van Author-X-Name-Last: Tran Title: Beam-steering reflectarray based on two-bit aperture-coupled reflectarray element Abstract: In this paper, a two-bit phase-shifter element for reconfigurable reflectarray antennas is presented. The element is formed by a cut-ring patch coupled to the delay line through an annular slot. The method using a shorting via is applied to this element to separate the line into two delay lines in order that the phase shift can be proportional linearly with respect to the length of two delay lines. The length of each delay line is optimized to provide four-phase states with a step of 90° according to ON/OFF states of two switches. A reflectarray prototype consisting of 8 × 12 elements has been fabricated and measured to validate the design. Experimental results indicate good characteristics of the reflectarray element and excellent beam-steering capabilities according to the ON/OFF states of the switches. Journal: Journal of Electromagnetic Waves and Applications Pages: 54-66 Issue: 1 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1366369 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1366369 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:1:p:54-66 Template-Type: ReDIF-Article 1.0 Author-Name: Adam Kusiek Author-X-Name-First: Adam Author-X-Name-Last: Kusiek Title: Finite element/mode-matching analysis of ferrite/dielectric line junctions of arbitrary cross-section Abstract: This paper is focused on the analysis of line junctions obtained as a cascade of dielectric and ferrite guides of arbitrary cross-section. The main application of such structures is nonreciprocal devices such as isolators, circulators, or phase shifters. The efficient finite element/mode-matching approach is proposed to the analysis of such structures. In this approach, the finite element method is applied to determine propagation coefficients and field distributions in cross-sections of the structure. Then using mode-matching technique the scattering parameters of investigated junction are calculated. Since, all the field integrals required in mode-matching are evaluated in the pre-processing stage of finite element method, only small numerical effort is required to calculate scattering parameters of the junction. The numerical efficiency of proposed approach is examined for different geometries of longitudinally magnetized shielded ferrite coupled line junction. Obtained results are compared with the ones calculated using commercial software and presented in literature. A very good agreement is achieved. Journal: Journal of Electromagnetic Waves and Applications Pages: 67-76 Issue: 1 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1369904 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1369904 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:1:p:67-76 Template-Type: ReDIF-Article 1.0 Author-Name: Chien-Ching Chiu Author-X-Name-First: Chien-Ching Author-X-Name-Last: Chiu Author-Name: Chien-Yu Yen Author-X-Name-First: Chien-Yu Author-X-Name-Last: Yen Author-Name: Gang-Ze Lee Author-X-Name-First: Gang-Ze Author-X-Name-Last: Lee Title: Dielectric objects reconstruction by combining subspace-based algorithm and randomly global optimization algorithm Abstract: This paper discusses an inverse scattering problem for the reconstruction of permittivity distribution of two-dimensional dielectric objects. Based on the boundary condition and the measured scattered field, a set of nonlinear integral equation is derived and the imaging problem is reformulated into optimization problem. We solved the problem by combining subspace-based algorithm and self-adaptive dynamic differential evolution (SADDE). SADDE can process numerous unknowns of electromagnetic imaging problems. Different scatterers and environment have used to verify the stability of subspace-based algorithm and SADDE. We also compare genetic algorithm (GA) to show the robustness and the searching speed of SADDE. Numerical results show that the permittivity distribution of the dielectric objects is well reconstructed by SADDE. Journal: Journal of Electromagnetic Waves and Applications Pages: 77-91 Issue: 1 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1369905 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1369905 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:1:p:77-91 Template-Type: ReDIF-Article 1.0 Author-Name: Zeeshan Qamar Author-X-Name-First: Zeeshan Author-X-Name-Last: Qamar Author-Name: S.Y. Zheng Author-X-Name-First: S.Y. Author-X-Name-Last: Zheng Author-Name: W.S. Chan Author-X-Name-First: W.S. Author-X-Name-Last: Chan Author-Name: Derek Ho Author-X-Name-First: Derek Author-X-Name-Last: Ho Title: Coupling coefficient range extension technique for broadband branch-line coupler Abstract: In a conventional branch-line coupler (BLC), high coupling coefficients require very narrow lines, which results in high fabrication complexity and reduction in power handling capacity. In addition, changes in multiple design parameters are required to realize arbitrary coupling coefficients. In this paper, we present the design, fabrication, and characterization of a novel broadband branch-line coupler that extends the range of arbitrary coupling coefficients. The proposed structure is also able to achieve different coupling through tuning only one design parameter, and therefore can be used as a tunable coupler. Closed-form design equations are presented for the synthesis of broadband BLCs based on the proposed structure. To validate the proposed structure and the corresponding design methodology, a variety of broadband BLCs with different coupling coefficients have been designed, fabricated, and measured. Measurements show that couplers with 6, 9, and 12 dB coupling coefficients provide wide fractional bandwidths of 49, 49, and 52%, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 92-112 Issue: 1 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1369906 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1369906 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:1:p:92-112 Template-Type: ReDIF-Article 1.0 Author-Name: Rajendra Kumar Verma Author-X-Name-First: Rajendra Kumar Author-X-Name-Last: Verma Author-Name: Shivendra Maurya Author-X-Name-First: Shivendra Author-X-Name-Last: Maurya Author-Name: V. V. P. Singh Author-X-Name-First: V. V. P. Author-X-Name-Last: Singh Title: A review on the advent of magnetrons at high frequency (mm and THz) gateway Abstract: Radio frequency vacuum electronic devices (RF VEDs) have been quite a promising milestone in radiowave and microwave generation for decades. With advance technologies, the VEDs are now heading toward higher frequency range viz. millimeter (mm) wave and Terahertz (THz) with substantial power. The prompted techniques, improvisations, and improvements, particularly in magnetrons, have been substantial for propelling the modern day high frequency application requirements. The paper now puts a review in the context of the various techniques, structures, and technologies suggested and implemented to reassert the feasibility of magnetrons as a promising representative of VEDs for mm and THz radiation generation. Performance parameters like power, operating frequency, efficiency, etc., serve to examine the development trends of mm and THz magnetrons. Journal: Journal of Electromagnetic Waves and Applications Pages: 113-127 Issue: 1 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1377641 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1377641 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:1:p:113-127 Template-Type: ReDIF-Article 1.0 Author-Name: Nguyen Khac Kiem Author-X-Name-First: Nguyen Khac Author-X-Name-Last: Kiem Author-Name: Dao Ngoc Chien Author-X-Name-First: Dao Ngoc Author-X-Name-Last: Chien Title: A transmission line decoupling technique for enhancement of port isolation of dual-band MIMO antennas Abstract: In this paper, a transmission line decoupling network (TLDN) technique is presented to enhance the isolation of a dual-band multiple input and multiple output (MIMO) antenna. The MIMO antenna with enhanced isolation is designed by the following steps: Firstly, each port of an initial 2-port MIMO antenna is connected with an admittance transformer formed by two transmission line sections. The length and the width of the admittance transformer are designed to retrieve mutual admittance between ports having only imaginary part. The two ports are then connected in parallel electrically with the proposed TLDN to cancel the resultant imaginary mutual admittance. At the final stage, a simple dual-band matching network is added to each port to improve matching performance. The proposed method is applied to two designs of dual-band printed MIMO antenna working at 2.45 GHz/5.25 GHz and 1.8 GHz/3.5 GHz. For the purpose of verification, the two designs were fabricated and measured. The measured results are in good agreement with the simulation ones. Both designs yielded a high isolation, low envelop correlation coefficient, simple structures for design and fabrication. These features demonstrated the feasibility of the technique in implementing MIMO antennas. Journal: Journal of Electromagnetic Waves and Applications Pages: 1195-1211 Issue: 10 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1426501 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1426501 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:10:p:1195-1211 Template-Type: ReDIF-Article 1.0 Author-Name: Deblina Chowdhury Author-X-Name-First: Deblina Author-X-Name-Last: Chowdhury Author-Name: Manimala Pal Author-X-Name-First: Manimala Author-X-Name-Last: Pal Author-Name: Rowdra Ghatak Author-X-Name-First: Rowdra Author-X-Name-Last: Ghatak Title: Vicsek fractal slot substrate integrated waveguide leaky wave antenna for X-band application Abstract: A substrate integrated waveguide based leaky wave antenna with Vicsek-cross fractal shaped slot is proposed. Vicsek cross fractal is used here to obtain wide band and compact structure for wideband applications in X-band. The proposed design achieves a wide impedance bandwidth of 1.98 GHz ranging from 8.96 to 10.94 GHz. A near identical pattern bandwidth with peak realized gain of 8.41dBi is achieved over the resonance frequency band of the proposed antenna. A prototype in X-band of the proposed design is examined and measured for verification. Journal: Journal of Electromagnetic Waves and Applications Pages: 1212-1220 Issue: 10 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1426502 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1426502 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:10:p:1212-1220 Template-Type: ReDIF-Article 1.0 Author-Name: Can Xia Author-X-Name-First: Can Author-X-Name-Last: Xia Author-Name: Huayong Zhang Author-X-Name-First: Huayong Author-X-Name-Last: Zhang Title: Scattering of electromagnetic beam by a chirally coated object Abstract: We present a semi-analytical solution to the electromagnetic scattering by a chirally coated object with arbitrary monochromatic illumination. The scattered fields and the internal fields in different regions are expanded in terms of appropriate spherical vector wave functions, and the unknown expansion coefficients are determined using the boundary conditions and the method of moments scheme. As examples, for a Gaussian beam, zero-order Bessel beam and Hertzian electric dipole radiation incident on a chirally coated spheroid and circular cylinder of finite length, numerical results of the normalized differential scattering cross section are provided to illustrate the validity and capability of the proposed method, and the scattering characteristics are discussed concisely. Journal: Journal of Electromagnetic Waves and Applications Pages: 1221-1231 Issue: 10 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1428119 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1428119 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:10:p:1221-1231 Template-Type: ReDIF-Article 1.0 Author-Name: Mahdi Moradian Author-X-Name-First: Mahdi Author-X-Name-Last: Moradian Title: Planar slotted array antennas fed by reduced height wiggly ridge waveguides Abstract: A reduced height single ridge waveguide is employed to feed an array of centerline longitudinal slots. The ridge has a wiggly shape at the slot position and an indentation is introduced to the ridge at the bending position. It is shown that in absence of the indentation, the propose slot antennas are impractical. The transverse electric field distribution along the slot is studied which indicates that the proposed longitudinal slot antenna can be represented as an equivalent shunt admittance across a fictitious transmission line. Considering this equivalent circuit for the proposed slot antenna and employing the design procedure previously introduced to design the slotted array antenna fed by wiggly ridge waveguide, a planar array is designed, constructed and tested. The effectiveness of the proposed antenna was verified by the simulation and the measurement results of a sample prototype. Journal: Journal of Electromagnetic Waves and Applications Pages: 1232-1248 Issue: 10 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1429953 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1429953 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:10:p:1232-1248 Template-Type: ReDIF-Article 1.0 Author-Name: Yunxian Tian Author-X-Name-First: Yunxian Author-X-Name-Last: Tian Author-Name: Weizhong Yan Author-X-Name-First: Weizhong Author-X-Name-Last: Yan Author-Name: Xiaoliang Gu Author-X-Name-First: Xiaoliang Author-X-Name-Last: Gu Author-Name: Xiaolin Jin Author-X-Name-First: Xiaolin Author-X-Name-Last: Jin Author-Name: Jianqing Li Author-X-Name-First: Jianqing Author-X-Name-Last: Li Author-Name: Bin Li Author-X-Name-First: Bin Author-X-Name-Last: Li Title: Study on the attenuation characteristic of terahertz wave through a non-uniform magnetized plasma Abstract: In this paper, the interaction between terahertz wave and a non-uniform magnetized plasma slab is investigated. The electric field distribution in non-uniform plasma is presented and used to calculate the attenuation of the electromagnetic wave through plasma. Several types of electron density profiles are proposed and discussed. Effects of different plasma parameters (electron density, collision frequency, plasma thickness) and magnetic field amplitudes on THz wave attenuation characteristic are investigated. The transmission ratios at several typical THz signal frequencies in both unmagnetized and magnetized plasma are presented as well. These simulation results are meaningful for the flight communication. Journal: Journal of Electromagnetic Waves and Applications Pages: 1249-1260 Issue: 10 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1430621 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1430621 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:10:p:1249-1260 Template-Type: ReDIF-Article 1.0 Author-Name: Diego M. Solís Author-X-Name-First: Diego M. Author-X-Name-Last: Solís Author-Name: Marta G. Araújo Author-X-Name-First: Marta G. Author-X-Name-Last: Araújo Author-Name: Santiago García Author-X-Name-First: Santiago Author-X-Name-Last: García Author-Name: Fernando Obelleiro Author-X-Name-First: Fernando Author-X-Name-Last: Obelleiro Author-Name: José M. Taboada Author-X-Name-First: José M. Author-X-Name-Last: Taboada Title: Multilevel fast multipole algorithm for fields Abstract: An efficient implementation of the multilevel fast multipole algorithm is herein applied to accelerate the calculation of the electromagnetic near- and far-fields after the equivalent surface currents have been obtained. In spite of all the research efforts being drawn to the latter, the electric and/or magnetic fields (or other parameters derived from these) are ultimately the magnitudes of interest in most of the cases. Though straightforward, their calculation can be computationally demanding, and hence the importance of finding a sped-up accurate representation of the fields via a suitable setup of the method. A complete self-contained formulation for both near- and far-fields and for problems including multiple penetrable regions is shown in full detail. Through numerical examples we show that the efficiency and scalability of the implementation leads to a drastic reduction of the computation time. Journal: Journal of Electromagnetic Waves and Applications Pages: 1261-1274 Issue: 10 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1431155 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1431155 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:10:p:1261-1274 Template-Type: ReDIF-Article 1.0 Author-Name: Bang-Qing Li Author-X-Name-First: Bang-Qing Author-X-Name-Last: Li Author-Name: Yu-Lan Ma Author-X-Name-First: Yu-Lan Author-X-Name-Last: Ma Title: Loop-like periodic waves and solitons to the Kraenkel–Manna–Merle system in ferrites Abstract: The Kraenkel–Manna–Merle system is investigated, which describes the propagations of the ferromagnetic particles in ferrite materials. A new series of the solutions are obtained via the auxiliary equation method. These solutions include periodic traveling wave solutions in Jacobi elliptic functions and soliton solutions in hyperbolic functions. Some of them are demonstrated in visualization. There exist loop-like periodic waves and loop-like solitons between independent variables related to the magnetization and the external magnetic fields vs. the time and space variables. The parameter influences on the periodic wave solutions are also discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1275-1286 Issue: 10 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1431156 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1431156 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:10:p:1275-1286 Template-Type: ReDIF-Article 1.0 Author-Name: Hai-Yan Chen Author-X-Name-First: Hai-Yan Author-X-Name-Last: Chen Author-Name: Min-qing Li Author-X-Name-First: Min-qing Author-X-Name-Last: Li Author-Name: You-Jie Deng Author-X-Name-First: You-Jie Author-X-Name-Last: Deng Author-Name: Xiao-long Weng Author-X-Name-First: Xiao-long Author-X-Name-Last: Weng Author-Name: Jian-Liang Xie Author-X-Name-First: Jian-Liang Author-X-Name-Last: Xie Author-Name: Long-Jiang Deng Author-X-Name-First: Long-Jiang Author-X-Name-Last: Deng Title: Design and implementation of electromagnetic soft surfaces for decoupling in between two microstrip patch antennas Abstract: In this paper, the design of the electromagnetic soft surfaces realized by metal strips loaded with C-shaped slots is demonstrated having good suppression of electromagnetic coupling in between two patch antennas. Electromagnetic bandgap properties of the as-prepared electromagnetic soft surfaces with C-shaped slots loading is proposed for normal incidence, and compared with that from the one of the same size but none C-shaped slots on the patches. The proposed structure possesses excellent miniaturization properties with working frequency of bandgap toward lower frequency but keeping the filtering level unchangeable. Then, the proposed structure is loaded in two patch antennas for decoupling in between them. Experimental results are presented and compared to numerical simulations, and they demonstrated that the proposed electromagnetic soft surfaces loading advances excellent suppression of electromagnetic coupling and the coupling decrease about 17 dB near the working frequency band. Journal: Journal of Electromagnetic Waves and Applications Pages: 1287-1297 Issue: 10 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1433075 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1433075 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:10:p:1287-1297 Template-Type: ReDIF-Article 1.0 Author-Name: Abhishek Sharma Author-X-Name-First: Abhishek Author-X-Name-Last: Sharma Author-Name: Anirban Sarkar Author-X-Name-First: Anirban Author-X-Name-Last: Sarkar Author-Name: Animesh Biswas Author-X-Name-First: Animesh Author-X-Name-Last: Biswas Author-Name: M. Jaleel Akhtar Author-X-Name-First: M. Author-X-Name-Last: Jaleel Akhtar Title: Compact dual-band hybrid dielectric resonator antenna loaded with magnetic-LC resonator Abstract: This article presents a compact dual-band hybrid dielectric resonator antenna for wireless communication systems. The proposed design uses a square dielectric resonator loaded with magnetic-LC resonator (complementary of electric-LC resonator) to achieve miniaturization and dual-band operation. Based on the parametric analysis, it is reveled that the two operational bands could be designed independently. The proposed antenna operates at 3.6 and 5.25 GHz with impedance bandwidths of 3.9% (3.53–3.67 GHz) and 3.24% (5.17–5.34 GHz), respectively. The antenna radiates with similar radiation pattern at both the operating frequencies with the cross polarized fields better than - $ - $ 20 dB. The peak gain of the antenna is 6.27 and 6.35 dBi at lower and upper operating frequency, respectively. The proposed antenna is suitable for worldwide interoperability for microwave access and wireless local area network band applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1298-1305 Issue: 10 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1433557 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1433557 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:10:p:1298-1305 Template-Type: ReDIF-Article 1.0 Author-Name: Tae-Wan Kim Author-X-Name-First: Tae-Wan Author-X-Name-Last: Kim Author-Name: Chan-Yong Jung Author-X-Name-First: Chan-Yong Author-X-Name-Last: Jung Author-Name: Seong-Ook Park Author-X-Name-First: Seong-Ook Author-X-Name-Last: Park Title: Microwave measurement of initial properties of ferrites using mode splitting phenomenon by the rod resonator method Abstract: This paper proposes an accurate method to calculate the permittivity and permeability of ferrites simultaneously at the demagnetized state. The eigenvalue equations for the resonator model can be obtained by applying the boundary condition of the structure of the resonator at both demagnetized and magnetized states. The complex permeability and permittivity are computed from the measured resonant frequencies and unloaded quality factors of the resonator using the mode splitting phenomenon. To verify the calculated magnetization values, the magneto-static simulation is performed by using CST EM studio based on the measured data of B–H curve. The measured complex permeability and permittivity of the demagnetized ferrite are verified by comparing with cavity perturbation method and statistic equation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1306-1315 Issue: 10 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1434017 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1434017 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:10:p:1306-1315 Template-Type: ReDIF-Article 1.0 Author-Name: Anurag Srivastava Author-X-Name-First: Anurag Author-X-Name-Last: Srivastava Author-Name: V. Latha Christie Author-X-Name-First: V. Latha Author-X-Name-Last: Christie Title: Design of a high gain and high efficiency W-band folded waveguide TWT using phase-velocity taper Abstract: The folded-waveguide (FW) slow-wave structure (SWS) is a very promising beam-wave interaction circuit for high-frequency traveling wave tubes (TWTs). This paper presents the design methodology for enhancing the gain and efficiency of a practical W-band FWTWT using phase-velocity taper. Initially, phase-velocity, interaction impedance, and gain-growth of a single-section FWTWT are predicted theoretically. Further, these parameters are optimized using the eigenmode solver and transient solver of 3-D CST Studio. The simulated results agreed with theoretically predicted results within ~1% discrepancy. Then the single-section SWS along with the input and output couplers consisting of quarter-wave impedance transformers and pillbox windows are simulated using transient solver and a return-loss of around −20 dB is obtained over the desired band. Finally, the output power, gain and electronic efficiency for a two-section TWT with the phase-velocity taper are obtained using particle-in-cell simulation of CST Studio. At an applied beam voltage of 20 kV and a current of 0.1 A, an output power of 130 W, corresponding to a saturated gain of 39.4 dB, an instantaneous 3-dB bandwidth of around 5.3%, and electronic efficiency of around 6.5% at 94 GHz has been obtained. It was found that at 94 GHz the ‘positively and negatively phase-velocity tapered’ sections enhanced the gain by almost 3 dB and doubles the electronic efficiency of the two-section FWTWT design as compared to the two-section FWSWS with the same interaction circuit length with no phase-velocity taper. Journal: Journal of Electromagnetic Waves and Applications Pages: 1316-1327 Issue: 10 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1435309 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1435309 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:10:p:1316-1327 Template-Type: ReDIF-Article 1.0 Author-Name: C. A. Rodrigues Junior Author-X-Name-First: C. A. Author-X-Name-Last: Rodrigues Junior Author-Name: M. C. Campos Filho Author-X-Name-First: M. C. Author-X-Name-Last: Campos Filho Author-Name: D. G. Sousa Author-X-Name-First: D. G. Author-X-Name-Last: Sousa Author-Name: A. J. M. Sales Author-X-Name-First: A. J. M. Author-X-Name-Last: Sales Author-Name: R. P. S. Leão Author-X-Name-First: R. P. S. Author-X-Name-Last: Leão Author-Name: A. S. B. Sombra Author-X-Name-First: A. S. B. Author-X-Name-Last: Sombra Author-Name: G. C. Barroso Author-X-Name-First: G. C. Author-X-Name-Last: Barroso Title: Structural and electrical properties of the SrBi4Ti4O15: V2O5 matrix in the microwave frequency range Abstract: In this present work, material has been developed to have thermal stability over microwave range. The SrBi4Ti4O15 ceramics are perovskite material from Aurivillius family and were produced by solid state reaction method with temperatures lower than other recent works reported. X-ray diffraction patterns have confirmed single phase and afterward the sample data were refined by using Rietveld method. V2O5 was added to the pure specimen with different amounts (5, 10 and 15 wt.%) to possibly enhance electrical and dielectric properties of SrBi4Ti4O15. An impedance analyzer and a network analyzer were used to obtain electrical measurements in the range of microwave. Thermal stability measures over a microwave range were used as well as numerical simulations of dielectric resonator antenna (DRA) using the HFSS software. The obtained results have shown an efficient synthesis, and the dielectric constants indicate a real possibility of miniaturization. It was also found that the specimen for 6 wt.% of V2O5 presented temperature coefficient (τ f ) near zero at microwave region. The bandwidths measured from the specimens were classified as S-type with wide bandwidth and it can be applied for meteorological radars and satellite communications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1329-1341 Issue: 11 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1436004 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1436004 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:11:p:1329-1341 Template-Type: ReDIF-Article 1.0 Author-Name: Zhenyu Zhang Author-X-Name-First: Zhenyu Author-X-Name-Last: Zhang Author-Name: Sikai Liu Author-X-Name-First: Sikai Author-X-Name-Last: Liu Title: Joint sparse representation for multi-resolution representations of SAR images with application to target recognition Abstract: In this paper, we propose a target recognition method for synthetic aperture radar (SAR) images based on multi-resolution representations. Considering that the discriminability of SAR targets may lie on different resolutions, the original images at a fixed resolution are used to generate the multi-resolution representations of the target. Then a multi-resolution dictionary is built, which includes the multi-resolution representations of the training samples. For the test sample, its multi-resolution representations are jointly classified using the joint sparse representation (JSR) model based on the multi-resolution dictionary. The multi-resolution dictionary can not only augment the representation capability of the dictionary but also enhance the robustness of the representation. Furthermore, the JSR can exploit the inner correlations among the multi-resolution representations of the test sample. Therefore, a more precise representation of the test sample can be obtained, which will effectively improve the recognition performance. Experiments are conducted on the moving and stationary target acquisition and recognition (MSTAR) data-set to validate the effectiveness and robustness of the proposed method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1342-1353 Issue: 11 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1436005 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1436005 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:11:p:1342-1353 Template-Type: ReDIF-Article 1.0 Author-Name: Behnam Mazdouri Author-X-Name-First: Behnam Author-X-Name-Last: Mazdouri Author-Name: S. Mohammad Hassan Javadzadeh Author-X-Name-First: S. Mohammad Hassan Author-X-Name-Last: Javadzadeh Title: Modelling of current distribution and nonlinearity in superconducting coplanar waveguide (CPW) transmission line Abstract: There are nonlinear behaviours such as harmonic generation and intermodulation distortion (IMD) in superconductive circuits especially at low temperatures. In this paper, current distribution in superconducting coplanar waveguide transmission line (CPWTL) was modelled. After that, nonlinear circuit model to predict nonlinear behaviours in superconducting CPWTLs was proposed. Current distribution in superconducting CPWTL geometry with finite ground planes was formulated using of numerical method based on 3D-FEM. These formulations can be used to obtain accurate closed-form expressions for nonlinear components in distributed circuit model based on considering both quadratic and modulus nonlinear dependence on current. This model was analysed nonlinearly using Harmonic Balance method as a nonlinear solver. The proposed model can be used to predict nonlinear behaviours such as IMD and harmonic generation in superconducting CPWTL in different input powers and different temperatures. There are good agreement between nonlinear results from our proposed model and measured ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 1354-1368 Issue: 11 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1437081 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1437081 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:11:p:1354-1368 Template-Type: ReDIF-Article 1.0 Author-Name: Zhen Meng Author-X-Name-First: Zhen Author-X-Name-Last: Meng Author-Name: Feng Shen Author-X-Name-First: Feng Author-X-Name-Last: Shen Author-Name: Weidong Zhou Author-X-Name-First: Weidong Author-X-Name-Last: Zhou Author-Name: Wang Lu Author-X-Name-First: Wang Author-X-Name-Last: Lu Title: Robust adaptive beamforming based on subspace method Abstract: The performance of adaptive beamformers is susceptible to the steering vector mismatches and covariance matrix uncertainties. In contrast to traditional subspace methods, the proposed subspace method is robust against model mismatches. The signal-plus-interference covariance matrix (SICM) is reconstructed by projecting the enhanced covariance matrix onto the signal-plus-interference subspace which is formed using the property of covariance matrix. The array steering vector is adjusted by projecting the presumed steering vector onto the signal subspace which is structured using the major eigenvectors of the enhanced covariance matrix. The major eigenvectors are selected when the correlation coefficient between the presumed steering vector and the eigenvector exceeds a certain threshold. By combining the reconstructed SICM with the adjusted array steering vector, the proposed beamformer can provide robust performance. In comparison with many existing robust techniques, the proposed method performs well in both high and low signal-to-noise ratio scenarios. Several examples are carried out to illustrate the superiority of our method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1369-1378 Issue: 11 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1437082 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1437082 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:11:p:1369-1378 Template-Type: ReDIF-Article 1.0 Author-Name: Ran Bao Author-X-Name-First: Ran Author-X-Name-Last: Bao Author-Name: An-Qi Wang Author-X-Name-First: An-Qi Author-X-Name-Last: Wang Author-Name: Zhi-Xiang Huang Author-X-Name-First: Zhi-Xiang Author-X-Name-Last: Huang Title: Fast simulations of electromagnetic scattering from rough surface over a frequency band using asymptotic waveform evaluation technique: horizontal polarization Abstract: The asymptotic waveform evaluation (AWE) technique combined with the scalar integral equation and the tapered plane wave is chosen to fast simulate the electromagnetic scattering from rough surface over a frequency band under horizontal (H) polarization in this paper. The tapered plane wave with the energy in a narrow beam is chosen as the incident wave to avoid the artificial edge diffraction due to the finite length of the simulated rough surface. And the scalar integral equation is used to obtain the surface unknowns along the rough surface induced by the incident wave. The validity and efficiency of the AWE are shown by comparing with the repeated calculation at every finer frequency increment through the method of moments (MoM). The influences of several important parameters, such as root-mean-square height, correlation length and incident angle are studied and discussed. And in this paper, the complex frequency hopping technique is also used to extend the validity of AWE. Journal: Journal of Electromagnetic Waves and Applications Pages: 1379-1388 Issue: 11 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1437083 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1437083 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:11:p:1379-1388 Template-Type: ReDIF-Article 1.0 Author-Name: Yury Smirnov Author-X-Name-First: Yury Author-X-Name-Last: Smirnov Author-Name: Eugene Smolkin Author-X-Name-First: Eugene Author-X-Name-Last: Smolkin Author-Name: Yury Shestopalov Author-X-Name-First: Yury Author-X-Name-Last: Shestopalov Title: On the existence of non-polarized azimuthal-symmetric electromagnetic waves in circular metal-dielectric waveguide filled with nonlinear radially inhomogeneous medium Abstract: Propagation of monochromatic nonlinear symmetric hybrid waves in a cylindrical nonlinear inhomogeneous metal–dielectric waveguide is considered. The physical problem is reduced to solving a transmission eigenvalue problem for a system of ordinary differential equations where spectral parameters are the wave propagation constants. The setting under study is reduced to a new type of nonlinear eigenvalue problem. An analytical method for solving this problem is elaborated. For the numerical solution, a method is proposed based on solving an auxiliary Cauchy problem (a version of the shooting method). As a result of comprehensive numerical modeling, new propagation regimes are discovered. Journal: Journal of Electromagnetic Waves and Applications Pages: 1389-1408 Issue: 11 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1438929 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1438929 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:11:p:1389-1408 Template-Type: ReDIF-Article 1.0 Author-Name: M.-M. Ma Author-X-Name-First: M.-M. Author-X-Name-Last: Ma Author-Name: Z.-X. Tang Author-X-Name-First: Z.-X. Author-X-Name-Last: Tang Author-Name: X. Cao Author-X-Name-First: X. Author-X-Name-Last: Cao Author-Name: T. Qian Author-X-Name-First: T. Author-X-Name-Last: Qian Title: Tri-band cross-coupling bandpass filter with rectangular defected ground structure array Abstract: A tri-band cross-coupling bandpass filter (BPF) with rectangular defected ground structure (DGS) array is proposed in this paper. Cross-coupling paths comprised of five resonators are employed to achieve general Chebyshev filtering frequency responses. Besides changing gaps among resonators, a novel rectangular DGS array is proposed to exactly meet coupling coefficients for specific demands for different passband in multi-band BPF. The centre frequency of the tri-band filter that is selected at 2.4, 3.4, 5.5 GHz are for LTE, Bluetooth, WiMAX and WLAN. The 3 dB bandwidth of the three passbands are 5, 3.23 and 3.45%, respectively, meanwhile, more transmission zeros are generated, leading to enhanced selectivity and high out of band isolation. The proposed tri-band filter is completed with a few simple calculations and several brief processes. Measured results of the fabricated filter demonstrate the theory prediction and proposed method well. Journal: Journal of Electromagnetic Waves and Applications Pages: 1409-1415 Issue: 11 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1439407 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1439407 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:11:p:1409-1415 Template-Type: ReDIF-Article 1.0 Author-Name: Xiao-Kun Wei Author-X-Name-First: Xiao-Kun Author-X-Name-Last: Wei Author-Name: Wei Shao Author-X-Name-First: Wei Author-X-Name-Last: Shao Author-Name: Shuai Ding Author-X-Name-First: Shuai Author-X-Name-Last: Ding Author-Name: Bing-Zhong Wang Author-X-Name-First: Bing-Zhong Author-X-Name-Last: Wang Title: Hybrid sub-gridded ADE-FDTD method for modeling ground-penetrating radar on dispersive soils Abstract: Based on the sub-gridding scheme, a hybrid method with explicit finite-difference time-domain (FDTD) and implicit Crank–Nicolson (CN) FDTD is presented for ground-penetrating radar (GPR) simulations on dispersive and conductive soils in this paper. The time step of CN-FDTD can be set to a large value so that the whole region can be run with a common time step determined by the coarse grid in a stable fashion. The missing information in the sub-gridded border region is obtained with an interpolation in space. The dispersion of the soil is modeled by a multi-pole Debye model and is solved with auxiliary differential equations (ADEs) for both FDTD and CN-FDTD. Additionally, examples of the GPR scenario are calculated to verify the accuracy and efficiency of the hybrid sub-gridded ADE-FDTD method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1416-1426 Issue: 11 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1439775 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1439775 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:11:p:1416-1426 Template-Type: ReDIF-Article 1.0 Author-Name: Rebba Esther Suhasini Author-X-Name-First: Rebba Esther Author-X-Name-Last: Suhasini Author-Name: Dasari Rama Krishna Author-X-Name-First: Dasari Author-X-Name-Last: Rama Krishna Author-Name: V. M. Pandharipande Author-X-Name-First: V. M. Author-X-Name-Last: Pandharipande Title: Design, development, and performance evaluation of switched wave oscillator (SWO) for high-power electromagnetic applications Abstract: This paper presents the design and fabrication details of a switched wave oscillator (SWO) which can be used to generate High Power Electromagnetic (HPEM) signals having a moderate bandwidth at an operating frequency of 680 MHz for mesoband applications. SWO has been designed using coaxial as well as an alternate type of transmission line. Numerical analysis of both the models is presented. A suitable antenna has been designed, fabricated, and integrated with the SWO. Finally, the overall performance of the system has been presented to validate its suitability as HPEM generator for Intentional Electromagnetic Interference applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1427-1439 Issue: 11 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1442260 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1442260 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:11:p:1427-1439 Template-Type: ReDIF-Article 1.0 Author-Name: Welyson T. S. Ramos Author-X-Name-First: Welyson T. S. Author-X-Name-Last: Ramos Author-Name: Renato C. Mesquita Author-X-Name-First: Renato C. Author-X-Name-Last: Mesquita Author-Name: Elson J. Silva Author-X-Name-First: Elson J. Author-X-Name-Last: Silva Title: Frequency selective surface using meander line inclusions Abstract: A frequency selective surface (FSS) composed of a periodic arrangement of meander line inclusions is numerically analysed. The study is presented with respect to the number of meanders and is a generalization of the U-shape (1-meander). A y-polarized incident wave is used to illuminate the structure. The results are obtained by the finite element method. By investigating the transmission coefficient, in this letter, it is seen that several stopbands may be exhibited within the operating frequency band and resonant frequency reduction can be associated with the number of meanders. For an incident wave with linear polarization, our findings suggest that the shift at the resonant frequency is also due to the increase in the effective length in the polarization direction of the incident wave. The validation of our model is performed by U-shape simulation already experimentally tested in other letters. A very good agreement has been achieved. Journal: Journal of Electromagnetic Waves and Applications Pages: 1440-1447 Issue: 11 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1442261 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1442261 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:11:p:1440-1447 Template-Type: ReDIF-Article 1.0 Author-Name: Wen Song Author-X-Name-First: Wen Author-X-Name-Last: Song Title: Comparison of thin-slot formalisms for the FDTD analyses of narrow apertures Abstract: Thin-slot formalisms (TSF) in the literature have been briefly summarized. High resolution standard FDTD simulation results are presented in this paper to support the comparison. From comparison of the coupled electric field component through two thin-slots at different distances from the slot plane, some conclusions are drawn. It is found the uniform TSF will result in huge error when used to simulate the coupling of the thin-slots. The capacitance TSF and an alternative expression of the capacitance TSF are not as accurate as the improved capacitance TSF. Instability may occur when the hybrid TSF is used. The improved capacitance TSF and the enhanced TSF are suitable for the simulation of thin-slots. Journal: Journal of Electromagnetic Waves and Applications Pages: 1448-1456 Issue: 11 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1442262 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1442262 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:11:p:1448-1456 Template-Type: ReDIF-Article 1.0 Author-Name: M. S. Osman Author-X-Name-First: M. S. Author-X-Name-Last: Osman Author-Name: J. A. T. Machado Author-X-Name-First: J. A. T. Author-X-Name-Last: Machado Title: The dynamical behavior of mixed-type soliton solutions described by (2+1)-dimensional Bogoyavlensky–Konopelchenko equation with variable coefficients Abstract: This paper investigates the (2+1)-dimensional Bogoyavlensky–Konopelchenko equation with variable coefficients via the generalized unified method. Mixed type of N-soliton solutions are obtained when N=1 $ N=1 $ and N=2 $ N=2 $ in a rational form. The propagation and the dynamical behavior of these solutions is analyzed for different choices of the arbitrary variable coefficients. When N=1 $ N=1 $ , it is verified that the velocity of the soliton cannot be influenced by the variable coefficients. Furthermore, the shape and the amplitude of the soliton cannot be affected. For N=2 $ N=2 $ , the collision between the solitons, either two kink periodic soliton solutions or two kink and anti-kink soliton solutions, are elastic whether the coefficients of the equation are constant or variable. Journal: Journal of Electromagnetic Waves and Applications Pages: 1457-1464 Issue: 11 Volume: 32 Year: 2018 Month: 7 X-DOI: 10.1080/09205071.2018.1445039 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1445039 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:11:p:1457-1464 Template-Type: ReDIF-Article 1.0 Author-Name: Vishal Kesari Author-X-Name-First: Vishal Author-X-Name-Last: Kesari Author-Name: B. N. Basu Author-X-Name-First: B. N. Author-X-Name-Last: Basu Title: Analysis of some periodic structures of microwave tubes: part II: analysis of disc-loaded fast-wave circular waveguide structures for gyro-travelling-wave tubes Abstract: In part I of the present paper, we analysed helical slow-wave structures of travelling-wave tubes (TWTs) taking into account the space harmonic effects arising from the axial periodicity of helix turns as well as azimuthal periodicity of the dielectric helix-supports and metal vanes of the envelope of the structure. Here, in part II of the paper, we extended the analysis to the fast-wave regime to study a disc-loaded circular waveguide interaction structure of a gyro-TWT taking into account the space harmonic effects arising from the axial periodicity of the annular discs. Four variants of the structure were studied. Two of these variants use thin and thick metal discs, respectively. The third variant has inherently two interwoven metal disc-loaded structures, and the fourth variant has dielectric discs interposed between consecutive metal discs. We studied the effect of tapering the disc parameters and predicted the optimized parameters for the wideband and high-gain gyro-TWT performance. The analyses presented in parts I and II of the paper should prove to be very useful in the design of wideband TWTs and gyro-TWTs, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 1465-1500 Issue: 12 Volume: 32 Year: 2018 Month: 8 X-DOI: 10.1080/09205071.2018.1451396 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1451396 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:12:p:1465-1500 Template-Type: ReDIF-Article 1.0 Author-Name: Andrey D. Andreev Author-X-Name-First: Andrey D. Author-X-Name-Last: Andreev Title: Computer simulations of frequency- and phase-locking of cavity magnetrons Abstract: The difference between frequency locking and phase locking of multi-cavity magnetrons (oscillators) is analyzed and the method of computer simulations of the locking phenomena in a virtually prototyped system of the coupled magnetrons operating within the same simulation domain is discussed. It is stated that while the frequency locking maybe demonstrated, if properly designed, by computer simulations of the coupled magnetrons operation during one simulation run only by showing an achievement of the same operating frequency of the simulated magnetrons, the evidence of the phase locking maybe demonstrated after at least two simulation runs by showing an achievement (in both simulation runs) of the same phase difference between simulated magnetrons already operating in the frequency-locked mode. The “phase difference” between magnetrons, θ, refers here and elsewhere below to the phase difference between induced electric field (magnetron) oscillations in the appropriate reference planes of the virtually prototyped system of the coupled magnetrons. Journal: Journal of Electromagnetic Waves and Applications Pages: 1501-1518 Issue: 12 Volume: 32 Year: 2018 Month: 8 X-DOI: 10.1080/09205071.2018.1452636 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1452636 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:12:p:1501-1518 Template-Type: ReDIF-Article 1.0 Author-Name: Miguel Angel Casas-Ramos Author-X-Name-First: Miguel Angel Author-X-Name-Last: Casas-Ramos Author-Name: Gabriel Eduardo Sandoval-Romero Author-X-Name-First: Gabriel Eduardo Author-X-Name-Last: Sandoval-Romero Title: Strain detection and measurement using a matched fibre Bragg grating Abstract: We present and describe a method to demodulate the incoming strain signal from sensors based on fibre Bragg gratings (FBGs). This demodulation is achieved by using a reference FBG with similar characteristics to those of the FBG sensor as a band-pass filter to recover the total power in the detected signal from the shift in the Bragg wavelength caused by the strain experienced by the FBG sensor. From the experimental data and the numerical simulation, the system static transfer characteristic curves are obtained and compared. Using this method, a linear measurement range of 227 pm (183 με), along with a precision of 0.8 με and a resolution of 1.6 με were achieved. This simple and inexpensive method is a practical alternative to conventional FBG interrogation units because few optical elements are used in the set-up, and the Bragg wavelength shifts are determined by the changes in the detected optical intensity. These intensity changes are caused by the mechanical axial strain experienced by the FBG sensor. Journal: Journal of Electromagnetic Waves and Applications Pages: 1519-1526 Issue: 12 Volume: 32 Year: 2018 Month: 8 X-DOI: 10.1080/09205071.2018.1446366 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1446366 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:12:p:1519-1526 Template-Type: ReDIF-Article 1.0 Author-Name: Do-Hyung Kim Author-X-Name-First: Do-Hyung Author-X-Name-Last: Kim Title: A linear algebraic derivation of Lorentz transformation from wave equations Abstract: It is shown that arbitrary dimensional Lorentz transformation can be obtained from invariance of wave equations using mathematically rigorous, linear algebraic arguments. Journal: Journal of Electromagnetic Waves and Applications Pages: 1527-1534 Issue: 12 Volume: 32 Year: 2018 Month: 8 X-DOI: 10.1080/09205071.2018.1448004 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1448004 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:12:p:1527-1534 Template-Type: ReDIF-Article 1.0 Author-Name: I. V. Andronov Author-X-Name-First: I. V. Author-X-Name-Last: Andronov Title: Axial diffraction of a dipole field by a strongly elongated spheroid Abstract: Axial diffraction of a dipole source on an elongated perfectly conducting spheroid is considered in high-frequency asymptotic approximation in a uniform manner with respect to the rate of elongation. Approximation is tested vs. numerical results. Effects of elongation on the induced currents distribution are illustrated. Journal: Journal of Electromagnetic Waves and Applications Pages: 1535-1540 Issue: 12 Volume: 32 Year: 2018 Month: 8 X-DOI: 10.1080/09205071.2018.1451395 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1451395 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:12:p:1535-1540 Template-Type: ReDIF-Article 1.0 Author-Name: Dena M. El-Amassi Author-X-Name-First: Dena M. Author-X-Name-Last: El-Amassi Author-Name: Sofyan A. Taya Author-X-Name-First: Sofyan A. Author-X-Name-Last: Taya Title: Reflected and transmitted powers of p-polarized electromagnetic waves through a dielectric slab surrounded by double negative materials Abstract: In this paper, reflected, transmitted, and loss powers of p-polarized electromagnetic waves through a lossless dielectric slab embedded between two double negative media are studied. Lorentz and Drude medium models are both considered for the dispersion of the double negative materials in the surroundings. The dependences of reflected, transmitted, and loss powers on the incidence angle, incident wave frequency, and dielectric slab thickness are investigated. The results reveal many interesting features. The damping frequency has a slight effect on reflected, transmitted, and loss powers in most waveguide configurations considered. Moreover, the loss power is small and can be significantly reduced by considering Drude dispersion model and careful choosing of the proposed structure parameters. Journal: Journal of Electromagnetic Waves and Applications Pages: 1541-1559 Issue: 12 Volume: 32 Year: 2018 Month: 8 X-DOI: 10.1080/09205071.2018.1453387 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1453387 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:12:p:1541-1559 Template-Type: ReDIF-Article 1.0 Author-Name: Boao Xu Author-X-Name-First: Boao Author-X-Name-Last: Xu Author-Name: Yantao Duan Author-X-Name-First: Yantao Author-X-Name-Last: Duan Author-Name: Bin Chen Author-X-Name-First: Bin Author-X-Name-Last: Chen Author-Name: Kang Luo Author-X-Name-First: Kang Author-X-Name-Last: Luo Author-Name: Dawei Zhu Author-X-Name-First: Dawei Author-X-Name-Last: Zhu Title: A novel ADI iterative algorithm for efficient 3-D WLP-FDTD method Abstract: In this letter, a novel alternating direction implicit (ADI) iterative algorithm for efficient 3-D weighted Laguerre polynomials finite-difference time-domain (WLP-FDTD) method is proposed. Using this approach, the Gauss–Seidel method can be applied in the whole iterative procedure, instead only the first step in the efficient WLP-FDTD. A correction item Ex∗$ E_{x}^{ * } $ is added to speed up the convergence. The proposed method is based on the iterative algorithm for linear equations, which makes it more flexible. Numerical examples are given to demonstrate the computation accuracy and efficiency of the proposed method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1560-1568 Issue: 12 Volume: 32 Year: 2018 Month: 8 X-DOI: 10.1080/09205071.2018.1456364 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1456364 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:12:p:1560-1568 Template-Type: ReDIF-Article 1.0 Author-Name: N. Saravanakumar Author-X-Name-First: N. Author-X-Name-Last: Saravanakumar Author-Name: K. Sathiyasekar Author-X-Name-First: K. Author-X-Name-Last: Sathiyasekar Title: Circular Array of Ultrasonic Sensor based DOA estimation: Location of multiple Partial Discharge in Transformer oil Abstract: Location of Partial Discharge (PD) in transformers is very important, and many methodologies that have been carried forward in previous decades have a restriction theoretically, specially, in power transformers they cannot locate multiple PDs. Based on array signal processing a novel multiple partial discharges localization is presented in this paper. Ultrasonic signal emission occurs when the partial discharge occurs inside the transformer oil tank. Using ultrasonic sensor arrays located on the wall of the transformer tank, emitted ultrasonic signals is detected. Generally a single partial discharge will not occur in transformer there may be multiple partial discharge occur at different location. For detection of multiple partial discharges, we have used circular array of ultrasonic sensors (CAUS) in our proposed method. Primarily, by using Translation Invariant Wavelet Transform the partial discharge signals are de noised. To change the wide-band signal received by CAUS to the narrowband one Total Least Square algorithm is utilized. After this, the number of PD signals is estimated and to find the directions of arrival (DOA) of the signal sparse representation of array covariance vector technique is utilized. Lastly, on the basis of estimation of DOA position of PD source is detected with the help of optimization algorithm in order to find the exact coordinates of the PD source. Journal: Journal of Electromagnetic Waves and Applications Pages: 1569-1585 Issue: 12 Volume: 32 Year: 2018 Month: 8 X-DOI: 10.1080/09205071.2018.1456365 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1456365 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:12:p:1569-1585 Template-Type: ReDIF-Article 1.0 Author-Name: Mohammad Alibakhshikenari Author-X-Name-First: Mohammad Author-X-Name-Last: Alibakhshikenari Author-Name: Bal Singh Virdee Author-X-Name-First: Bal Singh Author-X-Name-Last: Virdee Author-Name: Ernesto Limiti Author-X-Name-First: Ernesto Author-X-Name-Last: Limiti Title: Wideband planar array antenna based on SCRLH-TL for airborne synthetic aperture radar application Abstract: This paper presents empirical results of a novel planar microstrip array antenna based on a simplified composite right/left-handed transmission line (SCRLH-TL) for application in circularly polarized synthetic aperture radar (CP-SAR) systems operated in UHF, L, S, and C-Bands. The array antenna consists of 6 × 6 matrix of spiral-shaped radiating elements that are excited through proximity-coupled, single feed-line. Pattern synthesis technique is used to determine the excitation coefficients (amplitude and phase) to apply to the individual array elements to achieve the required pattern shape. The array antenna has dimensions of 111.5 × 96.06 mm2. The measured impedance bandwidth of the antenna is 3.85 GHz for S11 < −10 dB from 300 MHz to 4.15 GHz, corresponding to a fractional bandwidth of 173%. Maximum gain and radiation efficiency measured are 4.8 dBi and 79.5%, respectively, at 2.40 GHz. The antenna has a 3-dB axial-ratio bandwidth of 3.94 GHz from 144 MHz to 4.66 GHz. The antenna’s beamwidth in azimuth and elevation planes vary between 60° and 120° across its operational frequency range from 300 MHz to 4.15 GHz. The antenna design fulfills the challenging electrical and physical specifications required for CP-SAR employed onboard unmanned aerial vehicle (UAV). Journal: Journal of Electromagnetic Waves and Applications Pages: 1586-1599 Issue: 12 Volume: 32 Year: 2018 Month: 8 X-DOI: 10.1080/09205071.2018.1460280 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1460280 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:12:p:1586-1599 Template-Type: ReDIF-Article 1.0 Author-Name: Zhipeng Liang Author-X-Name-First: Zhipeng Author-X-Name-Last: Liang Author-Name: Jun Ouyang Author-X-Name-First: Jun Author-X-Name-Last: Ouyang Author-Name: Feng Yang Author-X-Name-First: Feng Author-X-Name-Last: Yang Title: A hybrid GA-PSO optimization algorithm for conformal antenna array pattern synthesis Abstract: This paper introduces a hybrid genetic algorithm and particle swarm optimization algorithm (GA-PSO) dedicated to pattern synthesis of conformal antenna arrays. Taking advantages of both methods, the proposed hybrid GA-PSO optimization algorithm has fast convergence speed and high convergence accuracy when applied to antenna array pattern synthesis. To show the performance of the hybrid optimization algorithm, several typical test functions and optimization examples of a linear array pattern synthesis are illustrated. Finally, a 4 × 2 cylindrical conformal microstrip antenna array as a practical synthesis example is studied to demonstrate the proposed algorithm. The simulated and measured results have shown the proposed method is effective and reliable for conformal antenna array pattern synthesis. Journal: Journal of Electromagnetic Waves and Applications Pages: 1601-1615 Issue: 13 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1462257 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1462257 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:13:p:1601-1615 Template-Type: ReDIF-Article 1.0 Author-Name: Narae Kim Author-X-Name-First: Narae Author-X-Name-Last: Kim Author-Name: Seunghyun Kim Author-X-Name-First: Seunghyun Author-X-Name-Last: Kim Author-Name: Hyobeen Park Author-X-Name-First: Hyobeen Author-X-Name-Last: Park Author-Name: Yunho Jung Author-X-Name-First: Yunho Author-X-Name-Last: Jung Author-Name: Seongjoo Lee Author-X-Name-First: Seongjoo Author-X-Name-Last: Lee Title: Low cost FMCW radar systems with the reduced number of FFT points under indoor environments Abstract: In this paper proposed is a cost-efficient signal processing algorithm of a frequency modulation continuous wave (FMCW) radar for the close range under indoor environments. Recently, the use of an FMCW radar has been expanded to short distance from long distance due to easy production and inexpensive designing costs. In order to obtain satisfying resolution of the close range radar, it still requires a wide modulation bandwidth, which results in high costing wideband RF devices. This paper proposes a cost-efficient signal processing method using correlations between a reflected signal in frequency-domain and a lookup table which holds the frequency information depending on distances. The proposed algorithm shows the similar performance to a wideband system just by updating a firmware of low costing narrowband RF FMCW radar devices without additional hardware modification. Journal: Journal of Electromagnetic Waves and Applications Pages: 1616-1628 Issue: 13 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1463179 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1463179 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:13:p:1616-1628 Template-Type: ReDIF-Article 1.0 Author-Name: Aliakbar Dastranj Author-X-Name-First: Aliakbar Author-X-Name-Last: Dastranj Title: Modified end-fire bow-tie antenna fed by microstrip line for wideband communication systems Abstract: A broadband microstrip-fed modified printed bow-tie antenna is proposed. Using a rounded ground plane, adding a pair of circular patches to the bow-tie arms, and optimizing the design parameters, an operation frequency band of 3.3–15.2 GHz is achieved. The development stages of the modified bow-tie radiator is exhibited and it is shown that by designing different antenna structures, the impedance bandwidth (defined by –10-dB reflection coefficient) can be improved from 37% to more than 128%. The modified antenna possesses advantages of not only a broad bandwidth of 128%, but also a small size of 34 × 34 × 1.2 mm3. The designed antenna was fabricated and tested. The impedance matching, group delay, and the antenna radiation characteristics, including co-polarized far-field patterns, cross-polarized patterns, radiation efficiency, and gain were analyzed with numerical simulation and experimental measurement. Measured data are in good agreement with the simulated results. Based on the obtained frequency- and time-domain characteristics, the designed antenna is an attractive candidate for broadband communication applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1629-1643 Issue: 13 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1464962 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1464962 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:13:p:1629-1643 Template-Type: ReDIF-Article 1.0 Author-Name: Fulya Callialp Kunter Author-X-Name-First: Fulya Callialp Author-X-Name-Last: Kunter Title: Prediction of SAR and temperature distribution in the human ear and mouth exposed to handheld transmitters Abstract: As the body centric communication technology develops in monitoring real-time healthcare, fitness, sports, and military, significant attention arises in regarding possible health risks. The aim of this study is to evaluate radio frequency exposure level of various types of wearable devices in terms of the available international recommendations. Specific absorption rate and maximum temperature increase are studied in the human ear and mouth when they are exposed to handheld transmitters. The human brain and the mouth are modeled using the simulation program and the handheld transmitters are realized with microstrip patch antenna. The simulations depict that the dosimetry for handheld transmitters operated next to the body is below the standards. Journal: Journal of Electromagnetic Waves and Applications Pages: 1644-1653 Issue: 13 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1464963 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1464963 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:13:p:1644-1653 Template-Type: ReDIF-Article 1.0 Author-Name: Ying Li Author-X-Name-First: Ying Author-X-Name-Last: Li Author-Name: Hang Xu Author-X-Name-First: Hang Author-X-Name-Last: Xu Author-Name: Jianguo Zhang Author-X-Name-First: Jianguo Author-X-Name-Last: Zhang Author-Name: Li Liu Author-X-Name-First: Li Author-X-Name-Last: Liu Title: A hybrid chaos-Doppler radar for through-wall life detection Abstract: We experimentally demonstrate a hybrid radar system that incorporates a wideband Boolean-chaos mode and a phase-based Doppler mode for human localization and life signal (respiration and heartbeat) monitoring. The measurement principle and signal-processing technology allow this radar to work simultaneously at two different modes for different purposes. The wideband Boolean-chaos mode is responsible for accurate range detection while the phase-based Doppler mode is utilized for life signal monitoring. Experimental results show that the proposed hybrid radar can realize the simultaneous detection for range and life signal with high-range resolution, high sensitivity, and large dynamic range. The down-range resolution and dynamic range for range detection behind a 20-cm-thick wall are 15 cm and 50 dB, respectively. Meanwhile, the dynamic ranges for heartbeat and respiration detection are 10 and 50 dB, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 1654-1663 Issue: 13 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1464964 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1464964 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:13:p:1654-1663 Template-Type: ReDIF-Article 1.0 Author-Name: Fang Rao Author-X-Name-First: Fang Author-X-Name-Last: Rao Author-Name: Zetai Yu Author-X-Name-First: Zetai Author-X-Name-Last: Yu Author-Name: Xiaojun Huang Author-X-Name-First: Xiaojun Author-X-Name-Last: Huang Author-Name: Sen Hu Author-X-Name-First: Sen Author-X-Name-Last: Hu Author-Name: Yan Jin Author-X-Name-First: Yan Author-X-Name-Last: Jin Author-Name: Helin Yang Author-X-Name-First: Helin Author-X-Name-Last: Yang Title: Metamaterial-inspired rotation sensor based on complementary single split-ring resonator (CSSRR) Abstract: In this paper, a new rotation sensor based on a complementary single split-ring resonator (CSSRR) coupled to a circularly shaped microstrip line is designed, simulated and verified by experiment. Rotating the upper resonator, the measurement results reveal the relationship of the rotated angles and the transmission characteristics. Compared to the previously published rotation sensors, the sensor proposed benefits from a well immunity to ambient conditions and nearly same resonance frequency responses at the relatively symmetrical angles. It even can get a high sensitivity around 100 MHz per 10° with a wide dynamic range of 0°–90°. The configured device is quite compacted with respect to the operational wavelength and will have tremendous potential applications in the micro-electromechanical systems technology. Journal: Journal of Electromagnetic Waves and Applications Pages: 1664-1674 Issue: 13 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1465480 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1465480 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:13:p:1664-1674 Template-Type: ReDIF-Article 1.0 Author-Name: Moti Zelig Author-X-Name-First: Moti Author-X-Name-Last: Zelig Author-Name: Ehud Heyman Author-X-Name-First: Ehud Author-X-Name-Last: Heyman Author-Name: Amir Boag Author-X-Name-First: Amir Author-X-Name-Last: Boag Title: A fast algorithm for the analysis of scattering by elongated cavities Abstract: Electromagnetic scattering from elongated, arbitrarily shaped, open-ended cavities (OEC) has been studied extensively over the years. In this paper, we introduce the fast encapsulating domain decomposition (EDD) scheme for the analysis of radar cross section (RCS) of such OEC. The EDD advantages stem from a domain decomposition along the elongated dimension, followed by a spectral representation of the fields in each segment, whereby the field is naturally separated into in- and out-going waves. This diagonalizes the translation between the cross sections, thus reducing the per segment computational complexity from O((NA)3) $ O((N^{\text{A}} )^{3} ) $ to O(NW(NA)2) $ O(N^{\text{W}} (N^{\text{A}} )^{2} ) $ , where NA $ N^{\text{A}} $ and NW $ N^{\text{W}} $ are the number of aperture and wall unknowns per segment, satisfying NW<29% for both ports, an isolation of >34 dB, a gain of >8.4, and a radiation efficiency of >80%. Also, a four-element array based on the proposed antenna is fed by non-uniform feeding networks to achieve a low sidelobe level (SLL). The array yielded an isolation of > 20 dB, a gain of >11.7 dBi, and an SLL of <–20 dB for both ± 45º polarizations. Journal: Journal of Electromagnetic Waves and Applications Pages: 1748-1767 Issue: 14 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1468284 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1468284 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:14:p:1748-1767 Template-Type: ReDIF-Article 1.0 Author-Name: Amit Patel Author-X-Name-First: Amit Author-X-Name-Last: Patel Author-Name: Riddhi Goswami Author-X-Name-First: Riddhi Author-X-Name-Last: Goswami Author-Name: Alpesh Vala Author-X-Name-First: Alpesh Author-X-Name-Last: Vala Author-Name: Keyur Mahant Author-X-Name-First: Keyur Author-X-Name-Last: Mahant Author-Name: Hiren Mewada Author-X-Name-First: Hiren Author-X-Name-Last: Mewada Author-Name: Pujita Bhatt Author-X-Name-First: Pujita Author-X-Name-Last: Bhatt Author-Name: K. Sathyanarayan Author-X-Name-First: K. Author-X-Name-Last: Sathyanarayan Author-Name: S. V. Kulkarni Author-X-Name-First: S. V. Author-X-Name-Last: Kulkarni Title: Millimeter-wave TE01–TE11–HE11 mode converter using overmoded circular waveguide Abstract: The paper presents overmoded circular waveguide mode converters (TE01 into HE11 with TE11 as an intermediate mode) used in a 42 ± 0.2 GHz, 200 kW gyrotron transmission line system for plasma heating in electron cyclotron resonance heating application. To convert mode from TE01 to TE11, we have used wriggle converter method with a deformation in the converter axis and for TE11 to HE11 mode converter the depth of corrugation decreases gradually from λ2 $ \frac{\lambda }{2} $ to λ4 $ \frac{\lambda }{4} $ . Both the converters are optimized in terms of design parameters using mode field matching technique. The TE01 to TE11 mode converter showed a conversion efficiency of 95% (predicted 99%) for a length of 1205 mm, while TE11 to HE11 mode converter gave conversion efficiency of 99% (predicted 99.98%) for a diameter of 32 mm. Cross-polarization isolation of 31.7 dB is obtained in TE11 to HE11 mode converter. Convergence of the theoretical values and the simulated results indicates that the converters meet the system requirements. Journal: Journal of Electromagnetic Waves and Applications Pages: 1768-1778 Issue: 14 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1468286 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1468286 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:14:p:1768-1778 Template-Type: ReDIF-Article 1.0 Author-Name: Sajeed Sirajuddin Mulla Author-X-Name-First: Sajeed Sirajuddin Author-X-Name-Last: Mulla Author-Name: Shraddha S. Deshpande Author-X-Name-First: Shraddha S. Author-X-Name-Last: Deshpande Title: Miniaturization of multiband annular slot ring antenna using reactive loading Abstract: A multiband annular slot ring (ASR) antenna for mobile communications is designed and analysed in this paper. Then, the miniaturized multiband ASR antenna loaded with distributed inductive stub is proposed, which is miniaturized by 20.28%. Another multiband ASR antenna loaded with meta-material (ASR-SRR) inspired Electromagnetically Coupled Split Ring Resonator (EC-SRR) is proposed, it is miniaturized by 30.55%. The surface wave of the proposed miniaturized ASR-SRR in higher mode has reduced due to increase in reactive impedance of the antenna surface, thus aperture efficiency is increased. The radiation characteristics of miniaturized antennas are approximately similar to the ASR antennas. Behaviour of antenna characteristics such as gain (G), impedance bandwidth (BW), aperture efficiency (η A ), Chu condition (ka ≤ 1) of proposed antenna is also studied, observed and analysed in this paper. Journal: Journal of Electromagnetic Waves and Applications Pages: 1779-1790 Issue: 14 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1470577 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1470577 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:14:p:1779-1790 Template-Type: ReDIF-Article 1.0 Author-Name: Meng-Lin Zhai Author-X-Name-First: Meng-Lin Author-X-Name-Last: Zhai Author-Name: De-Min Li Author-X-Name-First: De-Min Author-X-Name-Last: Li Title: Tunable resonators based on hybrid metal–graphene structures at mid-infrared frequencies using an improved Leapfrog WCS-FDTD method Abstract: In this paper, tunable resonators based on hybrid metal–graphene structures at mid-infrared frequencies are investigated using an improved Leapfrog weakly conditional stable finite-difference time-domain (WCS-FDTD) method. Simulation results reveal that the transmission responses of the proposed devices can be predicted efficiently and controlled conveniently by means of changing chemical potentials and operating temperatures. Moreover, the structures with symmetry and asymmetry metal ribbons can be used as high-sensitivity sensors and switches, respectively. This work may provide a novel method for designing ultrafast active optoelectronic devices in optical communication. Journal: Journal of Electromagnetic Waves and Applications Pages: 1791-1800 Issue: 14 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1471419 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1471419 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:14:p:1791-1800 Template-Type: ReDIF-Article 1.0 Author-Name: Jo-Yen Nieh Author-X-Name-First: Jo-Yen Author-X-Name-Last: Nieh Author-Name: Wei-Ming Syu Author-X-Name-First: Wei-Ming Author-X-Name-Last: Syu Author-Name: Shu-Chuan Chen Author-X-Name-First: Shu-Chuan Author-X-Name-Last: Chen Author-Name: Ching-Cheng Wang Author-X-Name-First: Ching-Cheng Author-X-Name-Last: Wang Title: Long-term evolution coupled-fed loop antenna installed in the hinge slot region of a laptop computer Abstract: The present study proposed a long-term evolution (LTE) couple-feeding antenna design for laptop computers. The proposed antenna was installed in a closed hinge slot region. The loop structure of the antenna was designed to excite the closed hinge slot’s resonance modes to extend operating bandwidth and antenna efficiency. Although the fabricated antenna measured only 25 mm × 4 mm, it was capable of covering the requirement for eight-band coverage to the LTE standard. Additionally, the antenna consisted of a feeding strip and a shorting strip, with which it was able to excite resonance modes in both its own loop’s modes and the closed hinge slot’s modes. Aside from a wide operating bandwidth, the minute antenna can also overcome the radiation efficiency problem caused by an all-metal environment. With antenna efficiency over 50% within the operating band, the design conforms to the actual needs of applications in laptop computers. Journal: Journal of Electromagnetic Waves and Applications Pages: 1801-1815 Issue: 14 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1472044 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1472044 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:14:p:1801-1815 Template-Type: ReDIF-Article 1.0 Author-Name: Bin You Author-X-Name-First: Bin Author-X-Name-Last: You Author-Name: Linyun Chen Author-X-Name-First: Linyun Author-X-Name-Last: Chen Author-Name: Guoqing Luo Author-X-Name-First: Guoqing Author-X-Name-Last: Luo Title: The novel reconfigurable double-layer half-mode SIW filter with tunable DMS structure Abstract: The contribution of this paper is to present a reconfigurable double-layer half-mode substrate integrated waveguide (HMSIW) bandpass filter with continuous center frequency and 3 dB bandwidth (BW) tuning capabilities. The double-layer rectangular HMSIW is subjected to vertical electrical coupling and magnetic coupling through the proposed semicircle aperture and rectangular slot etched on the middle metal layer. Due to this mixed electric and magnetic coupling structure, the 3 dB BW can be tuned and one adjustable transmission zero (TZ1) is introduced. Varactors (CV2) are used to adjust the center frequency. The parasitic passband produced by the higher-order mode TE102 can be suppressed, thanks to the proposed T-shapes defected microstrip structure. Compared with the conventional horizontal coupling SIW filters, the proposed HMSIW filter also shows a compact physical area. To demonstrate the proposed design method, a double-layer HMSIW bandpass filter is fabricated and measured. Both the simulation and measured results show a center frequency tuning range of 1.21–1.72 GHz, as well as demonstrate a 3 dB BW tuning range of 62–101 MHz around 1.21 GHz, 97–213 MHz around 1.45 GHz, 225–310 MHz around 1.72 GHz. The insertion loss ranges from 1.18 to 6.32 dB. Furthermore, simulated and measured results also show a good agreement. Journal: Journal of Electromagnetic Waves and Applications Pages: 1816-1823 Issue: 14 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1476183 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1476183 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:14:p:1816-1823 Template-Type: ReDIF-Article 1.0 Author-Name: Qiao Li Author-X-Name-First: Qiao Author-X-Name-Last: Li Author-Name: Xia Xiao Author-X-Name-First: Xia Author-X-Name-Last: Xiao Author-Name: Hao Fu Author-X-Name-First: Hao Author-X-Name-Last: Fu Author-Name: Liang Wang Author-X-Name-First: Liang Author-X-Name-Last: Wang Title: Glucose solution concentration detection using TE011 microwave resonant cavity Abstract: In this paper, a glucose solution concentration measurement method is proposed based on microwave resonant cavity perturbation technique. The mathematical model of TE011 cylindrical resonator in terms of solution concentration is derived. The optimal geometry of cavity is determined by high frequency structure simulator. A brass cavity with a PVC capillary tube is produced in this study. A microwave measurement system consisting of resonator, waveguide and network analyzer is constructed to measure glucose concentrations from 70 to 150 mg/dl, using frequency range 7.539–7.546 GHz. Statistical results indicate that the resonant frequency of solution increases linearly as glucose concentration increases. Frequency shift slope (FSS) of experiment is in good accordance with the FSS of theoretical calculation, which shows the feasibility and accuracy of the method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1824-1833 Issue: 14 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1476184 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1476184 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:14:p:1824-1833 Template-Type: ReDIF-Article 1.0 Author-Name: Kateryna S. Kuznetsova Author-X-Name-First: Kateryna S. Author-X-Name-Last: Kuznetsova Author-Name: Zoya E. Eremenko Author-X-Name-First: Zoya E. Author-X-Name-Last: Eremenko Title: Influence of high loss liquid on the bandwidth of a circular two-layer waveguide at microwaves Abstract: The electromagnetic waves propagation in a circular two-layer metal waveguide with a central low-loss dielectric rod surrounded by high loss liquid is studied in the microwave range. The dependence of the complex wave propagation coefficient on frequency and liquid layer thickness is obtained. The presence of high loss liquid surrounding the dielectric rod allows expanding the range of operating wavelengths of the standard waveguide from the millimeter to centimeter range, because the wave attenuation coefficient remains relatively small. We find that owing to a high loss liquid, such a waveguide does not have fixed values of cut-off frequencies. An extra low value of the wave attenuation coefficient is found in the centimeter wavelength range at certain liquid layer thicknesses. The proposed structure can be applied as a measuring cell for the determination of the complex permittivity of high loss liquids in small volumes and in a wide range of wavelengths. Journal: Journal of Electromagnetic Waves and Applications Pages: 1834-1846 Issue: 14 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1476185 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1476185 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:14:p:1834-1846 Template-Type: ReDIF-Article 1.0 Author-Name: You-Feng Cheng Author-X-Name-First: You-Feng Author-X-Name-Last: Cheng Author-Name: Xiao Ding Author-X-Name-First: Xiao Author-X-Name-Last: Ding Author-Name: Fu-Long Jin Author-X-Name-First: Fu-Long Author-X-Name-Last: Jin Author-Name: Wei Shao Author-X-Name-First: Wei Author-X-Name-Last: Shao Title: A bandwidth-enhanced planar endfire antenna based on surface waves Abstract: A surface-wave-based endfire antenna with an enhanced impedance bandwidth is presented in this paper. The antenna consists of a surface-wave guide (SWG) and five strips printed on the SWG. The endfire radiation benefits from the surface-wave diffraction of the SWG which is investigated with the Snell's law, effective surface impedance and eigenvalue analysis. A prototype is fabricated and measured, and the measured results indicate that the antenna has two resonances and its bandwidth is enhanced up to 16.1% (4.0–4.73 GHz). The proposed endfire antenna also exhibits high gain, good gain flatness, low cross-polarization level and low profile. Journal: Journal of Electromagnetic Waves and Applications Pages: 1847-1856 Issue: 14 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1476186 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1476186 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:14:p:1847-1856 Template-Type: ReDIF-Article 1.0 Author-Name: Aleksej Trofimov Author-X-Name-First: Aleksej Author-X-Name-Last: Trofimov Author-Name: Tatjana Gric Author-X-Name-First: Tatjana Author-X-Name-Last: Gric Title: Surface plasmon polaritons in hyperbolic nanostructured metamaterials Abstract: Here, new kinds of surface waves on nanostructured metamaterial (MM), crossing the light line with a substantial portion at lower frequencies lying above the free space light line, are considered. We present the numerical study of dispersion features of hyperbolic MMs for various cases, and the tunability of hyperbolic MMs based on grapheme-dielectirc multilayers and transparent conducting oxide-dielectric multilayers have been demonstrated. Similar to grapheme-dielectric MM, the propagation of the new surface waves on nanostructured MM presented in this manuscript is sensitive and can be controlled by the parameters of the materials employed in nanostructures. Remarkably, the parameters of the materials employed in nanostructures dramatically influence the propagation of such surface waves. Additionally, the Ferrell–Berreman modes are detected under certain conditions, providing a fertile ground for device fabrications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1857-1867 Issue: 14 Volume: 32 Year: 2018 Month: 9 X-DOI: 10.1080/09205071.2018.1467798 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1467798 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:14:p:1857-1867 Template-Type: ReDIF-Article 1.0 Author-Name: Farzad Ebrahimi Author-X-Name-First: Farzad Author-X-Name-Last: Ebrahimi Author-Name: Ali Dabbagh Author-X-Name-First: Ali Author-X-Name-Last: Dabbagh Title: On wave dispersion characteristics of double-layered graphene sheets in thermal environments Abstract: In this research, it is tried to inquire the wave propagation problem of a double-layered graphene sheet (DLGS) undergoing thermal loading for the first time. Here, uniform and linear temperature distributions are included to enucleate the effect of each one in comparison with the other. A classical plate theory is employed to derive the kinematic relations of each layer of DLGS. On the other hand, the non-local elasticity theory is introduced to account for the nanoscale effects. In addition, attachment of graphene sheets to a fixed surface is modeled by a visco-Pasternak foundation and the interactions between two layers are simulated utilizing van der Waals (vdW) model. By the means of Hamilton’s principle, the non-local governing equations are derived. Also, in the framework of an analytical procedure, the wave frequency and phase velocity values are obtained. Eventually, a complex of various diagrams is organized to separately investigate the influence of each parameter on the wave frequency, phase velocity, and escape frequency of DLGSs. Journal: Journal of Electromagnetic Waves and Applications Pages: 1869-1888 Issue: 15 Volume: 32 Year: 2018 Month: 10 X-DOI: 10.1080/09205071.2017.1417918 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1417918 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:15:p:1869-1888 Template-Type: ReDIF-Article 1.0 Author-Name: Kamlesh Patel Author-X-Name-First: Kamlesh Author-X-Name-Last: Patel Author-Name: Pulkit Sharma Author-X-Name-First: Pulkit Author-X-Name-Last: Sharma Title: Application of RLGC modeling in probing the electrical properties of monolayer graphene at microwave frequencies Abstract: The S-parameters of the microstrip line loaded with graphene on glass and graphene on quartz as a superstrate are measured from 10 MHz to 26.5 GHz. These parameters have shown only a little difference compared to glass or quartz loaded microstrip line. Then, de-embedded S-parameters of superstrate loaded microstrip line are modeled as the transmission line (RLGC) parameters and these parameters are obtained with frequency. Their comparison with unloaded microstrip line shows large changes in R and G whereas, in L and C parameters, no significant changes have been noticed with superstrates. In these parameters, larger percentage changes for graphene on glass have showed a poor contact between two than graphene and quartz. Changes in R and G parameters confirmed that graphene has modified the surface resistance and effective relative permittivity on loading the microstrip line. Journal: Journal of Electromagnetic Waves and Applications Pages: 1889-1897 Issue: 15 Volume: 32 Year: 2018 Month: 10 X-DOI: 10.1080/09205071.2017.1422441 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1422441 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:15:p:1889-1897 Template-Type: ReDIF-Article 1.0 Author-Name: Paramjeet Singh Author-X-Name-First: Paramjeet Author-X-Name-Last: Singh Author-Name: Neha Author-X-Name-First: Author-X-Name-Last: Neha Author-Name: Kamlesh Patel Author-X-Name-First: Kamlesh Author-X-Name-Last: Patel Title: Investigating the effects of graphene-based superstrate on characteristic of microwave filters Abstract: This paper presents a study based on changes in the cut-off frequency and sharpness of different types of filter by loading with glass and graphene–glass superstrate. Design and fabrication of four basic types of microwave filter – low-pass, high-pass, band pass, and band stop filter are presented and S-parameters are measured with superstrate. The impact of superstrate on the filter characteristics such as cut-off frequency, bandwidth, and sharpness are analyzed experimentally by comparing these characteristics for without superstrate and with superstrate. The superstrate loading resulted in the decrease of cut-off frequency for low-pass and high-pass filter, whereas the bandwidth is decreased for band pass filter and band stop filter with larger shift in high cut-off frequency. Such effects have been confirmed by the simulation of low-pass filter and band pass filter on placing a glass. It is estimated from the filter responses that graphene–glass has conducting as well as dielectric nature compared to glass in the frequency range of study. It has been shown that the cut-off frequency and bandwidth can be tuned by dielectric kind of superstrate without varying the physical dimension of filter. Journal: Journal of Electromagnetic Waves and Applications Pages: 1898-1910 Issue: 15 Volume: 32 Year: 2018 Month: 10 X-DOI: 10.1080/09205071.2018.1429952 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1429952 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:15:p:1898-1910 Template-Type: ReDIF-Article 1.0 Author-Name: Thanatcha Satitchantrakul Author-X-Name-First: Thanatcha Author-X-Name-Last: Satitchantrakul Author-Name: Prayoot Akkaraekthalin Author-X-Name-First: Prayoot Author-X-Name-Last: Akkaraekthalin Author-Name: Rardchawadee Silapunt Author-X-Name-First: Rardchawadee Author-X-Name-Last: Silapunt Author-Name: Danai Torrungrueng Author-X-Name-First: Danai Author-X-Name-Last: Torrungrueng Title: Compact wideband multi-section quarter-wave-like transformers Abstract: This paper proposes a novel design technique of the compact wideband transformer based on the quarter-wave-like transformer (QWLT) theory and the approximate theory of small reflections (ATSR). The ATSR for multi-section QWLTs is applied for analysing characteristics of multi-section QWLTs. The prototypes of two-section QWLTs operating at 2.4 GHz with 25% physical size reduction, comparing to that of the corresponding of wideband multi-section quarter-wave transformer (QWT), are implemented. It is found that measured results are matched reasonably well with results of the ATSR for multi-section QWLTs. In addition, the two-section QWLT prototypes provide slightly less bandwidth compared to that of the corresponding wideband multi-section QWT. Journal: Journal of Electromagnetic Waves and Applications Pages: 1911-1924 Issue: 15 Volume: 32 Year: 2018 Month: 10 X-DOI: 10.1080/09205071.2018.1482239 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1482239 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:15:p:1911-1924 Template-Type: ReDIF-Article 1.0 Author-Name: Roozbeh Negahdari Author-X-Name-First: Roozbeh Author-X-Name-Last: Negahdari Author-Name: Esmat Rafiee Author-X-Name-First: Esmat Author-X-Name-Last: Rafiee Author-Name: Farzin Emami Author-X-Name-First: Farzin Author-X-Name-Last: Emami Title: Design and simulation of a novel nano-plasmonic split-ring resonator filter Abstract: In this paper, a novel nano-plasmonic split-ring resonator filter is proposed and simulated. In this structure, split-ring resonator is situated between a T-shaped and a straight waveguide. Simulations are done based on Finite-Difference-Time Domain method. The filter is based on metal–insulator-metal (MIM) structure. Split-ring resonator, straight and T-shaped waveguides are consisted of air which are situated in a silver background. Effects of different structural parameters, such as the width of the straight waveguide, the distance between left waveguide and ring, T-shaped waveguide’s width and length and the split position on the transmission spectrum of the filter are being investigated. The proposed filter can confine light to sub-wavelength dimensions (of the order of nano-meter); therefore, it can be used in highly integrated optical circuits. Hence, by adjusting structural parameters, the best transmission peak value of 0.84 at 935 nm will be obtained which can be utilized in integrated optical communication systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 1925-1938 Issue: 15 Volume: 32 Year: 2018 Month: 10 X-DOI: 10.1080/09205071.2018.1482240 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1482240 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:15:p:1925-1938 Template-Type: ReDIF-Article 1.0 Author-Name: Yuna Kim Author-X-Name-First: Yuna Author-X-Name-Last: Kim Author-Name: Sangin Kim Author-X-Name-First: Sangin Author-X-Name-Last: Kim Author-Name: Yongshik Lee Author-X-Name-First: Yongshik Author-X-Name-Last: Lee Author-Name: Jong-Gwan Yook Author-X-Name-First: Jong-Gwan Author-X-Name-Last: Yook Title: Effect of plasma volume on monostatic radar cross section control Abstract: Under atmospheric pressure, dielectric barrier discharge (DBD) with a plasma layer is utilized to produce large-volume plasma without a vessel. When a 16-kV bias at 1 kHz is applied to 85 copper strips, the DBD actuator generates plasma with the dimensions 170 × 170 × 1 mm. When the incident wave with an electric wave vector perpendicular to the strip array is illuminated, the monostatic radar cross section (RCS) is reduced by a maximum of 3.5 dB. The measured results are validated using full-wave simulation based on homogeneous plasma, with estimated plasma parameters. By changing the number of copper strips connected to the feed line, the relative volume of plasma can be changed. If the relative volume decreases by 20%, the maximum RCS reduction is reduced by nearly 20%. This demonstrates the possibility of using plasma to control monostatic RCS in a wide bandwidth. Journal: Journal of Electromagnetic Waves and Applications Pages: 1939-1949 Issue: 15 Volume: 32 Year: 2018 Month: 10 X-DOI: 10.1080/09205071.2018.1482241 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1482241 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:15:p:1939-1949 Template-Type: ReDIF-Article 1.0 Author-Name: Mohammad Mahdi Ghods Author-X-Name-First: Mohammad Mahdi Author-X-Name-Last: Ghods Author-Name: Pejman Rezaei Author-X-Name-First: Pejman Author-X-Name-Last: Rezaei Title: Ultra-wideband microwave absorber based on uncharged graphene layers Abstract: In this paper, a novel method is presented to increase microwave absorbers bandwidth. The proposed method is based on coupling resonators which consist of a graphene layer at the top, a dielectric spacer and a metallic plate in the bottom. The first resonance frequency of every resonator is calculated by the thickness and relative permittivity of the substrate and the next harmonics are odd coefficients of the first resonance. Absorption rate growth is based on the electric field reinforcement in the graphene plane via tuning graphene Fermi energy. Finally, after combining the resonators and by considering reflection amplitude lower than −10 dB, a bandwidth of 11.9 GHz is obtained from 5.3 to 17.2 GHz for Fermi energy equal to zero. Low-profile and wideband absorption of the proposed structure can be effectively used in radar cross-section applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1950-1960 Issue: 15 Volume: 32 Year: 2018 Month: 10 X-DOI: 10.1080/09205071.2018.1486234 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1486234 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:15:p:1950-1960 Template-Type: ReDIF-Article 1.0 Author-Name: Zhijun Tang Author-X-Name-First: Zhijun Author-X-Name-Last: Tang Author-Name: Xiaofeng Wu Author-X-Name-First: Xiaofeng Author-X-Name-Last: Wu Author-Name: Jie Zhan Author-X-Name-First: Jie Author-X-Name-Last: Zhan Author-Name: Zaifang Xi Author-X-Name-First: Zaifang Author-X-Name-Last: Xi Author-Name: Shigang Hu Author-X-Name-First: Shigang Author-X-Name-Last: Hu Title: A novel miniaturized antenna with multiple band-notched characteristics for UWB communication applications Abstract: A novel miniaturization planar ultra-wideband antenna with triple-notched bands is proposed. The antenna mainly consists of an elliptical patch, a rectangular split-ring patch with a π-shaped slit and a T-shaped slit, and two small additional patches. Two different type slits are adopted to realize multiple-notched bands and reduce the antenna size. The designed antenna has a small dimension of 17 × 16 × 1.6 mm3. The simulated and measured results show the antenna has a very wide impedance bandwidth of 2.96–19.0 GHz with Return Loss less than −10 dB, except triple notched bands of 3.30–3.72, 5.13–5.82 and 7.04–7.92 GHz, respectively, covering the WiMAX, WLAN and X-band systems. Furthermore, surface current distributions, gain, efficiency, radiation patterns and group delay characteristics of the antenna are also discussed. The results show that the antenna has high radiation efficiency, stable radiation pattern and lower group delay time. Journal: Journal of Electromagnetic Waves and Applications Pages: 1961-1972 Issue: 15 Volume: 32 Year: 2018 Month: 10 X-DOI: 10.1080/09205071.2018.1486235 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1486235 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:15:p:1961-1972 Template-Type: ReDIF-Article 1.0 Author-Name: Ahmet Hayrettin Yuzer Author-X-Name-First: Ahmet Hayrettin Author-X-Name-Last: Yuzer Author-Name: Erhan Dursun Author-X-Name-First: Erhan Author-X-Name-Last: Dursun Title: Association of memory terms in a power amplifier modeling functions to the circuit components Abstract: The main purpose of this study is to find a relation between power amplifier (PA) circuit component values and delay terms of the PA model polynomial by using measurement results. A PA designer can use this relation to determine component values while designing memoryless/linear PAs. For this purpose, a behavioral model with memory is worked on; the model, modeling approach, experimental set-up and results are presented. Memory depths are determined for a 1–2 GHz 10 W Class AB power amplifier with parametric results. The advantages of the elaborated model are presented. Relations between the bias circuit components and the memory terms are investigated. Journal: Journal of Electromagnetic Waves and Applications Pages: 1973-1988 Issue: 15 Volume: 32 Year: 2018 Month: 10 X-DOI: 10.1080/09205071.2018.1486236 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1486236 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:15:p:1973-1988 Template-Type: ReDIF-Article 1.0 Author-Name: Andrew D. Groza Author-X-Name-First: Andrew D. Author-X-Name-Last: Groza Title: Near-zero-index nonlinear surface polaritons controlled by the surface conductivity of graphene Abstract: We study transverse magnetic polarized nonlinear surface polaritons (NLSP) propagating along the interface (a conductive layer of zero thickness) of a magnetic optically linear medium and a magnetic optically nonlinear medium with saturable permittivity. We obtained the exact solution of Maxwell’s equations for the NLSP and on this base investigated the dependences of the NLSP propagation constant on the NLSP energy flux and on the value of the dielectric permittivity at the surface of the nonlinear medium for different values of sheet conductance. The important for quantum information processing near-zero-index condition $ n \approx 0 $ n≈0 can be achieved if the products of permeability and permittivity of each medium are both negative. For both Kerr-like and saturable nonlinearities, the NLSP propagation constant trace for zero-conductivity splits into two traces for non-zero conductivity. Near the $ n \approx 0 $ n≈0 condition, the NLSP propagation constant is highly sensitive to the NLSP intensity as well as to the sheet conductance value. Journal: Journal of Electromagnetic Waves and Applications Pages: 1989-2001 Issue: 15 Volume: 32 Year: 2018 Month: 10 X-DOI: 10.1080/09205071.2018.1487339 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1487339 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:15:p:1989-2001 Template-Type: ReDIF-Article 1.0 Author-Name: Xue Wei Zhang Author-X-Name-First: Xue Wei Author-X-Name-Last: Zhang Author-Name: Tong He Author-X-Name-First: Tong Author-X-Name-Last: He Author-Name: Kai Li Author-X-Name-First: Kai Author-X-Name-Last: Li Title: Calibration of electric field data of DEMETER satellite Abstract: In this paper, based on the data measured by the space-borne ICE (Instrument Champ Electrique) electric field meters of the DEMETER (Detection of Electro-Magnetic Emission Transmitted from Earthquake Regions) satellite, the induced electric fields generated by the electric antennas of ICE when they cut the Earth’s geomagnetic lines during the satellite’s motion are computed, and the electrostatic field data in the range of ultra low frequency (ULF: f < 3 kHz) are calibrated. The numerical results indicate that the induced electric fields generated by the electric antennas of the space-borne electric field meters account for a considerable proportion among the data of electric fields measured by the DEMETER satellite. Besides, a more conspicuous regularity is presented as the magnitude of the modified electric fields varies with the Earth’s latitudes and longitudes. Journal: Journal of Electromagnetic Waves and Applications Pages: 2003-2012 Issue: 16 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1468285 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1468285 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:16:p:2003-2012 Template-Type: ReDIF-Article 1.0 Author-Name: Chien-Jen Wang Author-X-Name-First: Chien-Jen Author-X-Name-Last: Wang Author-Name: Kuan-Wei Li Author-X-Name-First: Kuan-Wei Author-X-Name-Last: Li Title: An open-slot antenna for multi-system integration utilizing inverted-L slit and inverted-C coupling strip Abstract: This article presents a microstrip broadband open-slot antenna with linear polarization and circular polarization (CP) for integration with multiple commercial wireless communication systems. Two open slots are etched in the ground plane and applied as radiator elements. By utilizing a T-shaped feeding stub, the inductive reactance of the prototype antenna is compensated by a capacitive loading. Additionally, etching an inverted-L slit in the top segment of the ground plane brings about CP at 2.33 GHz. To enhance impedance-matching condition in the middle frequency band, an inverted-C coupling strip is embedded in the dominant open-slot radiator. This technique also generates a new resonance at 5.3 GHz. The proposed antenna can be a candidate of the radiator for long term evolution applications or wireless communication systems with linear and CPs. Journal: Journal of Electromagnetic Waves and Applications Pages: 2013-2029 Issue: 16 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1485515 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1485515 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:16:p:2013-2029 Template-Type: ReDIF-Article 1.0 Author-Name: Daniele Inserra Author-X-Name-First: Daniele Author-X-Name-Last: Inserra Author-Name: Guangjun Wen Author-X-Name-First: Guangjun Author-X-Name-Last: Wen Author-Name: Wei Hu Author-X-Name-First: Wei Author-X-Name-Last: Hu Title: Linear optimization of antenna array for radiation pattern defined on a planar surface Abstract: In this contribution, the antenna array synthesis for radiation pattern defined on a planar surface is described. This can be required when the electric field r-decay factor effect cannot be neglected, e.g. an antenna array mechanically tilted and a specific pattern defined in terms of cartesian coordinates. Differently from the classical sidelobe level reduction optimization problem, the case in which both a constant power bounded area and a sidelobe suppression region are defined and required to be synthesized is herein addressed. The general nonlinear optimization problem is first presented; then, the derivation of some sub-optimal linear problems based on practical implementation hypothesis is described, with the advantage of a reduced computational complexity. Numerical results validate the effectiveness of the proposed method. Journal: Journal of Electromagnetic Waves and Applications Pages: 2030-2045 Issue: 16 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1488624 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1488624 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:16:p:2030-2045 Template-Type: ReDIF-Article 1.0 Author-Name: Özkan Kılıç Author-X-Name-First: Özkan Author-X-Name-Last: Kılıç Author-Name: Çiğdem Seçkin Gürel Author-X-Name-First: Çiğdem Seçkin Author-X-Name-Last: Gürel Title: Response of magnetized plasma having linearly varying electron density profile to oblique electromagnetic wave incidence Abstract: The response of magnetized plasma slab to obliquely incident electromagnetic wave is determined for different incidence angles and magnetic field intensity values in the case of linearly varying electron density profile along the plasma slab. It is shown that plasma slab provides wide-band absorption due to the proper adjustment of the slope of the electron density profile, incidence angle and magnetic field intensity values. Plasma medium providing wide-band absorption performance under oblique incidence is proposed for military stealth and current shielding applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 2046-2054 Issue: 16 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1489311 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1489311 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:16:p:2046-2054 Template-Type: ReDIF-Article 1.0 Author-Name: Deniz Kumlu Author-X-Name-First: Deniz Author-X-Name-Last: Kumlu Author-Name: Isin Erer Author-X-Name-First: Isin Author-X-Name-Last: Erer Title: Clutter removal in GPR images using non-negative matrix factorization Abstract: Ground-penetrating radar (GPR) is a commonly used high-resolution electromagnetic technique for subsurface imaging which has many applications such as landmine, cable and pipes detection. It is well known that the clutter presented in the GPR images deteriorates the image quality and decreases the performance of the target detection methods, especially for shallowly buried targets. To deal with this issue, we propose a new clutter removal method based on the low-rank approximation of the GPR image by non-negative matrix factorization (NMF). The proposed method is applied to real GPR images as well as to a realistic dataset provided by the new version of the electromagnetic software simulation tool gprMax. The visual and quantitative results obtained for different scenarios containing different soils, surfaces, burial depths and target types validate the effectiveness of the proposed method over the widely used state-of-the-art clutter removal methods. Journal: Journal of Electromagnetic Waves and Applications Pages: 2055-2066 Issue: 16 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1489740 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1489740 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:16:p:2055-2066 Template-Type: ReDIF-Article 1.0 Author-Name: Vishal Kesari Author-X-Name-First: Vishal Author-X-Name-Last: Kesari Author-Name: J. P. Keshari Author-X-Name-First: J. P. Author-X-Name-Last: Keshari Title: Broadbanding a gyro-traveling-wave tube by chiral-dielectric material loading Abstract: Loading the circular waveguide interaction structure of a gyro-traveling-wave tube (gyro-TWT) with chiral material was proposed to show the possibility of widening the device bandwidth. Outlines to obtain the dispersion relation of a circular waveguide enveloping a chiral-dielectric rod and a chiral-dielectric tube were presented, which further interpreted in special cases for the circular waveguides loaded with a chiral-dielectric coaxial rod (structure I) and with a chiral-dielectric wall-lining (structure II). A computer code was developed in MATLAB to solve the dispersion relations and the solutions were substituted into the Pierce-type small-signal gain equation of a gyro-TWT for the device-gain calculation. The electromagnetic analysis of the structure has been validated against simulation. The dispersion shaping and the broadbanding were presented for the two structures. The structure I was found to be more sensitive to chirality parameter than structure II. Journal: Journal of Electromagnetic Waves and Applications Pages: 2067-2077 Issue: 16 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1491895 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1491895 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:16:p:2067-2077 Template-Type: ReDIF-Article 1.0 Author-Name: S. A. Naqvi Author-X-Name-First: S. A. Author-X-Name-Last: Naqvi Author-Name: M. A. Baqir Author-X-Name-First: M. A. Author-X-Name-Last: Baqir Title: Ultra-wideband symmetric G-shape metamaterial-based microwave absorber Abstract: This paper investigates the absorption features of the symmetric G-shape metamaterial absorber (MA) at the microwave frequency range for the ultra-wideband. The proposed metamaterial structure attains above 95% absorptivity in the frequency range of 20–60 GHz. It also analyses the absorptivity of the ultra-wideband MA for the different incidence angles of the electromagnetic (EM) wave. The absorptivity is the function of the angle of incidence of EM waves for the proposed G-shape metamaterial structure and it attains maximum absorptivity for the normal incidence. Such a wideband absorber would be useful for the multifarious applications including wideband filtering and stealth metamaterial in the Ku, K-, Ka- Q- and U-bands. Journal: Journal of Electromagnetic Waves and Applications Pages: 2078-2085 Issue: 16 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1492976 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1492976 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:16:p:2078-2085 Template-Type: ReDIF-Article 1.0 Author-Name: Changfei Zhou Author-X-Name-First: Changfei Author-X-Name-Last: Zhou Author-Name: Sing Wai Cheung Author-X-Name-First: Sing Wai Author-X-Name-Last: Cheung Title: Metasurface-based antenna excited by the slotted radiator Abstract: A dual wideband metasurface (MS)-based antenna operating in triple modes is proposed for circularly polarized (CP) operation and these two bands can be controlled independently. The antenna consists of a cross-slot antenna and an MS to generate a dual band at about 3.5 and 5.2 GHz. In the low-frequency band, the large cross-slot radiator (CSR) and the MS are used to generate CP radiation by exciting the degenerate modes of TM10 and TM01. In the high-frequency band, the small CSR and the MS form a cavity, and the small CSR serves as a feeding element to excite two groups of orthogonal degenerate modes, i.e. the first group being TM10 and TM01, and the second being TM12 and TM21, alternately for wideband CP radiation. Simulation and measurement are used to study and design the MS slot antenna. Measured results show that the MS slot antenna has a dual operating band of 3.27–3.87 GHz (0.6 GHz, 16.8%) and 4.41–5.95 GHz (1.54 GHz, 29.7%), peak gains of 6.3 and 7.9 dBic within the low- and high-frequency bands. This antenna has the advantages of simple single feeding, simple structure, high gains, and dual independent bands. Journal: Journal of Electromagnetic Waves and Applications Pages: 2086-2098 Issue: 16 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1496037 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1496037 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:16:p:2086-2098 Template-Type: ReDIF-Article 1.0 Author-Name: Ubaid Ullah Author-X-Name-First: Ubaid Author-X-Name-Last: Ullah Author-Name: Slawomir Koziel Author-X-Name-First: Slawomir Author-X-Name-Last: Koziel Title: Design and optimization of a novel miniaturized low-profile circularly polarized wide-slot antenna Abstract: This paper presents a novel structure of a compact circularly polarized (CP) antenna. CP is obtained using a parasitic quasi-rectangular strip placed coplanar to the feedline. A ground plane perturbation combined with the asymmetric geometry of the coplanar waveguide ground planes is utilized to excite additional CP modes. All antenna dimensions are rigorously optimized to achieve the best possible performance in terms of the impedance and axial ratio bandwidth (ARBW). The size of the proposed antenna is only 24.7 × 25 mm2. The antenna performance is validated experimentally. A close agreement between simulation and experimental results is observed. A wide impedance bandwidth of 42.6% (3.93–6.06 GHz) and ARBW of 42% (3.96–6.03 GHz) is with 98.5% bandwidth overlap between |S11| and AR is achieved. The average realized gain of the antenna throughout the operating frequency is 3.4 dBic. Left-hand circular polarization radiation is achieved in the +z-direction. . Journal: Journal of Electromagnetic Waves and Applications Pages: 2099-2109 Issue: 16 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1496039 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1496039 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:16:p:2099-2109 Template-Type: ReDIF-Article 1.0 Author-Name: Saravana Selvan Author-X-Name-First: Saravana Author-X-Name-Last: Selvan Author-Name: Mukter Zaman Author-X-Name-First: Mukter Author-X-Name-Last: Zaman Author-Name: R. Gobbi Author-X-Name-First: R. Author-X-Name-Last: Gobbi Author-Name: Hin Yong Wong Author-X-Name-First: Hin Yong Author-X-Name-Last: Wong Title: Recent advances in the design and development of radio frequency-based energy harvester for powering wireless sensors: a review Abstract: Wireless sensor networks (WSNs) are spatially distributed sensor systems used to collect precise data from a large area of interest. WSN is usually deployed in the off-grid, and its widespread deployment is limited due to its requirement for the continuous and large amount of power. Energy harvesting has been recognized as a promising solution which has gained a lot of attention in recent years pertaining to enabling a self-sustainable operation of WSN. Radio Frequency (RF) is identified as an energy source that can be further used to harvest required energy for the WSN sensors. This paper outlines the motivation of RF energy harvesting for powering the WSN components. It is found that the rectenna circuit in RF harvester deals with very low amplitude of signals, and it requires further improvement in its feature and capabilities with reducing form factors. In this article, recent design and development consideration involved in rectenna circuit and corresponding performance trade-offs are being discussed. It also discusses the recent techniques involved in improving the overall power conversion efficiency of rectenna. The authors address the key challenging issues yet need to concentrate on further enhancements. This review will aid as a guide in the future, to develop an energy-efficient and high-performance RF harvester circuit, which needs to be taken to the next advance level. Journal: Journal of Electromagnetic Waves and Applications Pages: 2110-2134 Issue: 16 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1497548 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1497548 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:16:p:2110-2134 Template-Type: ReDIF-Article 1.0 Author-Name: Surendra Singh Author-X-Name-First: Surendra Author-X-Name-Last: Singh Author-Name: Sachin Tripathi Author-X-Name-First: Sachin Author-X-Name-Last: Tripathi Author-Name: Nitin Kumar Author-X-Name-First: Nitin Author-X-Name-Last: Kumar Title: An enhanced security-aware dynamic packet scheduling scheme for wireless networks using intelligent time slice-based krill herd algorithm Abstract: Wireless networks perform computing on grouped users together through networks that suffer with improper scheduling and less security awareness results in terms of bandwidth, increase in error rate, power constraints, authentication problem, etc. In order to tackle these problems, an enhanced security-aware dynamic packet scheduling is implemented by utilizing integrated speed packet scheduling which utilizes node distribution by the krill herd algorithm and packet evaluation by intelligent time slice, and reducing the dimensionality of packets with some evolutionary techniques for transmission. To protect these packets from attacks during transmission, the packets are secured by identifying the malicious node and protecting them with proper authentication by PKI (public key infrastructure) with the handshake of secure exchange of distributed signatures. The experimental execution in NS-3 simulator outcomes shows that the proposed system is more efficient in the packet delivery ratio and security than other existing techniques. Journal: Journal of Electromagnetic Waves and Applications Pages: 2135-2156 Issue: 16 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1497549 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1497549 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:16:p:2135-2156 Template-Type: ReDIF-Article 1.0 Author-Name: Sandeep Kumar Author-X-Name-First: Sandeep Author-X-Name-Last: Kumar Author-Name: Pappu Kumar Verma Author-X-Name-First: Pappu Kumar Author-X-Name-Last: Verma Author-Name: Manpreet Kaur Author-X-Name-First: Manpreet Author-X-Name-Last: Kaur Author-Name: Priyanka Jain Author-X-Name-First: Priyanka Author-X-Name-Last: Jain Author-Name: Sanjay Kumar Soni Author-X-Name-First: Sanjay Kumar Author-X-Name-Last: Soni Title: On the spectrum sensing of gamma shadowed Hoyt fading channel with MRC reception Abstract: Spectrum sensing (SS) is the important function of cognitive radio and energy detection is the most popular technique used for SS. When the channel is composite (multipath/shadowed) fading, the detection of unused spectrum holes becomes difficult for the secondary users. In this paper, the analytical expressions of average probability of detection and the average area under the receiver operating characteristic over Hoyt/Gamma composite fading channel with maximum ratio combining reception are derived. In addition, the optimized threshold has been incorporated to overcome the problem of SS at low signal to noise ratio. The effect of diversity on the performance of energy detector is also studied. To validate the accuracy of the derived results, Monte Carlo simulations are incorporated. Journal: Journal of Electromagnetic Waves and Applications Pages: 2157-2166 Issue: 16 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1493402 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1493402 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:16:p:2157-2166 Template-Type: ReDIF-Article 1.0 Author-Name: Mukesh K. Khandelwal Author-X-Name-First: Mukesh K. Author-X-Name-Last: Khandelwal Author-Name: Aditya Arora Author-X-Name-First: Aditya Author-X-Name-Last: Arora Author-Name: Sachin Kumar Author-X-Name-First: Sachin Author-X-Name-Last: Kumar Author-Name: Kang Wook Kim Author-X-Name-First: Kang Wook Author-X-Name-Last: Kim Author-Name: Hyun Chul Choi Author-X-Name-First: Hyun Chul Author-X-Name-Last: Choi Title: Dual band double negative (DNG) metamaterial with small frequency ratio Abstract: In this paper, a novel shaped metamaterial is proposed with Double Negative (DNG) properties. Dual band characteristics are achieved with a very small frequency ratio of 1.09848:1. For the proposed metamaterial, an analysis of different configurations is presented and all the parameters of unit cell metamaterial such as impedance Z, permittivity Ep, permeability Mu and refractive index n are extracted. Furthermore, the mathematical calculations for the extraction of parameters are presented. The analysis of the metamaterial is done with the help of Finite Element Method based tool Ansys HFSS and results have been validated by CST Microwave Studio and measured experimental results. Journal: Journal of Electromagnetic Waves and Applications Pages: 2167-2181 Issue: 17 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1498026 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1498026 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:17:p:2167-2181 Template-Type: ReDIF-Article 1.0 Author-Name: Nikitabahen N. Makwana Author-X-Name-First: Nikitabahen N. Author-X-Name-Last: Makwana Author-Name: Avijit Chatterjee Author-X-Name-First: Avijit Author-X-Name-Last: Chatterjee Title: Computing with large time steps in time-domain electromagnetics Abstract: The finite volume time-domain method is recast in a large time step (LTS) version to solve the time-domain Maxwell's equations. The LTS method allows the use of time steps much larger than that dictated by the Courant–Friedrich–Lewy criteria for numerical stability in a Godunov-based finite volume framework. Solutions can be obtained much faster and sometimes with higher accuracy compared to conventional time-stepping methods. Results are analyzed for electromagnetic wave propagation in 1D and 2D. Solutions are shown to remain unconditionally stable with an increase in the Courant number. Journal: Journal of Electromagnetic Waves and Applications Pages: 2182-2194 Issue: 17 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1500314 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1500314 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:17:p:2182-2194 Template-Type: ReDIF-Article 1.0 Author-Name: Pratibha Malik Author-X-Name-First: Pratibha Author-X-Name-Last: Malik Author-Name: Suresh C. Sharma Author-X-Name-First: Suresh C. Author-X-Name-Last: Sharma Author-Name: Rinku Sharma Author-X-Name-First: Rinku Author-X-Name-Last: Sharma Title: Coherent terahertz radiation from beam-driven upper hybrid wave in magnetostatic plasma Abstract: A scheme for generating tunable terahertz radiation using relativistic electron beam-induced upper hybrid wave immersed in a magnetized plasma is investigated. The ponderomotive force applied to the beam electrons because of electromagnetic radiation wave and pump wave generates the non-linear current density in the high-frequency regime. For an appropriate pump wave frequency, under the condition of phase matching the THz radiation wave is obtained. The enhancement in the radiation power occurs along the axial direction in the vicinity of Cerenkov resonance. Our analytical expression shows that the growth rate in the unstable modes of the THz radiation wave increases with beam density (beam current) and the modulation index. In addition, the growth rate of the instability decreases with an increase in radiation wave frequency and scales as the inverse cube root of radiation frequency. An interesting result obtained from our model is that an increase in cyclotron frequency causes the growth decrement in THz radiation emission, while the efficiency of THz radiation emission increases with the growth rate and the modulation index. Also, the emission of the THz radiation wave becomes larger as the modulation index approaches unity. Journal: Journal of Electromagnetic Waves and Applications Pages: 2195-2209 Issue: 17 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1500948 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1500948 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:17:p:2195-2209 Template-Type: ReDIF-Article 1.0 Author-Name: J. A. López-Toledo Author-X-Name-First: J. A. Author-X-Name-Last: López-Toledo Author-Name: H. Oviedo-Galdeano Author-X-Name-First: H. Author-X-Name-Last: Oviedo-Galdeano Title: Reflection and transmission of a Gaussian beam for an inhomogeneous layered medium using SPPS method Abstract: In this paper, the electromagnetic propagation of a Gaussian beam with oblique incidence is analyzed in an inhomogeneous stratified medium. The transmission and reflection coefficients of a finite inhomogeneous layer are calculated for a perpendicular polarization using the spectral parameter power series method; these coefficients are implicit in the asymptotic formulas obtained for the electric field, the complex stationary-phase method is applied to solve them. The results obtained of reflectance and transmittance by the SPPS method are compared against the results obtained by the DTMM and WKB methods, and it is calculated the absolute error respect to exact solutions, besides other numerical results are obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 2210-2227 Issue: 17 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1503097 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1503097 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:17:p:2210-2227 Template-Type: ReDIF-Article 1.0 Author-Name: B. Plaza Author-X-Name-First: B. Author-X-Name-Last: Plaza Author-Name: O. Ramajo Author-X-Name-First: O. Author-X-Name-Last: Ramajo Author-Name: D. López Author-X-Name-First: D. Author-X-Name-Last: López Author-Name: D. Poyatos Author-X-Name-First: D. Author-X-Name-Last: Poyatos Author-Name: D. Escot Author-X-Name-First: D. Author-X-Name-Last: Escot Title: Assessment of FEM simulations in EMC test setups for small aeronautical platforms Abstract: The rise of fly-by-wire systems together with the utilization of new composite materials make it more and more difficult to assess and guarantee aircraft electromagnetic compatibility (EMC). As a result, the design phase becomes of paramount importance in the aircraft production process. Performing actual EMC tests over different configurations in such a phase would be very costly and time consuming, so reliable computational techniques are being explored in the last years. However, proper validation is needed in order to gain confidence in the results obtained by simulations. In this regard, this paper presents the assessment of a simulation approach based on the finite element method to reproduce typical setups of an EMC test laboratory for small aeronautical platforms. The final test object is based on an unmanned aerial vehicle but, first, a simpler test case is used to tune and assess the simulation approach. Once the approach is both qualitatively and quantitatively validated with measurements, new setups involving the aeronautical specimen are analysed. Journal: Journal of Electromagnetic Waves and Applications Pages: 2228-2245 Issue: 17 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1503098 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1503098 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:17:p:2228-2245 Template-Type: ReDIF-Article 1.0 Author-Name: Surya Prakash Singh Author-X-Name-First: Surya Prakash Author-X-Name-Last: Singh Author-Name: Nilesh Kumar Tiwari Author-X-Name-First: Nilesh Kumar Author-X-Name-Last: Tiwari Author-Name: M. Jaleel Akhtar Author-X-Name-First: M. Jaleel Author-X-Name-Last: Akhtar Title: Quasi-optimization approach for millimeter wave imaging of multilayered dielectric media Abstract: In this paper, a quasi-optimization approach involving a two-step method for the millimeter wave imaging of the stratified media is proposed. The proposed method makes use of reflection data of the test media in the mm-wave band of 26-40 GHz, whose equivalent time domain data are also available using the standard IFFT routines. In the first step, a simple analytical method is applied to extract the real permittivity and the physical thickness of each layer from time domain reflection data. In the second step, an efficient optimization method is proposed to extract material parameters of each layer more accurately from the spectral domain reflection coefficients. The extracted real permittivity and thickness of each layer from the first step provide a quite good estimated value for the next optimization process and thus overall computation time is considerably reduced. The proposed method is experimentally tested for a number of multilayered media comprising various materials. Journal: Journal of Electromagnetic Waves and Applications Pages: 2246-2258 Issue: 17 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1503566 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1503566 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:17:p:2246-2258 Template-Type: ReDIF-Article 1.0 Author-Name: Chirag Mistry Author-X-Name-First: Chirag Author-X-Name-Last: Mistry Author-Name: S. K. Ghosh Author-X-Name-First: S. K. Author-X-Name-Last: Ghosh Title: Dynamic analysis of a multi-stage depressed collector for high-efficiency travelling wave tubes Abstract: High-efficiency helix travelling wave tubes (TWTs) use multi-stage depressed collectors (MDC) for efficiency enhancement. They are subjected to various and rigorous dynamic loads if the TWTs are to be used for space applications. The MDC is composed of several metal–metal, metal–ceramic joints and become considerably bulkier and robust than any other constituent parts of a TWT; hence, before integrating the MDC with the TWT, perhaps it could be important to subject the MDC for dynamic load tests. In this paper, we have presented a dynamic analysis of an MDC, to study the ruggedness of the structure before integrating it into the actual tube, under different stringent environmental conditions for space applications. The study was conducted, with respect to modal, static, sine and random vibration analyses in the software ANSYS to estimate the resonance frequency, structural deformations, stresses and so on. Journal: Journal of Electromagnetic Waves and Applications Pages: 2259-2264 Issue: 17 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1505557 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1505557 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:17:p:2259-2264 Template-Type: ReDIF-Article 1.0 Author-Name: Rekha Chaudhary Author-X-Name-First: Rekha Author-X-Name-Last: Chaudhary Author-Name: Arun Kumar Singh Author-X-Name-First: Arun Kumar Author-X-Name-Last: Singh Title: Power system stabilization using an optimal hybrid control strategy with a PID controller Abstract: As a power system turns out to be all the more heavily loaded and more unpredictable, maintaining stability becomes a difficult issue. In this paper, we propose an optimal control procedure for power system adjustment utilizing a proportional-integral-derivative (PID) controller in a coordinated power system. In modern applications, the most generally utilized controller is the PID controller, which necessitates productive techniques to control the distinctive parameters of the plant. The proposed strategy uses the particle swarm optimization algorithm-based way to deal with producing the optimal tuning parameters. This paper investigates the execution of the power system and dynamic execution of the controller is compared with the conventional controller with approval of the adequacy of the proposed mixture controller. Experimental results demonstrate that the proposed system has upgraded the system stability of the power system all the more adequately existing systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 2265-2280 Issue: 17 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1505558 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1505558 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:17:p:2265-2280 Template-Type: ReDIF-Article 1.0 Author-Name: Xuanxuan Zhang Author-X-Name-First: Xuanxuan Author-X-Name-Last: Zhang Author-Name: Qionghua Zhai Author-X-Name-First: Qionghua Author-X-Name-Last: Zhai Author-Name: Zhigang Li Author-X-Name-First: Zhigang Author-X-Name-Last: Li Author-Name: Wen Ou Author-X-Name-First: Wen Author-X-Name-Last: Ou Author-Name: Yi Ou Author-X-Name-First: Yi Author-X-Name-Last: Ou Title: Design of a K-band two-layer microstrip interdigital filter exploiting aggressive space mapping Abstract: The auxiliary diagnosis and debugging of filters play an increasingly important role in the design of microwave filters, where aggressive space mapping (ASM) is one of the most commonly used debugging methods. This paper introduces ASM and designs a sixth-order two-layer microstrip interdigital filter with a center frequency of 20.4 GHz and a bandwidth of 1.6 GHz using ASM. The filter reached design indexes after seven iterations, which greatly reduces the number of simulations in the fine model, thereby saving time. It was fabricated with Micro-Electro-Mechanical Systems technology and the size of the chip is 7 mm × 3 mm × 0.8 mm. The measurement result was in good agreement with the simulation result. Journal: Journal of Electromagnetic Waves and Applications Pages: 2281-2291 Issue: 17 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1505559 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1505559 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:17:p:2281-2291 Template-Type: ReDIF-Article 1.0 Author-Name: Jeet Ghosh Author-X-Name-First: Jeet Author-X-Name-Last: Ghosh Author-Name: Debasis Mitra Author-X-Name-First: Debasis Author-X-Name-Last: Mitra Author-Name: Sekhar Ranjan Bhadra Chaudhuri Author-X-Name-First: Sekhar Ranjan Author-X-Name-Last: Bhadra Chaudhuri Title: Reduction of leaky wave coupling in a superstrate loaded antenna using metamaterial Abstract: In this paper, an approach is presented for reducing leaky wave coupling of superstrate loaded slot array using zero index metamaterial structure. The dielectric superstrate generally aims at increasing the directivity of the antenna by the generation of leaky wave. In another aspect, the leaky wave reduces the isolation between radiating elements in multiple antenna system. Here, the metamaterial has been used to mitigate the mutual coupling by reducing the generation of the leaky wave. By the help of this approach, the isolation is improved throughout the operational bandwidth and maximum 15 dB isolation improvement is achieved with an edge to edge distance of 4 mm between radiating elements. Journal: Journal of Electromagnetic Waves and Applications Pages: 2292-2303 Issue: 17 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1507842 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1507842 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:17:p:2292-2303 Template-Type: ReDIF-Article 1.0 Author-Name: Zhipeng Liang Author-X-Name-First: Zhipeng Author-X-Name-Last: Liang Author-Name: Jun Ouyang Author-X-Name-First: Jun Author-X-Name-Last: Ouyang Author-Name: Feng Yang Author-X-Name-First: Feng Author-X-Name-Last: Yang Title: Design and characteristic mode analysis of a low-profile wideband patch antenna using metasurface Abstract: A low-profile linearly polarized patch antenna using metasurface is proposed for wideband operation at 5-GHz Wi-Fi bands. The antenna is comprised of a rectangle patch sandwiched between a lattice of 3 × 3 periodic metasurface and the ground plane. The adopted coaxial probe feed is easy to fabricate and match. Characteristic mode analysis (CMA) is utilized to explain and understand the working mechanism of the proposed antenna. It is found that two dominant characteristic modes are well excited, leading to the broadband operation and linearly polarized radiation. The proposed dielectric-filled antenna with a low profile of 0.057λ0 (λ0 is the operating wavelength at 5.7 GHz in free space) attains about 30% measured −10 dB impedance bandwidth (4.89–6.62 GHz) with 7.28 dBi average gain. Across the bandwidth, the antenna efficiency is greater than 90%, and cross-polarization levels are less than 18 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 2304-2313 Issue: 17 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1507843 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1507843 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:17:p:2304-2313 Template-Type: ReDIF-Article 1.0 Author-Name: Jianqiong Zhang Author-X-Name-First: Jianqiong Author-X-Name-Last: Zhang Author-Name: Qingxiang Liu Author-X-Name-First: Qingxiang Author-X-Name-Last: Liu Author-Name: Xiangqiang Li Author-X-Name-First: Xiangqiang Author-X-Name-Last: Li Author-Name: Yuan Liang Author-X-Name-First: Yuan Author-X-Name-Last: Liang Title: A compact TE11-TM01 mode converter for HPM application Abstract: A mode converter using circular waveguide has been investigated. The conversion is based on the structure of two orthogonal circular waveguide and there is a tuning screw placed at the short-end used to increase conversion efficiency and bandwidth. The results show that the converter is not only compact but also wide-band, which realize a bandwidth of 11∼14 GHz for conversion efficiency over 90%. The simulated power capacity is 798 MW at 12.7 GHz under vacuum condition. Journal: Journal of Electromagnetic Waves and Applications Pages: 2314-2320 Issue: 17 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1509736 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1509736 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:17:p:2314-2320 Template-Type: ReDIF-Article 1.0 Author-Name: I.V. Andronov Author-X-Name-First: I.V. Author-X-Name-Last: Andronov Title: New developments in high-frequency diffraction by smooth surfaces Abstract: This review reports on some progress in high-frequency diffraction by smooth surfaces. Specific effects related to the special cases of the impedance boundary conditions and the effects that take place in the case of very much elongated surfaces are particularly discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 2321-2338 Issue: 17 Volume: 32 Year: 2018 Month: 11 X-DOI: 10.1080/09205071.2018.1500950 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1500950 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:17:p:2321-2338 Template-Type: ReDIF-Article 1.0 Author-Name: Tong He Author-X-Name-First: Tong Author-X-Name-Last: He Author-Name: Li Na He Author-X-Name-First: Li Na Author-X-Name-Last: He Author-Name: Kai Li Author-X-Name-First: Kai Author-X-Name-Last: Li Title: Poynting vector of an ELF electromagnetic wave in three-layered ocean floor Abstract: In the present study, the Poynting vector of an ELF electromagnetic wave in the presence of a three-layered ocean floor is treated both analytically and numerically. It is verified that the derived locus of the Poynting vector in a three-layered region reduces to exactly the same form for a two-layered region once the thickness of the intermediate layer decreases to zero. When studying the magnitude of the Poynting vector, it is found that the locations of the turning points accurately match the coordinates of maximum penetration. Moreover, despite that the lateral wave can reach a larger depth of penetration as the propagation distance increases, the electromagnetic field at the receiving point will also bear greater attenuation. Figuring out the required penetration depth before determining the location of the receiver is a possible way to ease this issue. Journal: Journal of Electromagnetic Waves and Applications Pages: 2339-2349 Issue: 18 Volume: 32 Year: 2018 Month: 12 X-DOI: 10.1080/09205071.2018.1506365 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1506365 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:18:p:2339-2349 Template-Type: ReDIF-Article 1.0 Author-Name: Naveen Gupta Author-X-Name-First: Naveen Author-X-Name-Last: Gupta Title: Self-action effects of quadruple-Gaussian laser beam in media possessing cubic–quintic nonlinearity Abstract: Theoretical investigation self-action effects of Quadruple-Gaussian (Q.G) laser beams in media possessing cubic–quintic nonlinearity in their dielectric properties has been presented. Numerical solution of the nonlinear Schrodinger wave equation for the field of incident laser beam has been obtained by making the use of moment theory approach. Particular emphasis is laid on the dynamical variations of the spot size and longitudinal phase of the laser beam with distance of propagation. Self-trapping of the laser beam resulting from the balance between diffraction broadening and nonlinear refraction has been also investigated. Journal: Journal of Electromagnetic Waves and Applications Pages: 2350-2366 Issue: 18 Volume: 32 Year: 2018 Month: 12 X-DOI: 10.1080/09205071.2018.1509024 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1509024 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:18:p:2350-2366 Template-Type: ReDIF-Article 1.0 Author-Name: Prakash Ranjan Author-X-Name-First: Prakash Author-X-Name-Last: Ranjan Author-Name: Arvind Choubey Author-X-Name-First: Arvind Author-X-Name-Last: Choubey Author-Name: Santosh Kumar Mahto Author-X-Name-First: Santosh Kumar Author-X-Name-Last: Mahto Author-Name: Rashmi Sinha Author-X-Name-First: Rashmi Author-X-Name-Last: Sinha Title: A six-band ultra-thin polarization-insensitive pixelated metamaterial absorber using a novel binary wind driven optimization algorithm Abstract: In this article, a novel binary Wind Driven Optimization (WDO) algorithm is presented for the synthesis of six-band Metamaterial Absorber (MA). Synthesis of the unit cell structure of MA is done by optimizing the presence of each unit pixel of pixelated Frequency Selective Surface (FSS). Numerical simulation of this optimized absorber shows six discrete bands of absorptions at 7.6, 10.1, 13.3, 14.7, 15.8 and 16.7 GHz with more than 90% absorptivity under normal incidence of the wave. The proposed absorber is ultra-thin, polarization insensitive and has good performance over a wide angle of incidence. The numerical simulation and experimental results are in close agreement. Journal: Journal of Electromagnetic Waves and Applications Pages: 2367-2385 Issue: 18 Volume: 32 Year: 2018 Month: 12 X-DOI: 10.1080/09205071.2018.1510344 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1510344 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:18:p:2367-2385 Template-Type: ReDIF-Article 1.0 Author-Name: Biao Zhou Author-X-Name-First: Biao Author-X-Name-Last: Zhou Author-Name: Changqiang Jing Author-X-Name-First: Changqiang Author-X-Name-Last: Jing Author-Name: Chao Sun Author-X-Name-First: Chao Author-X-Name-Last: Sun Author-Name: Youngok Kim Author-X-Name-First: Youngok Author-X-Name-Last: Kim Title: A joint indoor positioning scheme exploiting pedestrian dead reckoning and radio frequency tomography Abstract: The pedestrian dead reckoning (PDR) is a popular technique for recognizing a pedestrian’s trajectory. However, its inherent disadvantage of susceptibility to error accumulation limits its performance as the travelled distance is increased. Various techniques are combined with PDR to mitigate the error accumulation by regular position resetting. The radio frequency (RF) Tomography is an emerging technology for localization by sensing the received signal strength (RSS) fluctuation on a line-of-sight wireless link (LOSL). Conventional RF Tomography based schemes need specific large-scale networks and face with the problem of harsh environments and high hardware costs. Thus in this paper, we proposed the flexible and practical GF operators for PDR resetting work, in which we introduce the displacement estimation by PDR technique and the LOSL triggering sequence to build a PDR geometrical formulation (PDR-GF) model, and then this model is optimized by Particle Swarm Optimization (PSO) algorithm for crossing point (CP) estimation on the LOSLs. Finally, the estimated CP is in turn used for regular position resetting. Practical experiments are performed to evaluate the proposed positioning scheme. According to the results, the proposed scheme can achieve a finer accuracy of less than 1 m, outperforming the existing RSS-PDR positioning scheme. Journal: Journal of Electromagnetic Waves and Applications Pages: 2386-2403 Issue: 18 Volume: 32 Year: 2018 Month: 12 X-DOI: 10.1080/09205071.2018.1511478 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1511478 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:18:p:2386-2403 Template-Type: ReDIF-Article 1.0 Author-Name: Gaoya Dong Author-X-Name-First: Gaoya Author-X-Name-Last: Dong Author-Name: Weimin Wang Author-X-Name-First: Weimin Author-X-Name-Last: Wang Author-Name: Bo Zhang Author-X-Name-First: Bo Author-X-Name-Last: Zhang Author-Name: Yuanan Liu Author-X-Name-First: Yuanan Author-X-Name-Last: Liu Title: Wideband filtering Yagi antenna array Abstract: A novel wideband high-gain antenna array with filtering response is presented. The proposed array consists of four Yagi antenna elements and one feeding network, which could realize signal filtering, power splitting as well as impedance transforming characteristics simultaneously. The operating mechanism is analyzed and the detailed design procedure is presented. For demonstration, a 2 × 2 array is designed at the center frequency of 3.0 GHz with the measured fractional bandwidth of 73.3%. Measured in-band maximum gain is 13.2 dB, whereas the out-of-band suppression level is better than 23.2 dB. Compared with the conventional array, the proposed filtering array shows high suppression in the stopband, good selectivity at passband edges and flat antenna gain in the passband. Simulated and measured results provide a good verification for the theoretical concepts. Journal: Journal of Electromagnetic Waves and Applications Pages: 2404-2414 Issue: 18 Volume: 32 Year: 2018 Month: 12 X-DOI: 10.1080/09205071.2018.1514791 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1514791 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:18:p:2404-2414 Template-Type: ReDIF-Article 1.0 Author-Name: Shankar Bhattacharjee Author-X-Name-First: Shankar Author-X-Name-Last: Bhattacharjee Author-Name: Manas Midya Author-X-Name-First: Manas Author-X-Name-Last: Midya Author-Name: Sekhar Ranjan Bhadra Chaudhuri Author-X-Name-First: Sekhar Ranjan Author-X-Name-Last: Bhadra Chaudhuri Author-Name: Monojit Mitra Author-X-Name-First: Monojit Author-X-Name-Last: Mitra Title: Design of a miniaturized dual-band textile antenna using characteristic modal analysis for on-body applications Abstract: A novel dual band textile antenna for ON body communication in the 2.45 and 5.8 GHz ISM bands is presented. The overall size of the antenna is 60 × 30 × 3.75 mm3 and the merit of the antenna lies in its design simplicity. To realize a small antenna size, the lower resonant frequency is generated by the ground plane which is larger than the radiator normally. The ground plane has been miniaturized with the addition of two alternate quarter wavelength slots placed parallel to each other. Through characteristic modal analysis, the ground plane of the antenna is optimized for radiating field parallel to the body which could facilitate ON body communication. The patch at the top has been folded in opposite directions to resonant at higher frequency. An equivalent circuit showing the working mechanism of the ground and the patch is shown. Simulation results were verified by measurement for the given antenna. Journal: Journal of Electromagnetic Waves and Applications Pages: 2415-2430 Issue: 18 Volume: 32 Year: 2018 Month: 12 X-DOI: 10.1080/09205071.2018.1515038 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1515038 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:18:p:2415-2430 Template-Type: ReDIF-Article 1.0 Author-Name: Gaoya Dong Author-X-Name-First: Gaoya Author-X-Name-Last: Dong Author-Name: Weimin Wang Author-X-Name-First: Weimin Author-X-Name-Last: Wang Author-Name: Bo Zhang Author-X-Name-First: Bo Author-X-Name-Last: Zhang Author-Name: Yuanan Liu Author-X-Name-First: Yuanan Author-X-Name-Last: Liu Title: Wideband filtering Yagi antenna array Abstract: A novel wideband high-gain antenna array with filtering response is presented. The proposed array consists of four Yagi antenna elements and one feeding network, which could realize signal filtering, power splitting as well as impedance transforming characteristics simultaneously. The operating mechanism is analysed and the detailed design procedure is presented. For demonstration, a 2×2 array is designed at the center frequency of 3.0 GHz with the measured fractional bandwidth of 73.3%. Measured in-band maximum gain is 13.2 dB, whereas the out-of-band suppression level is better than 23.2 dB. Compared with the conventional array, the proposed filtering array shows high suppression in the stopband, good selectivity at passband edges and flat antenna gain in the passband. The simulated and measured results provide a good verification for the theoretical concepts. Journal: Journal of Electromagnetic Waves and Applications Pages: 2431-2441 Issue: 18 Volume: 32 Year: 2018 Month: 12 X-DOI: 10.1080/09205071.2018.1515039 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1515039 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:18:p:2431-2441 Template-Type: ReDIF-Article 1.0 Author-Name: Chao Xue Author-X-Name-First: Chao Author-X-Name-Last: Xue Author-Name: Yanpeng Mao Author-X-Name-First: Yanpeng Author-X-Name-Last: Mao Author-Name: Wenlong Wang Author-X-Name-First: Wenlong Author-X-Name-Last: Wang Author-Name: Zhanlong Song Author-X-Name-First: Zhanlong Author-X-Name-Last: Song Author-Name: Xiqiang Zhao Author-X-Name-First: Xiqiang Author-X-Name-Last: Zhao Author-Name: Jing Sun Author-X-Name-First: Jing Author-X-Name-Last: Sun Author-Name: Chunyuan Ma Author-X-Name-First: Chunyuan Author-X-Name-Last: Ma Title: Study of microwave-induced metal discharge under high pressure based on spectrum analysis Abstract: Discharge phenomena can occur when metals are exposed to microwave radiation. The mechanism of the discharge can be effectively studied by using spectral analysis. In this study, a reactor that can withstand long-term high pressure was used in combination with a spectrometer to investigate the effects of pressure and other parameters on the microwave metal discharge plasma. It was observed that the increase of radiation power, pressure, and metal wire diameter can have positive effects on the intensity of spectral lines. If other experimental conditions remain unchanged, the spectral lines and discharge intensity exhibit dynamic changes because the wire melts and changes its shape under the high local temperature associated with discharge. Because factors like radiation power and pressure can enhance the intensity of the plasma significantly, they can be reasonably utilized to accelerate the chemical reactions or improve the degradation rate of pollutants, e.g. in microwave wet oxidation applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 2442-2457 Issue: 18 Volume: 32 Year: 2018 Month: 12 X-DOI: 10.1080/09205071.2018.1515668 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1515668 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:18:p:2442-2457 Template-Type: ReDIF-Article 1.0 Author-Name: Hao Zhang Author-X-Name-First: Hao Author-X-Name-Last: Zhang Author-Name: Wei Kang Author-X-Name-First: Wei Author-X-Name-Last: Kang Author-Name: Wen Wu Author-X-Name-First: Wen Author-X-Name-Last: Wu Title: A new approach to the push–push oscillator based on a differential SIW bandpass filter Abstract: A novel push–push oscillator based on a differential bandpass filter (BPF) using substrate integrated waveguide (SIW) technique is presented in this paper. For the first time, the differential SIW BPF is utilized as a frequency stabilization element to provide differential outputs in designing the push–push oscillator. The complex quality factor (Qsc)-peak frequency of the BPF is chosen for the design at approximately half the final output frequency to achieve low phase noise performance. Moreover, two transmission zeros (TZs) below the passband and two TZs above the passband which highly improve the out-of-band rejection are obtained by using both electromagnetic coupling and cross coupling. An SIW power combiner is also designed to obtain the desired signal. A push–push oscillator has been proposed and experimentally demonstrated at 27.8 GHz to verify the above design concept. The measured results show that the output power is −17.3 dBm with a phase noise of 128.6 dBc/Hz at 1-MHz offset. Journal: Journal of Electromagnetic Waves and Applications Pages: 2458-2469 Issue: 18 Volume: 32 Year: 2018 Month: 12 X-DOI: 10.1080/09205071.2018.1517614 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1517614 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:18:p:2458-2469 Template-Type: ReDIF-Article 1.0 Author-Name: Viacheslav Zemlyakov Author-X-Name-First: Viacheslav Author-X-Name-Last: Zemlyakov Author-Name: Sergey Krutiev Author-X-Name-First: Sergey Author-X-Name-Last: Krutiev Author-Name: Mikhail Tyaglov Author-X-Name-First: Mikhail Author-X-Name-Last: Tyaglov Title: Complex geometry apertures for resonant diaphragms in rectangular waveguides Abstract: In the paper, we investigate thin metal transverse resonant diaphragms with a complex aperture in rectangular waveguides and develop some new aperture profiles with advanced properties. The presented resonant diaphragms are produced by the metallization of the thin dielectric substrate and allow to construct band-pass and band-stop filters with high Q-factor and transmission zeros. An original approach to develop the ultra-compact and robust waveguide filters is described. As an example, we demonstrate the band-pass filter on WR-90 rectangular waveguides with the length of 8 mm and the pass-band of 10%. Journal: Journal of Electromagnetic Waves and Applications Pages: 2470-2480 Issue: 18 Volume: 32 Year: 2018 Month: 12 X-DOI: 10.1080/09205071.2018.1518160 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1518160 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:18:p:2470-2480 Template-Type: ReDIF-Article 1.0 Author-Name: Chuan Li Author-X-Name-First: Chuan Author-X-Name-Last: Li Author-Name: Zhongyin Xiao Author-X-Name-First: Zhongyin Author-X-Name-Last: Xiao Author-Name: Wei Li Author-X-Name-First: Wei Author-X-Name-Last: Li Author-Name: Huanling Zou Author-X-Name-First: Huanling Author-X-Name-Last: Zou Title: Tunable multiband band-stop filter based on graphene metamaterial in THz frequency Abstract: In this paper, a tunable multiband band-stop filter based on single-layer and few-layer doped periodically graphene rings is designed at THz wavelength. The performance of the proposed structure is calculated by using the finite-difference time-domain method. The metamaterial structure is comprised of the concentric graphene ring resonators printed on substrate layer of silica medium. The multiband band-stop filter can be achieved by adjusting the numbers of graphene ring resonator. More importantly, a dynamically tunable filter can be designed by adjusting the applied voltage or chemical potential doping to manipulate graphene’s Fermi energy. The z-component electric field is investigated to explain the physical mechanism of the transmission. In addition, the proposed filter has the advantage of independence to polarization and insensitivity to the angles of the incident wave. Our design can have potential applications in various fields of tunable photonic devices, sensors and multi-band communication. Journal: Journal of Electromagnetic Waves and Applications Pages: 2481-2489 Issue: 18 Volume: 32 Year: 2018 Month: 12 X-DOI: 10.1080/09205071.2018.1518161 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1518161 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:18:p:2481-2489 Template-Type: ReDIF-Article 1.0 Author-Name: Won-Kwang Park Author-X-Name-First: Won-Kwang Author-X-Name-Last: Park Title: Fast identification of small perfectly conducting cracks without diagonal elements of multi-static response matrix Abstract: We explore mathematical structures of indicator functions used in subspace migration to identify the location of a set of perfectly conducting cracks with small lengths when the diagonal elements of a Multi-Static Response (MSR) matrix cannot be obtained. By using the asymptotic formula for the presence of cracks and the structure of the singular vectors linked to the nonzero singular values of the MSR matrix, we prove that the indicator function can be represented by a Bessel function of order zero of the first kind and the total number of incident and observation directions in a full-view inverse scattering problem. We also present experimental results of numerical simulations with noisy data to validate our findings. Journal: Journal of Electromagnetic Waves and Applications Pages: 2490-2502 Issue: 18 Volume: 32 Year: 2018 Month: 12 X-DOI: 10.1080/09205071.2018.1518162 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1518162 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:18:p:2490-2502 Template-Type: ReDIF-Article 1.0 Author-Name: Wenhe Xia Author-X-Name-First: Wenhe Author-X-Name-Last: Xia Author-Name: Yingfeng Meng Author-X-Name-First: Yingfeng Author-X-Name-Last: Meng Author-Name: Weiqin Li Author-X-Name-First: Weiqin Author-X-Name-Last: Li Title: Study on multipath channels model of microwave propagation in a drill pipe Abstract: In the process of air drilling, underground monitoring data can be transmitted by a microwave signal in the drill pipe. In this paper, we analyze the characteristics of the microwave transmission channel in a drill pipe, by regarding the drill pipe as an irregular lossy cylindrical waveguide. We use multipath transmission theory and an experimental statistical method to research the characteristics of the microwave channel and the attenuation law. The existing research results only focus on the dielectric loss of the drill stem; however, herein we point out that there are numerous reflective surfaces that can produce a great deal of reflected waves in the joint section of the drill pipe. Hence, the drill pipe has microwave multipath channel characteristics; consequently, multipath fading and delay are the main factors affecting the transmission quality. According to actual measurement results, the microwave channel composed of a drill pipe unit is in accordance with the ultra-wideband channel standard and has dual cluster multipath channel characteristics. The relative time delay between the two clusters is 51 ns, the mean square delay is 22.58 ns, and the maximum data rate in a drill pipe is about 7 Mb/s. Journal: Journal of Electromagnetic Waves and Applications Pages: 129-137 Issue: 2 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1368418 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1368418 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:2:p:129-137 Template-Type: ReDIF-Article 1.0 Author-Name: Farzad Ebrahimi Author-X-Name-First: Farzad Author-X-Name-Last: Ebrahimi Author-Name: Ali Dabbagh Author-X-Name-First: Ali Author-X-Name-Last: Dabbagh Title: Wave dispersion characteristics of rotating heterogeneous magneto-electro-elastic nanobeams based on nonlocal strain gradient elasticity theory Abstract: The coupled influences of shear deformation and angular velocity of a FG rotary nanobeam are going to be analyzed in the existence of external magnetic and electric fields. The effective material properties seem to be defined by the means of power law formulation. Moreover, the influences of small scale are included precisely in the framework of a nonlocal strain gradient theory. The magneto-electric potentials are supposed to vary through the thickness with a combination of linear and cosine approximations. Employing Hamilton’s principle, the nonlocal governing equations of magneto-electro-elastic functionally graded (MEE-FG) rotary size-dependent beams are derived in terms of displacement fields. Afterwards, the obtained governing equations are solved analytically to gather wave frequency, phase velocity, and escape frequency of the MEE-FG rotary nanobeam. The obtained results are validated with those of former researches. At the end, a numerical study is performed to show the influence of involved parameters on the wave propagation behaviors of MEE-FG rotary nanobeams. Journal: Journal of Electromagnetic Waves and Applications Pages: 138-169 Issue: 2 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1369903 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1369903 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:2:p:138-169 Template-Type: ReDIF-Article 1.0 Author-Name: Hemant Kumar Dashora Author-X-Name-First: Hemant Kumar Author-X-Name-Last: Dashora Author-Name: Giuseppe Buja Author-X-Name-First: Giuseppe Author-X-Name-Last: Buja Author-Name: Manuele Bertoluzzo Author-X-Name-First: Manuele Author-X-Name-Last: Bertoluzzo Author-Name: Rosanna Pinto Author-X-Name-First: Rosanna Author-X-Name-Last: Pinto Author-Name: Vanni Lopresto Author-X-Name-First: Vanni Author-X-Name-Last: Lopresto Title: Analysis and design of DD coupler for dynamic wireless charging of electric vehicles Abstract: In dynamic wireless charging (DWC) of battery-powered electric vehicles (BEVs), inductive power transfer takes place between two coils, one buried into the road and the other one installed onboard BEVs. This paper deals with the design of the coils of a lumped DWC system. At first, the concept of polarized coil is explicated and a DWC-suitable structure of polarized coil, namely the double-D (DD) coil, is illustrated. Then, the paper analyzes the inductive properties of a DD coupler and presents its design for a case study. The design embraces the dimensions of the coils and the magnetic cores, thickness included, and usage of bars instead of plates for the cores in order to save magnetic material. After developing closed-form expressions of the inductive parameters of the coils useful for their preliminary sizing, the analysis and design activities are carried out with the assistance of finite element method codes. Relevant results supporting the design are presented by help of tables, maps, and graphs. Journal: Journal of Electromagnetic Waves and Applications Pages: 170-189 Issue: 2 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1373036 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1373036 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:2:p:170-189 Template-Type: ReDIF-Article 1.0 Author-Name: Vishnu Srivastava Author-X-Name-First: Vishnu Author-X-Name-Last: Srivastava Title: Nonlinear analysis of beam-wave interaction in a planar THz travelling-wave tube amplifier Abstract: Large-signal analysis is presented for analysing non-linear beam-wave interaction in a planar THz TWT with a sheet electron beam. The sheet beam within one RF beam wavelength is represented by uniform rectangular charged discs for confined flow of the beam, and the discs are tracked in small distance steps of forward integration. For a planar THz TWT, a staggered double-vane loaded rectangular waveguide slow-wave structure (SDVSWS) is used. Frequency-domain analysis is used to define the RF circuit field in the SDVSWS and the interaction of the RF circuit field with the electron beam is carried out for steady-state TWT operation. The RF circuit field is considered to be continuous as in a helix SWS and it is represented by transmission line theory at each integration plane. A large-signal analysis code of a helix TWT with pencil beam (SUNRAY-1D) was modified for a planar TWT with a sheet beam. The accuracy of the modified SUNRAY code was checked against the 3D e.m. field simulator (CST-PS) by comparing the output performance for a 0.22-THz planar TWT. The results for the gain and the output power over the operating band given by the two codes were found to be comparable. A significant advantage of the SUNRAY code is that it is very fast compared to the CST code. It takes less than a minute to simulate the RF performance of a typical THz TWT at a single frequency and drive power on a standard PC. The SUNRAY code can therefore, be used interactively for design a complete SWS with input/output couplers, sever, loss profiles and phase velocity taper for a high efficiency high gain THz TWT. Journal: Journal of Electromagnetic Waves and Applications Pages: 190-203 Issue: 2 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1374217 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1374217 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:2:p:190-203 Template-Type: ReDIF-Article 1.0 Author-Name: Di Wu Author-X-Name-First: Di Author-X-Name-Last: Wu Author-Name: Xiaoxue Hua Author-X-Name-First: Xiaoxue Author-X-Name-Last: Hua Author-Name: Sing Wai Cheung Author-X-Name-First: Sing Wai Author-X-Name-Last: Cheung Author-Name: Bo Wang Author-X-Name-First: Bo Author-X-Name-Last: Wang Author-Name: Min Li Author-X-Name-First: Min Author-X-Name-Last: Li Author-Name: Bing Xiao Author-X-Name-First: Bing Author-X-Name-Last: Xiao Title: A compact slot MIMO antenna for smartphones with metal housing Abstract: A compact slot multiple-input multiple-output Antenna (CSMA) for smartphones with metal housing is proposed in this paper. The antenna has a slot radiator shared between two input ports and a T-shaped defect-ground slot (DGS) for decoupling. A function for selecting the best dimensions of the DGS for optimum decoupling is derived using the transmission theory. The CSMA antenna is designed using simulation to operate in the 2.4-GHz wireless-area-network (WLAN) system and then fabricated for measurement. Measured results show that the antenna has an impedance bandwidth (IMBW) of 2.4–2.48 GHz, mutual coupling from −19 to −29 dB and envelope-correlation coefficient (ECC) below 0.0867 within the IMBW. The antenna is very easy to fabricate and is a potential candidate for the MIMO smartphones antennas with metal housing. Journal: Journal of Electromagnetic Waves and Applications Pages: 204-214 Issue: 2 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1374883 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1374883 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:2:p:204-214 Template-Type: ReDIF-Article 1.0 Author-Name: Heeralal Gargama Author-X-Name-First: Heeralal Author-X-Name-Last: Gargama Author-Name: Sanjay K. Chaturvedi Author-X-Name-First: Sanjay K. Author-X-Name-Last: Chaturvedi Author-Name: Awalendra K. Thakur Author-X-Name-First: Awalendra K. Author-X-Name-Last: Thakur Title: Experimental validation of reliability-based design optimization models for designing EMI shielding and absorbing structures Abstract: This paper aims to comprehend and demonstrate the validity of the theoretical models proposed recently for designing electromagnetic interference (EMI) shielding [Gargama H, Chaturvedi SK, Thakur AK. Reliability-based design optimization scheme for designing electromagnetic shielding structures. J. Electromagn. Waves Appl. 2014;28(6):765–776] and absorbing structures [Gargama H, Chaturvedi SK, Thakur AK. Reliability-based design optimization of broadband microwave absorbers. J. Electromagn. Waves Appl. 2013;27:1407–1418]. Initially, the composites of polyvinylidene fluoride comprising varying concentration of nickel, iron, iron oxide, and activated carbon are prepared through compression hot-molding technique. Subsequently, the number of composite layers and the desirable material parameters for each of the layers are optimized using the composite’s database for a three layered EMI shielding and absorbing structures. The structures are fabricated and evaluated for the performance as an EMI shield and absorber for electromagnetic waves considering their state of polarization and angle of incidence on the designed structures. A comparison and a close agreement within an acceptable error of the theoretically optimized and experimentally realized parameters are the real strength of this work. Journal: Journal of Electromagnetic Waves and Applications Pages: 215-228 Issue: 2 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1377120 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1377120 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:2:p:215-228 Template-Type: ReDIF-Article 1.0 Author-Name: Anirban Pathak Author-X-Name-First: Anirban Author-X-Name-Last: Pathak Author-Name: Ajoy Ghatak Author-X-Name-First: Ajoy Author-X-Name-Last: Ghatak Title: Classical light vs. nonclassical light: characterizations and interesting applications Abstract: We briefly review the ideas that have shaped modern optics and have led to various applications of light ranging from spectroscopy to astrophysics, and street lights to quantum communication. The review is primarily focused on the modern applications of classical light and nonclassical light. Specific attention has been given to the applications of squeezed, antibunched, and entangled states of radiation field. Applications of Fock states (especially single photon states) in the field of quantum communication are also discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 229-264 Issue: 2 Volume: 32 Year: 2018 Month: 1 X-DOI: 10.1080/09205071.2017.1398109 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1398109 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:2:p:229-264 Template-Type: ReDIF-Article 1.0 Author-Name: Qi Zheng Author-X-Name-First: Qi Author-X-Name-Last: Zheng Author-Name: Chenjiang Guo Author-X-Name-First: Chenjiang Author-X-Name-Last: Guo Author-Name: Haixiong Li Author-X-Name-First: Haixiong Author-X-Name-Last: Li Author-Name: Jun Ding Author-X-Name-First: Jun Author-X-Name-Last: Ding Title: Wideband and high efficiency reflective polarization rotator based on metasurface Abstract: A wideband and high efficiency reflective polarization rotator (PR) based on metasurface is presented. The unit cell of the PR consisting of two oblique symmetry triangle split rings and simulated results show the PR has more than 90% polarization conversion efficiency from 9.24 to 17.64 GHz (a relative bandwidth of 62.50%) under normal incidence. The broad polarization conversion bandwidth and high efficiency results from multiple plasmon resonances and nearly 100% polarization conversion is obtained at three plasmon resonances. The mechanism of the proposed PR is analyzed by surface current distributions. Electric and magnetic resonances generate broad polarization conversion bandwidth and high polarization conversion ratio within the operating band. In addition, we analyze the polarization states of the PR unit numerically based on the reflected fields, which serves as theoretical predictions of polarization conversion. To verify the simulation results and analysis, a sample was fabricated and measured. The measured results are in good agreement with simulated results and numerical analysis. Journal: Journal of Electromagnetic Waves and Applications Pages: 265-273 Issue: 3 Volume: 32 Year: 2018 Month: 2 X-DOI: 10.1080/09205071.2017.1377640 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1377640 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:3:p:265-273 Template-Type: ReDIF-Article 1.0 Author-Name: Deming Sun Author-X-Name-First: Deming Author-X-Name-Last: Sun Author-Name: Peng Wang Author-X-Name-First: Peng Author-X-Name-Last: Wang Author-Name: Peng Gao Author-X-Name-First: Peng Author-X-Name-Last: Gao Author-Name: Yalong Zhang Author-X-Name-First: Yalong Author-X-Name-Last: Zhang Title: A novel dual-band MIMO antenna with two rings for WIMAX applications Abstract: A new equivalent-circuit model consisted of three transmission lines is proposed and a decoupling equation is derived for determining the electric parameters of required the three transmission lines. In order to further verify the feasibility of the equivalent circuit, a novel dual-band two-port multiple-input-multiple-output antenna with two rings working in the 2.35- and 3.5-GHz bands of the WIMAX is presented. The details of the building circuit model and the experimental results and discussion are given. Journal: Journal of Electromagnetic Waves and Applications Pages: 274-280 Issue: 3 Volume: 32 Year: 2018 Month: 2 X-DOI: 10.1080/09205071.2017.1377642 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1377642 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:3:p:274-280 Template-Type: ReDIF-Article 1.0 Author-Name: Yugandhara R. Yadam Author-X-Name-First: Yugandhara R. Author-X-Name-Last: Yadam Author-Name: Balamurugan T. Sivaprakasam Author-X-Name-First: Balamurugan T. Author-X-Name-Last: Sivaprakasam Author-Name: Krishnamurthy C. Venkata Author-X-Name-First: Krishnamurthy C. Author-X-Name-Last: Venkata Author-Name: Kavitha Arunachalam Author-X-Name-First: Kavitha Author-X-Name-Last: Arunachalam Title: Step frequency continuous wave RADAR sensor for level measurement of molten solids Abstract: Step frequency continuous wave (SFCW) RAdio Detection And Ranging (RADAR) sensor is proposed for non-contact measurement of the absolute level of molten solids in industrial furnaces. A conical horn is optimized for operation over 10–16 GHz in mono-static configuration for level measurement. The absolute distance of a stationary target was measured with 3 mm accuracy using the SFCW RADAR sensor in mono-static mode. Stable measurements were recorded for 4.35 h in a furnace at 450 °C. Level measurements of molten glass and aluminum in 1100 °C furnace indicate the feasibility of industrial-level gauging. Journal: Journal of Electromagnetic Waves and Applications Pages: 281-292 Issue: 3 Volume: 32 Year: 2018 Month: 2 X-DOI: 10.1080/09205071.2017.1380540 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1380540 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:3:p:281-292 Template-Type: ReDIF-Article 1.0 Author-Name: Qing He Author-X-Name-First: Qing Author-X-Name-Last: He Author-Name: Chunchen Qi Author-X-Name-First: Chunchen Author-X-Name-Last: Qi Author-Name: Chao Liu Author-X-Name-First: Chao Author-X-Name-Last: Liu Author-Name: Xiaoping Lou Author-X-Name-First: Xiaoping Author-X-Name-Last: Lou Author-Name: Lianqing Zhu Author-X-Name-First: Lianqing Author-X-Name-Last: Zhu Title: A compact arbitrary power division coupler with nonstandard phase-difference Abstract: This paper presents a new coupler configuration which can be designed with both arbitrary power division and nonstandard phase difference at the output ports. The planar coupler ring is composed of four section microstrip lines and an open stub resulting in ease of fabrication. Its circuit parameters can be easily determined by the derived closed-form equations and the corresponding performance in terms of power division ratio, output phase difference, and the tunable parameters is mainly analyzed. Compared with the previous counterparts, its bandwidth and area have obvious superiority. For experimental verification, two prototypes, operating at 1 GHz, have been designed and implemented in microstrip process. One demonstrates a 45° phase difference with equal outputs and the other is designed for a 105° phase difference with 6.02 dB power division ratio. The design theory has been supported with good agreement between the simulated and measured responses. Journal: Journal of Electromagnetic Waves and Applications Pages: 293-305 Issue: 3 Volume: 32 Year: 2018 Month: 2 X-DOI: 10.1080/09205071.2017.1380541 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1380541 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:3:p:293-305 Template-Type: ReDIF-Article 1.0 Author-Name: Deepender Kant Author-X-Name-First: Deepender Author-X-Name-Last: Kant Author-Name: Lalit Mohan Joshi Author-X-Name-First: Lalit Mohan Author-X-Name-Last: Joshi Author-Name: Vijay Janyani Author-X-Name-First: Vijay Author-X-Name-Last: Janyani Title: Design of a multi beam electron gun for 352.2 MHz, 100 kW (CW) power klystron Abstract: Conventional klystrons using single beam of electrons have several limitations for increasing of beam voltage or current which can be overcome using multiple electron beams. The paper presents the design of a single beam electron gun for a practical 100 kW CW conventional klystron and then translation of the design into a five-beam gun for reducing operating voltage and overall improvement in tube performance. The design parameters of multi beam electron gun have been derived from existing single beam parameters using some scaling laws, and are further optimized through CST Particle Studio. The simulation results of CST have been cross-validated using Opera-3D code. The electron gun is currently under development. Journal: Journal of Electromagnetic Waves and Applications Pages: 306-318 Issue: 3 Volume: 32 Year: 2018 Month: 2 X-DOI: 10.1080/09205071.2017.1381648 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1381648 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:3:p:306-318 Template-Type: ReDIF-Article 1.0 Author-Name: Xiaodong Qu Author-X-Name-First: Xiaodong Author-X-Name-Last: Qu Author-Name: Bing Xue Author-X-Name-First: Bing Author-X-Name-Last: Xue Author-Name: Guangyou Fang Author-X-Name-First: Guangyou Author-X-Name-Last: Fang Title: The propagation model and characteristics for extremely low frequency electromagnetic wave in Earth-ionosphere system and its application in geophysics prospecting Abstract: This paper employs the finite-difference time-domain method (FDTD) to model and study the propagation characteristics and distribution features for extremely low frequency (ELF) in Earth-ionosphere (EI) system. For electromagnetic pulse source whose bandwidth is 10 Hz, the ELF electromagnetic wave forms standing wave. When the bandwidth is 100 Hz, there exists 180° phase reversals. Due to EI system, the electromagnetic field generated by horizontal dipole antenna is mainly vertical electric field and horizontal magnetic field when the receiver is away from the source antenna and locates on the surface of the earth. The distribution is mainly determined by the polarization direction of the source antenna other than the topographic feature and the conductivity. The ELF electromagnetic field can be used as incident field to detect conductivity anomaly underground. Thus, this paper may provide valuable information for long distance and large-scale underground detection, showing potential applications in geophysics prospecting. Journal: Journal of Electromagnetic Waves and Applications Pages: 319-331 Issue: 3 Volume: 32 Year: 2018 Month: 2 X-DOI: 10.1080/09205071.2017.1383194 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1383194 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:3:p:319-331 Template-Type: ReDIF-Article 1.0 Author-Name: Mstislav E. Kaliberda Author-X-Name-First: Mstislav E. Author-X-Name-Last: Kaliberda Author-Name: Leonid M. Lytvynenko Author-X-Name-First: Leonid M. Author-X-Name-Last: Lytvynenko Author-Name: Sergey A. Pogarsky Author-X-Name-First: Sergey A. Author-X-Name-Last: Pogarsky Title: Singular integral equations in diffraction problem by an infinite periodic strip grating with one strip removed: E–polarization case Abstract: The E- polarized plane wave diffraction by the infinite periodic grating with removed strip is considered. The scattered field is represented as a sum of the field of the infinite periodic grating and the field of the correction currents excited due to extraction of a single strip. The problem is reduced to the dual integral equations relatively unknown spectral function of the correction field. After differentiation of these equations the singular integral equation with additional conditions with respect to the correction current density is obtained. For comparison, the single mode current approximation model is also presented. The currents on the strips and far-field distribution of correction current are analyzed. Journal: Journal of Electromagnetic Waves and Applications Pages: 332-346 Issue: 3 Volume: 32 Year: 2018 Month: 2 X-DOI: 10.1080/09205071.2017.1383943 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1383943 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:3:p:332-346 Template-Type: ReDIF-Article 1.0 Author-Name: A. F. Coşkun Author-X-Name-First: A. F. Author-X-Name-Last: Coşkun Author-Name: O. Karabayır Author-X-Name-First: O. Author-X-Name-Last: Karabayır Author-Name: H. A. Serim Author-X-Name-First: H. A. Author-X-Name-Last: Serim Title: A statistical-based examination on wind turbines’ bi-static scatterings at 1 GHz frequency Abstract: This paper aims to introduce a statistical modeling approach for wind turbines’ (WTs) bi-static scattering characteristics in free-space environments. By using the analytical signal model proposed in the literature for the complex bi-static scattering of WTs, the statistical features of the long-term magnitude and phase variation for different bi-static scenarios (i.e. several discrete receiver locations for a fixed-point transmitter) are characterized with the help of the distribution-fitting process for several probability densities via maximum-likelihood estimation. The results of distribution-fitting process are interpreted with the help of goodness-of-fit considerations such as minimum square error, Kolmogorov–Smirnov Test, Kuiper’s V Test, and Watson’s U2$ U^2 $ Test, in order to qualify the suitability of each considered probability density. Moreover, by carrying out the examination by including a polynomial series approximation approach on the estimated parameters of two best-matching densities (i.e. α$ \alpha $-stable and Student’s t), the outputs are rendered as to be valid for any receiver locations. In addition to the insightful outcomes and conclusions for the considered electronic system scenario including the operating frequency (i.e. 1 GHz) and orientations, the investigation presented in this paper also introduces a simple, fast-responding methodology of data pool generation, distribution-fitting and performance assessment for the WTs’ bi-static scattering effects. Journal: Journal of Electromagnetic Waves and Applications Pages: 347-362 Issue: 3 Volume: 32 Year: 2018 Month: 2 X-DOI: 10.1080/09205071.2017.1391127 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1391127 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:3:p:347-362 Template-Type: ReDIF-Article 1.0 Author-Name: Debidas Kundu Author-X-Name-First: Debidas Author-X-Name-Last: Kundu Author-Name: Rintu Kumar Gayen Author-X-Name-First: Rintu Kumar Author-X-Name-Last: Gayen Author-Name: Akhilesh Mohan Author-X-Name-First: Akhilesh Author-X-Name-Last: Mohan Author-Name: Ajay Chakrabarty Author-X-Name-First: Ajay Author-X-Name-Last: Chakrabarty Title: Moment method analysis of periodic array of thin conducting strips using waveguide simulator Abstract: In this paper, analysis of free-standing periodic array of thin conducting strips using waveguide simulator is presented. The method of moment is applied to numerically obtain its scattering parameters. With only two elements inside the waveguide simulator, scattering response of the infinite array illuminated by plane waves is accurately achieved. Coupled integral equations, due to the presence of two elements, are solved using pulse expansion and point matching technique. Numerically obtained results are compared with waveguide and plane wave simulations in CST MWS and measurement results for validation. Journal: Journal of Electromagnetic Waves and Applications Pages: 363-370 Issue: 3 Volume: 32 Year: 2018 Month: 2 X-DOI: 10.1080/09205071.2017.1391128 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1391128 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:3:p:363-370 Template-Type: ReDIF-Article 1.0 Author-Name: Takashi Tanaka Author-X-Name-First: Takashi Author-X-Name-Last: Tanaka Title: Numerical methods for free electron laser simulations Abstract: The free electron laser (FEL) is a new type of coherent light source, which is based on amplification of radiation by a high-energy electron beam generated in an electron accelerator. The lasing mechanism of FELs is completely different from that of conventional optical lasers and it has nothing to do with quantum physics, and can be purely described by classical electrodynamics. Even though there are several analytical formulas to describe the amplification process in FELs, we usually need to perform numerical simulations to precisely quantify the light source performances available in FELs under practical conditions. In this paper, numerical methods for such FEL simulations are reviewed, especially focusing on how to improve the computational efficiency, together with a number of practical examples. Journal: Journal of Electromagnetic Waves and Applications Pages: 371-401 Issue: 3 Volume: 32 Year: 2018 Month: 2 X-DOI: 10.1080/09205071.2017.1399830 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1399830 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:3:p:371-401 Template-Type: ReDIF-Article 1.0 Author-Name: Denghui Huang Author-X-Name-First: Denghui Author-X-Name-Last: Huang Author-Name: Hu Yang Author-X-Name-First: Hu Author-X-Name-Last: Yang Author-Name: Yuqing Wu Author-X-Name-First: Yuqing Author-X-Name-Last: Wu Author-Name: Fei Zhao Author-X-Name-First: Fei Author-X-Name-Last: Zhao Author-Name: Xiang Liu Author-X-Name-First: Xiang Author-X-Name-Last: Liu Title: A high-gain antipodal Vivaldi antenna with multi-layer planar dielectric lens Abstract: A high-gain antipodal Vivaldi antenna with multi-layer planar dielectric lens (AVA-MPDL) is proposed. Compared to the conventional AVA design, the gain of the antenna has been greatly improved by applying the MPDL in front of the antenna’s aperture at the upper working frequencies. Additionally, beam-tilting in E-plane at higher frequencies has also been overcome. The modified antenna has been fabricated and measured, the measurement results show that the frequency band for S11 < −10 dB is from 1.3 to more than 30 GHz, and it is in good agreement with the simulated ones. Gain of the antenna has been improved by the MPDL lens in a wide frequency band (4–27 GHz) and the gain up to 16 dB at higher frequencies. Journal: Journal of Electromagnetic Waves and Applications Pages: 403-412 Issue: 4 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1393350 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1393350 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:4:p:403-412 Template-Type: ReDIF-Article 1.0 Author-Name: Son Xuat Ta Author-X-Name-First: Son Xuat Author-X-Name-Last: Ta Author-Name: Quang Son Ho Author-X-Name-First: Quang Son Author-X-Name-Last: Ho Author-Name: Khac Kiem Nguyen Author-X-Name-First: Khac Kiem Author-X-Name-Last: Nguyen Author-Name: Chien Dao-Ngoc Author-X-Name-First: Chien Author-X-Name-Last: Dao-Ngoc Title: Single-dipole antenna on a metasurface for broadband circularly polarized radiation Abstract: This paper investigates a low-profile broadband circularly polarized (CP) antenna, which is composed of a single-dipole on a metasurface. Surface waves propagating on the metasurface are excited to generate extra-resonances for the antenna system, which are utilized to broaden the antenna bandwidth. The metasurface, which is a lattice of 5 × 5 truncated-corner square patches, is used for converting the linearly polarized wave from the dipole source to CP wave at the broadside. A prototype operating at the frequency of about 2.4 GHz is designed, fabricated, and tested. For an easy realization and a low-cost, the dipole and metasurface are printed on top and bottom sides of a single substrate, respectively, which is placed above the ground plane via a structural-foam. The final design, with an overall size of 100 mm × 100 mm × 14.2 mm (0.8λo × 0.8λo × 0.114λo at 2.4 GHz), resulted in a |S11| < –10 dB bandwidth of 2.0–2.72 GHz (27.6%) and a 3-dB axial ratio bandwidth of 2.3–2.8 GHz (19.6%). In addition, the antenna yielded a broadside right-hand CP radiation with a peak gain of 8.67 dBic and radiation efficiency of >93% within the operational bandwidth. Journal: Journal of Electromagnetic Waves and Applications Pages: 413-427 Issue: 4 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1394224 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1394224 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:4:p:413-427 Template-Type: ReDIF-Article 1.0 Author-Name: Zhengbin Xu Author-X-Name-First: Zhengbin Author-X-Name-Last: Xu Author-Name: Jie Xu Author-X-Name-First: Jie Author-X-Name-Last: Xu Author-Name: Yinjie Cui Author-X-Name-First: Yinjie Author-X-Name-Last: Cui Author-Name: Jian Guo Author-X-Name-First: Jian Author-X-Name-Last: Guo Author-Name: Cheng Qian Author-X-Name-First: Cheng Author-X-Name-Last: Qian Title: A low-cost W-band SPDT switch with Q-MMIC concept using quartz substrate Abstract: In this paper, a high-performance PIN diode single-pole-double-throw (SPDT) switch for W-band application is developed. By employing quasi-monolithic millimeter-wave integrated circuit (Q-MMIC) technology, the cost of the switch is significantly reduced while maintaining performance and size with conventional MMIC counterpart. A 3-D PIN diode model is used to describe the diode characteristic under both forward and reverse biasing states. In order to alleviate parasitic parameters effect on performance of the switch, compensation structures are analyzed and adopted. The measurement results show the insertion loss is less than 2 dB from 82 to 100 GHz and the isolation is greater than 32 dB from 82 to 105 GHz. The total size of the SPDT switch is 2.1 mm × 4.3 mm. Journal: Journal of Electromagnetic Waves and Applications Pages: 428-438 Issue: 4 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1394915 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1394915 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:4:p:428-438 Template-Type: ReDIF-Article 1.0 Author-Name: Richards Joe Stanislaus Author-X-Name-First: Richards Joe Author-X-Name-Last: Stanislaus Author-Name: Naveen Babu Gnanamoorthi Author-X-Name-First: Naveen Babu Author-X-Name-Last: Gnanamoorthi Title: Large-signal field analysis of a linear beam travelling wave tube amplifier for the anisotropically conducting tape helix slow-wave structure supported by dielectric rods Abstract: The large-signal behavior of traveling wave tube amplifier for a linear beam dielectric loaded anisotropically conducting tape helix slow wave structure (SWS) is realized through a swift and reliable field analysis. Using Green’s function sequence, the field components in the SWS are designated as nonlinear functionals of electron arrival time. The electron arrival time in the beam region is formulated into a nonlinear operator in the Banach space mapping form by substituting the axial electric field component into the electron ballistic equation. The nonlinear beam–wave interaction is then obtained by determining the electron arrival time through extensive successive approximations, and thus exact electric and magnetic field components in the tape helix SWS are attained. The numerical computation of the proposed model yields definitive analytical results for the electron exit velocity, induced surface current density, power gain, conversion efficiency, and optimum interaction length. Journal: Journal of Electromagnetic Waves and Applications Pages: 439-470 Issue: 4 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1394916 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1394916 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:4:p:439-470 Template-Type: ReDIF-Article 1.0 Author-Name: Li Chen Author-X-Name-First: Li Author-X-Name-Last: Chen Author-Name: Henghui Yin Author-X-Name-First: Henghui Author-X-Name-Last: Yin Author-Name: Lin Chen Author-X-Name-First: Lin Author-X-Name-Last: Chen Author-Name: Yiming Zhu Author-X-Name-First: Yiming Author-X-Name-Last: Zhu Title: Ultra-sensitive fluid fill height sensing based on spoof surface plasmon polaritons Abstract: We analyzed fluid fill height sensing supported by terahertz spoof surface plasmon polaritons (SPPs). The existence of spoof SPPs was proved experimentally and was discussed from perspective of dispersion and field distribution. For the application, we designed a fluid fill height sensor based on spoof SPPs, which is much more sensitive than previous work based on parallel plate waveguide (PPWG). For example, resonant shift of spoof SPPs is almost four times larger than the shift of PPWG at the height of 250 μm. This fluid fill height sensor calibrated the fluid volume in grooves, which contributes to improving the accuracy of high refractive index sensing. The experiment is in good agreement with simulation. Such proposed fluid height sensor has another advantage of being suitable for the fluid with refractive index higher than prism, which further benefits spoof SPPs refractive index sensing, such as blood detection in future. Journal: Journal of Electromagnetic Waves and Applications Pages: 471-482 Issue: 4 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1395367 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1395367 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:4:p:471-482 Template-Type: ReDIF-Article 1.0 Author-Name: Krzysztof A. Michalski Author-X-Name-First: Krzysztof A. Author-X-Name-Last: Michalski Author-Name: Hung-I Lin Author-X-Name-First: Hung-I Author-X-Name-Last: Lin Title: On the Sommerfeld half-space problem: appraisal of approximate solutions with extensions to plasmonics Abstract: The classical Sommerfeld problem of a vertical electric dipole radiating over an imperfectly conducting half-space is revisited. Two variants of the modified saddle-point integration method are employed to derive new, closed-form, second-order approximations of the far-zone electromagnetic fields. The new formulas are applied to compute radiation patterns and surface fields for sample problems including both ordinary and plasmonic media, and their accuracy is assessed by comparison with the results of rigorous numerical evaluation of the Sommerfeld integrals. Journal: Journal of Electromagnetic Waves and Applications Pages: 483-503 Issue: 4 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1395368 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1395368 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:4:p:483-503 Template-Type: ReDIF-Article 1.0 Author-Name: Min-Jie Dong Author-X-Name-First: Min-Jie Author-X-Name-Last: Dong Author-Name: Shou-Fu Tian Author-X-Name-First: Shou-Fu Author-X-Name-Last: Tian Author-Name: Xue-Wei Yan Author-X-Name-First: Xue-Wei Author-X-Name-Last: Yan Author-Name: Li Zou Author-X-Name-First: Li Author-X-Name-Last: Zou Author-Name: Tian-Tian Zhang Author-X-Name-First: Tian-Tian Author-X-Name-Last: Zhang Title: Bright-dark solitary waves, complexitons, Guassian solitons, and traveling wave solitons of the second-order non-linear Schrödinger equation with spatial and temporal dispersion Abstract: In this paper, we consider the non-linear Schrödinger equation in fibers with the presence of group velocity dispersion, selfphase modulation and second-order dispersion terms. Using the ansatz method, we derive its bright, dark, complexitons, Gaussian, and traveling wave solitons, respectively. Moreover, we provide the graphical analysis of some solutions in order to better understand their dynamical behavior. Journal: Journal of Electromagnetic Waves and Applications Pages: 504-515 Issue: 4 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1398684 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1398684 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:4:p:504-515 Template-Type: ReDIF-Article 1.0 Author-Name: A. Massa Author-X-Name-First: A. Author-X-Name-Last: Massa Author-Name: G. Oliveri Author-X-Name-First: G. Author-X-Name-Last: Oliveri Author-Name: M. Salucci Author-X-Name-First: M. Author-X-Name-Last: Salucci Author-Name: N. Anselmi Author-X-Name-First: N. Author-X-Name-Last: Anselmi Author-Name: P. Rocca Author-X-Name-First: P. Author-X-Name-Last: Rocca Title: Learning-by-examples techniques as applied to electromagnetics Abstract: There is a wide number of problems in electromagnetic (EM) engineering that require a real-time response or in which the input–output relationship is not a-priori known or cannot be defined due to the complexity of the scenario at hand. These issues have induced researchers toward the development and application of Learning-by-Examples (LBE) techniques thanks to their extremely high computational efficiency and to their capability to emulate the behavior of complex systems on the basis of a set of collected examples. In this framework, this paper aims to present an overview of the state-of-the-art and recently developed LBE-based strategies as applied to the solution of engineering problems in the field of Electromagnetics. Starting from a general and basic introduction to LBE techniques, the most popular LBE methods used in EM engineering will be re-called. Afterwards, a review on how the LBE methodologies have been applied by various researchers in different application contexts, including among others antennas, microwave circuits, inverse scattering and remote sensing, will be given. Finally, current research trends and envisaged developments are discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 516-541 Issue: 4 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1402713 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1402713 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:4:p:516-541 Template-Type: ReDIF-Article 1.0 Author-Name: A. Mercy Latha Author-X-Name-First: A. Mercy Author-X-Name-Last: Latha Author-Name: Vishant Gahlaut Author-X-Name-First: Vishant Author-X-Name-Last: Gahlaut Author-Name: S. K. Ghosh Author-X-Name-First: S. K. Author-X-Name-Last: Ghosh Title: A model for quick thermal prediction of multi-stage depressed collector Abstract: Multi-stage depressed collectors (MDCs) aid in efficiency enhancement of travelling-wave tubes (TWTs) by recovering the unused energy from the spent electron beam. Evaluation of the thermal performance of a MDC is crucial for an optimal design. Although several commercial software tools are readily available for performing the thermal analysis, (1) they are time-consuming and (2) the final results depend largely on few critical parameters (like thermal contact resistances at various joints, convection heat transfer coefficient, etc.). Hence, here a simple analytical model has been developed for quick prediction of the worst-case thermal behaviour of the MDC. Brazing non-uniformities that arise in any practical scenario have been taken into consideration in terms of their thermal contact resistances. Moreover, any cooling mechanism used, either convection or radiation, can also be correspondingly incorporated. Analytical results obtained from the model have been validated with simulated and experimental results. This model also aids in accurate calculation of few vital input parameters required for performing simulation with commercial software tools. Journal: Journal of Electromagnetic Waves and Applications Pages: 543-553 Issue: 5 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1399831 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1399831 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:5:p:543-553 Template-Type: ReDIF-Article 1.0 Author-Name: E. N. Baikova Author-X-Name-First: E. N. Author-X-Name-Last: Baikova Author-Name: L. Romba Author-X-Name-First: L. Author-X-Name-Last: Romba Author-Name: S. S. Valtchev Author-X-Name-First: S. S. Author-X-Name-Last: Valtchev Author-Name: R. Melicio Author-X-Name-First: R. Author-X-Name-Last: Melicio Author-Name: V. Fernão Pires Author-X-Name-First: V. Author-X-Name-Last: Fernão Pires Author-Name: A. Krusteva Author-X-Name-First: A. Author-X-Name-Last: Krusteva Author-Name: G. Gigov Author-X-Name-First: G. Author-X-Name-Last: Gigov Title: Electromagnetic field generated by a wireless energy transfer system: comparison of simulation to measurement Abstract: This paper presents a wireless energy transfer system operating at the frequency values of kHz order: modeling, simulation, and comparison with prototype measurement results. Wireless energy transfer system model using finite element method was carried out to simulate the electric field and the magnetic flux density for different air gap sizes between the transmitter and the receiver coils. Results are presented and compared with the electromagnetic emission measurements radiated by the wireless energy transfer system prototype. The electric field comparison between the simulated and the prototype measurement values shows an error of roughly 8.7%. In the recent years, the interest in the wireless energy transfer technology, especially for electric vehicles batteries charging, is rapidly increasing. As a result of the increasing application of this technology in the industrial and consumer electronic products, more concerns are raised about the electromagnetic compatibility, since the wireless energy transfer systems produce electromagnetic emissions in the surrounding environment. Journal: Journal of Electromagnetic Waves and Applications Pages: 554-571 Issue: 5 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1399832 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1399832 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:5:p:554-571 Template-Type: ReDIF-Article 1.0 Author-Name: Ignacio Rodríguez-Rodríguez Author-X-Name-First: Ignacio Author-X-Name-Last: Rodríguez-Rodríguez Author-Name: José-Víctor Rodríguez Author-X-Name-First: José-Víctor Author-X-Name-Last: Rodríguez Author-Name: Concepción Sanchis-Borrás Author-X-Name-First: Concepción Author-X-Name-Last: Sanchis-Borrás Title: On the impact of the type of wave incidence in multiple-cylinder diffraction analysis at millimeter-wave frequencies Abstract: A comparison of plane against spherical-wave incidence consideration in multiple-cylinder diffraction analysis is performed, at several millimeter-wave frequencies, in order to clarify the margin in which both incidence results converge or differ. The mentioned comparison is carried out through a pair of two-dimensional (2D) hybrid uniform theory of diffraction-physical optics (UTD-PO) solutions (the plane-wave formulation for cylinders is firstly proposed in this work), and is intended to show the validity of each wave-incidence assumption in environments where millimeter or sub-millimeter-wave bands are being employed. In this sense, results can be used to achieve a more accurate and realistic planning of such radio communication systems when multiple-diffraction over rounded obstacles has to be considered (e.g. communication systems operating in stadiums). Journal: Journal of Electromagnetic Waves and Applications Pages: 572-578 Issue: 5 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1399833 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1399833 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:5:p:572-578 Template-Type: ReDIF-Article 1.0 Author-Name: DongFeng Ji Author-X-Name-First: DongFeng Author-X-Name-Last: Ji Author-Name: Bo Zhang Author-X-Name-First: Bo Author-X-Name-Last: Zhang Author-Name: JunLong Wang Author-X-Name-First: JunLong Author-X-Name-Last: Wang Author-Name: Dong Xing Author-X-Name-First: Dong Author-X-Name-Last: Xing Author-Name: Yong Fan Author-X-Name-First: Yong Author-X-Name-Last: Fan Author-Name: XiaoDong Chen Author-X-Name-First: XiaoDong Author-X-Name-Last: Chen Title: Wide stopband millimeter/terahertz lowpass filter using improved split ring resonator Abstract: In this paper, an improved split-ring resonator (ISRR) cell is proposed to realize wide stopband and miniaturization. This cell comprises a transverse microstrip branch in middle and two gaps on both sides with tapped-line input and output. The transmission coefficient is derived for ISRR based on the distributed circuit theory and odd-even mode theory. Then the novel low-pass filter (LPF) is designed by cascading several ISRR cells in terahertz and millimeter. The ISRR LPF possesses great characteristics such as wide stopband, deep transmission zeros and small size. Finally, the proposed filter was processed and tested in millimeter. The measured results show that the proposed filter has low insertion loss from 0.5 to 0.7 dB in U-band and a stopband inhibition at 31.7 dB in 110 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 579-590 Issue: 5 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1400472 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1400472 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:5:p:579-590 Template-Type: ReDIF-Article 1.0 Author-Name: Tatjana Gric Author-X-Name-First: Tatjana Author-X-Name-Last: Gric Author-Name: Ortwin Hess Author-X-Name-First: Ortwin Author-X-Name-Last: Hess Title: Surface waves supported by the nanostructured semiconductor metamaterials Abstract: We discover a new kind of surface wave on semiconductor nanostructured metamaterial, which crosses the light line with a substantial portion at lower frequencies lying above the free space light line. Interestingly, the propagation of such surface wave is found to be sensitive to the parameters of the semiconductor. Furthermore, the Ferrel-Berreman modes are observed under the certain conditions, opening a gateway toward device fabrications. Journal: Journal of Electromagnetic Waves and Applications Pages: 591-600 Issue: 5 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1400473 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1400473 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:5:p:591-600 Template-Type: ReDIF-Article 1.0 Author-Name: Zhenyu Guo Author-X-Name-First: Zhenyu Author-X-Name-Last: Guo Author-Name: Tao Yang Author-X-Name-First: Tao Author-X-Name-Last: Yang Title: A novel compact Wilkinson power divider with controllable harmonic suppression and simple structure Abstract: In this paper, based on the equivalent circuit of spiral-shaped CPW resonators, a novel compact cascaded inhomogeneous coupled-line (CIHCL) with two tunable transmission zeros is proposed to replace the quarter-wavelength microstrip line of the conventional power divider (CPD). The modified power divider with CIHCL could achieve the same frequency responses of CPD and also realize controllable harmonic suppression with compact size. To verify the expected results, two power dividers with different harmonic suppression ratios are designed and one of them is fabricated to demonstrate the performances of the proposed power divider. The simulated and measured results illustrate that the return loss and isolation at center frequency 3 GHz are better than 25 dB and the insert loss is better than 0.4 dB. In addition, about 30 dB suppression for second and third harmonic is achieved. Journal: Journal of Electromagnetic Waves and Applications Pages: 601-608 Issue: 5 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1400926 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1400926 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:5:p:601-608 Template-Type: ReDIF-Article 1.0 Author-Name: Luhang Jiang Author-X-Name-First: Luhang Author-X-Name-Last: Jiang Author-Name: Jianhong Hao Author-X-Name-First: Jianhong Author-X-Name-Last: Hao Author-Name: Yanfei Gong Author-X-Name-First: Yanfei Author-X-Name-Last: Gong Title: Electromagnetic coupling to an apertured enclosure via a penetrated transmission line based on electromagnetic topology Abstract: An efficient analytical model based on electromagnetic topology (EMT) has been developed for predicting the electromagnetic (EM) field coupling to a rectangular enclosure with an electrically large aperture via a penetrated transmission line (TL), excited by an external plane wave of oblique incidence. First, the electric field in the enclosure is calculated based on the modified Bethe’s small holes theory and mirror procedure. Then, the topology networks of the EM interaction are constructed by analyzing the coupling paths and mechanism, and the electric current induced at the termination loads of the TL is obtained using the generalized Baum–Liu–Tesche equation combined with the Agrawal’s model. The analytical model has been successfully verified by the finite difference time domain method over a wide frequency band of 0.5~3 GHz, which consumes less time than numerical methods. Finally, the analytical model is employed to analyze the effect of various parameters on the induced current, including the length, the height, and the direction of the line. Journal: Journal of Electromagnetic Waves and Applications Pages: 609-623 Issue: 5 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1401489 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1401489 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:5:p:609-623 Template-Type: ReDIF-Article 1.0 Author-Name: Linwen Jiang Author-X-Name-First: Linwen Author-X-Name-Last: Jiang Author-Name: Shanshan Yang Author-X-Name-First: Shanshan Author-X-Name-Last: Yang Author-Name: Anhua Wu Author-X-Name-First: Anhua Author-X-Name-Last: Wu Author-Name: Jinjun Liu Author-X-Name-First: Jinjun Author-X-Name-Last: Liu Author-Name: Hongbing Chen Author-X-Name-First: Hongbing Author-X-Name-Last: Chen Title: The matching design of electromagnetic parameters for obtaining excellent microwave-absorption properties by numerical simulation method Abstract: Currently, most of microwave-absorption work has focused on the theoretical formula and design rules of microwave absorber in broadband absorption at low frequencies, especially below 6 GHz. In this work, the detailed matching relation of complex permeability, permittivity, absorber thickness, and microwave-absorption properties were studied by setting up the numerical simulation program of microwave absorption according to the transmission-line theory based on cyclic algorithms. By which, the reason why most materials possess weak microwave-absorption performances below 6 GHz was explained, and the methods how to design desired absorbers utilizing the matching relation were also introduced. The concept presented here is suitable and applicable for a tuned microwave-absorber, which is useful while designing a low frequency absorber. Journal: Journal of Electromagnetic Waves and Applications Pages: 624-634 Issue: 5 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1401490 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1401490 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:5:p:624-634 Template-Type: ReDIF-Article 1.0 Author-Name: Bhagirath Sahu Author-X-Name-First: Bhagirath Author-X-Name-Last: Sahu Author-Name: Soni Singh Author-X-Name-First: Soni Author-X-Name-Last: Singh Author-Name: Manoj Kumar Meshram Author-X-Name-First: Manoj Kumar Author-X-Name-Last: Meshram Author-Name: S. P. Singh Author-X-Name-First: S. P. Author-X-Name-Last: Singh Title: Super-compact ultra-wideband microstrip band-pass filter with improved performance using defected ground structure-based low-pass filter Abstract: A super-compact ultra-wideband (UWB) microstrip band-pass filter (BPF) with good selectivity and wide stopband is proposed in this paper. The super-compactness along with wide stopband of the proposed filter is achieved by integrating modified multimode resonator-based UWB BPF and defected ground structure (DGS)-based compact low-pass filter (LPF). The LPF structure is designed using four non-uniform configurations of DGS units along with a 50 Ω microstrip line. Each DGS unit is formed by cascading three isosceles U-shaped DGSs. Further, an equivalent RLC circuit model of the LPF is proposed to validate the numerical simulation and experimental results of LPF. The proposed filter has simulated passband frequency range 3–11 GHz with wide stopband: attenuation better than 40 dB and 25 dB over the frequency ranges 11.7–20.5 GHz and 11.2–30 GHz respectively. The experimental results for the proposed filter are nearly in agreement with corresponding numerical simulation results. Journal: Journal of Electromagnetic Waves and Applications Pages: 635-650 Issue: 5 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1402712 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1402712 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:5:p:635-650 Template-Type: ReDIF-Article 1.0 Author-Name: Wei Li Author-X-Name-First: Wei Author-X-Name-Last: Li Author-Name: Zhongyin Xiao Author-X-Name-First: Zhongyin Author-X-Name-Last: Xiao Author-Name: Xinyan Ling Author-X-Name-First: Xinyan Author-X-Name-Last: Ling Author-Name: Xiaoxia Zheng Author-X-Name-First: Xiaoxia Author-X-Name-Last: Zheng Author-Name: Chuan Li Author-X-Name-First: Chuan Author-X-Name-Last: Li Author-Name: Huanling Zou Author-X-Name-First: Huanling Author-X-Name-Last: Zou Title: Design of a broadband, wide-angle metamaterial absorber base on hybrid structure Abstract: In this paper, we presented and investigated a special metamaterial absorber to achieve broadband absorption. Firstly, we proposed a two-dimensional (2D) structure, which include a hybrid layer on the top, a dielectric layer in the middle, and a metal ground on the bottom. By the hybrid design on the top layer of the absorber, we achieved broadband absorption. The relative bandwidth is 22.57%. Furthermore, in order to improve the absorption bandwidth, we changed the absorber as a three-dimensional (3D) structure. The simulated results show that the absorber can be obtained a broadband absorption, the relative bandwidth up to 82.93%. Compared to the two-dimensional structure, it is clear that the three-dimensional structure has a better absorption. According to the effective medium theory, the relative impedance is calculated to explain the absorption mechanism. Finally, we believe it will have many potential applications in sensing, energy harvest and so on. Journal: Journal of Electromagnetic Waves and Applications Pages: 651-660 Issue: 5 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1403379 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1403379 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:5:p:651-660 Template-Type: ReDIF-Article 1.0 Author-Name: BaoLiang Hao Author-X-Name-First: BaoLiang Author-X-Name-Last: Hao Author-Name: Li Zheng Author-X-Name-First: Li Author-X-Name-Last: Zheng Author-Name: YanYan Tian Author-X-Name-First: YanYan Author-X-Name-Last: Tian Author-Name: BaoCheng Sun Author-X-Name-First: BaoCheng Author-X-Name-Last: Sun Author-Name: XiaoMeng Yang Author-X-Name-First: XiaoMeng Author-X-Name-Last: Yang Author-Name: Ning Chen Author-X-Name-First: Ning Author-X-Name-Last: Chen Author-Name: JinJun Feng Author-X-Name-First: JinJun Author-X-Name-Last: Feng Title: Millimeter wave helix TWTs’ development for ECM and communication Abstract: A series of studies of high-power millimeter-wave Traveling wave tubes (TWTs) for electronic countermeasure (ECM) and communication have been conducted in recent years. The helix TWTs with wide bandwidth and high efficiency can produce output power of over 150 W in the frequency range of 18–26.5 GHz and output power of over 120 W from 26.5 to 40 GHz. The mini-TWTs can produce a stable RF output power of over 40 W in the frequency range of 30–37 GHz. The communication TWTs can produce output power of over 250 W covering 27.5–31 GHz with good linearity and output power of 100 W covering 40–47 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 661-669 Issue: 5 Volume: 32 Year: 2018 Month: 3 X-DOI: 10.1080/09205071.2017.1406825 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1406825 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:5:p:661-669 Template-Type: ReDIF-Article 1.0 Author-Name: Christos I. Salis Author-X-Name-First: Christos I. Author-X-Name-Last: Salis Author-Name: Theodoros T. Zygiridis Author-X-Name-First: Theodoros T. Author-X-Name-Last: Zygiridis Title: An unconditionally stable technique for uncertainty assessment in random media based on the ADI scheme Abstract: Stochastic media problems present a severe impact on the properties of the electromagnetic fields that usually deterministic methods tend to overlook. In this paper, we present a finite-difference time-domain (FDTD) technique, which is free from time step restrictions and manages to efficiently calculate the statistics of the involved fields in one realization. The proposed algorithm is a variation of the Stochastic FDTD method and exhibits satisfactory outcomes in high density grids. Numerical results verify the validity of our scheme compared to other methods, such as the Stochastic FDTD and the Monte Carlo techniques. Journal: Journal of Electromagnetic Waves and Applications Pages: 671-684 Issue: 6 Volume: 32 Year: 2018 Month: 4 X-DOI: 10.1080/09205071.2017.1403961 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1403961 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:6:p:671-684 Template-Type: ReDIF-Article 1.0 Author-Name: Xuan Xiong Author-X-Name-First: Xuan Author-X-Name-Last: Xiong Author-Name: Bingo Wing-Kuen Ling Author-X-Name-First: Bingo Wing-Kuen Author-X-Name-Last: Ling Author-Name: Haiyan Zhang Author-X-Name-First: Haiyan Author-X-Name-Last: Zhang Author-Name: Guangchi Zhang Author-X-Name-First: Guangchi Author-X-Name-Last: Zhang Title: Coplanar waveguide fed multiple input multiple output antenna with higher isolation and multi-sense circular polarization Abstract: A coplanar waveguide (CPW)-fed multiple input multiple output (MIMO) antenna with higher isolation and multi-bandwidth circular polarization (CP) is presented. This antenna covers the impedance operations from 2.2 to 6.8 GHz with |S11|$ |{{S}}_{11} | $ < −10 dB, |S21|$ |{{S}}_{21} | $ < −14 dB and |S22|$ |{{S}}_{22} | $ < −10 dB. Employing two orthogonally placed T-shaped patches (TSP) and three L-shaped parasitic patches (LSPP) in the ground, the dual sense CP in the frequency band between 2.28 and 3.48 GHz (42.5%) and meanwhile between 6.03 and 6.28 GHz (4.1%) can be achieved when the left port (port_1) is excited, while the down port (port_2) is terminated by a 50 Ω load. When Port_2 is excited and port_1 is terminated by a 50 Ω load, the CP of the antenna in frequency band from 1.75 to 2.1 GHz (18.2%). On the other hand, CP from 4 to 4.47 GHz (11.1%) and 5.1 to 5.22 GHz (2.3%) can be obtained while both ports are excited. The CP frequency band covers the frequency bands for LTE (between 1.71 and 2.17 GHz), the WCDMA (between 1.92 and 2.17 GHz), the WiMax (between 2.3 and 2.5 GHz) and the WLAN. Meanwhile, the slot between these two TSP in the ground enhances the isolation of the proposed antenna. The measured and the simulated results are agreed with each other. Journal: Journal of Electromagnetic Waves and Applications Pages: 685-694 Issue: 6 Volume: 32 Year: 2018 Month: 4 X-DOI: 10.1080/09205071.2017.1403962 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1403962 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:6:p:685-694 Template-Type: ReDIF-Article 1.0 Author-Name: J. F. Gómez-Aguilar Author-X-Name-First: J. F. Author-X-Name-Last: Gómez-Aguilar Title: Analytical and numerical solutions of the telegraph equation using the Atangana–Caputo fractional order derivative Abstract: This paper describes the telegraph equation using the Atangana–Caputo’s fractional derivative with two fractional orders α$ \alpha $ and β$ \beta $. The new definition is based on the concept of the power law and the generalized Mittag-Leffler function. The first order of the derivative equation was included in the power law function and the second was included in the generalized Mittag-Leffler function. This approach considers media which have two different properties. The fractional spatial derivative equation and the fractional temporal derivative equation were analyzed separately. The generalization of these equations exhibit different cases of anomalous behavior. Numerical solutions using an iterative scheme were obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 695-712 Issue: 6 Volume: 32 Year: 2018 Month: 4 X-DOI: 10.1080/09205071.2017.1403963 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1403963 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:6:p:695-712 Template-Type: ReDIF-Article 1.0 Author-Name: Gholamhosein Moloudian Author-X-Name-First: Gholamhosein Author-X-Name-Last: Moloudian Author-Name: Massoud Dousti Author-X-Name-First: Massoud Author-X-Name-Last: Dousti Author-Name: Asghar Ebrahimi Author-X-Name-First: Asghar Author-X-Name-Last: Ebrahimi Title: Design and fabrication of a compact microstrip low-pass filter with ultra-wide stopband and sharp roll-off-rate Abstract: Microstrip low-pass filters (LPFs) with good performance are used in most telecommunication systems. In this study, a modified T-shaped hairpin resonator is used to design LPF, and suppression cells are used to improve the performance of the filter in the stopband up to 22 GHz. The proposed LPF had a -3 dB cut-off frequency of 1.89 GHz. The proposed LPF is designed, fabricated and measured. The simulated and measured results for the proposed LPF are in good agreement with each other. Attenuation in the stopband is 34 dB, which is an extremely large number. Roll-off-rate (ROF or ζ) parameter is sharp and equal to 96.3 dB/GHz. The group delay in the passband is almost constant and in the range of 0.3-0.42 ns. In the following, an SMV-1247-079LF SMD varactor diode is used to adjust the proposed LPF. The tuning range for the proposed LPF is 0.46-3.2 GHz.. Journal: Journal of Electromagnetic Waves and Applications Pages: 713-725 Issue: 6 Volume: 32 Year: 2018 Month: 4 X-DOI: 10.1080/09205071.2017.1403964 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1403964 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:6:p:713-725 Template-Type: ReDIF-Article 1.0 Author-Name: Timor Melamed Author-X-Name-First: Timor Author-X-Name-Last: Melamed Author-Name: Tatiana Danov Author-X-Name-First: Tatiana Author-X-Name-Last: Danov Title: Time-dependent plane wave spectral analysis of the dyadic Green’s function of a fast moving dielectric-magnetic medium Abstract: We investigate the plane wave spectral representations of the time-dependent relativistic electric and magnetic dyadic Green’s functions (GFs) of an isotropic dielectric-magnetic medium that is moving in a constant velocity. We distinguish two speed regimes in which the medium is moving slower or faster than its wave speed. Using a scalarization process for the EM vectorial problem, the EM dyads are evaluated from scalar GF. The spectral plane wave representations of the dyadic GFss are obtained using the those of the scalar ones according to the appropriate speed regime. We investigate the resulting spectral representations and the associated wave phenomena. Such spectral representations are essentials for solving different canonical scattering problems in which the sources are decomposed into time-dependent (transient) plane waves as part of the boundary problem solutions. Journal: Journal of Electromagnetic Waves and Applications Pages: 726-738 Issue: 6 Volume: 32 Year: 2018 Month: 4 X-DOI: 10.1080/09205071.2017.1403965 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1403965 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:6:p:726-738 Template-Type: ReDIF-Article 1.0 Author-Name: Alexey Vitalievich Donchenko Author-X-Name-First: Alexey Vitalievich Author-X-Name-Last: Donchenko Author-Name: Gennadiy Philippovich Zargano Author-X-Name-First: Gennadiy Philippovich Author-X-Name-Last: Zargano Author-Name: Viacheslav Viktorovich Zemlyakov Author-X-Name-First: Viacheslav Viktorovich Author-X-Name-Last: Zemlyakov Title: Electrodynamic analysis of electromagnetic fields of hybrid waves propagating in the single-ridged waveguide Abstract: The article considers the algorithm for calculating characteristics of fields of hybrid types of waves in waveguides with complex cross sections. The presented algorithm takes into account the singularities of the components of the electromagnetic field near the dielectric and metal edges of the waveguide. The calculation results of electrodynamic characteristics of hybrid HE- and EH- waves propagating in the single-ridged waveguide with layered and piecewise-layered lossy dielectric filling are presented. Cutoff frequencies of hybrid waves are shown in tables and the structures of electromagnetic fields of hybrid types of waves are visualized. A comparative analysis of the results obtained by the presented method and the numerical methods is carried out. Journal: Journal of Electromagnetic Waves and Applications Pages: 739-749 Issue: 6 Volume: 32 Year: 2018 Month: 4 X-DOI: 10.1080/09205071.2017.1403966 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1403966 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:6:p:739-749 Template-Type: ReDIF-Article 1.0 Author-Name: Tatjana Gric Author-X-Name-First: Tatjana Author-X-Name-Last: Gric Author-Name: Ortwin Hess Author-X-Name-First: Ortwin Author-X-Name-Last: Hess Title: Long-range surface plasmons supported by the disordered nanowire metamaterials Abstract: Considering the losses of metal and semiconductor and by obtaining exact dispersion relations of the modes, we theoretically study the propagation characteristics of surface plasmons supported by disordered nanowire metamaterials. The metamaterials are composed of disordered nanowires made of metal or semiconductor embedded into the dielectric material. In the case of the semiconductor nanowires, it is possible to considerably improve the propagation characteristics of surface plasmons supported by the system, as compared to the metallic nanowires. Journal: Journal of Electromagnetic Waves and Applications Pages: 750-757 Issue: 6 Volume: 32 Year: 2018 Month: 4 X-DOI: 10.1080/09205071.2017.1404940 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1404940 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:6:p:750-757 Template-Type: ReDIF-Article 1.0 Author-Name: Stela Aronov Author-X-Name-First: Stela Author-X-Name-Last: Aronov Author-Name: Moshe Einat Author-X-Name-First: Moshe Author-X-Name-Last: Einat Author-Name: Olga Furman Author-X-Name-First: Olga Author-X-Name-Last: Furman Author-Name: Moritz Pilossof Author-X-Name-First: Moritz Author-X-Name-Last: Pilossof Author-Name: Konstantin Komoshvili Author-X-Name-First: Konstantin Author-X-Name-Last: Komoshvili Author-Name: Roey Ben-Moshe Author-X-Name-First: Roey Author-X-Name-Last: Ben-Moshe Author-Name: Asher Yahalom Author-X-Name-First: Asher Author-X-Name-Last: Yahalom Author-Name: Jacob Levitan Author-X-Name-First: Jacob Author-X-Name-Last: Levitan Title: Millimeter-wave insertion loss of mice skin Abstract: We measure the insertion loss of mice skin for millimeter waves. Millimeter waves are used today for various applications such as communications, fog penetrating radar, and detection of concealed weapons and drugs. High-power millimeter wave has been suggested as a non-lethal weapon and recently also for selective cancer treatment. Mice serve as biological models for human beings. Hence, in order to study various effects of millimeter waves on human beings, it is of paramount importance to understand how much millimeter-wave power penetrates the mouse skin and affects the layers beneath the skin, which is the purpose of this experimental paper. Journal: Journal of Electromagnetic Waves and Applications Pages: 758-767 Issue: 6 Volume: 32 Year: 2018 Month: 4 X-DOI: 10.1080/09205071.2017.1404941 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1404941 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:6:p:758-767 Template-Type: ReDIF-Article 1.0 Author-Name: Izabela Slomian Author-X-Name-First: Izabela Author-X-Name-Last: Slomian Author-Name: Krzysztof Wincza Author-X-Name-First: Krzysztof Author-X-Name-Last: Wincza Author-Name: Slawomir Gruszczynski Author-X-Name-First: Slawomir Author-X-Name-Last: Gruszczynski Title: Composite right-/left-handed leaky-wave antenna utilizing coupled-line sections Abstract: A novel method of realization of composite right-/left-handed leaky-wave antennas featuring through broadside-beam-scanning capability and utilizing coupled-line sections has been proposed. The unique feature of the presented concept is that it allows to adjust both the beam-scanning bandwidth and the distance between consecutive unit cells thanks to the introduction of additional identical transmission-line sections to the unit cell. The concept has been theoretically analyzed as well as experimentally verified by the simulations and measurements of the developed antenna operating with the transition frequency of 3 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 768-780 Issue: 6 Volume: 32 Year: 2018 Month: 4 X-DOI: 10.1080/09205071.2017.1405745 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1405745 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:6:p:768-780 Template-Type: ReDIF-Article 1.0 Author-Name: Z. Menachem Author-X-Name-First: Z. Author-X-Name-Last: Menachem Author-Name: S. Tapuchi Author-X-Name-First: S. Author-X-Name-Last: Tapuchi Title: Helical hollow waveguide with three dielectric layers in the cross section Abstract: The main objective is to understand the influence of the three dielectric layers and a metallic layer (Ag) in the cross section of the helical hollow waveguide on the output fields, output power density, and output power transmission. The contribution of the proposed technique to calculate the refractive indices and the transverse derivative of the dielectric profile for three dielectric layers is important to reduce the transmission losses of the dielectric-coated metal waveguides, especially for the helical hollow waveguide. This contribution is very important to improve the method that based on the mode model. The output power transmission and output power density are improved using with three dielectric layers in the cross section of the helical hollow waveguide and by increasing the step’s angle or the radius of the cylinder of the helix, especially in the cases of space curved waveguides. This mode model can be a useful tool to improve the output results in all the cases of the helical hollow waveguide with three dielectric layers and a metallic layer (Ag) for practical applications, before carrying out experiments in the laboratory. The applications are useful for the helical hollow waveguide in the infrared regime. Journal: Journal of Electromagnetic Waves and Applications Pages: 781-796 Issue: 6 Volume: 32 Year: 2018 Month: 4 X-DOI: 10.1080/09205071.2017.1406826 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1406826 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:6:p:781-796 Template-Type: ReDIF-Article 1.0 Author-Name: Kah Hou Teng Author-X-Name-First: Kah Hou Author-X-Name-Last: Teng Author-Name: Andy Shaw Author-X-Name-First: Andy Author-X-Name-Last: Shaw Author-Name: Muhammad Ateeq Author-X-Name-First: Muhammad Author-X-Name-Last: Ateeq Author-Name: Ahmed Al-Shamma’a Author-X-Name-First: Ahmed Author-X-Name-Last: Al-Shamma’a Author-Name: Stephen Wylie Author-X-Name-First: Stephen Author-X-Name-Last: Wylie Author-Name: Salim Newaz Kazi Author-X-Name-First: Salim Newaz Author-X-Name-Last: Kazi Author-Name: Bee Teng Chew Author-X-Name-First: Bee Teng Author-X-Name-Last: Chew Author-Name: Patryk Kot Author-X-Name-First: Patryk Author-X-Name-Last: Kot Title: Design and implementation of a non-invasive real-time microwave sensor for assessing water hardness in heat exchangers Abstract: A non-invasive-monitoring of concentration and dielectric properties of calcium hardness in heat exchanger cooling water was conducted with a 2.5 GHz microwave cavity resonator designed and fabricated locally for the experiment. The principle of electric dipole moment theories were used to analyse the sample solution that occurs as a function of calcium ion content. Artificial difference of water hardness was prepared by mixing CaCl2 in deionised water. The sample was centrally positioned in the electric field of the TM010 mode of a resonant cylindrical cavity. COMSOL simulation package was used to compare and validate the experimental cavity resonator frequency. Transmission signal (S21) measurements via vector network analyser at different concentrations were observed a linear relationship in amplitude with different frequency changes. In addition, calcium absorption provides a first-order change in material polarisation (i.e. real permittivity), and second-order transitions associated dielectric losses (i.e. imaginary permittivity). These research findings introduce a novel technique of real-time monitoring of water hardness concentration by using non-invasive microwave sensor. Journal: Journal of Electromagnetic Waves and Applications Pages: 797-811 Issue: 7 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1406408 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1406408 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:7:p:797-811 Template-Type: ReDIF-Article 1.0 Author-Name: D. B. Kuryliak Author-X-Name-First: D. B. Author-X-Name-Last: Kuryliak Author-Name: O. M. Sharabura Author-X-Name-First: O. M. Author-X-Name-Last: Sharabura Title: Axially symmetric TM-wave diffraction from bi-cone formed by semi-infinite and truncated semi-infinite cones Abstract: The problem of axially symmetric TM-wave diffraction from the perfectly conducting bi-cone formed by the semi-infinite and truncated semi-infinite cones is considered. The bi-cone is excited by the ring magnetic source. The problem is formulated in spherical coordinate system as a mixed boundary value problem for Helmholtz equation with respect of the unknown diffracted field. The solution of the problem is reduced to the infinite set of linear algebraic equations (ISLAE) of the second kind by means of the mode matching technique and the analytical regularization procedure. Two sorts of the second kind ISLAE are obtained based on the left- and right-side regularizations. The unknown expansion coefficients can be determined from each of the ISLAE with the given accuracy by the reduction method. The correlations between the ISLAE of our problem and of the supplementary problem of wave diffraction by the bi-cone formed with finite and semi-infinite shoulders are found. The approximate solution is obtained in the analytical form for the small aperture of the truncated shoulder. The numerically obtained results are focused on the practically important diffraction from the bi-cone formed by an infinite plane with circular hole and the semi-infinite conical probe. Journal: Journal of Electromagnetic Waves and Applications Pages: 812-825 Issue: 7 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1407262 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1407262 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:7:p:812-825 Template-Type: ReDIF-Article 1.0 Author-Name: Yanmin Zhang Author-X-Name-First: Yanmin Author-X-Name-Last: Zhang Author-Name: Yunhua Wang Author-X-Name-First: Yunhua Author-X-Name-Last: Wang Author-Name: Honglei Zheng Author-X-Name-First: Honglei Author-X-Name-Last: Zheng Author-Name: Yue Yu Author-X-Name-First: Yue Author-X-Name-Last: Yu Title: Doppler characteristics of EM scattering from sinusoidal or weakly nonlinear choppy waves Abstract: The spectra of electromagnetic (EM) scattering fields from sinusoidal or weakly nonlinear choppy waves are presented. In general, we always consider that the Doppler shift of EM scattering from a Bragg resonant wave is determined by the phase velocity of the water wave. However, the recent wave tank experiments and the numerical simulations demonstrate that not only the spectral peak corresponding to the phase velocity of water wave but also other equally spaced harmonic peaks can be found when a EM wave is illuminated on a sinusoidal or a simple weakly nonlinear choppy wave. The intensities of the harmonic peaks are affected by the amplitude, the frequency, and the hydrodynamic model of the water wave. To better explain these phenomena, a theoretical model for the spectra from the simple water waves are derived by the first-order small slope approximation theory (SSA-I). The comparisons with the numerical simulations illustrated that all the interesting phenomena could be successfully explained the theoretical spectral model. Journal: Journal of Electromagnetic Waves and Applications Pages: 826-841 Issue: 7 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1407263 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1407263 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:7:p:826-841 Template-Type: ReDIF-Article 1.0 Author-Name: V. S. Gangwar Author-X-Name-First: V. S. Author-X-Name-Last: Gangwar Author-Name: R. K. Samminga Author-X-Name-First: R. K. Author-X-Name-Last: Samminga Author-Name: A. K. Singh Author-X-Name-First: A. K. Author-X-Name-Last: Singh Author-Name: M. Jijenth Author-X-Name-First: M. Author-X-Name-Last: Jijenth Author-Name: K. K. Suman Author-X-Name-First: K. K. Author-X-Name-Last: Suman Author-Name: S. P. Singh Author-X-Name-First: S. P. Author-X-Name-Last: Singh Title: A novel strategy for the synthesis of thinned planar antenna array which furnishes lowest possible peak side lobe level without appearance of grating lobes over wide steering angles Abstract: In this paper, we propose a novel strategy for the synthesis of uniformly excited thinned planar antenna (UE-TPA) arrays which renders maximum possible reduction in the peak side lobe level (PSLL) with minimum number of turn ‘ON’ elements over wide steering angles. The main objective of this paper is to investigate an efficient variant of genetic algorithm (GA) which yields good quality solution at affordable computational complexity. Towards this aim, authors attempted to develop a powerful synthesis tool denoted as improved binary coded GA (IBc-GA) by investigating novel chromosome arrangements and ameliorated process techniques for crossover and mutation operations to improve the flexibility as well as the global search ability in achieving the best possible reduction in PSLL without increasing computational burden. In order to corroborate the effectiveness and superiority of the proposed synthesis technique, two examples consisting of 10 × 10- and 14 × 14-elements UE-TPA arrays are numerically examined at antenna boresight as well as when the arrays are electronically steered up to 40° with respect to antenna boresight in both azimuth and elevation planes. The numerical results of 10 × 10-element UE-TPA obtained through the proposed synthesis method at antenna boresight are compared with those determined at 20° and 40° scan angles and with those of same size arrays reported in the literature. In addition, results at antenna boresight achieved by proposed method for the case of 14 × 14-element UE-TPA array are compared with those determined at 20° and 40° scan angles. It is inferred from the investigation that wide angle scanning with lowest possible PSLL and without appearance of grating lobes is achieved at comparable computational cost. Journal: Journal of Electromagnetic Waves and Applications Pages: 842-857 Issue: 7 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1407264 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1407264 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:7:p:842-857 Template-Type: ReDIF-Article 1.0 Author-Name: Mustafa Inc Author-X-Name-First: Mustafa Author-X-Name-Last: Inc Author-Name: Aliyu Isa Aliyu Author-X-Name-First: Aliyu Isa Author-X-Name-Last: Aliyu Author-Name: Abdullahi Yusuf Author-X-Name-First: Abdullahi Author-X-Name-Last: Yusuf Author-Name: Dumitru Baleanu Author-X-Name-First: Dumitru Author-X-Name-Last: Baleanu Title: Optical solitons, conservation laws and modulation instability analysis for the modified nonlinear Schrödinger’s equation for Davydov solitons Abstract: In this paper, the optical solitons to the modified nonlinear Schrödinger’s equation for davydov solitons are investigate. The modified F-expansion method is the integration technique employed to achieve this task. This yielded a combined and other soliton solutions. The Lie point symmetry generators of a system of partial differential equations acquired by decomposing the equation into real and imaginary components are derived. We prove that the system is nonlinearly self-adjoint with an explicit form of a differential substitution satisfying the nonlinear self-adjoint condition. Then we use these facts to construct a set of local conservation laws (Cls) for the system using the general Cls theorem presented by Ibragimov. Furthermore, the modulation instability (MI) is analyzed based on the standard linear-stability analysis and the MI gain spectrum is got. Numerical simulation of the obtained results are analyzed with interesting figures showing the physical meaning of the solutions. Journal: Journal of Electromagnetic Waves and Applications Pages: 858-873 Issue: 7 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1408499 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1408499 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:7:p:858-873 Template-Type: ReDIF-Article 1.0 Author-Name: Xiaowei Mei Author-X-Name-First: Xiaowei Author-X-Name-Last: Mei Author-Name: Yong Zhang Author-X-Name-First: Yong Author-X-Name-Last: Zhang Author-Name: Hai Lin Author-X-Name-First: Hai Author-X-Name-Last: Lin Author-Name: Pengcheng Gao Author-X-Name-First: Pengcheng Author-X-Name-Last: Gao Title: An efficient and accurate OpenMP-MPI based 3D beam tracing method for radio propagation simulation in large scale urban environments Abstract: A modified adaptive division beam tracing (MADBT) technique based on the localized kd-tree and the OpenMP–MPI parallel techniques is presented for the simulation of radio propagation in large-scale urban environments. Beams launched from a transmitter are recursively traced by applying the MADBT method and beam trees recorded the propagation path info are generated. By traversing the beam trees, all the valid propagation (transmitted, reflected and diffracted) paths are efficiently determined. Then the receiver power strength can be calculated based on geometrical optics (GO) and uniform theory of diffraction along the arrival paths. By tracing the continuous beams instead of a number of rays, the proposed method performs higher efficiency than the widely used ray tracing method. During the beam tracing procedure, several techniques are adopted to accelerate the calculation. Firstly, a localized kd-tree is built according to the coverage area of the transmitter, which is more efficient than the global kd-tree to do the beam-triangle intersection during the tracing procedure. Secondly, a virtual simulation face is generated to speed up the searching for ray paths. Lastly, the OpenMP and the MPI parallel technique are implemented to further enhance efficiency of the proposed method. As expected, the simulated results for the realistic Malaysia urban environment show good agreement with measured results and performance high efficiency. Journal: Journal of Electromagnetic Waves and Applications Pages: 874-885 Issue: 7 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1409136 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1409136 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:7:p:874-885 Template-Type: ReDIF-Article 1.0 Author-Name: M. D. Malykh Author-X-Name-First: M. D. Author-X-Name-Last: Malykh Author-Name: L. A. Sevastianov Author-X-Name-First: L. A. Author-X-Name-Last: Sevastianov Author-Name: A. A. Tiutiunnik Author-X-Name-First: A. A. Author-X-Name-Last: Tiutiunnik Author-Name: N. E. Nikolaev Author-X-Name-First: N. E. Author-X-Name-Last: Nikolaev Title: On the representation of electromagnetic fields in closed waveguides using four scalar potentials Abstract: The investigation of the electromagnetic field in a regular waveguide filled with a homogeneous substance reduces to the study of two independent boundary value problems for the Helmholtz equation. In the case of a waveguide filled with an inhomogeneous substance, a relationship arises between the modes of these two problems, which in numerical experiments can not always be fully taken into account. In this paper, we will show how to rewrite the Helmholtz equations in the “Hamiltonian form” to express this connection explicitly. In this case, the problem of finding monochromatic waves in a waveguide with arbitrary filling will be reduced to an infinite system of ordinary differential equations in a properly constructed Hilbert space. The results of numerical experiments on finding normal waves, realized in the computer algebra system Sage, are presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 886-898 Issue: 7 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1409137 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1409137 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:7:p:886-898 Template-Type: ReDIF-Article 1.0 Author-Name: Valery G. Yakhno Author-X-Name-First: Valery G. Author-X-Name-Last: Yakhno Title: An explicit formula for modeling wave propagation in magneto-electro-elastic materials Abstract: A new method for construction of an explicit solution of the initial value problem for the partial differential equations of magneto-electro-elasticity is suggested. This method consists of the reduction of the time-dependent equations of magneto-electro-elasticity to a symmetric hyperbolic system of the first-order partial differential equations. The explicit formula for the solution is found by application of the theory and methods of symmetric hyperbolic systems. This formula can be applied for modelling wave propagation in magneto-electro-elastic materials as well as in artificial magneto-electro-elastic materials obtained from laminated heterostructure composed of materials by asymptotic homogenization method. Journal: Journal of Electromagnetic Waves and Applications Pages: 899-912 Issue: 7 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1410076 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1410076 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:7:p:899-912 Template-Type: ReDIF-Article 1.0 Author-Name: Chong Gao Author-X-Name-First: Chong Author-X-Name-Last: Gao Author-Name: En Li Author-X-Name-First: En Author-X-Name-Last: Li Author-Name: Qi Su Author-X-Name-First: Qi Author-X-Name-Last: Su Author-Name: Yunpeng Zhang Author-X-Name-First: Yunpeng Author-X-Name-Last: Zhang Title: Rapid location and online detection of plate material defects with multi-row crossed antenna pairs in the case of material movement Abstract: This paper introduces a new rapid detection model with multi-row crossed antenna pairs and a corresponding algorithm for online rapid detection. The way of multi-row crossed antennas leads to data offset of adjacent columns, so a method of magnitude and phase restoration is discussed in the case of material movement. For reducing the effective testing scope and improving the resolution, a modified Vivaldi antenna with more concentrated E-field distribution was designed and fabricated, which operates at a ultra-wideband range from 3.9 to 40 GHz with S11 less than –10 dB for covering the detection frequency. To measure the dimension and accurately locate the positions of material defects, a proposed algorithm that combines 2-D cubic spline interpolation together with Laplace of Gaussian is introduced. This algorithm can extract the dimension of defects (5 mm minimum) from the original magnitudes and phases of materials. To evaluate the proposed method, the cystosepiment with a high-loss dielectric piece (5, 10, and 15 mm in diameter) inside was fabricated and an experimental testing system was established to achieve the rapid detection. Compared with the existed method with a-row antennas to detect, the proposed detection model of the multi-row antennas and corresponding algorithm are effective to locate the defect with a offset less than 0.5 cm. Journal: Journal of Electromagnetic Waves and Applications Pages: 913-926 Issue: 7 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2018.1425641 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1425641 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:7:p:913-926 Template-Type: ReDIF-Article 1.0 Author-Name: M. Salucci Author-X-Name-First: M. Author-X-Name-Last: Salucci Author-Name: G. Oliveri Author-X-Name-First: G. Author-X-Name-Last: Oliveri Author-Name: N. Anselmi Author-X-Name-First: N. Author-X-Name-Last: Anselmi Author-Name: G. Gottardi Author-X-Name-First: G. Author-X-Name-Last: Gottardi Author-Name: A. Massa Author-X-Name-First: A. Author-X-Name-Last: Massa Title: Performance enhancement of linear active electronically scanned arrays by means of MbD-synthesized metalenses Abstract: The key problem of improving the radiation performances or enabling additive functionalities of linear active electronically scanned arrays (AESAs), without increasing the number of radiating elements nor requiring a re-design of the radiators and/or the feeding network, is addressed by means of a suitably formulated Material-by-Design (MbD) approach. The quasi-conformal transformation optics (QCTO) technique and a customized source inversion (SI) strategy are jointly exploited to synthesize enhanced architectures, composed by a metamaterial lens and a tapered version of the original feeding network, able to match the radiation characteristics of significantly larger and/or different (from the original one) apertures. A set of representative benchmark results is reported to assess the effectiveness of the proposed MbD-designed architecture as well as to highlight the existing trade-off between achievable improvements and the complexity of the arising architectural solution. Journal: Journal of Electromagnetic Waves and Applications Pages: 927-955 Issue: 8 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1410077 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1410077 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:8:p:927-955 Template-Type: ReDIF-Article 1.0 Author-Name: Kazi S. Zubair Author-X-Name-First: Kazi S. Author-X-Name-Last: Zubair Author-Name: Sadiq A. Alhuwaidi Author-X-Name-First: Sadiq A. Author-X-Name-Last: Alhuwaidi Author-Name: Heather H. Song Author-X-Name-First: Heather H. Author-X-Name-Last: Song Author-Name: Yiqun G. Shellman Author-X-Name-First: Yiqun G. Author-X-Name-Last: Shellman Author-Name: William A. Robinson Author-X-Name-First: William A. Author-X-Name-Last: Robinson Author-Name: Allison J. Applegate Author-X-Name-First: Allison J. Author-X-Name-Last: Applegate Author-Name: Carol M. Amato Author-X-Name-First: Carol M. Author-X-Name-Last: Amato Title: Investigation of dielectric spectroscopy response in normal and cancerous biological tissues using S-parameter measurements Abstract: Dielectric spectroscopy is conducted in terahertz frequency range to differentiate human normal tissues from the cancerous ones. Due to sensitivity of terahertz waves on water content of the biological tissues, when incident, it shows different dielectric constant values for normal and cancerous tissues. Analytical calculations using the Debye model, simulations using a 3D electromagnetic code, and measurements of the biological tissues employing free space technique were performed to investigate the difference in dielectric properties of the normal and cancerous tissues. New algorithm is developed to convert the measured transmission and reflection coefficients to dielectric constants. The biological samples were processed using various methods and measurement was performed for tissues from different parts of the body. The results show approximately 10% greater dielectric constant values for cancerous tissues, which is believed to be attributed to higher water content. The proposed terahertz dielectric spectroscopy may be used to identify the cancer tissues. Journal: Journal of Electromagnetic Waves and Applications Pages: 956-971 Issue: 8 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1411835 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1411835 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:8:p:956-971 Template-Type: ReDIF-Article 1.0 Author-Name: Robert Smolarz Author-X-Name-First: Robert Author-X-Name-Last: Smolarz Author-Name: Krzysztof Wincza Author-X-Name-First: Krzysztof Author-X-Name-Last: Wincza Author-Name: Slawomir Gruszczynski Author-X-Name-First: Slawomir Author-X-Name-Last: Gruszczynski Title: Impedance transforming rat-race couplers with modified Lange section Abstract: The relation between load impedances and the characteristic impedance of the rat-race ring has been derived. To minimize the circuit size, the 270°-long section has been replaced by a shorted coupled-line section. Moreover, to achieve appropriate coupling coefficient in the required coupled-line section, a modified Lange structure consisting of five-coupled lines has been applied. Furthermore, the second structure has been proposed having improved operational bandwidth, in which coupled-line matching sections are added. The theoretical analysis has been verified by measurements of the fabricated rat-race couplers operating at the center frequency 1 GHz. The designed couplers transforms 50 Ω input impedance into 10 Ω, which proves their practical applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 972-983 Issue: 8 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1411836 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1411836 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:8:p:972-983 Template-Type: ReDIF-Article 1.0 Author-Name: Phirun Kim Author-X-Name-First: Phirun Author-X-Name-Last: Kim Author-Name: Girdhari Chaudhary Author-X-Name-First: Girdhari Author-X-Name-Last: Chaudhary Author-Name: Yongchae Jeong Author-X-Name-First: Yongchae Author-X-Name-Last: Jeong Title: Unequal termination impedance parallel-coupled lines band-pass filter with arbitrary image impedance Abstract: This paper presents an analytical design for a microstrip parallel-coupled line bandpass filter (BPF) with arbitrary termination and image impedances. Using the proposed design formulas, multistage arbitrary termination impedance BPFs can be designed with a very high impedance transforming ratio (r). The fractional bandwidth and return losses are maintained even though the r and image impedance are varied. To validate the design formulas, two- and three-stage BPFs are fabricated and measure at the center frequency (f0) of 2.6 GHz. The filter 1 and filter 2 are designed with termination impedances of 50–300 Ω and 20–50 Ω, respectively. The measured results of both filters show a good agreement with the simulations. The measured passband insertion and return losses of filter 1 are better than 0.8 and 19.6 dB, respectively. Similarly, the measured passband insertion and return losses of filter 2 are better than 1.5 and 19 dB, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 984-996 Issue: 8 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1411837 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1411837 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:8:p:984-996 Template-Type: ReDIF-Article 1.0 Author-Name: Rafal Lech Author-X-Name-First: Rafal Author-X-Name-Last: Lech Title: Resonance microstrip structure with patch of arbitrary convex geometry with the use of field matching technique Abstract: An analysis of the resonance frequency problem of planar microstrip structure with patch of arbitrary convex geometry is presented. A full-wave analysis is employed utilizing a combination of Galerkin’s moment method and field matching technique. In this approach, a field matching technique is adopted to calculate the patch surface current densities, and next the method of moments is utilized to calculate resonance frequencies of the microstrip structure. Different convex shapes of patches are considered to verify the validity of the approach. The results agree with those obtained from commercial software and presented in literature. Journal: Journal of Electromagnetic Waves and Applications Pages: 997-1007 Issue: 8 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1412357 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1412357 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:8:p:997-1007 Template-Type: ReDIF-Article 1.0 Author-Name: Sandeep Kumar Vyas Author-X-Name-First: Sandeep Kumar Author-X-Name-Last: Vyas Author-Name: T. Tiwari Author-X-Name-First: T. Author-X-Name-Last: Tiwari Title: Study of hole and slot type S-band pulsed power magnetron Abstract: This paper deals with the electromagnetic design of a high power pulsed magnetron capable of delivering 3.25 MW output power at operating frequency 2.998 ± 0.005 GHz using CST microwave studio. Eigen mode solver is used to find out the cold frequencies and RF field patterns of different modes of the magnetron. A capacitive type tuning mechanism is included in the magnetron simulation model to study the frequency tuning range. The cold test simulation of complete magnetron model with straps, output window, coupling loops and output coupler is carried out to compute the resonance spectrum, quality factor and circuit efficiency using frequency domain solver of CST microwave studio. Particle in cell simulation of the magnetron predicts output power, anode current and efficiency which are 3.25 MW, 117A and 56%, respectively, at operating voltage 50 kV and magnetic field of 1630 Gauss. A complete virtual prototype magnetron both in cold and hot conditions is demonstrated on computer. Journal: Journal of Electromagnetic Waves and Applications Pages: 1008-1017 Issue: 8 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1412358 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1412358 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:8:p:1008-1017 Template-Type: ReDIF-Article 1.0 Author-Name: Jung-Nam Lee Author-X-Name-First: Jung-Nam Author-X-Name-Last: Lee Author-Name: Myung Don Kim Author-X-Name-First: Myung Don Author-X-Name-Last: Kim Author-Name: Tae Joong Kim Author-X-Name-First: Tae Joong Author-X-Name-Last: Kim Title: A dual-polarized small base station antenna having a high Tx/Rx isolation characteristics for 900 MHz small-cell MIMO systems Abstract: A dual-polarized base station (BS) antenna is proposed that has a spiral isolator, a T-shaped matching stub, and a metal cube. The antenna is composed of a metallic cube, micro-strip feed line board, metallic feeding cylinders, spiral isolator, isolator connecting pins, micro-strip patch, and T-shaped matching stubs. The measured frequency bandwidth is 898–970 MHz at ports-1 and 2. The measured isolation is 40 dB over the operating frequency band and the measured antenna peak gain is 7.5 dBi. Journal: Journal of Electromagnetic Waves and Applications Pages: 1018-1028 Issue: 8 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1412359 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1412359 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:8:p:1018-1028 Template-Type: ReDIF-Article 1.0 Author-Name: Ali Kursad Gorur Author-X-Name-First: Ali Kursad Author-X-Name-Last: Gorur Author-Name: Ceyhun Karpuz Author-X-Name-First: Ceyhun Author-X-Name-Last: Karpuz Author-Name: Adnan Gorur Author-X-Name-First: Adnan Author-X-Name-Last: Gorur Title: Electronically switchable compact quad-band microstrip bandpass filter using varactor perturbed dual-mode resonators Abstract: In this paper, an electronically switchable quad-band microstrip bandpass filter is designed using varactor perturbed dual-mode resonators. For this purpose, four meandered dual-mode square loop resonators (DMSLRs) having reference patches are nested and varactor diodes are used to serve as perturbation elements. The designed resonator is analyzed by deriving even/odd mode resonance conditions. S-parameters are also calculated according to the even and odd mode input impedances. Stub loaded feedlines are used to couple the DMSLRs to Input/Output (I/O) ports. According to the capacitances of varactor diodes, each passband can be independently turned on and off. Coupling scheme and coupling matrix of the designed filter are introduced to realize the coupling descriptions. Switching operations are also investigated over the frequency responses obtained from coupling matrix. Passbands of the filter are adjusted to 1.4, 1.7, 2.25, and 2.7 GHz. The designed filter was also fabricated and measured results show a good agreement with the simulated and theoretical results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1029-1039 Issue: 8 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2017.1414000 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1414000 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:8:p:1029-1039 Template-Type: ReDIF-Article 1.0 Author-Name: Hyungju Kim Author-X-Name-First: Hyungju Author-X-Name-Last: Kim Author-Name: Noh Hoon Myung Author-X-Name-First: Noh Hoon Author-X-Name-Last: Myung Title: ISAR imaging method of radar target with short-term observation based on ESPRIT Abstract: A 2-D Inverse synthetic aperture radar (ISAR) imaging method is proposed, which only requires a short period of time for target observation. Typically, a long period of observing time is necessary to achieve high cross-range resolution in ISAR imaging since a wide observing angle is critical. However, long-term observation accompanies disadvantage in discriminating the target especially when the target has complicated motion. In this paper, we propose a 2-D ISAR imaging method with short-term observation. The down-range of scatterers is obtained by inverse fast Fourier transform (IFFT) and the cross-range of scatterers is obtained by estimation of signal parameters via rotational invariance technique (ESPRIT). To improve computational efficiency, we sort out the signal region and noise region with a certain threshold level and then the ESPRIT method is only applied to the signal region. A set of simulated and measured data of Boeing 727 as an aircraft target is used to validate the proposed imaging method in this paper. By adopting the proposed method, the required observation time of target can be reduced to 12.5%. Journal: Journal of Electromagnetic Waves and Applications Pages: 1040-1051 Issue: 8 Volume: 32 Year: 2018 Month: 5 X-DOI: 10.1080/09205071.2018.1429323 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1429323 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:8:p:1040-1051 Template-Type: ReDIF-Article 1.0 Author-Name: Rajat Arora Author-X-Name-First: Rajat Author-X-Name-Last: Arora Author-Name: Shashi B. Rana Author-X-Name-First: Shashi B. Author-X-Name-Last: Rana Author-Name: Sandeep Arya Author-X-Name-First: Sandeep Author-X-Name-Last: Arya Title: Performance analysis of ZnO and HfO2 micro-pillars based capacitive antennas Abstract: In this research paper, performance analysis of two different material-based micropillars capacitive antennas is proposed. The method involves formation of self-organized mask, micropillar formation by using process of etching and metal deposition (Au/Cr) on the top and bottom of micropillars. For fabrication of these capacitive antennas, we considered 2-inch p-type silicon (Si) wafers as a substrates material while upper and lower plates of capacitive antenna were fabricated by using gold as plating material on top and bottom. Both capacitive antennas were fabricated by taking the two different materials (ZnO and HfO2) micropillars which acts a dielectric material between two upper and lower gold plates. For realization of both antennas firstly we have simulated both the antenna using CST Microwave studio software and thereafter fabricated by using appropriate microfabrication technique. Both the metamaterial-based capacitive antennas were designed by taking dimension of 35 × 26 mm on the 2″ Si substrate. The thickness (h) and dielectric constant (εr) of silicon substrate were taken as 0.270 mm and 11.7, respectively. The proposed antenna was designed to operate at frequency range of 1–10 GHz, which signifies that return loss (S11) parameter must be less than −10 dB and voltage standing wave ratio must be less than 2. To validate the design, various parameters of RF antenna such as the return loss, gain, surface current distribution, and radiation patterns were obtained and compared for the fabricated antennas. The simulated and experimental results were found to show good agreement. Journal: Journal of Electromagnetic Waves and Applications Pages: 1053-1068 Issue: 9 Volume: 32 Year: 2018 Month: 6 X-DOI: 10.1080/09205071.2017.1415823 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1415823 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:9:p:1053-1068 Template-Type: ReDIF-Article 1.0 Author-Name: Qun Li Author-X-Name-First: Qun Author-X-Name-Last: Li Author-Name: Yonghong Zhang Author-X-Name-First: Yonghong Author-X-Name-Last: Zhang Author-Name: Lili Qu Author-X-Name-First: Lili Author-X-Name-Last: Qu Author-Name: Yong Fan Author-X-Name-First: Yong Author-X-Name-Last: Fan Title: High isolation and miniaturized quad-channel diplexer using short stub-loaded resonators and distributed coupling feeding line Abstract: This paper presents a high isolation and miniaturized microstrip quad-channel diplexer. The quad-channel diplexer consists of a distributed coupling feeding line, two coupling feeding lines, and two pairs of short stub-loaded resonators combined by the pseudo-interdigital structure. Based on the even–odd mode method, the resonant modes of the short stub-loaded resonator are investigated. The mode splitting is created when a pair of short stub-loaded resonators are combined by a pseudo-interdigital structure. Each mode of the short stub-loaded resonator is split into two modes to form a two-order channel filter. The center frequencies of the quad-channel diplexer can be adjusted independently, while the bandwidths of channel filters can be tuned by the external quality factor and the coupling coefficient. Taking advantage of the distributed coupling feeding line, no extra matching network is needed and the loading effect is very small. For demonstration, a quad-channel diplexer working at 2.4, 3.15, 4.4, 5.8 GHz with better than 40 dB isolation is presented. The measured results agree well with the full-wave simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1069-1078 Issue: 9 Volume: 32 Year: 2018 Month: 6 X-DOI: 10.1080/09205071.2017.1415824 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1415824 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:9:p:1069-1078 Template-Type: ReDIF-Article 1.0 Author-Name: Hua Zhao Author-X-Name-First: Hua Author-X-Name-Last: Zhao Author-Name: Lixin Guo Author-X-Name-First: Lixin Author-X-Name-Last: Guo Author-Name: Tiange Chen Author-X-Name-First: Tiange Author-X-Name-Last: Chen Author-Name: Wei Liu Author-X-Name-First: Wei Author-X-Name-Last: Liu Title: Electromagnetic scattering of coated objects over sea surface based on SBR-SDFSM Abstract: An efficient approach to analyze the electromagnetic (EM) scattering from coated objects above a three-dimensional (3-D) dielectric random rough surface is proposed in this paper. The electric and magnetic current densities on the sea surface are analytically realized using the semi-deterministic facet scattering model (SDFSM). Considering Fresnel reflection coefficient, a scheme combining the shooting and bouncing rays (SBR) and the physical theory of diffraction (PTD) is developed to calculate the scattering of the coated objects. Simulation results obtained with the combined method are verified by comparison with exact simulations using the multilevel fast multiple method (MLFMM). Scattering of large coated objects over sea surface composite model are too large and complex to be calculated using exact methods. With the asymptotic approach in this paper, the scattering performance can be analyzed with rather moderate computational efforts. Numerical results of composite scattering from an electric large three-dimensional model, e.g. an airplane target over a randomly rough surface with Pierson Moskowitz (PM) spectrum are presented and discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1079-1092 Issue: 9 Volume: 32 Year: 2018 Month: 6 X-DOI: 10.1080/09205071.2017.1417917 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1417917 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:9:p:1079-1092 Template-Type: ReDIF-Article 1.0 Author-Name: Tukur Abdulkadir Sulaiman Author-X-Name-First: Tukur Abdulkadir Author-X-Name-Last: Sulaiman Author-Name: Tolga Aktürk Author-X-Name-First: Tolga Author-X-Name-Last: Aktürk Author-Name: Hasan Bulut Author-X-Name-First: Hasan Author-X-Name-Last: Bulut Author-Name: Haci Mehmet Baskonus Author-X-Name-First: Haci Mehmet Author-X-Name-Last: Baskonus Title: Investigation of various soliton solutions to the Heisenberg ferromagnetic spin chain equation Abstract: This study uses two mathematical approaches in constructing dark, bright, kink-type and singular soliton solutions to the Heisenberg ferromagnetic spin chain equation. The (2+1)-dimensional Heisenberg ferromagnetic spin chain equation describes nonlinear dynamics of magnets. The acquired results in this study may help in explaining some physical meanings of some nonlinear physical models arising in electromagnetic waves. For instance, the hyperbolic tangent arises in the calculation of magnetic moment and rapidity of special relativity, the hyperbolic cotangent arises in the Langevin function for magnetic polarization. The 2-, 3-dimensional and the contour plots of all the acquired solutions are presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 1093-1105 Issue: 9 Volume: 32 Year: 2018 Month: 6 X-DOI: 10.1080/09205071.2017.1417919 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1417919 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:9:p:1093-1105 Template-Type: ReDIF-Article 1.0 Author-Name: J. Alejandro Gonzaga-Galeana Author-X-Name-First: J. Alejandro Author-X-Name-Last: Gonzaga-Galeana Author-Name: Jorge R. Zurita-Sánchez Author-X-Name-First: Jorge R. Author-X-Name-Last: Zurita-Sánchez Title: Alternative angular spectrum derivation of beam-shape coefficients of generalized Lorenz–Mie theory: scattering of light coming from two pinholes Abstract: In the scattering theory of light by a spherical particle, the crucial step for solving the scattering problem is to determine the so-called beam-shape coefficients (weighting coefficients of multipolar expansions) for an arbitrary incident electromagnetic field. We present an alternative analytical derivation of such coefficients using the angular spectrum method of field propagation. Different from previous approaches, our derivation requires only recurrence relations and orthogonality properties of associated Legendre functions. We provide closed-form expressions to obtain these coefficients in terms of the distribution of either electric or magnetic field of the secondary source. Our general expressions for obtaining the beam-shape coefficients are applied to the scattering problem in which a sphere is illuminated with light coming from two pinholes. For this problem, the beam-shape coefficients can be analytically obtained and they are merely related to the Cartesian components of the vector spherical harmonics whose arguments are the vector positions from the pinholes to the center of the sphere. Specifically, we simulate the scattering fields when the scatterer is a dielectric sphere (size larger than the wavelength of the incident field) for on- and off-resonance conditions; subwavelength confinement of the electromagnetic field is attained. Journal: Journal of Electromagnetic Waves and Applications Pages: 1106-1125 Issue: 9 Volume: 32 Year: 2018 Month: 6 X-DOI: 10.1080/09205071.2017.1422809 File-URL: http://hdl.handle.net/10.1080/09205071.2017.1422809 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:9:p:1106-1125 Template-Type: ReDIF-Article 1.0 Author-Name: Chandan Kumar Ghosh Author-X-Name-First: Chandan Kumar Author-X-Name-Last: Ghosh Author-Name: Sourav Moitra Author-X-Name-First: Sourav Author-X-Name-Last: Moitra Title: Study of decoupling between patch elements of microstrip array using electromagnetic soft surface Abstract: Electromagnetic coupling is one of the important and necessary issues for the design of antenna arrays. Mutual coupling degrades array performances like antenna gain, radiation pattern, antenna efficiency etc. In this paper, the authors have put forward a novel technique for reduction of mutual coupling between microstrip patch elements. A 4-element antenna array loaded with electromagnetic soft surfaces (EMSS) has been designed to achieve considerable suppression of mutual coupling between two adjacent patch elements. The EMSS are designed using metal strips loaded with reverse C-shaped slots. With the introduction of two EMSS unit cells between patch elements, a noticeable reduction in mutual coupling between patch elements is achieved without degradation in other performances of the array. The experimental results presented are compared with the simulated ones and it is observed that the proposed EMSS loaded array structures cause excellent suppression of electromagnetic coupling with a reduction of about 35 dB at the designed frequency of 3.65 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1126-1135 Issue: 9 Volume: 32 Year: 2018 Month: 6 X-DOI: 10.1080/09205071.2018.1424041 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1424041 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:9:p:1126-1135 Template-Type: ReDIF-Article 1.0 Author-Name: Qiang Chen Author-X-Name-First: Qiang Author-X-Name-Last: Chen Author-Name: Xing Chen Author-X-Name-First: Xing Author-X-Name-Last: Chen Author-Name: Xin Duan Author-X-Name-First: Xin Author-X-Name-Last: Duan Title: Investigation on beam collection efficiency in microwave wireless power transmission Abstract: The beam collection efficiency (BCE), which defined as the microwave power transfer efficiency between the transmitting and receiving aperture, plays a key role in the overall transmission efficiency of the microwave wireless power transmission (MWPT) system. However, due to many long distance MWPT applications are near-field microwave power transmission and transmitting antennas are not designed with optimal Gaussian aperture field distributions, widely used Friis formula and Gouban formula may result in considerably errors. This work explores evaluating the BCE using a numerical integration method that is based on the transmitting antenna’s three-dimensional (3D) radiation pattern. Furthermore to facilitate engineering applications of MWPT, a revised formula is proposed, which is based on the numerical integration results and modified from the Gaubau formula. Moreover, a MWPT system working at X band (10 GHz) is designed and its BCE under various transmission distances is measured. Through a comparative analysis, the accuracy of the proposed numerical integration method and modified formula is validated. Journal: Journal of Electromagnetic Waves and Applications Pages: 1136-1151 Issue: 9 Volume: 32 Year: 2018 Month: 6 X-DOI: 10.1080/09205071.2018.1425158 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1425158 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:9:p:1136-1151 Template-Type: ReDIF-Article 1.0 Author-Name: Abhishek Sharma Author-X-Name-First: Abhishek Author-X-Name-Last: Sharma Author-Name: Anirban Sarkar Author-X-Name-First: Anirban Author-X-Name-Last: Sarkar Author-Name: Animesh Biswas Author-X-Name-First: Animesh Author-X-Name-Last: Biswas Author-Name: M. Jaleel Akhtar Author-X-Name-First: M. Jaleel Author-X-Name-Last: Akhtar Title: Dual-band multiple-input multiple-output antenna based on half split cylindrical dielectric resonator Abstract: In this article, a dual-band half split cylindrical dielectric resonator antenna is proposed for multiple-input multiple-output (MIMO) applications. The dual-band operation is achieved by simultaneously exciting TE01δ$ \text{ TE}_{01\delta } $ and TE02δ$ \text{ TE}_{02\delta } $ modes in an aperture coupled fed half split cylindrical dielectric resonator. The topology of four element MIMO antenna is such that it provides both spatial and polarization diversities. Over both the operating bands, the measured port-to-port isolation is better than 20 dB. The proposed antenna exhibits broadside radiation with cross polarization level below -15$ -15 $ dB in both xz- and yz-plane. The peak gain of antenna is 4.88 and 5.32 dBi at lower and upper operating frequency, respectively. The MIMO performance of the proposed antenna is found to be good with ECC<$ < $0.06. Moreover, the channel capacity of the proposed MIMO is near to uncorrelated case for uniform propagation scenario. The proposed antenna could be suitable for LTE 22/LTE 42 and WLAN applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1152-1163 Issue: 9 Volume: 32 Year: 2018 Month: 6 X-DOI: 10.1080/09205071.2018.1425159 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1425159 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:9:p:1152-1163 Template-Type: ReDIF-Article 1.0 Author-Name: M. Salucci Author-X-Name-First: M. Author-X-Name-Last: Salucci Author-Name: A. Gelmini Author-X-Name-First: A. Author-X-Name-Last: Gelmini Author-Name: L. Poli Author-X-Name-First: L. Author-X-Name-Last: Poli Author-Name: G. Oliveri Author-X-Name-First: G. Author-X-Name-Last: Oliveri Author-Name: A. Massa Author-X-Name-First: A. Author-X-Name-Last: Massa Title: Progressive compressive sensing for exploiting frequency-diversity in GPR imaging Abstract: The microwave imaging of buried targets from wide-band ground penetrating radar (GPR) signals is addressed. By considering a contrast source inversion (CSI) formulation of the inverse scattering equations and taking advantage of both the intrinsic frequency diversity of GPR data and the sparseness of the unknown buried scatterers within the subsurface domain of investigation, a multi-task Bayesian compressive sensing (MT-BCS) approach is integrated within a frequency hopping (FH) inversion scheme. Towards this end, an innovative “constrained” relevance vector machine (C-RVM) solver is developed to effectively exploit the information, progressively acquired at each frequency step, on the unknown scattering scenario. Representative numerical benchmarks and preliminary experimental results are presented to assess the effectiveness and the potentialities of the proposed subsurface imaging method (namely, the FH-MT-BCS technique). Journal: Journal of Electromagnetic Waves and Applications Pages: 1164-1193 Issue: 9 Volume: 32 Year: 2018 Month: 6 X-DOI: 10.1080/09205071.2018.1425160 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1425160 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:32:y:2018:i:9:p:1164-1193 Template-Type: ReDIF-Article 1.0 Author-Name: Mohamed Talbi Author-X-Name-First: Mohamed Author-X-Name-Last: Talbi Author-Name: Gérard Gréhan Author-X-Name-First: Gérard Author-X-Name-Last: Gréhan Author-Name: Sébastien Coëtmellec Author-X-Name-First: Sébastien Author-X-Name-Last: Coëtmellec Author-Name: Marc Brunel Author-X-Name-First: Marc Author-X-Name-Last: Brunel Title: Self-generated off-axis holography in interferometric out-of-focus imaging of ice particles Abstract: Interferometric out-of-focus imaging of ice particles is realized. A review of the recent developments performed to analyse the speckle-like out-of-focus images of rough particles is first proposed. A remaining challenge is the analysis of overlapping out-of-focus images. In a second part, the overlapping defocused images of two nearby ice particles are analysed. If one particle is much smaller than the other one, the pattern constitutes an off-axis hologram whose analysis gives the exact size and shape of the biggest particle. Using two angles of view, we obtain a 3D description of the biggest ice particle. Journal: Journal of Electromagnetic Waves and Applications Pages: 1-17 Issue: 1 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1524797 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1524797 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:1:p:1-17 Template-Type: ReDIF-Article 1.0 Author-Name: Rajorshi Bandyopadhyay Author-X-Name-First: Rajorshi Author-X-Name-Last: Bandyopadhyay Author-Name: Rajib Chakraborty Author-X-Name-First: Rajib Author-X-Name-Last: Chakraborty Title: Antisymmetric distributed Bragg reflector as hybrid filter for compact integrated photonics Abstract: Antisymmetric multi cavity resonator useful for flat top transmission is reported which is simple and compact than the similar conventional structures. The study of the output spectra is carried out in terms of layer thickness and change in angle of incidence. Electro-optic property of the EO polymer is utilized to convert flat-top output with full width half maximum (FWHM) bandwidth of 10 nm into narrowband output of 0.64 nm (FWHM bandwidth) by applying a maximum voltage of 500 V across the structure. It was shown here that by controlling the low index layer widths, angle of incidence of the light and applying a voltage of 300 V results in a flattop spectrum of FWHM bandwidth of 2.5 nm with tuning sensitivity 0.033 nm/V. The tuning sensitivity and bandwidth of the reported hybrid filter can also be customized comparatively at lower applied voltage than the previously reported electro-optically tunable filters. Journal: Journal of Electromagnetic Waves and Applications Pages: 18-30 Issue: 1 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1518731 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1518731 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:1:p:18-30 Template-Type: ReDIF-Article 1.0 Author-Name: Hui Gu Author-X-Name-First: Hui Author-X-Name-Last: Gu Author-Name: Jianpeng Wang Author-X-Name-First: Jianpeng Author-X-Name-Last: Wang Author-Name: Lei Ge Author-X-Name-First: Lei Author-X-Name-Last: Ge Author-Name: Lijie Xu Author-X-Name-First: Lijie Author-X-Name-Last: Xu Title: A reconfigurable patch antenna with independent frequency and polarization agility Abstract: A frequency and polarization reconfigurable patch antenna is proposed in this letter. The antenna consists of a circular patch surrounded by four sector-shaped patches. Four pairs of varactor diodes are introduced to bridge the gaps between the circular patch and the sector-shaped patches; the capacitance of the varactors is controlled by two DC signals. By adjusting the reverse bias voltage of the varactors, the proposed antenna can switch between linear polarization (LP), right-hand circular polarization (RHCP) and left-hand circular polarization (LHCP). Furthermore, the operating frequency of each polarization state can be independently tuned. A prototype has been designed and fabricated. The results indicate the proposed antenna with a continuously tunable frequency range from 1.82 to 2.28 GHz in LP states, and from 1.88 to 2.25 GHz in either RHCP or LHCP states. Meanwhile, stable radiation patterns with low cross-polarization and back radiation levels (<−15 dB) are achieved for all states. Journal: Journal of Electromagnetic Waves and Applications Pages: 31-40 Issue: 1 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1519462 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1519462 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:1:p:31-40 Template-Type: ReDIF-Article 1.0 Author-Name: Awatef Djouimaa Author-X-Name-First: Awatef Author-X-Name-Last: Djouimaa Author-Name: Mohammed Titaouine Author-X-Name-First: Mohammed Author-X-Name-Last: Titaouine Author-Name: Raouia Saidi Author-X-Name-First: Raouia Author-X-Name-Last: Saidi Author-Name: Ibtissem Adoui Author-X-Name-First: Ibtissem Author-X-Name-Last: Adoui Author-Name: Thayuan Rollim de Sousa Author-X-Name-First: Thayuan Rollim Author-X-Name-Last: de Sousa Author-Name: Alfredo Gomes Neto Author-X-Name-First: Alfredo Gomes Author-X-Name-Last: Neto Author-Name: Henri Baudrand Author-X-Name-First: Henri Author-X-Name-Last: Baudrand Title: Characterization of dual band and double polarized notched metallic ring FSS and their equivalent parallel metallic strip structures Abstract: In this work three rejecting band filters for multi band and dual polarization applications are proposed. The first proposed structure is an open quasi square FSS with a centered notch. The variation of the notch position to the left leads to the tenability of frequencies in both directions of polarization. The addition of a second notch has resulted in a third frequency in the y direction maintaining two resonant frequencies in the x direction. The structures are simulated by the Wave concept Iterative Method and the Comsol Multiphysics software 4.3b. In the second part of this paper a new approach is proposed to obtain an equivalent FSS structures based on non-coupled parallel metallic strips. The new equivalent FSS structures allow the frequency adjustment by the variation of the corresponding strip lengths. The results obtained by the WCIP method and measurements are compared and a good agreement is obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 41-56 Issue: 1 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1519463 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1519463 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:1:p:41-56 Template-Type: ReDIF-Article 1.0 Author-Name: Saeedeh Barzegar-Parizi Author-X-Name-First: Saeedeh Author-X-Name-Last: Barzegar-Parizi Title: Effective medium of stacked structure composed of periodic arrays of holes for low terahertz regime Abstract: In this paper, we study wave transmission via the stacked structures of the periodic arrays of two-dimensional holes drilled in metallic films using a simple analytical circuit model. The circuit model well explains the behavior of the multilayered structure for both thick and very thin metallic films. For very thin metallic films (equivalent to metallic meshes), the proposed surface admittance indicates that capacitive effects appear at high frequencies, while the common surface admittance obtained by heuristic approaches is purely inductive. We extract the effective medium of the structure. The effective medium is computed by solving the eigenvalues problem corresponding to the transfer matrix of a single unit cell of the structure. The comparison between the outcomes and those achieved through full-wave simulations shows excellent accordance with each other. The effective medium obtained for the structure shows which structure can act as the negative permittivity and epsilon-near-zero metamaterials at some frequencies regime. Journal: Journal of Electromagnetic Waves and Applications Pages: 57-70 Issue: 1 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1519464 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1519464 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:1:p:57-70 Template-Type: ReDIF-Article 1.0 Author-Name: Lei Xi Author-X-Name-First: Lei Author-X-Name-Last: Xi Author-Name: Huiqing Zhai Author-X-Name-First: Huiqing Author-X-Name-Last: Zhai Author-Name: Long Li Author-X-Name-First: Long Author-X-Name-Last: Li Title: A low-profile antenna system with compact new structure for reducing mutual coupling Abstract: This paper proposes a low-profile antenna system with the compact new structure for reducing mutual coupling. A rectangular artificial magnetic conductor (AMC) reflector plane is utilized to decrease the height of the proposed antenna. By adopting two new approaches, the isolation is significantly increased in an antenna system. Firstly, two inverted H-shaped metal walls with a low profile are introduced to suppress electromagnetic spatial couplings. Secondly, thanks to a compact folded T-shaped branch the electromagnetic surface wave couplings are reduced rapidly. An impendence bandwidth of 20.6% is achieved, ranging from 2.44 GHz to 3 GHz for |S11|<-10 dB. Owing to the inverted H-shaped metal walls and the compact folded T-shaped branch introduced, the isolation is significantly improved by almost 20 dB in the most band. Besides, the envelope correlation coefficient (ECC) calculated by radiation pattern is less than 0.01. Finally, fabrication and measurement of the construction are presented to demonstrate the proposed methodology. Journal: Journal of Electromagnetic Waves and Applications Pages: 71-83 Issue: 1 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1524796 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1524796 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:1:p:71-83 Template-Type: ReDIF-Article 1.0 Author-Name: R. V. Leite Author-X-Name-First: R. V. Author-X-Name-Last: Leite Author-Name: F. O. S. Costa Author-X-Name-First: F. O. S. Author-X-Name-Last: Costa Author-Name: Mailadil T. Sebastian Author-X-Name-First: Mailadil T. Author-X-Name-Last: Sebastian Author-Name: A. J. M. Sales Author-X-Name-First: A. J. M. Author-X-Name-Last: Sales Author-Name: A. S. B. Sombra Author-X-Name-First: A. S. B. Author-X-Name-Last: Sombra Title: Experimental and numerical investigation of dielectric resonator antenna based on doped Ba(Zn1/3Ta2/3)O3 ceramic Abstract: This paper reports a numerical and experimental investigation of the microwave dielectric properties of ZrO2 and Cr2O3 doped Ba(Zn1/3Ta2/3)O3 ceramic prepared the conventional solid-state ceramic route. The influence of these doping on the dielectric properties in the microwave frequencies of the Ba(Zn1/3Ta2/3)O3 matrix is investigated. The pure sample showed a dielectric permittivity around 28.98, with loss of around 10−5 and $ {\boldsymbol{\tau }_{\boldsymbol{f}}} $ τf close to zero. ZrO2 and Cr2O3 were added to the pure specimen with differents amounts 0.5 mol% and 1 mol%. The experimental and theoretical characteristics of the resonator like return loss, bandwidth, input impedance are in good agreement. The simulations of radiation patterns are presented. The samples showed a frequency response bandwidth (BW−10 dB) of around 3% (simulated) for the frequency operation. Journal: Journal of Electromagnetic Waves and Applications Pages: 84-95 Issue: 1 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1526131 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1526131 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:1:p:84-95 Template-Type: ReDIF-Article 1.0 Author-Name: Benjamin F. Akers Author-X-Name-First: Benjamin F. Author-X-Name-Last: Akers Author-Name: Jonah A. Reeger Author-X-Name-First: Jonah A. Author-X-Name-Last: Reeger Title: Numerical simulation of thermal blooming with laser-induced convection Abstract: High energy laser propagation through an absorbing fluid is examined via numerical simulation. In contrast to typical thermal blooming studies, both the laser and fluid dynamics are simulated. The beam propagation is modeled with the paraxial equation. The fluid medium is modeled with the incompressible Navier–Stokes equations. The Boussinesq approximation is used to couple the temperature to density variations. In this context, the interplay between laser-induced convection and refraction is observed. The fluid is taken to be initially homogeneous and quiescent; scintillation due to background fluctuations is ignored. Journal: Journal of Electromagnetic Waves and Applications Pages: 96-106 Issue: 1 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1528183 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1528183 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:1:p:96-106 Template-Type: ReDIF-Article 1.0 Author-Name: Bhagirath Sahu Author-X-Name-First: Bhagirath Author-X-Name-Last: Sahu Author-Name: Soni Singh Author-X-Name-First: Soni Author-X-Name-Last: Singh Author-Name: Manoj Kumar Meshram Author-X-Name-First: Manoj Kumar Author-X-Name-Last: Meshram Author-Name: S. P. Singh Author-X-Name-First: S. P. Author-X-Name-Last: Singh Title: A new compact ultra-wideband filtering antenna with improved performance Abstract: A new compact ultra-wideband (UWB) filtering antenna having good band-edge selectivity and suppressed unwanted harmonics is proposed in this paper. The proposed UWB filtering antenna is obtained by integrating modified elliptic-shaped UWB antenna with super-compact UWB bandpass filter (BPF). Initially, a UWB antenna is designed and investigated through numerical simulation and experimentally. Further, the geometrical parameters of BPF are optimized using numerical simulation software for its integration with the proposed UWB antenna to improve the passband selectivity and unwanted harmonic suppression capability of the proposed UWB filtering antenna. The proposed UWB filtering antenna has simulated −10 dB impedance bandwidth of 7.65 GHz (3.07–10.72 GHz) and unwanted harmonic suppression up to 30 GHz. It has nearly stable omnidirectional radiation patterns over whole UWB frequency band. The proposed filtering antenna was fabricated and experimentally tested. The experimental results for the filtering antenna are nearly in agreement with corresponding simulation results. Journal: Journal of Electromagnetic Waves and Applications Pages: 107-124 Issue: 1 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1529630 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1529630 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:1:p:107-124 Template-Type: ReDIF-Article 1.0 Author-Name: Muhammad Abdullah Author-X-Name-First: Muhammad Author-X-Name-Last: Abdullah Author-Name: Qinlong Li Author-X-Name-First: Qinlong Author-X-Name-Last: Li Author-Name: Wei Xue Author-X-Name-First: Wei Author-X-Name-Last: Xue Author-Name: Gantao Peng Author-X-Name-First: Gantao Author-X-Name-Last: Peng Author-Name: Yifeng He Author-X-Name-First: Yifeng Author-X-Name-Last: He Author-Name: Xiaoming Chen Author-X-Name-First: Xiaoming Author-X-Name-Last: Chen Title: Isolation enhancement of MIMO antennas using shorting pins Abstract: This paper provides an effective technique to reduce the mutual coupling between two adjacent probe-fed microstrip antenna elements operating at 3.5 GHz in multiple input multiple output (MIMO) configurations. The required reduction in the mutual coupling is achieved via loading of six metallic pins near the adjacent edges of two square patch radiators to ground the radiating elements in order to alter the polarization of the antennas. The two radiating elements are closely spaced with an edge-to-edge separation of 0.012λo and a centre-to-centre separation of 0.027λo. The idea is to make the two antennas orthogonal in terms of polarization via loading of shorting pins at appropriate locations. In order to validate the proposed technique, a two-element MIMO antenna is designed, fabricated, and measured. A good agreement between measurement and simulation is observed. Simulated and measured results are used to analyse the performance of the proposed technique in terms of mutual coupling between the two ports, radiation pattern, and realized peak gain. The measurement results show that the isolation between the two elements is enhanced from 2.8 dB to 20 dB at around 3.5 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1249-1263 Issue: 10 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1606738 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1606738 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:10:p:1249-1263 Template-Type: ReDIF-Article 1.0 Author-Name: Jinpeng Yang Author-X-Name-First: Jinpeng Author-X-Name-Last: Yang Author-Name: Xiaoying Sun Author-X-Name-First: Xiaoying Author-X-Name-Last: Sun Author-Name: Yu Zhao Author-X-Name-First: Yu Author-X-Name-Last: Zhao Author-Name: Jian Chen Author-X-Name-First: Jian Author-X-Name-Last: Chen Author-Name: Xuezhi Yan Author-X-Name-First: Xuezhi Author-X-Name-Last: Yan Title: An efficient SPICE-compatible circuit model for transmission line response excited by an electrically short dipole inside a metallic cavity Abstract: For the transmission line response excited by an electrically short dipole inside a rectangular cavity, a SPICE-compatible broadband Foster type equivalent circuit is presented. The electric field inside a cavity is represented by the eigenmode decomposition of Helmholtz equation, while the current of transmission line is expanded using the eigenmode of transmission line equation. The field-to-line coupling effect is described by the Agrawal formula. The convergence of the circuit is accelerated by the extraction of quasi-static inductances and capacitances. The validity and efficiency of the presented method is verified both in frequency and time domain. Also, the effects of lossy filling material are discussed. Besides, in order to show the aggravation effect of metallic cavity on the electromagnetic interference, the induced currents on the transmission line with and without a metallic casing are given and compared. Journal: Journal of Electromagnetic Waves and Applications Pages: 1264-1286 Issue: 10 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1606739 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1606739 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:10:p:1264-1286 Template-Type: ReDIF-Article 1.0 Author-Name: Xin Zhang Author-X-Name-First: Xin Author-X-Name-Last: Zhang Author-Name: Jinhong Wang Author-X-Name-First: Jinhong Author-X-Name-Last: Wang Author-Name: Xiaoji Zhang Author-X-Name-First: Xiaoji Author-X-Name-Last: Zhang Title: Relay transmission for air-to-undersea magnetic induction communication Abstract: The magnetic induction (MI) communication is an emerging undersea communication method, but its practical application is restricted by its limited communication distance. In this paper, an air-to-undersea magnetic induction communication scheme based on relay transmission is proposed, which can not only increase the penetrating depth but also expand the radial distance, so as to obtain a large submerged coverage of magnetic induction communication. What's more, the undersea magnetic field distribution is used to define the submerged communication range which is used as a measurement for evaluating the performance of the proposed scheme. The numerical results demonstrate that the relay transmission can multiply the submerged depth and radial distance of MI communication by deploying multiple relay nodes in predetermined positions, thus significantly increase underwater coverage of the air-to-undersea MI communication. Journal: Journal of Electromagnetic Waves and Applications Pages: 1287-1296 Issue: 10 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1607565 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1607565 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:10:p:1287-1296 Template-Type: ReDIF-Article 1.0 Author-Name: Gideon Naah Author-X-Name-First: Gideon Author-X-Name-Last: Naah Author-Name: Songbai He Author-X-Name-First: Songbai Author-X-Name-Last: He Author-Name: Weimin Shi Author-X-Name-First: Weimin Author-X-Name-Last: Shi Author-Name: Caoyu Li Author-X-Name-First: Caoyu Author-X-Name-Last: Li Author-Name: Rocco Giofrè Author-X-Name-First: Rocco Author-X-Name-Last: Giofrè Title: Impacts of continuous modes approach on the back-off efficiency of Doherty power amplifiers Abstract: This paper analyses the impacts of the harmonic-tuned hybrid continuous modes (HTHCMs) approach on the back-off efficiency of Doherty power amplifiers (DPAs). Based on the HTHCMs strategy, formulations are derived for designing the impedance inverting network (IIN) and impedance transforming network (ITN) in the DPA. Via the proposed approach, multiple impedance solutions for realizing broadband DPAs with substantial output back-off efficiency recovery is made possible. The potentiality of the design method is demonstrated by the realized prototype working from 1.4 to 2.45 GHz. Test results have shown over 50% drain efficiency at 6 dB back-off power. Journal: Journal of Electromagnetic Waves and Applications Pages: 1297-1306 Issue: 10 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1607566 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1607566 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:10:p:1297-1306 Template-Type: ReDIF-Article 1.0 Author-Name: Jie Chen Author-X-Name-First: Jie Author-X-Name-Last: Chen Author-Name: Yingzeng Yin Author-X-Name-First: Yingzeng Author-X-Name-Last: Yin Title: Multi-dimension to one-dimension transformation approach for multi-dimensional antenna array pattern synthesis Abstract: A new multi-dimension to one-dimension transformation (MTOT) approach is presented to synthesize multi-dimensional antenna array pattern. In the new approach the multi-dimensional antenna array pattern synthesis issue is mathematically transformed into a one-dimensional (1D) pattern synthesis issue by taking advantage of the general characteristics of the pattern function, which makes all existing linear array pattern synthesis and beamforming methods applicable to addressing relevant multi-dimensional array pattern synthesis issues. The new method provides a general way for multi-dimensional array pattern synthesis. Simulations of the new approach are conducted to show its effectiveness. The simulation results show that the new method can well accomplish the pattern synthesis mission for different multi-dimensional array configurations. Journal: Journal of Electromagnetic Waves and Applications Pages: 1307-1317 Issue: 10 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1607567 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1607567 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:10:p:1307-1317 Template-Type: ReDIF-Article 1.0 Author-Name: Vasa Radonić Author-X-Name-First: Vasa Author-X-Name-Last: Radonić Author-Name: Slobodan Birgermajer Author-X-Name-First: Slobodan Author-X-Name-Last: Birgermajer Author-Name: Norbert Cselyuszka Author-X-Name-First: Norbert Author-X-Name-Last: Cselyuszka Author-Name: Vesna Crnojević-Bengin Author-X-Name-First: Vesna Author-X-Name-Last: Crnojević-Bengin Title: Compact dual-band bandstop filter based on coupled open-ended Hilbert resonators Abstract: In this paper, the design procedure of a compact dual-band bandstop filter (DBBSF) based on coupled open-ended Hilbert lines is proposed. The proposed filter topology consists of two pairs of coupled open-ended lines bended in the shape of the Hilbert fractal curves and a stepped-impedance line section (SIS). In that manner, tree transmission paths are crated allowing the independent control of filter characteristic in both bands. To obtain appropriate coupling between resonators, and the independent control of the center frequencies and in-band characteristics of the filter, the SIS is introduced as matching section. Design rules are derived using lossless transmission line model and even/odd analysis. To validate the design concept, two compact DBBSFs have been designed, fabricated, and measured. The proposed filters exhibit excellent in-band characteristics, high selectivity, and small dimensions. Journal: Journal of Electromagnetic Waves and Applications Pages: 1318-1328 Issue: 10 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1607568 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1607568 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:10:p:1318-1328 Template-Type: ReDIF-Article 1.0 Author-Name: Irfan Shahid Author-X-Name-First: Irfan Author-X-Name-Last: Shahid Author-Name: Dushmantha Thalakotuna Author-X-Name-First: Dushmantha Author-X-Name-Last: Thalakotuna Author-Name: Michael Heimlich Author-X-Name-First: Michael Author-X-Name-Last: Heimlich Title: A bi-patch loaded microstrip line based 1-D periodic structure with enhanced stop bandwidth and band switching characteristics Abstract: A one-dimensional periodic structure comprising of eight unit cells each having two metallic patches sandwiched between microstrip line and ground plane has been investigated. Patches bearing dissimilar dimensions present distinct reactive loads, determined by their respective areas, to generate relatively wider bandgap. Patches can be selectively connected to ground or left floating through a combination of vias and externally controlled FET switches. Dispersion analysis of the structure has been carried out to determine the propagating modes of the line for all four possible states of the unit cell. A top-down, design guide approach has been adopted with the effect of parameters determining performance attributes captured. The proposed structure acts as an all pass filter from DC to 19.5 GHz with all patches floating and exhibits stopband characteristics from 6 to 19.5 GHz with different combinations of the switches offering an overall stop bandwidth greater than 100%. The proposed structure offers tunability from no bandgap to bandgap with added advantages of band switching capability with double the number of unique reconfigurable switch patterns as compared to conventional single patch structures. Journal: Journal of Electromagnetic Waves and Applications Pages: 1329-1342 Issue: 10 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1607781 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1607781 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:10:p:1329-1342 Template-Type: ReDIF-Article 1.0 Author-Name: Sofiane Ben Mbarek Author-X-Name-First: Sofiane Author-X-Name-Last: Ben Mbarek Author-Name: Aicha Tennich Author-X-Name-First: Aicha Author-X-Name-Last: Tennich Author-Name: Fethi Choubani Author-X-Name-First: Fethi Author-X-Name-Last: Choubani Title: Analytical modeling of cross metallic metasurfaces absorption for Terahertz Band Abstract: In this paper, models of cross metallic metasurfaces absorbers for electromagnetic waves in the terahertz (THz) frequency range are reported and discussed. The absorption of a cross unit cell with linear and circular polarization for high frequencies is investigated. The analytical modeling presented by this paper allows to have a modeling support to optimize the design of metallic absorbers for terahertz applications. This study proves that the absorption coefficient depends on the impedance of the metasurface and its dimensions. Also, these results show that inductive meatsurfaces are used when the cell size is too smaller than the wavelength while capacitive metasurfaces are used in the other case. Our simulations demonstrate that the optimum width of this structure (grid) at frequency around 200 GHz is around $20\,\mu {\rm m} $20μm. All the results indicate the cross metallic structure is promising for terahertz absorption applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1343-1353 Issue: 10 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1608317 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1608317 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:10:p:1343-1353 Template-Type: ReDIF-Article 1.0 Author-Name: Nihar Sarkar Author-X-Name-First: Nihar Author-X-Name-Last: Sarkar Author-Name: Soumen De Author-X-Name-First: Soumen Author-X-Name-Last: De Author-Name: Nantu Sarkar Author-X-Name-First: Nantu Author-X-Name-Last: Sarkar Title: Memory response in plane wave reflection in generalized magneto-thermoelasticity Abstract: This paper demonstrates the reflection phenomenon of the magneto-thermoelastic plane waves from a stress-free surface of a homogeneous, isotropic, thermally and electrically conducting solid half-space. We employ the generalized thermoelasticity model with memory-dependent derivative (MDD) for this study. We find that three basic plane waves consisting of two sets of coupled longitudinal waves and one independent shear type wave may travel with distinct speeds in the medium. The speeds of the coupled longitudinal waves are plotted graphically to predict a comparison for the MDD and Lord–Shulman models. At last, for an appropriate material, the reflection coefficients are computed numerically and presented graphically with the angle of incidence of the incident (vertically polarized) shear type wave and the obtained results are explained. Journal: Journal of Electromagnetic Waves and Applications Pages: 1354-1374 Issue: 10 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1608318 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1608318 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:10:p:1354-1374 Template-Type: ReDIF-Article 1.0 Author-Name: Bo Fang Author-X-Name-First: Bo Author-X-Name-Last: Fang Author-Name: Zhiyu Cai Author-X-Name-First: Zhiyu Author-X-Name-Last: Cai Author-Name: Yandong Peng Author-X-Name-First: Yandong Author-X-Name-Last: Peng Author-Name: Chenxia Li Author-X-Name-First: Chenxia Author-X-Name-Last: Li Author-Name: Zhi Hong Author-X-Name-First: Zhi Author-X-Name-Last: Hong Author-Name: Xufeng Jing Author-X-Name-First: Xufeng Author-X-Name-Last: Jing Title: Realization of ultrahigh refractive index in terahertz region by multiple layers coupled metal ring metamaterials Abstract: We report a polarization-independent unnaturally high refractive index metamaterial. It is found that the effective permittivity of the designed metamaterial can be drastically increased by the capacitive coupling effect. Also, the effective permeability of metamaterial can be increased by reducing the diamagnetic effect by designing a thin structure. In our work, the single-layer multi-band high refractive index metamaterials with a peak achieving to 26.8 at 0.9 THz is demonstrated. Furthermore, the three-dimensional metamaterial possessing high refractive index more than 85 around 0.91 THz can be constructed by a double-layer tricyclic structure. Ultrabroadband and ultrahigh refractive index of designed metamaterials can be obtained by multilayer coupling effect. In addition, the polarization-independent property and wide-angle performance of high refractive index metamaterial are exhibited. Journal: Journal of Electromagnetic Waves and Applications Pages: 1375-1390 Issue: 11 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1608868 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1608868 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:11:p:1375-1390 Template-Type: ReDIF-Article 1.0 Author-Name: Anumoy Ghosh Author-X-Name-First: Anumoy Author-X-Name-Last: Ghosh Author-Name: Tapan Mandal Author-X-Name-First: Tapan Author-X-Name-Last: Mandal Author-Name: Santanu Das Author-X-Name-First: Santanu Author-X-Name-Last: Das Title: Design and analysis of triple notch ultrawideband antenna using single slotted electromagnetic bandgap inspired structure Abstract: A microstrip line fed pentagonal printed ultra wideband (UWB) monopole antenna with partial ground plane having triple notches is proposed. The realized antenna has an operating bandwidth (VSWR ≤ 2) ranging from 3.1 GHz and continuing beyond 12 GHz. A novel mushroom-shaped slotted electromagnetic bandgap (EBG) inspired structure is used near the feedline to introduce triple notches at CBRS (3.5–3.7) GHz, WLAN (5.15–5.725) GHz and X-band downlink satellite communication (7.25–7.75) GHz frequencies. The band notch characteristics are demonstrated with current distribution and impedance analysis. Further, the proposed structure has stable radiation patterns, gain and group delay in the UWB range except the notch frequencies. Finally, a prototype of the proposed antenna is fabricated and measured results are in good agreement with the simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1391-1405 Issue: 11 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1609377 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1609377 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:11:p:1391-1405 Template-Type: ReDIF-Article 1.0 Author-Name: Liansheng Wang Author-X-Name-First: Liansheng Author-X-Name-Last: Wang Author-Name: Dongyan Xia Author-X-Name-First: Dongyan Author-X-Name-Last: Xia Author-Name: Quanhong Fu Author-X-Name-First: Quanhong Author-X-Name-Last: Fu Author-Name: Yuan Wang Author-X-Name-First: Yuan Author-X-Name-Last: Wang Author-Name: Xueyong Ding Author-X-Name-First: Xueyong Author-X-Name-Last: Ding Author-Name: Bo Yang Author-X-Name-First: Bo Author-X-Name-Last: Yang Title: Thermally tunable ultra-thin metamaterial absorber at P band Abstract: We report a new kind of ultra-thin tunable metamaterial absorber at P band based on the high permittivity and its thermally tunable property of strontium titanate. It is composed of a copper ring and strontium titanate at the top layer, FR4 and copper film at the middle and bottom sections. The absorption of metamaterial absorber reaches 96% at 684 MHz at 300 K and acquires the tunable property of absorption frequency by altering its external temperature. Moreover, we study the surface current and electric field distribution of the metamaterial absorber at 684 MHz at 300 K to explore the physical mechanism of electromagnetic wave absorption. Finally, we prove that the absorption is insensitive to the polarization due to the rotational symmetry of the unit cell, but sensitive to the incident angle and structure size. Our study opens a new prospect in designing the ultra-thin metamaterial absorber at P band. Journal: Journal of Electromagnetic Waves and Applications Pages: 1406-1415 Issue: 11 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1610080 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1610080 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:11:p:1406-1415 Template-Type: ReDIF-Article 1.0 Author-Name: Slawomir Koziel Author-X-Name-First: Slawomir Author-X-Name-Last: Koziel Author-Name: Piotr Kurgan Author-X-Name-First: Piotr Author-X-Name-Last: Kurgan Title: Rapid multi-objective design of integrated on-chip inductors by means of Pareto front exploration and design extrapolation Abstract: Identification of the best trade-offs between conflicting design objectives allows for making educated design decisions as well as assessing suitability of a given component or circuit for a specific application. In case of inductors, the typical objectives include maximization of the quality factor and minimization of the layout area, as well as maintaining a required inductance at a given operating frequency. This work demonstrates low-cost multi-objective design optimization of integrated inductors. The primary technique utilized here is a point-by-point Pareto front exploration where subsequent Pareto-optimal designs are obtained by moving along the front using local search methods. Considerable reduction of the design cost is achieved by extrapolating inductor dimensions at the subsequent optimal point, based on already available data as well as size constraints. The proposed methodology is verified using two examples of spiral inductors implemented in 65-nm CMOS technology. Comparisons with point-by-point optimization without extrapolation are also provided. Journal: Journal of Electromagnetic Waves and Applications Pages: 1416-1426 Issue: 11 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1610504 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1610504 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:11:p:1416-1426 Template-Type: ReDIF-Article 1.0 Author-Name: J. Kaur Author-X-Name-First: J. Author-X-Name-Last: Kaur Author-Name: Nitika Author-X-Name-First: Author-X-Name-Last: Nitika Author-Name: R. Panwar Author-X-Name-First: R. Author-X-Name-Last: Panwar Title: Design and optimization of a dual-band slotted microstrip patch antenna using Differential Evolution Algorithm with improved cross polarization characteristics for wireless applications Abstract: This work presents a rectangular microstrip-line-fed patch antenna for Long Term Evolution, Universal Mobile Telecommunication Systems, Local Area Network, Bluetooth, Industrial, Scientific and Medical, Wireless Broadband, Worldwide Interoperability for Microwave Access, International Mobile Telecommunication, Radio Frequency Identification and Wireless Fidelity applications. The overall dimensions of antenna are 70 × 70 mm2. The antenna consists of a slotted radiating patch and defected ground structure, which is used to achieve dual-band frequency characteristics with appreciable bandwidth satisfying several communication standards simultaneously. Differential Evolution (DE) Algorithm is enforced in this work for achieving the best antenna geometrical design parameters and to obtain the desired results. The proposed antenna covers dual-frequency bands viz. 2.34–2.68 and 5.28–6.32 GHz with their resonating frequencies at 2.53 and 5.77 GHz, respectively. Further, an improvement in cross polarization discrimination of 15.4 dB for E plane and 9 dB for H plane is observed using DE algorithm. The fabrication and measurement of proposed antenna was carried out to verify the simulation results in the succeeding sections. Journal: Journal of Electromagnetic Waves and Applications Pages: 1427-1442 Issue: 11 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1612283 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1612283 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:11:p:1427-1442 Template-Type: ReDIF-Article 1.0 Author-Name: Ayşegül Pekmezci Author-X-Name-First: Ayşegül Author-X-Name-Last: Pekmezci Author-Name: Ercan Topuz Author-X-Name-First: Ercan Author-X-Name-Last: Topuz Title: Modal properties of parallel plate waveguide partially loaded with double negative materials Abstract: Properties of eigen-solutions in parallel plate waveguides partially loaded with Lorentz type Double Negative Materials (DNG), modelled by lossless/lossy, identical/non-identical electric, magnetic parameters are presented. Modal cut-off phenomena associated with surface waves, transitions between evanescent/propagating, forward/backward waves and their dependence on frequency, filling factor and dispersive material parameters are investigated. Novel conditions are given for the existence of surface waves and for the emergence of complex eigenvalues in the absence of losses, and supported with numerical results of exact frequency domain analysis. Journal: Journal of Electromagnetic Waves and Applications Pages: 1443-1452 Issue: 11 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1614096 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1614096 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:11:p:1443-1452 Template-Type: ReDIF-Article 1.0 Author-Name: Haiyan Piao Author-X-Name-First: Haiyan Author-X-Name-Last: Piao Author-Name: M. Zeeshan Zahid Author-X-Name-First: M. Zeeshan Author-X-Name-Last: Zahid Author-Name: Yunnan Jin Author-X-Name-First: Yunnan Author-X-Name-Last: Jin Author-Name: Longyue Qu Author-X-Name-First: Longyue Author-X-Name-Last: Qu Title: Compact loop-type antenna with ground-mode tuning for dual-band IoT applications Abstract: A compact dual-band loop-type antenna is proposed in a small-sized ground plane for Internet-of-Things (IoT) applications. The antenna element is comprised of two adjacent resonance loops, excited by two feeding loops at the back side of the substrate, to achieve independent control of dual-band IoT applications at 0.92 and 2.45 GHz, respectively. To improve the radiation performance of the lower band, the metal frames are adopted as ground-mode tuning structures to generate a new ground-mode resonance, producing dual-resonance characteristics at 0.9 GHz bands and generating greatly improved bandwidth and radiation efficiency. Therefore, both lower and higher bands with high performances are achieved in simulation and verified in measurement. Journal: Journal of Electromagnetic Waves and Applications Pages: 1453-1462 Issue: 11 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1614097 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1614097 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:11:p:1453-1462 Template-Type: ReDIF-Article 1.0 Author-Name: Hua-Juan Lee Author-X-Name-First: Hua-Juan Author-X-Name-Last: Lee Author-Name: Eric S. Li Author-X-Name-First: Eric S. Author-X-Name-Last: Li Author-Name: Chung-Yi Li Author-X-Name-First: Chung-Yi Author-X-Name-Last: Li Author-Name: Yu-You Lin Author-X-Name-First: Yu-You Author-X-Name-Last: Lin Author-Name: Roger Lu Author-X-Name-First: Roger Author-X-Name-Last: Lu Author-Name: Kuo-Sheng Chin Author-X-Name-First: Kuo-Sheng Author-X-Name-Last: Chin Title: Bandwidth and gain enhancement of LTCC 60-GHz patch antenna by using AMC structure Abstract: This study presents 60-GHz patch antennas backed by artificial magnetic conductor (AMC) arrays for bandwidth and gain enhancement. Low-temperature cofired ceramic technology was adopted for antenna fabrication. Three patch antennas implemented with different AMC configurations were simulated and compared. The patch-shaped AMC was selected for final antenna fabrication because of its superior performance. The proposed antenna provided a measured impedance bandwidth of 50.2 − 68 GHz or an equivalent fractional bandwidth of 30.3%. The measured maximum gain was 7.8 dBi at 63 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1463-1476 Issue: 11 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1614483 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1614483 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:11:p:1463-1476 Template-Type: ReDIF-Article 1.0 Author-Name: Chunteng Li Author-X-Name-First: Chunteng Author-X-Name-Last: Li Author-Name: Yuzhong Jiang Author-X-Name-First: Yuzhong Author-X-Name-Last: Jiang Author-Name: Fangjun Liu Author-X-Name-First: Fangjun Author-X-Name-Last: Liu Title: Improved generalized sidelobe cancelation algorithm combined with signal preprocessing about interference suppression in ELF communication Abstract: In order to effectively address the two problems in extremely-low frequency (ELF) communication, a new receiving array composed by four magnetic antennas with higher sensitivity is designed, various analog filter modules are designed, which can suppress 50 Hz interference and its harmonic components effectively. Considering the low SINR in ELF communication, based on generalized sidelobe cancellation (GSC) algorithm, a new improved algorithm combined with signal preprocessing is proposed, making the proposed algorithm obtain the more reference information about the noise and interference component of the main signal, enhancing the estimation accuracy of the component, thereby achieving the better interference suppression effect. In order to test the performance of the proposed algorithm, an experimental platform is set up and multiple sets of controlled experiments are performed. The experimental results show that the proposed algorithm is better than the original algorithm, and promotes the SINR gain within the signal bandwidth to a great extent. Journal: Journal of Electromagnetic Waves and Applications Pages: 1477-1485 Issue: 11 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1614484 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1614484 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:11:p:1477-1485 Template-Type: ReDIF-Article 1.0 Author-Name: I. Gil Author-X-Name-First: I. Author-X-Name-Last: Gil Author-Name: X. Colom Author-X-Name-First: X. Author-X-Name-Last: Colom Title: Antennas based on low-cost thermoplastic polymer substrates for communication in the industrial, scientific and medical radio band Abstract: This work addresses the design guidelines, manufacturing process and experimental test of antennas based on low cost and low loss thermoplastic polymer substrates. The proposed antennas are based on patch topologies operating at the 2.45 GHz industrial scientific and medical radio band for wireless body area network applications. Several substrates composed of ethylene vinyl acetate (EVA) and reused waste chicken feather have been used. Electromagnetic simulations and experimental results have been compared. The reported results reveal a notable performance in terms of antenna parameters: return loss, radiation pattern, realized gain, and efficiency. In particular, EVA and EVA with chicken feathers present competitive return losses and gains. Moreover, on-voxel analysis reveals that specific absorption rate standards are satisfied for both public and occupational sector with a significant safety margin. The study demonstrates the viability of those polymer substrates to deploy cost-effective solutions for wireless electronic systems including reusable material substrates. Journal: Journal of Electromagnetic Waves and Applications Pages: 1486-1502 Issue: 11 Volume: 33 Year: 2019 Month: 7 X-DOI: 10.1080/09205071.2019.1614485 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1614485 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:11:p:1486-1502 Template-Type: ReDIF-Article 1.0 Author-Name: P. Rocca Author-X-Name-First: P. Author-X-Name-Last: Rocca Author-Name: F. Yang Author-X-Name-First: F. Author-X-Name-Last: Yang Author-Name: L. Poli Author-X-Name-First: L. Author-X-Name-Last: Poli Author-Name: S. Yang Author-X-Name-First: S. Author-X-Name-Last: Yang Title: Time-modulated array antennas – theory, techniques, and applications Abstract: This paper aims to present an up-to-date overview of the state-of-the-art about time-modulated arrays (TMAs). Starting from a description of the TMA fundamentals and basic theory in the time and frequency domain, the most popular techniques for synthesizing TMAs are revised. Afterwards, a survey of the main application contexts in which TMAs have been proposed is reported. Finally, current research trends are discussed and future developments envisaged. Journal: Journal of Electromagnetic Waves and Applications Pages: 1503-1531 Issue: 12 Volume: 33 Year: 2019 Month: 8 X-DOI: 10.1080/09205071.2019.1627251 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1627251 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:12:p:1503-1531 Template-Type: ReDIF-Article 1.0 Author-Name: Nilesh K. Tiwari Author-X-Name-First: Nilesh K. Author-X-Name-Last: Tiwari Author-Name: S.P. Singh Author-X-Name-First: S.P. Author-X-Name-Last: Singh Author-Name: D. Mondal Author-X-Name-First: D. Author-X-Name-Last: Mondal Author-Name: M. Jaleel Akhtar Author-X-Name-First: M. Jaleel Author-X-Name-Last: Akhtar Title: Design of frequency controlled 4G and 5G band dielectric sensors using cross-polarized metamaterial particle dedicated to communication industry Abstract: A novel approach is presented to design the dual-band planar sensor for the communication system. The proposed sensor is based on the complementary split ring resonator (CSRR) topology employing the cross-polarized excitation, which facilitates its operation even at the higher frequency band (28 GHz). The cross-polarized excitation of a CSRR allows efficient coupling of both electric and magnetic fields from the microstrip line, thereby producing the frequency-controlled dual resonance response. The prime focus here is to use the proposed approach to design two sensors with one sensor being simultaneously operated in the X-band and 5G band, while another sensor is operated in the 4G LTE band. The cross-polarized arrangement helps to achieve the higher dielectric sensitivity (17.21%) and Q factor (90) as compared to that of the co-polarized CSRR-loaded microstrip line sensor (14%, 73), where split of rings is aligned in the direction orthogonal to the microstrip line. Journal: Journal of Electromagnetic Waves and Applications Pages: 1532-1556 Issue: 12 Volume: 33 Year: 2019 Month: 8 X-DOI: 10.1080/09205071.2019.1615003 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1615003 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:12:p:1532-1556 Template-Type: ReDIF-Article 1.0 Author-Name: Mstislav E. Kaliberda Author-X-Name-First: Mstislav E. Author-X-Name-Last: Kaliberda Author-Name: Leonid M. Lytvynenko Author-X-Name-First: Leonid M. Author-X-Name-Last: Lytvynenko Author-Name: Sergey A. Pogarsky Author-X-Name-First: Sergey A. Author-X-Name-Last: Pogarsky Title: Electromagnetic interaction of two semi-infinite coplanar gratings of flat PEC strips with arbitrary gap between them Abstract: The problem of interaction between two coplanar semi-infinite gratings is considered. The total current on the flat perfectly electric conducting strips is represented as current on the isolated semi-infinite gratings and correction current. The current on every isolated semi-infinite grating is represented, in turn, as current on the infinite periodic grating and correction current. The characteristics of the scattered field are obtained from the singular integral equations. The results are validated through comparison with results obtained for the infinite periodic grating without a single strip. The current density on the strips, near- and far-field patterns is represented. Journal: Journal of Electromagnetic Waves and Applications Pages: 1557-1573 Issue: 12 Volume: 33 Year: 2019 Month: 8 X-DOI: 10.1080/09205071.2019.1615996 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1615996 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:12:p:1557-1573 Template-Type: ReDIF-Article 1.0 Author-Name: Guillermo Mejías Author-X-Name-First: Guillermo Author-X-Name-Last: Mejías Author-Name: Jose Sanchez Author-X-Name-First: Jose Author-X-Name-Last: Sanchez Author-Name: Rosario Martínez-Herrero Author-X-Name-First: Rosario Author-X-Name-Last: Martínez-Herrero Title: Parametrical characterization of the induced electric field in materials Abstract: In this work, we present a parametrical characterization of the features of the total electric field induced in material in response to an external incident field. We propose global parameters enabling characterization of the volume in which the squared modulus of the induced electric field is mainly concentrated, as well as the predominant state of polarization over the region where the power is significant. In addition, an uncertainty relationship is proven linking the region of concentration of the induced electric field and the region where its maximum rate of change occurs. Journal: Journal of Electromagnetic Waves and Applications Pages: 1574-1580 Issue: 12 Volume: 33 Year: 2019 Month: 8 X-DOI: 10.1080/09205071.2019.1617197 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1617197 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:12:p:1574-1580 Template-Type: ReDIF-Article 1.0 Author-Name: Md Nazmul Hasan Author-X-Name-First: Md Nazmul Author-X-Name-Last: Hasan Author-Name: Shahid Bashir Author-X-Name-First: Shahid Author-X-Name-Last: Bashir Author-Name: Son Chu Author-X-Name-First: Son Author-X-Name-Last: Chu Title: Dual band omnidirectional millimeter wave antenna for 5G communications Abstract: A planar dual band millimeter wave printed monopole antenna and a $2\times 2 $2×2 MIMO antenna are presented for 28/38 GHz future 5G wireless communications. The shape of the radiating element of the proposed antenna is derived from a 28 GHz rectangular monopole. The radiating element isproducing a second resonance at 38 laterally slimmed in a hemispherical manner to intensify the surface current density along the hemispherical contour, producing a second resonance at 38 GHz. The measured impedance bandwidth confirms its dual band characteristics, covering 26.65–29.2 and 36.95–39.05 GHz where $|S_{11}| \leq -10\,{\rm dB} $|S11|≤−10dB. The measured radiation patterns are omnidirectional, with a peak gain value of 1.27 and 1.83 dBi at 28 and 38 GHz, respectively. Moreover, diversity performance of the proposed MIMO antenna is evaluated in terms of MIMO performance metrics. such as envelope correlation coefficient, diversity gain, isolation and channel loss capacity. Journal: Journal of Electromagnetic Waves and Applications Pages: 1581-1590 Issue: 12 Volume: 33 Year: 2019 Month: 8 X-DOI: 10.1080/09205071.2019.1617790 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1617790 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:12:p:1581-1590 Template-Type: ReDIF-Article 1.0 Author-Name: Akinwale O. Fadamiro Author-X-Name-First: Akinwale O. Author-X-Name-Last: Fadamiro Author-Name: Oluwole J. Famoriji Author-X-Name-First: Oluwole J. Author-X-Name-Last: Famoriji Author-Name: Rabiu Sale Zakariyya Author-X-Name-First: Rabiu Sale Author-X-Name-Last: Zakariyya Author-Name: Zhongxiang Zhang Author-X-Name-First: Zhongxiang Author-X-Name-Last: Zhang Author-Name: Fujiang Lin Author-X-Name-First: Fujiang Author-X-Name-Last: Lin Title: Design of H-Tree fractal slots frequency reconfigurable hexagonal patch antenna using PIN diodes Abstract: In this paper, a frequency reconfigurable hexagonal patch antenna with the ability to operate in L and S bands is been presented. This patch incorporates a H-Tree fractal slot on the patch and ground plane of the resonating element with five (5) PIN diodes integrated on the antenna surface to change the current distribution which consequently changes the resonance frequency under different conditions of switches, thereby making it a frequency reconfigurable antenna. The proposed patch antenna allows reconfigurable switching in multiple frequency bands between 1 and 3 GHz, with relative narrow bandwidths. Computer simulation technology (CST) microwave studio software is used to analyze the design and it’s fabricated on a Rogers R4350 substrate (0.508 mm thickness) with an area of 63 mm × 69.75 mm. Both simulation and measurement have shown good agreements with each other, satisfying the requirements for Bluetooth, GSM and WLAN antenna applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1591-1604 Issue: 12 Volume: 33 Year: 2019 Month: 8 X-DOI: 10.1080/09205071.2019.1618740 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1618740 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:12:p:1591-1604 Template-Type: ReDIF-Article 1.0 Author-Name: Wissem Chouchene Author-X-Name-First: Wissem Author-X-Name-Last: Chouchene Author-Name: Chiraz Larbi Author-X-Name-First: Chiraz Author-X-Name-Last: Larbi Author-Name: Taoufik Aguili Author-X-Name-First: Taoufik Author-X-Name-Last: Aguili Title: A secure multi-frequency resonator for printable chipless RFID tag based on multifractal planar geometry Abstract: In this paper, we are presenting a secure, compact and directly printable resonator for chipless RFID tag based on multifractal planar shape. The multifractal Cantor set shows an interesting performance of the monostatic radar cross section for chipless RFID tag. Unlike the classical RFID tag, where for each frequency a resonator is needed, so the number of resonators increases when the identification range increases, by using the Iterated Function System (IFS) the obtained resonator has many resonant frequencies leading to decreasing the number of resonators in chipless RFID tag. In addition, due to their auto similarities and multiscale resolutions resonant frequencies generated by the multifractal Cantor set are not independents: all resonant frequencies are correlated, so we cannot map a frequency peak to only one resonator, because the resonator itself represents a multi frequencies signature. These lead to a more secure tag, which is a challenge for many growing applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1605-1620 Issue: 12 Volume: 33 Year: 2019 Month: 8 X-DOI: 10.1080/09205071.2019.1619628 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1619628 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:12:p:1605-1620 Template-Type: ReDIF-Article 1.0 Author-Name: Vyacheslav V. Komarov Author-X-Name-First: Vyacheslav V. Author-X-Name-Last: Komarov Title: Design equation for thin metal gratings exposed by S-polarized electromagnetic waves Abstract: The transmission characteristics of freestanding 1-D metallic gratings with rectangular lamels are studied numerically in a wide range of their sizes variations. Investigations were performed at frequencies from 75 to 350 GHz, for s-polarized incident electromagnetic waves. It is shown that obtained numerical data can be approximated by the simple analytical expression valid for different values of the grating period and metallization thicknesses from 10 to 50 mkm. Analytical data agree well with the results of numerical simulations and measurements. Journal: Journal of Electromagnetic Waves and Applications Pages: 1621-1631 Issue: 12 Volume: 33 Year: 2019 Month: 8 X-DOI: 10.1080/09205071.2019.1619629 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1619629 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:12:p:1621-1631 Template-Type: ReDIF-Article 1.0 Author-Name: Jun Yang Author-X-Name-First: Jun Author-X-Name-Last: Yang Author-Name: Ke Cai Author-X-Name-First: Ke Author-X-Name-Last: Cai Author-Name: Guangsheng Deng Author-X-Name-First: Guangsheng Author-X-Name-Last: Deng Author-Name: Zhiping Yin Author-X-Name-First: Zhiping Author-X-Name-Last: Yin Author-Name: Jiufu Ruan Author-X-Name-First: Jiufu Author-X-Name-Last: Ruan Author-Name: Fei Cai Author-X-Name-First: Fei Author-X-Name-Last: Cai Author-Name: Yong Fang Author-X-Name-First: Yong Author-X-Name-Last: Fang Title: A staggered double-vane slow-wave structure with double sheet electron beams for 340 GHz traveling wave tube Abstract: An improved slow-wave structure (SWS) for a 340 GHz traveling wave tube (TWT) is proposed. The dispersion curve and transmission characteristics of SWS have been calculated and analyzed. The transmission and reflection of the RF structure are S21 > −7 dB and S11 < −16 dB, respectively. Two sheet electron beams with identical physical parameters are used to control the operation of a TWT. In addition, the output power, gain, and bandwidth of the TWT were studied using three-dimensional particle-in-cell (PIC) simulation method. A uniform constant magnetic field with the magnetic field density of 0.2 T is used to focus the sheet electron beam. The results of the PIC simulations show that the TWT achieves the maximum output power of 12 W and the 3 dB bandwidth of 25 GHz (328–353 GHz) at the input power of 10 mW. At 340 GHz, the output power of 12 W and the gain of 30.8 dB are obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 1632-1643 Issue: 12 Volume: 33 Year: 2019 Month: 8 X-DOI: 10.1080/09205071.2019.1624628 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1624628 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:12:p:1632-1643 Template-Type: ReDIF-Article 1.0 Author-Name: Jose-Luis Olvera-Cervantes Author-X-Name-First: Jose-Luis Author-X-Name-Last: Olvera-Cervantes Author-Name: Alonso Corona-Chavez Author-X-Name-First: Alonso Author-X-Name-Last: Corona-Chavez Author-Name: Tejinder Kaur Author-X-Name-First: Tejinder Author-X-Name-Last: Kaur Author-Name: Miguel-Antonio Romero-Ramirez Author-X-Name-First: Miguel-Antonio Author-X-Name-Last: Romero-Ramirez Title: Novel microwave balanced bandpass filter with high common mode rejection ratio and wide rejection band under common mode operation Abstract: In this work, a new balanced band pass filter and its design procedure are proposed. The filter is based on a novel resonator, named LTLC resonator, which consists of two inductors (L), two Transmission Lines (TLs) and one capacitor (Cs). The resonators are designed by using its equivalent circuits and its design equations which are presented in this work. The filter exhibits central frequency at f0d = 0.988 GHz, Fractional Band Width (FBW) of 10.1%, Common Mode Rejection Ratio (CMRR) better than 51 dB at the center frequency, Common Mode (CM) rejection better than −40 dB from 0.5 GHz to 3.3f0d and better than −30 dB from 0.5 GHz to 4f0d. This paper includes analysis, design methodology and experiments. Journal: Journal of Electromagnetic Waves and Applications Pages: 1644-1651 Issue: 12 Volume: 33 Year: 2019 Month: 8 X-DOI: 10.1080/09205071.2019.1626294 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1626294 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:12:p:1644-1651 Template-Type: ReDIF-Article 1.0 Author-Name: Ye Wan Author-X-Name-First: Ye Author-X-Name-Last: Wan Author-Name: Xiao-Hua Wang Author-X-Name-First: Xiao-Hua Author-X-Name-Last: Wang Author-Name: You-Cheng Wang Author-X-Name-First: You-Cheng Author-X-Name-Last: Wang Title: A planar strongly confined spoof surface plasmonic waveguide with compact cells Abstract: A new planar waveguide structure, based on spoof surface plasmon polaritons (SSPPs), is proposed featuring compact size, low loss, and good subwavelength field confinement. Compared with the rectangular- and trapezoidal-type cells in the conventional spoof surface plasmonic waveguides (SSPWs), the proposed cell has 50.7% and 27.8% size reduction at the same cut-off frequency, respectively. Moreover, the simulated electrical field distributions show that there are good improvements in the field enhancement and subwavelength confinement. To further validate the transmission characteristics of the proposed waveguide, coplanar waveguide (CPW) and corresponding transition structures are used to get a high efficient mode conversion. A CPW-SSPW-CPW structure on a dielectric board is designed, fabricated, and measured in the microwave region. Good agreement is achieved between the simulated and measured results. The last results show that the proposed waveguide has low insertion loss and flat group delay in an ultra-wideband from 2.4 to 10.3 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1652-1659 Issue: 12 Volume: 33 Year: 2019 Month: 8 X-DOI: 10.1080/09205071.2019.1627250 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1627250 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:12:p:1652-1659 Template-Type: ReDIF-Article 1.0 Author-Name: Imen Soltani Author-X-Name-First: Imen Author-X-Name-Last: Soltani Author-Name: Takoua Soltani Author-X-Name-First: Takoua Author-X-Name-Last: Soltani Author-Name: Taoufik Aguili Author-X-Name-First: Taoufik Author-X-Name-Last: Aguili Title: Electromagnetic modeling of a reconfigurable graphene-based metasurface using MoM-GEC method for 3D digital holography Abstract: Viewing the trend of beam shaping, beam steering, and metasurface holograms, a reconfigurable graphene-based metasurface is proposed and modeled using the method of moments combined with the generalized equivalent circuit (MoM-GEC) approach. The scattering state of each individual unit cell of the metasurface can be controlled by applying different biased voltages into the graphene antennas. In fact, the complex surface conductivity of graphene is introduced in our mathematical formulation in order to tune the magnitude and phase of the local reflection coefficient. Benefitting from this scalability, our graphene-based metasurface will regenerate a 3D medical hologram. The proposed approach is validated and paves the way for the generation a 3D digital holograms. There are several important areas where this study makes an original contribution such as medical imaging 3D displays. Journal: Journal of Electromagnetic Waves and Applications Pages: 1661-1680 Issue: 13 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1627911 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1627911 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:13:p:1661-1680 Template-Type: ReDIF-Article 1.0 Author-Name: Deepender Kant Author-X-Name-First: Deepender Author-X-Name-Last: Kant Author-Name: L. M. Joshi Author-X-Name-First: L. M. Author-X-Name-Last: Joshi Author-Name: Rakesh Meena Author-X-Name-First: Rakesh Author-X-Name-Last: Meena Author-Name: Bijendra Kumar Author-X-Name-First: Bijendra Author-X-Name-Last: Kumar Author-Name: V. S. Rawat Author-X-Name-First: V. S. Author-X-Name-Last: Rawat Author-Name: V. Janyani Author-X-Name-First: V. Author-X-Name-Last: Janyani Title: Design of a 352.2 MHz, 100 kW CW power klystron Abstract: A 352.2 MHz klystron with an output power of 100 kW CW is under development at CSIR-CEERI for charged particle accelerator application. The paper presents various design results achieved through simulation of the electron gun, radio frequency (RF)  interaction structure and collector for the device. Based on the design results, a beam stick tube has been developed and hot tested for which the test results are given. A study for the design of RF interaction structure of this klystron has been carried out to get the optimized design parameters using 1-D code AJDISK and MAGIC (2D/3D). The intermediate RF cavities have been developed and characterized for their designed frequencies and the results of cold RF measurements are given. Journal: Journal of Electromagnetic Waves and Applications Pages: 1681-1699 Issue: 13 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1630324 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1630324 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:13:p:1681-1699 Template-Type: ReDIF-Article 1.0 Author-Name: Prashant Kumar Varshney Author-X-Name-First: Prashant Kumar Author-X-Name-Last: Varshney Author-Name: M. Jaleel Akhtar Author-X-Name-First: M. Jaleel Author-X-Name-Last: Akhtar Title: A compact planar cylindrical resonant RF sensor for the characterization of dielectric samples Abstract: A conventional cavity-based planar cylindrical resonant sensor for the RF characterization of dielectric materials is proposed in this work. The designed planar cylindrical sensor is about 22% more compact providing 25% higher sensitivity as compared to its rectangular counterpart working at the same frequency. The proposed sensor is designed for the fundamental TM010 mode at 1.5 GHz resonant frequency and is excited using the coaxial probe instead of conventional microstrip feeding, which aids in obtaining further compactness. The sensor is designed on low-cost FR4 substrate and experimentally validated using various dielectric samples like Teflon, polyethylene, PVC and plexiglass yielding a good match between the retrieved dielectric constants and data available in the literature. For characterization of dielectrics, a slot is drilled at the center of the sensor having the maximum electric field for inserting the test sample and later optimized for higher sensitivity. For determining the loss tangent in terms of the transmission coefficient at the resonant frequency, a numerical model is derived using the curve fitting technique. Journal: Journal of Electromagnetic Waves and Applications Pages: 1700-1717 Issue: 13 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1630325 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1630325 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:13:p:1700-1717 Template-Type: ReDIF-Article 1.0 Author-Name: Keyur Mahant Author-X-Name-First: Keyur Author-X-Name-Last: Mahant Author-Name: Hiren Mewada Author-X-Name-First: Hiren Author-X-Name-Last: Mewada Title: A novel substrate integrated waveguide (SIW) based highly selective filter for radar applications Abstract: In this paper, a novel Substrate Integrated Waveguide (SIW) based narrow bandpass filter is presented. In the proposed design, filtering response is achieved by inserting inductive posts in the SIW structure. Simulation of the proposed structure is carried out using commercial software Ansoft High Frequency Structure Simulator (HFSS), which is a three-dimensional full wave solver utilizing the finite element method (FEM). The proposed filter is fabricated on the dielectric material RT duroid 5880 with the dielectric constant ϵr = 2.2, dissipation factor tanδ = 4 × 10−4 and height h = 0.508 mm. The measured insertion and return losses are 1.22 and 18.34 dB, respectively. The measured 3-dB fractional bandwidth (FBW) is 1.475% at the center frequency of 12.2 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1718-1725 Issue: 13 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1632747 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1632747 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:13:p:1718-1725 Template-Type: ReDIF-Article 1.0 Author-Name: Aziza Zermane Author-X-Name-First: Aziza Author-X-Name-Last: Zermane Author-Name: Bruno Sauviac Author-X-Name-First: Bruno Author-X-Name-Last: Sauviac Author-Name: Linda Djouablia Author-X-Name-First: Linda Author-X-Name-Last: Djouablia Author-Name: Abdelmadjid Benghalia Author-X-Name-First: Abdelmadjid Author-X-Name-Last: Benghalia Title: Tunability of metamaterial compact band-stop filters using YIG substrate Abstract: In this paper, the design of a tunable and compact metamaterial microstrip band-stop filter is proposed. The device is designed to operate in the X band, it is based on a metamaterial pattern (single-turn square planar resonator) implemented on a ferrite substrate. The study focuses on the metamaterial band-stop filter and on the way to tune its frequency properties. For this reason, the magnetic material is a perfect solution, using YIG (Yttrium Iron Garnet) substrates. As a result, the central frequency of the filter can be tuned by varying the magnetic bias applied to the YIG substrate. A tunability up to 10.81% is obtained. The size of the proposed filter is electrically reduced to 3.7 mm2. Journal: Journal of Electromagnetic Waves and Applications Pages: 1726-1734 Issue: 13 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1632748 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1632748 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:13:p:1726-1734 Template-Type: ReDIF-Article 1.0 Author-Name: Taejun Lim Author-X-Name-First: Taejun Author-X-Name-Last: Lim Author-Name: Jungje Ha Author-X-Name-First: Jungje Author-X-Name-Last: Ha Author-Name: Seungku Lee Author-X-Name-First: Seungku Author-X-Name-Last: Lee Author-Name: Yongshik Lee Author-X-Name-First: Yongshik Author-X-Name-Last: Lee Title: Design method for dual-band filters with completely independent passbands Abstract: A design method for transmission-line-based dual-band filters with completely independent passbands is demonstrated. The proposed method completely ignores the conventional restrictions imposed on the electrical lengths of the transmission lines. Consequently, each resonator is designed separately by the predetermined parameters. Unlike conventional dual-band filters, the susceptance slope parameters at two center frequencies do not need to be maintained in all sections. As a result, the proposed filter can be designed to not only have different bandwidths, but also different responses. In addition, tuning the J-inverter values increases the design’s flexibility and compensate the theoretical limitation. The experimental results for various filters verify the proposed method, including the outstanding passband insertion loss. For the first time, a filter with a Chebyshev response in one passband and a maximally flat time-delay response in the other is demonstrated in this work. Journal: Journal of Electromagnetic Waves and Applications Pages: 1735-1748 Issue: 13 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1636720 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1636720 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:13:p:1735-1748 Template-Type: ReDIF-Article 1.0 Author-Name: Nahid Khalili Palandi Author-X-Name-First: Nahid Author-X-Name-Last: Khalili Palandi Author-Name: Najmeh Nozhat Author-X-Name-First: Najmeh Author-X-Name-Last: Nozhat Author-Name: Raheleh Basiri Author-X-Name-First: Raheleh Author-X-Name-Last: Basiri Title: Design and fabrication of small and low profile microstrip monopole antenna using CRLH-TL structures Abstract: This paper presents compact and low profile microstrip monopole antenna using composite right/left-handed transmission line (CRLH-TL) structures, which has multiband performance. The physical size of the antenna is 30 mm×30 mm×1.6 mm. The antenna is simulated utilizing the CST CAD tool, and the circuit model of the antenna is designed using ADS software. The simulated reflection coefficient of ADS is in good compromise with the CST. Also, the antenna is fabricated and the simulation and measurement results are in good agreement with each other. The proposed antenna with two unit cells has good reflection coefficient and quasi-omnidirectional patterns with the peak gain of 3.43 dBi at 8.37 GHz and the radiation efficiency of 70% at 2.4 GHz and 4.58 GHz. Also, the antenna with three unit cells has the peak gain of 5.2 dBi at 4.19 GHz and the efficiency of 85% at 3.04 GHz that covers WiMAX/WLAN/ITU bands. Journal: Journal of Electromagnetic Waves and Applications Pages: 1749-1763 Issue: 13 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1637285 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1637285 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:13:p:1749-1763 Template-Type: ReDIF-Article 1.0 Author-Name: Qinlong Li Author-X-Name-First: Qinlong Author-X-Name-Last: Li Author-Name: Muhammad Abdullah Author-X-Name-First: Muhammad Author-X-Name-Last: Abdullah Author-Name: Xiaoming Chen Author-X-Name-First: Xiaoming Author-X-Name-Last: Chen Title: Defected ground structure loaded with meandered lines for decoupling of dual-band antenna Abstract: A defected ground structure (DGS) loaded with meandered lines is proposed to reduce mutual coupling of a dual-band planar multiple-input multiple-output (MIMO) antenna. To verify the effectiveness of a proposed DGS, a dual-band MIMO antenna is designed and manufactured. The antenna consists of two planar-inverted F-antenna (PIFA) elements printed symmetrically for dual-band operation. The DGS is placed between these two PIFA elements to reduce mutual coupling. The DGS consists of a slot and a pair of meander lines inside it, hence generating two independently tuneable resonances. A two element MIMO antenna is studied using computer simulation and a final design is manufactured. The antenna is measured using the Satimo Starlab system. Simulation results show that the MIMO antenna has the bandwidths (S11 & S22<−10 dB, S21 & S12<−15 dB) of 1.56–2.71 GHz (1.15 GHz or 54%) and 4.82–5.9 GHz (1.08 GHz or 20%) in the lower and higher frequency bands, respectively. Measurement results agree well with the simulation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1764-1775 Issue: 13 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1643261 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1643261 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:13:p:1764-1775 Template-Type: ReDIF-Article 1.0 Author-Name: Wei Jie Fu Author-X-Name-First: Wei Jie Author-X-Name-Last: Fu Author-Name: Ping Du Author-X-Name-First: Ping Author-X-Name-Last: Du Author-Name: Rong Chuang Hu Author-X-Name-First: Rong Chuang Author-X-Name-Last: Hu Title: Fast wideband scattering analysis of large-scale finite-sized periodic arrays with planar cells using ASED basis function and interpolation technique Abstract: In this paper, the accurate sub-entire-domain (ASED) basis function method is combined with the interpolation technique to efficiently analyze the wideband electromagnetic scattering from the large-scale finite-sized periodic arrays with planar cells. Comparing with the conventional method of moments (MoM), the ASED basis function method can tremendously reduce the number of unknowns. Thus, the computational complexity can be tremendously reduced. It is a single-frequency technique. The impedance matrix needs to be calculated repeatedly at each frequency. The interpolation technique can speed up the wideband simulation because the impedance matrices can be efficiently obtained using the interpolation technique. To validate the accuracy and efficiency of the proposed method, several numerical examples are carried out. Simulation results show that the results of the proposed technique agree well with those of the ASED bases. Both the CPU time and the memory cost are significantly reduced by using the proposed method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1776-1788 Issue: 13 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1643790 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1643790 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:13:p:1776-1788 Template-Type: ReDIF-Article 1.0 Author-Name: Keqiang Wang Author-X-Name-First: Keqiang Author-X-Name-Last: Wang Author-Name: Hao Li Author-X-Name-First: Hao Author-X-Name-Last: Li Author-Name: Tianming Li Author-X-Name-First: Tianming Author-X-Name-Last: Li Author-Name: Yong Luo Author-X-Name-First: Yong Author-X-Name-Last: Luo Author-Name: Haiyang Wang Author-X-Name-First: Haiyang Author-X-Name-Last: Wang Author-Name: Jianing Zhao Author-X-Name-First: Jianing Author-X-Name-Last: Zhao Author-Name: Chaoxiong He Author-X-Name-First: Chaoxiong Author-X-Name-Last: He Title: Analysis and design of a novel dual-band coaxial waveguide mode converter for high-power microwave applications Abstract: Based on the derived coupling coefficients of the circular waveguide and coaxial waveguide, a novel dual-band serpentine coaxial mode converter is proposed in this paper. This dual-band converter consists of two parts: an inner inserted circular waveguide TM01-TE11 converter operating at Ka-band, and an outer coaxial waveguide TEM-TE11 converter working at Ku-band. The inner and outer converters have the same curvature distribution along the propagation direction with a structure length of 800 mm. Simulated results exhibit that the maximum conversion efficiencies of the inner and outer converters reach 98.7% and 98.9% at 35 and 15 GHz, respectively. The bandwidths of the inner and outer converter are 1.9 and 2.5 GHz when the conversion efficiency is over 90%. Furthermore, the dual-band mode converter has a symmetry and reciprocity structure with coaxial-parallel input/output port. The good agreement between theoretical calculations and simulation demonstrates the feasibility of this design. Journal: Journal of Electromagnetic Waves and Applications Pages: 1789-1800 Issue: 13 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1643791 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1643791 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:13:p:1789-1800 Template-Type: ReDIF-Article 1.0 Author-Name: Z. Menachem Author-X-Name-First: Z. Author-X-Name-Last: Menachem Title: Propagation in curved waveguides and applications Abstract: This paper is a review of the various methods described in the literature for propagation in curved waveguides for many applications. Marcatili and Schmeltzer were the first researchers in the field of bent waveguides. Other researchers have included Marhic, Miyagi, Kawakami, Falciai and Harrington. Many other interesting methods have been suggested by the other researchers in the literature as improved solutions to the problems of bending. Some recent authors have presented methods to solve the problems of curved waveguides as well (improved ray model, improved mode model, etc.). This paper is meant to allow researchers to be updated with recent publications in the entire field of propagation in bent waveguides. The methods described may serve for an analysis of curved waveguides in the IR regimes and in the microwave and millimeter wave regimes, with potential applications for medical devices and for using diffused optical waveguides in integrated optics. Journal: Journal of Electromagnetic Waves and Applications Pages: 1801-1833 Issue: 14 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1660234 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1660234 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:14:p:1801-1833 Template-Type: ReDIF-Article 1.0 Author-Name: Guoping Gao Author-X-Name-First: Guoping Author-X-Name-Last: Gao Author-Name: Bin Hu Author-X-Name-First: Bin Author-X-Name-Last: Hu Author-Name: Chen Yang Author-X-Name-First: Chen Author-X-Name-Last: Yang Author-Name: Shaofei Wang Author-X-Name-First: Shaofei Author-X-Name-Last: Wang Author-Name: Ruifeng Zhang Author-X-Name-First: Ruifeng Author-X-Name-Last: Zhang Title: Design of a dual band-notched UWB antenna and improvement of the 5.5 GHz WLAN notched characteristic Abstract: A novel dual band-notched ultra-wideband (UWB) planar antenna with improved characteristic in 5.5 GHz WLAN notched band is presented. Two kinds of L-shaped slots are inserted in the radiator in order to obtain the dual notched characteristics. A separated strip is added in the middle of the U-shaped radiator for further improving the performance. The antenna has a measured impedance bandwidth of 3.1–11.0 GHz with VSWR < 2, while it has dual notched bands of 3.4–4.0 GHz and 4.9–6.0 GHz. Besides, the equivalent circuit model, transmission line model and transfer function are also studied to investigate the band-notched performance of the proposed antenna. Journal: Journal of Electromagnetic Waves and Applications Pages: 1834-1845 Issue: 14 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1638836 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1638836 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:14:p:1834-1845 Template-Type: ReDIF-Article 1.0 Author-Name: Chenyin Yu Author-X-Name-First: Chenyin Author-X-Name-Last: Yu Author-Name: Shuhui Yang Author-X-Name-First: Shuhui Author-X-Name-Last: Yang Author-Name: Yinchao Chen Author-X-Name-First: Yinchao Author-X-Name-Last: Chen Author-Name: Dongdong Zeng Author-X-Name-First: Dongdong Author-X-Name-Last: Zeng Title: Radiation enhancement for a triband microstrip antenna using an AMC reflector characterized with three zero-phases in reflection coefficient Abstract: A compact tricyclic nested triband microstrip antenna is designed in this paper, which is composed of three metal rectangular rings, an input feed line, and an elliptic-shaped defected ground structure (DGS). To enhance the antenna's radiation performance, a novel artificial magnetic conductor (AMC) reflector characterized with three zero-phases in the reflection coefficient at 2.4, 4.2 and 5.8 GHz is proposed, which mainly consists of complementary split ring resonators (CSRR). The measured S-parameters and radiation patterns agree well with the simulated data. The antenna's three impedance bandwidths span in the ranges of 2.22-2.49, 2.94-4.96, and 5.41-6.62 GHz, respectively, which effectively cover all the 2.4/5.2/5.8-GHz WLAN frequency bands and the 2.5/3.5/5.5-GHz WiMAX bands. Particularly, by adding the designed AMC reflector, the measured antenna gains at the frequency points of 2.4, 2.5, 3.5, 5.5 and 5.8 GHz have been improved with 4.22, 4.42, 1.99, 6.44 and 3.46 dB, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 1846-1859 Issue: 14 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1645743 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1645743 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:14:p:1846-1859 Template-Type: ReDIF-Article 1.0 Author-Name: Anurag Srivastava Author-X-Name-First: Anurag Author-X-Name-Last: Srivastava Author-Name: Siva Penmetsa Author-X-Name-First: Siva Author-X-Name-Last: Penmetsa Author-Name: Latha Christie Author-X-Name-First: Latha Author-X-Name-Last: Christie Author-Name: K. N. Bhat Author-X-Name-First: K. N. Author-X-Name-Last: Bhat Title: Electromagnetic design of a 220 GHz BWO with experimental study of micro-fabricated folded waveguide structure Abstract: Backward-wave oscillator (BWO) is the most promising source for the generation of a few watts of power at millimetre wave and sub-millimetre wave frequencies. This paper presents the electrical design of a folded waveguide BWO at 220 GHz. The dispersion of the structure was theoretically calculated and further validated by numerical simulation using CST MWS. A minimum output power of 5 W at 220 GHz, was obtained using the particle-in-cell simulation of CST MWS, at the beam voltage of 10 kV and a current of 50 mA. Also, a power of around 1 W is obtained over a band of 4.5 GHz by voltage tuning. The ultra-thick ∼750 µm height Au-structure is fabricated using multi-step photolithography and etching processes while keeping the surface roughness well below the skin depth. The slow wave structure was tested and it was found that the return-loss is in good agreement with the simulation results within ∼5 dB, throughout the 185–260 GHz band. Journal: Journal of Electromagnetic Waves and Applications Pages: 1860-1873 Issue: 14 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1645744 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1645744 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:14:p:1860-1873 Template-Type: ReDIF-Article 1.0 Author-Name: Sadegh Rayatzadeh Author-X-Name-First: Sadegh Author-X-Name-Last: Rayatzadeh Author-Name: Gholamhosein Moloudian Author-X-Name-First: Gholamhosein Author-X-Name-Last: Moloudian Title: Design and fabrication of a miniaturized lowpass-bandpass diplexer with wide tuning range and high isolation Abstract: In this article, a compact lowpass-bandpass (LP-BP) diplexer with high isolation for wireless telecommunication applications is presented. The −3 dB cut-off frequency of the lowpass filter (LPF) is equal to 1 GHz. The roll-off-rate (ROF or ζ) parameter is sharp and equal to 108.8 dB/GHz, and the rejection level in the stopband is 20 dB. The center frequency of bandpass filter (BPF) is 2.4 GHz. The tuning range of −3 dB cut-off frequency of the LPF is wide and ranges from 0.3 to 0.89 GHz. The tuning range of center frequency of the BPF is wide and ranges from 2.65 to 3.1 GHz. The obtained isolation between the two output ports is better than 30 dB. The proposed tunable LP-BP diplexer is designed, simulated, fabricated and measured. The results of measurement and simulation are in good agreement with each other. The proposed diplexer has a compact size of 64 × 38 mm2. Journal: Journal of Electromagnetic Waves and Applications Pages: 1874-1889 Issue: 14 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1649604 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1649604 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:14:p:1874-1889 Template-Type: ReDIF-Article 1.0 Author-Name: Seyit Ahmet Sis Author-X-Name-First: Seyit Ahmet Author-X-Name-Last: Sis Author-Name: Fuat Kilic Author-X-Name-First: Fuat Author-X-Name-Last: Kilic Author-Name: Serkan Sezen Author-X-Name-First: Serkan Author-X-Name-Last: Sezen Title: Multi sub-coil flux pipe couplers and their use in a misalignment-adaptive wireless power transfer system Abstract: Flux pipe couplers are compact coils used in wireless power transfer (WPT) applications. The first part of this paper investigates the effect number of sub-coils on the magnetic characteristics. Flux pipe couplers with more than two sub-coils exhibit higher coupling coefficient as compared to traditional flux pipe couplers with two sub-coils. Furthermore, multi sub-coil flux pipe couplers better distribute the magnetic flux inside the core, making them attractive in high power applications. The second part presents an experimental WPT system employing multi sub-coil flux pipe couplers with three sub-coils. More than 82% power transfer efficiency is observed when couplers are separated with 100 mm vertical gap. Lateral misalignments up to 200 mm are then applied, and meantime, the separation between sub-coils is varied for achieving maximum efficiency. A near-constant efficiency is obtained up to 150 mm misalignment. Therefore, this paper announces another potential use of flux pipe couplers realizing an adaptive WPT system. Journal: Journal of Electromagnetic Waves and Applications Pages: 1890-1904 Issue: 14 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1652117 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1652117 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:14:p:1890-1904 Template-Type: ReDIF-Article 1.0 Author-Name: Chien-Ching Chiu Author-X-Name-First: Chien-Ching Author-X-Name-Last: Chiu Author-Name: Gang-Ze Lee Author-X-Name-First: Gang-Ze Author-X-Name-Last: Lee Author-Name: Hao Jiang Author-X-Name-First: Hao Author-X-Name-Last: Jiang Author-Name: Bo-Jie Hong Author-X-Name-First: Bo-Jie Author-X-Name-Last: Hong Title: Microwave imaging of a periodic homogeneous dielectric object buried in rough surfaces Abstract: This paper presents the reconstruction of a periodic homogeneous dielectric object buried in rough surfaces. First, a TM (Transverse Magnetic) polarized wave is transmitted through the surface to a buried object. Integral equations are derived by using the Maxwell equation, the two-dimensional periodic Green function, Green identity and the boundary condition. The integral equations are solved numerically by the method of moment (MOM) to obtain the scattering field. The problem of inverse scattering is transformed into an optimization problem. Next, the Self-Adaptive Dynamic Differential Evolution (SADDE) method is used for object reconstruction. Numerical results show that the SADDE converges to the overall extreme value (global extreme) regardless of the initial guess. We have found that the convergence speed of the periodic length is always better than the shape function and dielectric constant. Moreover, we can still obtain good reconstruction results even if the noise is added in the scattered field. Journal: Journal of Electromagnetic Waves and Applications Pages: 1905-1919 Issue: 14 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1653229 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1653229 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:14:p:1905-1919 Template-Type: ReDIF-Article 1.0 Author-Name: Mohammad Amin Imani Author-X-Name-First: Mohammad Amin Author-X-Name-Last: Imani Author-Name: Farzin Shama Author-X-Name-First: Farzin Author-X-Name-Last: Shama Author-Name: Mohsen Alirezapoori Author-X-Name-First: Mohsen Author-X-Name-Last: Alirezapoori Author-Name: Saeed Haghiri Author-X-Name-First: Saeed Author-X-Name-Last: Haghiri Author-Name: Abbas Ghadrdan Author-X-Name-First: Abbas Author-X-Name-Last: Ghadrdan Title: Ultra-Miniaturized Wilkinson Power Divider with Harmonics Suppression for Wireless Applications Abstract: In this paper, an ultra-compact size microstrip Wilkinson Power Divider (WPD) has been proposed with nth harmonic suppression. Two symmetrical lowpass filters have been applied to suppress third to 11th harmonics. These cells are replaced by quarter-wavelength transmission lines to achieve desired harmonic suppression. The central frequency of the PD is located in 2.5 GHz, and the physical size is only 9.4×7.2= 67 mm2, which is normalized as 0.06 λg *0.08 λg. The applied lowpass filter has analyzed and then, the proposed PD presented with the insertion loss of less than 0.6 dB and return loss of 35 dB. The measured S-parameters showed a good adaption with the simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1920-1932 Issue: 14 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1653230 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1653230 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:14:p:1920-1932 Template-Type: ReDIF-Article 1.0 Author-Name: Adam Steckiewicz Author-X-Name-First: Adam Author-X-Name-Last: Steckiewicz Author-Name: Agnieszka Choroszucho Author-X-Name-First: Agnieszka Author-X-Name-Last: Choroszucho Title: Optimization-based synthesis of a metamaterial electric cloak using nonhomogeneous composite materials Abstract: In the paper the synthesis of an electric cloak is discussed. The nonhomogeneous composite material was proposed as a realization of a stationary electric field metamaterial with anisotropic properties necessary for cloaking objects. The particle swarm optimization (PSO) method was applied for the synthesis of nonhomogeneous material composed of periodically arranged unit cells. Anisotropic properties of metamaterial were achieved by adjusting the internal geometry of a porous unit cell structure. Proposed elements have a wide range of effective electrical conductivities in orthogonal directions of an external static electric field. Optimization scheme was applied to design the required unit cell structure, defined by four geometrical parameters modified and adjusted by the PSO. The numerical models of the conductive background, non-conductive object and several types of cloaks were investigated. The results obtained by The Finite element method (FEM) were characterized with respect to theoretical values of the required conductivities and cloaking effectiveness. Journal: Journal of Electromagnetic Waves and Applications Pages: 1933-1941 Issue: 14 Volume: 33 Year: 2019 Month: 9 X-DOI: 10.1080/09205071.2019.1654928 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1654928 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:14:p:1933-1941 Template-Type: ReDIF-Article 1.0 Author-Name: Shahid Ullah Author-X-Name-First: Shahid Author-X-Name-Last: Ullah Author-Name: Cunjun Ruan Author-X-Name-First: Cunjun Author-X-Name-Last: Ruan Author-Name: Tanveer Ul Haq Author-X-Name-First: Tanveer Ul Author-X-Name-Last: Haq Author-Name: Xingyun Zhang Author-X-Name-First: Xingyun Author-X-Name-Last: Zhang Title: High performance THz patch antenna using photonic band gap and defected ground structure Abstract: In this work, a high-performance THz microstrip patch antenna is designed using defected ground structure and photonic band-gap. The operating frequency of the proposed antenna is 0.690 THz. DGS and PBG are used to enhance gain, directivity, return loss and VSWR of the antenna. The proposed antenna is simulated in two different design software’s (CST2015, HFSS2018). First, a rectangular microstrip patch antenna is designed, at 0.696 THz, than RSRR structures are used in the substrate as a PBG. Next, the same RSRR structures are used in the ground known as DGS which enhances the VSWR and return loss of the antenna. The last step decreases the size of the substrate to enhance the value of VSWR up to 1.0015 which is close to unity and return loss, gain and directivity are −64.16 dBi, 6.793 dBi, and 6.914 dBi respectively. The bandwidth of the antenna is 26.7 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1943-1954 Issue: 15 Volume: 33 Year: 2019 Month: 10 X-DOI: 10.1080/09205071.2019.1654929 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1654929 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:15:p:1943-1954 Template-Type: ReDIF-Article 1.0 Author-Name: E. Moreno Author-X-Name-First: E. Author-X-Name-Last: Moreno Author-Name: E. Michael Author-X-Name-First: E. Author-X-Name-Last: Michael Title: Illumination study of a quantum MIM diode for the mid-infrared Abstract: Metal-insulator-metal (MIM) junctions with insulators a few nanometers thick are quantum-tunneling diodes able to operate at frequencies up to $10^{15} $1015 Hz. However, their main limitation is their poor harvested current. This paper demonstrates that a distributed illumination produced by combining a beam splitter with the Kretschmann and Reather prism-based configuration extends the tunneling event to the entire junction length with the same probability all along the junction. This increases the harvested quantum-tunneling current and the diode responsivity. Journal: Journal of Electromagnetic Waves and Applications Pages: 1955-1977 Issue: 15 Volume: 33 Year: 2019 Month: 10 X-DOI: 10.1080/09205071.2019.1659188 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1659188 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:15:p:1955-1977 Template-Type: ReDIF-Article 1.0 Author-Name: Honglei Wang Author-X-Name-First: Honglei Author-X-Name-Last: Wang Author-Name: Kunde Yang Author-X-Name-First: Kunde Author-X-Name-Last: Yang Author-Name: Yixin Yang Author-X-Name-First: Yixin Author-X-Name-Last: Yang Title: Electromagnetic fields in air produced by underwater magnetic dipoles with attitude variation in real marine environment Abstract: Wireless data transmission from seawater to air is a challenging and valuable research hotspot. Ideally and theoretically, underwater electromagnetic (EM) waves can propagate across sea-air interface and the trans-media component in air can reach a great distance. However, in real marine environment, underwater antenna's attitude varies due to water current. In this paper, EM fields in air produced by underwater magnetic dipoles with varying attitude are investigated. The field distributions and intensity variations in air are presented. Experiments on sea were conducted and the data are compared with theoretical simulations. The results show that field in air is greatly affected by underwater antenna's attitude, and the effect is more obvious in vertical magnetic dipole than in horizontal one. In conclusion, it is indicated that EM waves have a great potential in wireless data transmission from seawater to air even if underwater antenna would have some attitude variation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1978-1995 Issue: 15 Volume: 33 Year: 2019 Month: 10 X-DOI: 10.1080/09205071.2019.1661288 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1661288 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:15:p:1978-1995 Template-Type: ReDIF-Article 1.0 Author-Name: Zhigang Lu Author-X-Name-First: Zhigang Author-X-Name-Last: Lu Author-Name: Ruidong Wen Author-X-Name-First: Ruidong Author-X-Name-Last: Wen Author-Name: Weihua Ge Author-X-Name-First: Weihua Author-X-Name-Last: Ge Author-Name: Zhicheng Su Author-X-Name-First: Zhicheng Author-X-Name-Last: Su Author-Name: Kesen Ding Author-X-Name-First: Kesen Author-X-Name-Last: Ding Author-Name: Meiling Zhu Author-X-Name-First: Meiling Author-X-Name-Last: Zhu Author-Name: Zhanliang Wang Author-X-Name-First: Zhanliang Author-X-Name-Last: Wang Author-Name: Tao Tang Author-X-Name-First: Tao Author-X-Name-Last: Tang Title: Design of a low-gain high-power W-band sheet-beam traveling wave tube using a double-staggered grating slow wave structure Abstract: In order to further improve the output power of W-band traveling wave tube (TWT), a low gain TWT was proposed as a secondary amplifier. It uses a double staggered grating slow wave structure (DSG-SWS) and a sheet beam. Firstly, the design of DSG-TWT was given. Through simulation, the DSG-TWT could provide a saturation output power of more than 1000 W in the frequency range of 93–97 GHz, and the maximum output power could reach 1200 W at 95 GHz. No oscillation and current interception were found. Then DSG-SWS was fabricated by E-plane partition method using high-precision CNC milling. The SWS was fed with a high-power input-output coupler which consists of a mode converter and an impedance transformer. Simulation and cold-test results were presented, showing that the S11 is less than −10 dB and the voltage standing wave ratio (VSWR) is less than 2.0 in the frequency range of 93–100 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1996-2008 Issue: 15 Volume: 33 Year: 2019 Month: 10 X-DOI: 10.1080/09205071.2019.1661798 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1661798 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:15:p:1996-2008 Template-Type: ReDIF-Article 1.0 Author-Name: O. N. Bikeev Author-X-Name-First: O. N. Author-X-Name-Last: Bikeev Author-Name: A. N. Bogolyubov Author-X-Name-First: A. N. Author-X-Name-Last: Bogolyubov Author-Name: K. P. Lovetskiy Author-X-Name-First: K. P. Author-X-Name-Last: Lovetskiy Author-Name: N. E. Nikolaev Author-X-Name-First: N. E. Author-X-Name-Last: Nikolaev Author-Name: L. A. Sevastianov Author-X-Name-First: L. A. Author-X-Name-Last: Sevastianov Title: Electromagnetic surface waves guided by a twist discontinuity in a uniaxial dielectric with optic axis lying in the discontinuity plane Abstract: A method for calculating the eigenwaves in a “semi-infinite” uniaxial dielectric medium (UDM) is proposed. The term “semi-infinite” medium implies the presence of at least one flat boundary of such medium. This method allowed writing out all the components of the total fields in UDM. With the help of that analytical representation of the fields, the problem of the propagation of Dyakonov surface waves guided by the planar interface of two identical UDM with their optic axes lying in the interface plane was investigated to derive an exact analytical expression for the phase speed, when the direction of propagation bisects the angle formed by the two optic axes. On the basis of the solutions found, the energy characteristics were studied, which demonstrated the presence of the flux of average over a period power of the Dyakonov wave along the coordinate axes lying in the plane of UDM boundary. Journal: Journal of Electromagnetic Waves and Applications Pages: 2009-2021 Issue: 15 Volume: 33 Year: 2019 Month: 10 X-DOI: 10.1080/09205071.2019.1655486 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1655486 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:15:p:2009-2021 Template-Type: ReDIF-Article 1.0 Author-Name: Miryam Paredes Author-X-Name-First: Miryam Author-X-Name-Last: Paredes Author-Name: Silvano Bertoldo Author-X-Name-First: Silvano Author-X-Name-Last: Bertoldo Author-Name: Lorenzo Carosso Author-X-Name-First: Lorenzo Author-X-Name-Last: Carosso Author-Name: Claudio Lucianaz Author-X-Name-First: Claudio Author-X-Name-Last: Lucianaz Author-Name: Emanuele Marchetta Author-X-Name-First: Emanuele Author-X-Name-Last: Marchetta Author-Name: Marco Allegretti Author-X-Name-First: Marco Author-X-Name-Last: Allegretti Author-Name: Patrizia Savi Author-X-Name-First: Patrizia Author-X-Name-Last: Savi Title: Propagation measurements for a LoRa network in an urban environment Abstract: LoRa is a relatively new proprietary communication technology that allows long-range communication distances while consuming very little power. It utilizes license-free Industrial, Scientific and Medical ISM frequency bands to exchange information at low data rates. LoRa is favourable when looking for limited exchange of data and low-cost devices and infrastructure. This work presents some preliminary propagation measurements in a typical urban environment by using prototype transmitters and receivers working in a private network. Results highlight that LoRa can be used as a communication technology for different ad-hoc networks deployed in an urban area. Journal: Journal of Electromagnetic Waves and Applications Pages: 2022-2036 Issue: 15 Volume: 33 Year: 2019 Month: 10 X-DOI: 10.1080/09205071.2019.1661287 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1661287 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:15:p:2022-2036 Template-Type: ReDIF-Article 1.0 Author-Name: Intikhab Hussain Author-X-Name-First: Intikhab Author-X-Name-Last: Hussain Author-Name: Frederick Cawood Author-X-Name-First: Frederick Author-X-Name-Last: Cawood Author-Name: Rex van Olst Author-X-Name-First: Rex Author-X-Name-Last: van Olst Title: A line-of-sight propagation performance study for underground mining in an arched-shaped tunnel environment Abstract: This article investigates the effect of antenna polarization, directivity and placement on the line-of-sight wideband radio channel characteristics of an arch-shaped underground mine tunnel over the 2.4 GHz frequency band. Access point-to-access point and access point-to-mobile wireless communication configurations were examined for linearly and circularly polarized antennas mounted in the center, on the wall and ceiling. The circularly polarized directional antennas offer higher coherent bandwidth, whereas the linearly polarized omni-directional antennas offer lower attenuation rate. A higher directive antenna enhances coverage area, coverage reliability and channel coherent bandwidth. For access point-to-mobile communication, a circularly polarized directional antenna with a horizontally polarized omni-directional antenna gives the best performance in terms of attenuation rate and coherent bandwidth. Journal: Journal of Electromagnetic Waves and Applications Pages: 2037-2045 Issue: 15 Volume: 33 Year: 2019 Month: 10 X-DOI: 10.1080/09205071.2019.1662334 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1662334 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:15:p:2037-2045 Template-Type: ReDIF-Article 1.0 Author-Name: Takoua Soltani Author-X-Name-First: Takoua Author-X-Name-Last: Soltani Author-Name: Imen Soltani Author-X-Name-First: Imen Author-X-Name-Last: Soltani Author-Name: Taoufik Aguili Author-X-Name-First: Taoufik Author-X-Name-Last: Aguili Title: Electromagnetic modeling of an active integrated antenna with a MESFET device using MoM-GEC method for UWB applications Abstract: This paper presents electromagnetic modeling of an active integrated antenna (AIA) with a MESFET device, located inside an infinite rectangular waveguide. This work highlights the influence of the active device in the antenna performance for Ultra Wide Band (UWB) systems. In fact, the method of Moments (MoM) combined with the generalized equivalent circuits (GEC) approach in conjunction with the physical-based small-signal model is applied to compute the input impedance, the reflection coefficient, the current density and the electric field distributions of the AIA resonating at 4 GHz. The physical-based small-signal model was employed to characterize the active device. For validation purpose, the calculated results are compared to the simulated ones on the ADS Agilent simulator. Using S11 < −10 dB technique, it was found that the antenna bandwidth is superior to 500 MHz. In this sense, the collective gain is therefore investigated and calculated for the entire AIA. Journal: Journal of Electromagnetic Waves and Applications Pages: 2046-2067 Issue: 15 Volume: 33 Year: 2019 Month: 10 X-DOI: 10.1080/09205071.2019.1663272 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1663272 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:15:p:2046-2067 Template-Type: ReDIF-Article 1.0 Author-Name: Housseyn Sedra Author-X-Name-First: Housseyn Author-X-Name-Last: Sedra Author-Name: Slobodan Simić Author-X-Name-First: Slobodan Author-X-Name-Last: Simić Author-Name: Bojan Milanović Author-X-Name-First: Bojan Author-X-Name-Last: Milanović Author-Name: Dimitrije Bujaković Author-X-Name-First: Dimitrije Author-X-Name-Last: Bujaković Author-Name: Milenko Andrić Author-X-Name-First: Milenko Author-X-Name-Last: Andrić Title: Partial angular-diversity RCS-based target recognition using subsequence dynamic time-warping Abstract: In this paper, angular-diversity Radar Cross Section (RCS) based target recognition using Subsequence Dynamic Time-Warping (S-DTW) algorithm is proposed. The goal is to identify the similarity between an RCS segment of unknown and full RCS pattern of known targets through collected partial angular-diversity RCS. The unknown target is the test target, while the known targets are previously seen targets in a database. The partial angular-diversity technique can greatly reduce the efforts of collecting RCS because only a small number of measuring locations are required to achieve accurate recognition. The ability to determinate scattered angle is also investigated. Our simulation shows that using S-DTW algorithm the recognition scheme will have good abilities in both discriminating targets and angle determination. This approach provides good trade-off between data collection complexity and quality of target classification. Journal: Journal of Electromagnetic Waves and Applications Pages: 2068-2080 Issue: 15 Volume: 33 Year: 2019 Month: 10 X-DOI: 10.1080/09205071.2019.1656112 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1656112 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:15:p:2068-2080 Template-Type: ReDIF-Article 1.0 Author-Name: Luca Bossi Author-X-Name-First: Luca Author-X-Name-Last: Bossi Author-Name: Pierluigi Falorni Author-X-Name-First: Pierluigi Author-X-Name-Last: Falorni Author-Name: Lorenzo Capineri Author-X-Name-First: Lorenzo Author-X-Name-Last: Capineri Title: Performance comparison for the detection of defects in thermal insulating materials using microwave holograms acquired manually and with a robotized scanner Abstract: In many cryogenic systems, during useful life, defects or degradation of performance are found. Frequently these malfunctions are due to the presence of alterations in the characteristics of the thermal insulating materials used to coat the metal parts of the system. It is useful to evaluate methods for investigating the quality of insulating coatings by means of instruments, with low cost, that can be easily used during production. Thermal insulating materials are characterized by a relative dielectric constant close to the unit and a low Loss Factor: this work aims to investigate the use of microwave holographic radar for the detection of defects in such materials. The results show good detectability of defects when they are oriented as the antenna axis. Finally, it is shown that the robotic scan can examine large areas with the same detection performances of manual scan but with less set up and scanning time. Journal: Journal of Electromagnetic Waves and Applications Pages: 2081-2095 Issue: 16 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1663273 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1663273 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:16:p:2081-2095 Template-Type: ReDIF-Article 1.0 Author-Name: Ghanshyam Singh Author-X-Name-First: Ghanshyam Author-X-Name-Last: Singh Author-Name: Binod Kumar Kanaujia Author-X-Name-First: Binod Kumar Author-X-Name-Last: Kanaujia Author-Name: Vijay K. Pandey Author-X-Name-First: Vijay K. Author-X-Name-Last: Pandey Author-Name: Deepak Gangwar Author-X-Name-First: Deepak Author-X-Name-Last: Gangwar Author-Name: Sachin Kumar Author-X-Name-First: Sachin Author-X-Name-Last: Kumar Title: Design of compact dual-band patch antenna loaded with D-shaped complementary split ring resonator Abstract: In this paper, an inset-fed dual-band patch antenna with truncated corners is presented. The ground plane of the antenna is loaded with D-shaped complementary split ring resonator (D-CSRR) structures to obtain dual-band resonance and size miniaturization. The overall electrical size of the antenna is 0.29λ0 × 0.25λ0 and patch size is 0.14λ0 × 0.13λ0, where λ0 is evaluated at the lowest resonating frequency. The proposed planar antenna is low profile and does not need a dual feed or any external feeding mechanism for obtaining circular polarization. A size reduction of 66% is achieved as compared to the conventional patch antenna. The newly designed D-CSRR results in better miniaturization factor making proposed antenna suitable for modern wireless applications. The prototype of the antenna is fabricated and experimental findings are compared with electromagnetic and analytical results. Journal: Journal of Electromagnetic Waves and Applications Pages: 2096-2111 Issue: 16 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1663274 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1663274 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:16:p:2096-2111 Template-Type: ReDIF-Article 1.0 Author-Name: Hongwei Yang Author-X-Name-First: Hongwei Author-X-Name-Last: Yang Author-Name: Yuqi Wang Author-X-Name-First: Yuqi Author-X-Name-Last: Wang Author-Name: Shuo Peng Author-X-Name-First: Shuo Author-X-Name-Last: Peng Title: Analysis of the propagation properties of photonic crystals with defect by the precise integration time domain method Abstract: Propagation properties of photonic crystals with defect are analyzed by the precise integration time domain (PITD) method in the paper. The precise integration is applied to the finite difference time domain in this method. The Yee cell differential discretization technique is used in space, and the precise integration method is adopted in time. The correctness of the method is demonstrated by calculating the one-dimensional photonic crystals with defect. The transmission coefficients of the transverse electric (TE) and transverse magnetic (TM) modes in the two-dimensional photonic crystals with defect are also obtained by the method. Furthermore, the stability, precision and efficiency of the method are discussed. Numerical results reveal that the PITD method is not limited by the Courant stability condition and has higher calculation precision and efficiency, which provides a new and effective analytical method for studying the propagation properties of photonic crystals with defect. Journal: Journal of Electromagnetic Waves and Applications Pages: 2112-2125 Issue: 16 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1663275 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1663275 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:16:p:2112-2125 Template-Type: ReDIF-Article 1.0 Author-Name: Jakub Sorocki Author-X-Name-First: Jakub Author-X-Name-Last: Sorocki Author-Name: Kamil Staszek Author-X-Name-First: Kamil Author-X-Name-Last: Staszek Author-Name: Ilona Piekarz Author-X-Name-First: Ilona Author-X-Name-Last: Piekarz Author-Name: Slawomir Gruszczynski Author-X-Name-First: Slawomir Author-X-Name-Last: Gruszczynski Author-Name: Krzysztof Wincza Author-X-Name-First: Krzysztof Author-X-Name-Last: Wincza Title: Selectivity improved directional filters using cross-coupling introduced transmission zeros Abstract: In this paper, the realization of traveling-wave directional filters allowing for selectivity improvement without increasing filter’s order is presented and studied. It is shown that the introduction of loose cross-coupling between #(n-1)th loop resonator and isolated port of the nth-order directional filter allows for generating transmission zeros in the bandpass branch and thus to improve the filter`s roll-off. Moreover, the electrical length of the cross-coupling connecting transmission line allows for adjusting the location of transmission zeros and realizing symmetric or asymmetric frequency response. The presented approach is theoretically analyzed and experimentally verified. Exemplary second- and third-order directional filters with symmetrically placed transmission zeros were designed to operate at f0 = 1 GHz, manufactured and measured. The obtained results prove their applicability towards the realization of frequency multiplexers. Journal: Journal of Electromagnetic Waves and Applications Pages: 2126-2141 Issue: 16 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1663371 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1663371 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:16:p:2126-2141 Template-Type: ReDIF-Article 1.0 Author-Name: Chao Rong Author-X-Name-First: Chao Author-X-Name-Last: Rong Author-Name: Bo Zhang Author-X-Name-First: Bo Author-X-Name-Last: Zhang Title: Fractional electromagnetic waves in circular waveguides with fractional-order inductance characteristics Abstract: The Maxwell equations play a vital role in the electromagnetic theory. With the development of Fractional Calculus and its applications, new fractional Maxwell equations are required to describe fractional electromagnetic fields. In this paper, the fractional electromagnetic induction law is presented with considering the properties of fractional inductance. Based on this, we have obtained the fractional Maxwell equations. In addition, the non-homogeneous fractional wave equations and the homogeneous fractional vector Helmholtz equations are deduced. Using these results, we investigate the behavior of electromagnetic waves in fractional circular waveguides with fractional-order inductance characteristics. The results show that the electromagnetic fields change with different fractional orders. Journal: Journal of Electromagnetic Waves and Applications Pages: 2142-2154 Issue: 16 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1664335 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1664335 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:16:p:2142-2154 Template-Type: ReDIF-Article 1.0 Author-Name: Honggui Li Author-X-Name-First: Honggui Author-X-Name-Last: Li Author-Name: Maria Trocan Author-X-Name-First: Maria Author-X-Name-Last: Trocan Author-Name: Dimitri Galayko Author-X-Name-First: Dimitri Author-X-Name-Last: Galayko Title: Virtual fingerprint and two-way ranging-based Bluetooth 3D indoor positioning with RSSI difference and distance ratio Abstract: This paper proposes a new method of 3D indoor positioning based on Bluetooth devices. Virtual Received Signal Strength Indicator (RSSI) fingerprint is built on RSSI difference and distance ratio. The concepts and stability of 1D and 2D virtual fingerprints are introduced, and the property of uniqueness for virtual fingerprint is proved. 2D virtual fingerprint is more stable than that of 1D for indoor positioning. Various positioning algorithms, based on virtual fingerprint and one-way ranging, are discussed, such as NN, KNN, Multi-Step and nonlinear optimization, inference and regression. Multi-Step algorithm holds the best performance in time and error. The proposed method utilizes virtual fingerprint and two-way ranging to overcome the four evident shortcomings of the traditional RRSI fingerprint-based methods. Firstly, measured RSSI is calibration-less for different Bluetooth devices and varying battery status. Secondly, virtual fingerprint of training is obtained by computing, not measured point by point in whole 3D indoor environment. Thirdly, 3D indoor positioning method is employed to substitute for the classical 2D positioning methods. Finally, two-way ranging is adopted to take the place of the conventional one-way ranging and improve the positioning precision. The correctness and availability of the proposed method are testified by the simulation and hardware experiments. Journal: Journal of Electromagnetic Waves and Applications Pages: 2155-2174 Issue: 16 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1667268 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1667268 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:16:p:2155-2174 Template-Type: ReDIF-Article 1.0 Author-Name: Peng-Ju Yang Author-X-Name-First: Peng-Ju Author-X-Name-Last: Yang Author-Name: Rui Wu Author-X-Name-First: Rui Author-X-Name-Last: Wu Author-Name: Xin-Cheng Ren Author-X-Name-First: Xin-Cheng Author-X-Name-Last: Ren Author-Name: Yu-Qiang Zhang Author-X-Name-First: Yu-Qiang Author-X-Name-Last: Zhang Author-Name: Ye Zhao Author-X-Name-First: Ye Author-X-Name-Last: Zhao Title: Doppler spectra of electromagnetic wave scattered from an object flying above time-varying nonlinear sea surfaces Abstract: Doppler spectra of electromagnetic wave scattered from an object flying above time-varying nonlinear sea surfaces are investigated by utilizing a hybrid algorithm combining method of moments (MoM) and Kirchhoff approximation (KA). The “choppy wave” model is employed for describing nonlinear hydrodynamic interactions between ocean waves. Doppler spectra of scattered wave are simulated and analyzed for different incidence angles, target velocities, target heights, sea states as well as sea surface models, and an obvious broadening of Doppler spectrum is observed due to the coupling scattering between the flying target and rough sea surfaces. In comparison with the normalized radar cross section, Doppler spectra of scattered wave have the advantage of extracting information regarding target flying above dynamic sea surfaces. This study is of great value for the analysis of coupling scattering between flying target and rough sea surface as well as for the detection low-flying target in sea clutter environment. Journal: Journal of Electromagnetic Waves and Applications Pages: 2175-2198 Issue: 16 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1674191 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1674191 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:16:p:2175-2198 Template-Type: ReDIF-Article 1.0 Author-Name: Milad Hadei Author-X-Name-First: Milad Author-X-Name-Last: Hadei Author-Name: Mohammad Khalaj-Amirhosseini Author-X-Name-First: Mohammad Author-X-Name-Last: Khalaj-Amirhosseini Title: Design, simulation, and fabrication of microstrip lens with non-uniform contour for 360 degree scanning Abstract: In designing lens as a beamformer, the phase error is one of the most important challenges. Non-focal lens design for 360-degree scanning is the sufficient method for reducing phase error. In this paper, a novel method for reducing phase error of 360-degree scanning non-focal lens has introduced by considering nonlinear contour as a new optimization parameter based on Fourier series expansion. The average phase error is lowered by about 40% in comparison with previously reported work. To evaluate the proposed method, the non-focal lens has been implemented at 10 GHz and measurements are in good agreement with simulation results. The Results show improvements of array factor in side lobe level, beam direction and uniformity of beam width at 10 GHz. The bandwidth of the structure is 2 GHz. Because of the unique features of this lens, it can be used in 5G systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 2199-2214 Issue: 16 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1675537 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1675537 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:16:p:2199-2214 Template-Type: ReDIF-Article 1.0 Author-Name: Maria C. Pechlivanidou Author-X-Name-First: Maria C. Author-X-Name-Last: Pechlivanidou Author-Name: Ioannis D. Chasiotis Author-X-Name-First: Ioannis D. Author-X-Name-Last: Chasiotis Author-Name: Yannis L. Karnavas Author-X-Name-First: Yannis L. Author-X-Name-Last: Karnavas Title: A comparative study on 2D and 3D magnetic field analysis of permanent magnet synchronous motor using FEM simulations Abstract: Permanent magnet synchronous motors (PMSMs) have recently gained increasing industrial and research interest. The PMSM design and especially its performance evaluation through two-dimensional (2D) and three-dimensional (3D) magnetic field analysis using finite element method (FEM) is not trivial, as it is a quite demanding and time consuming procedure. Furthermore, there has always been doubt on the accuracy of 2D analysis results and on which type of analysis is the most preferable one for the specific motor. This work aims to emphasize the difficulties and the advantages that arise from the 3D analysis. The aforementioned simulations were performed for the case of a four-pole PMSM. Several magnetic and electromechanical quantities have been determined. Additionally, various materials were utilized for the construction of stator and rotor cores and their effect on the motor’s behavior was investigated. Finally, the derived results are compared and useful conclusions regarding the solution accuracy are given. Journal: Journal of Electromagnetic Waves and Applications Pages: 2215-2241 Issue: 17 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1674190 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1674190 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:17:p:2215-2241 Template-Type: ReDIF-Article 1.0 Author-Name: Puspraj Singh Chauhan Author-X-Name-First: Puspraj Singh Author-X-Name-Last: Chauhan Author-Name: Diwaker Tiwari Author-X-Name-First: Diwaker Author-X-Name-Last: Tiwari Author-Name: Sanjay Kumar Soni Author-X-Name-First: Sanjay Kumar Author-X-Name-Last: Soni Author-Name: Sandeep Kumar Author-X-Name-First: Sandeep Author-X-Name-Last: Kumar Title: Energy detector performance over log-normal fading channel with diversity reception Abstract: In this work, the performance of energy detection (ED)-based spectrum-sensing in cognitive radio (CR) networks over the Log-Normal (LN) fading channel has been analyzed. More specifically, accurate analytical expressions for the average detection probability using various diversity techniques, namely maximal ratio combining (MRC), equal gain combining (EGC), and selection combining (SC) are derived and evaluated. To get the improved system performance, the detection threshold parameter is optimized by minimizing the probability of error. The impact of the shadowing parameters on the performance of energy detectors is studied in the light of complimentary receiver operating characteristics (CROC) and area under the receiver operating characteristics curve (AUC). The derived analytical framework is generic which can be used for both integer and non-integer values of the shadowing parameters. To verify the correctness of our analysis, the derived results are corroborated via Monte-Carlo simulations. Journal: Journal of Electromagnetic Waves and Applications Pages: 2242-2256 Issue: 17 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1675538 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1675538 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:17:p:2242-2256 Template-Type: ReDIF-Article 1.0 Author-Name: Bin Wu Author-X-Name-First: Bin Author-X-Name-Last: Wu Author-Name: Zhe Chen Author-X-Name-First: Zhe Author-X-Name-Last: Chen Author-Name: Jun-Ge Liang Author-X-Name-First: Jun-Ge Author-X-Name-Last: Liang Author-Name: Cong Wang Author-X-Name-First: Cong Author-X-Name-Last: Wang Author-Name: Yihui Jin Author-X-Name-First: Yihui Author-X-Name-Last: Jin Author-Name: Xiaoxin Zhang Author-X-Name-First: Xiaoxin Author-X-Name-Last: Zhang Author-Name: Xiaofeng Gu Author-X-Name-First: Xiaofeng Author-X-Name-Last: Gu Title: Compact and low-loss diplexer design and fabrication for WLAN/WiMAX application Abstract: In this paper, a compact and low-loss diplexer is designed and fabricated using integrated passive device (IPD) technique. This IPD-based diplexer can be utilized in antenna system for WLAN and WiMAX applications. It is composed of a low-pass filter and a high-pass filter, built on the GaAs substrate with the overall size of 0.95 × 0.95 mm2. The IPD diplexer realizes a dual-mode operation of 2.4 GHz for WLAN and 3.3 GHz to 3.8 GHz for WiMAX, respectively. The measurement results match well with the simulation results, in which the insertion loss at operation bands are below 0.5 dB (2.4 GHz) and 0.64 dB (3.3 GHz to 3.8 GHz), and the stopband suppression keeps higher than 20 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 2257-2265 Issue: 17 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1676827 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1676827 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:17:p:2257-2265 Template-Type: ReDIF-Article 1.0 Author-Name: Teng-Fei Wei Author-X-Name-First: Teng-Fei Author-X-Name-Last: Wei Author-Name: Xiao-Hua Wang Author-X-Name-First: Xiao-Hua Author-X-Name-Last: Wang Author-Name: Cheng-Hui Qu Author-X-Name-First: Cheng-Hui Author-X-Name-Last: Qu Title: Swapped double-sided EBG power/ground plane for broadband suppression of noise and radiation emission Abstract: A novel swapped double-sided electromagnetic bandgap (DS-EBG) power/ground plane is proposed with broadband suppression of the simultaneous switching noise (SSN) and low radiation emission. By using the double-sided structure, the equivalent inductance between the EBG cells can be well improved and result in the broadband suppression of SSN. In the proposed structure, pairs of via are used to build the three-dimensional bridges between the swapped power/ground planes. They also lead to the suppressions of SSN be improved. Simulated and measured results show good agreements with each other. Additionally, the measured radiation emission of the proposed structure shows that it has lower electromagnetic interference compared with the two typical reference boards. Journal: Journal of Electromagnetic Waves and Applications Pages: 2266-2272 Issue: 17 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1676828 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1676828 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:17:p:2266-2272 Template-Type: ReDIF-Article 1.0 Author-Name: Sharhabeel Alyones Author-X-Name-First: Sharhabeel Author-X-Name-Last: Alyones Author-Name: Michael Granado Author-X-Name-First: Michael Author-X-Name-Last: Granado Author-Name: Charles. W. Bruce Author-X-Name-First: Charles. W. Author-X-Name-Last: Bruce Title: Investigations toward highly absorbing particulate aerosols with minimal total scattering in the UV spectral region Abstract: In this computational and experimental study, we investigate appropriate available particulate materials dispersed as aerosols using two in-situ methods of dispersal in a search for maximal absorption and minimal scattering, with an objective of obtaining less than one percent total scattering in the UV spectral region (300–400 nm). Fifteen commercial carbon nano-particulate materials have been investigated and categorized according to their extinction efficiencies and scattering percentages when measured in-situ. The extinction efficiencies were measured both in liquid suspensions, which allows various mechanisms for particle separation, and in-situ. The size distributions were produced, and the corresponding scattering percentages of the extinction efficiencies were calculated, using the discrete dipole–dipole approximation theory. This study shows that high efficiency particles with no more than a few percent total scattering could be aerosolized in-situ in the UV spectral region. Journal: Journal of Electromagnetic Waves and Applications Pages: 2273-2286 Issue: 17 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1676829 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1676829 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:17:p:2273-2286 Template-Type: ReDIF-Article 1.0 Author-Name: Longyue Qu Author-X-Name-First: Longyue Author-X-Name-Last: Qu Author-Name: Yunxue Xu Author-X-Name-First: Yunxue Author-X-Name-Last: Xu Author-Name: Haiyan Piao Author-X-Name-First: Haiyan Author-X-Name-Last: Piao Author-Name: Hyeongdong Kim Author-X-Name-First: Hyeongdong Author-X-Name-Last: Kim Title: Antenna performance improvement by utilizing a small parasitic slot in stacked PCBs for IoT devices Abstract: This paper proposes a simple and efficient technique to improve the antenna radiation performance in stacked printed circuit boards (PCBs) for Internet-of-Things (IoT) applications. In the proposed design, a planner loop-type ground radiation antenna with compact size is implemented at the upper PCB for 2.4 GHz applications, while the lower PCB overlaps with the upper PCB, inducing out-of-phase current distributions over the lower PCB, thereby resulting in a narrow bandwidth and low efficiency. Therefore, a small parasitic resonator is utilized on the lower PCB to diminish the undesired out-of-phase current. Higher efficiency and wider bandwidth are thus achieved by tuning the impedance characteristic of the parasitic slot, indicating the proposed technique is effective in improving antenna performance for devices with stacked PCBs. Journal: Journal of Electromagnetic Waves and Applications Pages: 2287-2295 Issue: 17 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1676830 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1676830 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:17:p:2287-2295 Template-Type: ReDIF-Article 1.0 Author-Name: E. Allahyari Author-X-Name-First: E. Author-X-Name-Last: Allahyari Author-Name: M. Asgari Author-X-Name-First: M. Author-X-Name-Last: Asgari Title: Effect of magnetic-thermal field on nonlinear wave propagation of circular nanoplates Abstract: In this article, an analytical approach is developed to investigate the nonlinear vibrational behavior of an graphene sheet. In order to be a practical instance, the circular nanoplate is also resting on an external Pasternak elastic medium including the Winkler modulus and shear modulus parameters. At the same time, it is subjected to the magnetic field and a thermal load. The modified couple stress theory as well as Eringen nonlocal elasticity theory involving small scale parameters are implemented to justify the size-dependent effects. The governing equations are derived based on von Kármán nonlinear strain–displacement relations. The presented method is verified by comparing the obtained results to their counterparts reported in the published literature. Effects of various parameters such as nonlocal parameters, temperature change, and elastic medium coefficients for different boundary conditions are also discussed. Numerical results reveal that the intrinsic size-dependent property of material increases the natural frequency. Journal: Journal of Electromagnetic Waves and Applications Pages: 2296-2316 Issue: 17 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1677271 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1677271 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:17:p:2296-2316 Template-Type: ReDIF-Article 1.0 Author-Name: Mariam A. Shahinyan Author-X-Name-First: Mariam A. Author-X-Name-Last: Shahinyan Author-Name: Ara P. Antonyan Author-X-Name-First: Ara P. Author-X-Name-Last: Antonyan Author-Name: Vitali P. Kalantaryan Author-X-Name-First: Vitali P. Author-X-Name-Last: Kalantaryan Author-Name: Marieta S. Mikaelyan Author-X-Name-First: Marieta S. Author-X-Name-Last: Mikaelyan Author-Name: Poghos O. Vardevanyan Author-X-Name-First: Poghos O. Author-X-Name-Last: Vardevanyan Title: Study of the influence of millimeter range electromagnetic waves on methylene blue complexes with human serum albumin Abstract: In the present work the thermostability and fluorescence peculiarities of the methylene blue complexes with human serum albumin have been studied under the effect of millimeter range electromagnetic waves. For this aim the denaturation of the complexes was measured using the double-beam spectrophotometer Unicam-SP8-100 and the fluorescence measurements were carried out on the spectrofluorometer Cary Eclipse. The albumin solutions were irradiated by electromagnetic waves with 41.8 and 51.8 GHz frequencies. The irradiation was shown to result in the thermostability increasing of the complexes and this effect depends on the frequency. It was also revealed that at the irradiation the fluorescence properties of the methylene blue complexes with albumin change, which, in turn, is connected to the alteration of the protein folding. Journal: Journal of Electromagnetic Waves and Applications Pages: 2317-2327 Issue: 17 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1677508 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1677508 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:17:p:2317-2327 Template-Type: ReDIF-Article 1.0 Author-Name: Esra Şengün Ermeydan Author-X-Name-First: Esra Author-X-Name-Last: Şengün Ermeydan Author-Name: İlyas Çankaya Author-X-Name-First: İlyas Author-X-Name-Last: Çankaya Author-Name: Asaf Behzat Şahin Author-X-Name-First: Asaf Behzat Author-X-Name-Last: Şahin Title: Super-resolution algorithm applied to images acquired at millimeter wave frequency in single pixel and computational ghost imaging configurations Abstract: The lack of low cost, high-resolution two-dimensional imaging detectors and the expensiveness of the measurements make millimeter wave imaging challenging. Single detector configurations are promising to solve data acquisition problem in millimeter wave imaging. In this study, millimeter wave imaging in transmission mode is done with single pixel imaging and computational ghost imaging configurations. In order to reduce the number of measurements in each configuration, Compressed Sensing architecture is used. To increase the image resolution, software-based super-resolution is applied. To the best of our knowledge, this is first study comparing the computational ghost imaging with single pixel imaging, besides software-based super-resolution method is applied to the real world millimeter wave images. It is seen that super-resolution increases the quality in both configurations while computational ghost imaging has better quality compared to single pixel imaging in millimeter waves. Journal: Journal of Electromagnetic Waves and Applications Pages: 2328-2340 Issue: 17 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1678525 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1678525 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:17:p:2328-2340 Template-Type: ReDIF-Article 1.0 Author-Name: Prakash Ranjan Author-X-Name-First: Prakash Author-X-Name-Last: Ranjan Author-Name: Arvind Choubey Author-X-Name-First: Arvind Author-X-Name-Last: Choubey Author-Name: Santosh Kumar Mahto Author-X-Name-First: Santosh Kumar Author-X-Name-Last: Mahto Author-Name: Rashmi Sinha Author-X-Name-First: Rashmi Author-X-Name-Last: Sinha Author-Name: Chetan Barde Author-X-Name-First: Chetan Author-X-Name-Last: Barde Title: A novel ultrathin wideband metamaterial absorber for X-band applications Abstract: In this paper, a wideband Metamaterial Absorber (MA) is presented for various applications of X-band spectra. MA consists of an array of a unit cell arranged in a periodic fashion having two split square resonators printed on FR4 substrate whose relative permittivity is 4.4. The simulation result reveals that $-10 $−10 dB absorption bandwidth of 5.98 GHz (from 5.94 GHz to 11.92 GHz) and the Full Width Half Maxima (FWHM) bandwidth of 7.55 GHz (from 5.58 GHz to 13.13 GHz). It has three peaks of absorption at 6.2, 8.1 and 11.1 GHz with Absorptivity of 99.59, 99.92 and 99.85 $\% $%, respectively. $0.095\lambda _0 $0.095λ0 $\lambda _0 $λ0 The profile of absorber is low due to unit cell size dimensions of 9 mm×9 mm. The absorption mechanism is explained by taking effective electromagnetic parameters ( $\epsilon _{\rm eff} $ϵeff and $\mu _{\rm eff} $μeff) which are reacquired. The absorber has been investigated for a wide angle of oblique incidence and for different polarization angles as well. The proposed absorber is fabricated and its Absorptivity is tested experimentally. Journal: Journal of Electromagnetic Waves and Applications Pages: 2341-2353 Issue: 17 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1681299 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1681299 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:17:p:2341-2353 Template-Type: ReDIF-Article 1.0 Author-Name: Zailei Luo Author-X-Name-First: Zailei Author-X-Name-Last: Luo Author-Name: Bin Han Author-X-Name-First: Bin Author-X-Name-Last: Han Author-Name: Xueming He Author-X-Name-First: Xueming Author-X-Name-Last: He Author-Name: Dexin Zhao Author-X-Name-First: Dexin Author-X-Name-Last: Zhao Title: Failure correction of linear antenna array using complex method enhanced teaching-learning based optimization algorithm Abstract: The relatively high probability of elements failure is a concerning problem for large scale phased antenna arrays, which leads to degrade the antenna’s performance significantly. The array performance degradation can be corrected by re-optimizing the array excitations. Teaching-learning based optimization (TLBO) is newly proposed swarm intelligence based evolutionary algorithm, which imitates the social behavior of teaching-learning process in the classroom. In this paper, an effective approach using complex method enhanced teaching-learning based optimization (ETLBO) algorithm is proposed for correction of antenna arrays in the presence of faulty elements. Numerical simulation results show that the proposed ETLBO algorithm having more advantages in finding global optimal solution than original TLBO algorithms. Experimental results of a 32-element phased array are presented to demonstrate that the proposed ETLBO algorithm is effective in practical engineering field. Journal: Journal of Electromagnetic Waves and Applications Pages: 2354-2371 Issue: 17 Volume: 33 Year: 2019 Month: 11 X-DOI: 10.1080/09205071.2019.1681300 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1681300 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:17:p:2354-2371 Template-Type: ReDIF-Article 1.0 Author-Name: Krishnaswamy Sankaran Author-X-Name-First: Krishnaswamy Author-X-Name-Last: Sankaran Title: Protecting oceans from illicit oil spills: environment control and remote sensing using spaceborne imaging radars Abstract: Oceans are the largest ecosystems of our planet and the most abused ones. Accidental and intentional pollution continue to damage the marine environment to unfathomable scale and consequences. We present the problem of illicit vessel oil discharges on oceans and discuss the technological solutions possible through spaceborne radar imaging. We highlight various milestones and important historical developments in this domain applied to ocean oil spill monitoring and environment control. We introduce different detection techniques and evaluate their performance for detecting illicit oil spills on oceans. Finally, we discuss the current status, highlight some of the open challenges and possible future directions for spaceborne radar imaging of the oceans. Journal: Journal of Electromagnetic Waves and Applications Pages: 2373-2403 Issue: 18 Volume: 33 Year: 2019 Month: 12 X-DOI: 10.1080/09205071.2019.1685409 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1685409 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:18:p:2373-2403 Template-Type: ReDIF-Article 1.0 Author-Name: Giada M. Battaglia Author-X-Name-First: Giada M. Author-X-Name-Last: Battaglia Author-Name: Gennaro G. Bellizzi Author-X-Name-First: Gennaro G. Author-X-Name-Last: Bellizzi Author-Name: Andrea F. Morabito Author-X-Name-First: Andrea F. Author-X-Name-Last: Morabito Author-Name: Gino Sorbello Author-X-Name-First: Gino Author-X-Name-Last: Sorbello Author-Name: Tommaso Isernia Author-X-Name-First: Tommaso Author-X-Name-Last: Isernia Title: A general effective approach to the synthesis of shaped beams for arbitrary fixed-geometry arrays Abstract: We propose a new approach to the mask-constrained synthesis of shaped beams through generic array antennas having arbitrary layouts and element patterns. The introduced general methodology allows casting the design problem as a finite number of Convex Programming optimizations and can generate different excitation solutions all fulfilling the required specifications. Numerical examples, including planar arrays and the full-wave synthesis of an aperiodic array, are provided in support of the given theory. Journal: Journal of Electromagnetic Waves and Applications Pages: 2404-2422 Issue: 18 Volume: 33 Year: 2019 Month: 12 X-DOI: 10.1080/09205071.2019.1683472 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1683472 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:18:p:2404-2422 Template-Type: ReDIF-Article 1.0 Author-Name: Mohammad Habibur Rahaman Author-X-Name-First: Mohammad Habibur Author-X-Name-Last: Rahaman Author-Name: Tamal Sarkar Author-X-Name-First: Tamal Author-X-Name-Last: Sarkar Author-Name: Brandon A. Kemp Author-X-Name-First: Brandon A. Author-X-Name-Last: Kemp Title: Tunable and large plasmonic field enhancement in core-shell heterodimer/trimer Abstract: Heterodimer/trimer are two/three closely adjacent nanoparticles dissimilar in shape or size, and represent a simple nanoscale geometry which gives rise to a remarkably rich set of properties. The core-shell nanostructure has advantages of tunability and stability over a similar homogeneous particle. We theoretically demonstrate tunable and significant field enhancement in both heterodimer and heterotrimer systems using core-shell geometry with a metal shell and dielectric core and compared our results with core-shell homodimer and homotrimer. The analytical modeling is based on the Rayleigh theory for small particles and Foldy–Lax multi-scattering theory for multiple particles. It is shown that the E-field can be enhanced in core-shell dimer/trimer due to the plasmonic resonance in the metal shell, which can be easily tunable by changing the core-shell ratio, composition of the core and shell, relative size and distance between the particles, and wavelength of the incident light. We report significant maximum field intensity enhancement near the particles. Moreover, this tunable nanostructures with high field intensity can be useful as potential bio-sensing applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 2423-2433 Issue: 18 Volume: 33 Year: 2019 Month: 12 X-DOI: 10.1080/09205071.2019.1683473 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1683473 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:18:p:2423-2433 Template-Type: ReDIF-Article 1.0 Author-Name: Biplab Bag Author-X-Name-First: Biplab Author-X-Name-Last: Bag Author-Name: Priyabrata Biswas Author-X-Name-First: Priyabrata Author-X-Name-Last: Biswas Author-Name: Rahul Mondal Author-X-Name-First: Rahul Author-X-Name-Last: Mondal Author-Name: Sushanta Biswas Author-X-Name-First: Sushanta Author-X-Name-Last: Biswas Author-Name: Partha Pratim Sarkar Author-X-Name-First: Partha Pratim Author-X-Name-Last: Sarkar Title: Dual-band dual-sense circularly polarized U- and L-shaped strip monopole antenna for WiMAX/WLAN applications Abstract: In this paper, a single-layer dual-band dual-sense circularly polarized monopole antenna is presented for Wireless Local Area Network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) applications. The proposed antenna consists L, U shape strips and a 50 Ω microstrip feedline. This antenna is printed on one side of low-cost FR4 epoxy substrate with a thickness of 1.6 mm and partial ground plane is on the other side of the substrate. The overall dimension of the substrate is 0.417λ0 × 0.292λ0 × 0.0133λ0. The antenna may operate in two bands: the lower band is from 2.35 to 3.22 GHz, centred at 2.52 GHz (percentage bandwidth od 34.52%) and the upper band is from 4.78 to 5.79 GHz, centred at 5.49 GHz (percentage bandwidth of 18.39%). In addition, 3 dB axial ratio bandwidth of the lower and upper bands are 650 and 650 MHz, respectively. The detailed performances of the proposed antenna are demonstrated along with the measured and simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 2434-2448 Issue: 18 Volume: 33 Year: 2019 Month: 12 X-DOI: 10.1080/09205071.2019.1684387 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1684387 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:18:p:2434-2448 Template-Type: ReDIF-Article 1.0 Author-Name: Jae-Ho Lee Author-X-Name-First: Jae-Ho Author-X-Name-Last: Lee Author-Name: Dong-Wook Seo Author-X-Name-First: Dong-Wook Author-X-Name-Last: Seo Title: Compact and tissue-insensitive implantable antenna on magneto-dielectric substrate for wireless biotelemetry Abstract: A novel implantable antenna, which is compact and insensitive to the implant locations in the human body, is proposed for wireless biotelemetry in the medical device radio communications (MedRadio) service frequency band (401–406 MHz). By adopting a magneto-dielectric material as an antenna substrate, the proposed antenna can be minimized and the bandwidth of the antenna is expected to be widened enough to perform in the various implant locations within the MedRadio band. The potential of the proposed antenna aimed at biotelemetry applications was verified through simulations and measurements with a 2/3 human muscle-emulating block. The designed antenna is 20 mm × 10 mm × 1.275 mm in volume and shows the bandwidth (return loss of 10 dB) of 22.65 MHz and the maximum gain of −32 dBi at 402 MHz, which are quite competitive for the wireless biotelemetry applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 2449-2461 Issue: 18 Volume: 33 Year: 2019 Month: 12 X-DOI: 10.1080/09205071.2019.1684388 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1684388 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:18:p:2449-2461 Template-Type: ReDIF-Article 1.0 Author-Name: Aijaz Ali Author-X-Name-First: Aijaz Author-X-Name-Last: Ali Author-Name: Qaisar Abbas Naqvi Author-X-Name-First: Qaisar Abbas Author-X-Name-Last: Naqvi Author-Name: Muhammad Abuzar Baqir Author-X-Name-First: Muhammad Abuzar Author-X-Name-Last: Baqir Title: Investigation of the plasmon resonance of core-shell nanoparticle in the near-infrared region Abstract: In this paper, we investigated the surface plasmon resonance of metallo-dielectric core-shell nanoparticle in the near-infrared (NIR) regime of the light. The wavelength-dependent permittivity of the metal has been deduced by the Lorentz-Drude (LD) model. We have analytically analyzed the polarizability and scattering cross-section of the core-shell nanoparticle in the NIR regime, i.e. 1400–3000 nm. The resonance has been attained due to the surface plasmon resonance (SPR) at the interface of the metal (with negative permittivity) and dielectric interface. Furthermore, the effects of core-shell radii on polarizability and scattering cross-section of core-shell nanoparticle have been taken up. It has been noticed that resonance can be altered by tailoring core-shell radii of the metallo-dielectric nanoparticle. Such a structure would be useful in integrated photonic applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 2462-2475 Issue: 18 Volume: 33 Year: 2019 Month: 12 X-DOI: 10.1080/09205071.2019.1685008 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1685008 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:18:p:2462-2475 Template-Type: ReDIF-Article 1.0 Author-Name: Narinder Sharma Author-X-Name-First: Narinder Author-X-Name-Last: Sharma Author-Name: Sumeet Singh Bhatia Author-X-Name-First: Sumeet Singh Author-X-Name-Last: Bhatia Title: Double split labyrinth resonator-based CPW-fed hybrid fractal antennas for PCS/UMTS/WLAN/Wi-MAX applications Abstract: In this manuscript, the design of double split labyrinth resonator (DSLR)-based Coplanar waveguide (CPW)-fed hybrid fractal antennas has been presented for distinct wireless applications. The proposed hybrid antennas are designed by fusing the Hilbert and Koch fractal geometries together and the resulted structure is named Hilbert Koch–Koch Hybrid Fractal Antenna (HKKHFA). The proposed antennas differ from each other in the feed line locations only. The CPW feed line is applied to excite the antennas at two different locations as Left and Right CPW-fed, and the proposed antennas are also named HKKHFA with Left CPW-fed and HKKHFA with Right CPW-fed. The ground plane of the proposed antennas is being modified to attain the better results. The proposed HKKHFA with Left and Right CPW-fed are also being loaded with DSLR on the reverse side of substrate for attaining wideband characteristics, better impedance matching and enhanced gain. The overall size of the proposed HKKHFAs is 30 × 30 × 1.6 mm3 and is being designed on low-cost FR4 glass epoxy substrate with a relative permittivity of 4.4 and a thickness of 1.6. The results of unloaded and loaded proposed antennas (HKKHFA with Left and Right CPW-fed) are juxtaposed with each other and revealed that the loaded HKKHFA exhibits wider bandwidth and better impedance matching. Prototypes of HKKHFAs loaded with DSLR for both the feed locations are fabricated and tested for their results, and found good agreement between simulated and experimental results. The proposed HKKHFA loaded with DSLR for both CPW-feds exhibits the peak gain of 4.40/4.95 dB and a maximum bandwidth of 7.69/7.36 GHz, and it is useful for different wireless standards. Journal: Journal of Electromagnetic Waves and Applications Pages: 2476-2498 Issue: 18 Volume: 33 Year: 2019 Month: 12 X-DOI: 10.1080/09205071.2019.1685009 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1685009 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:18:p:2476-2498 Template-Type: ReDIF-Article 1.0 Author-Name: Sensong Shen Author-X-Name-First: Sensong Author-X-Name-Last: Shen Author-Name: Bing Xue Author-X-Name-First: Bing Author-X-Name-Last: Xue Author-Name: Minglei Shi Author-X-Name-First: Minglei Author-X-Name-Last: Shi Author-Name: Jun Xu Author-X-Name-First: Jun Author-X-Name-Last: Xu Title: Odd-mode and even-mode SSPPs transmissions based on complementary comb-like structure Abstract: The odd-mode and even-mode spoof surface plasmon polariton (SSPPs) transmission based on a complementary plasmonic structure are studied in this paper. The dispersion properties and electromagnetic field distributions of odd-mode and even-mode are analyzed. The odd-mode SSPPs transmission line is fed by a microstrip line, in which its measured insertion losses are within 2.58 ± 1.67 dB from 3.0 to 10.0 GHz. The first even-mode SSPP transmission line is fed by the microstrip line, in which its measured insertion losses are within 3.65 ± 1.33 dB from 5.0 to 16.0 GHz. And the second even-mode SSPPs transmission line is fed by a coplanar waveguide, in which its measured insertion losses are within 3.60 ± 1.25 dB from 5.0 to 16.0 GHz. The measured data are consistent with the simulated results, indicating their excellent transmission performances at microwave frequencies. Journal: Journal of Electromagnetic Waves and Applications Pages: 2499-2512 Issue: 18 Volume: 33 Year: 2019 Month: 12 X-DOI: 10.1080/09205071.2019.1687337 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1687337 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:18:p:2499-2512 Template-Type: ReDIF-Article 1.0 Author-Name: Ji-Eun Kim Author-X-Name-First: Ji-Eun Author-X-Name-Last: Kim Author-Name: Sang-Min Lee Author-X-Name-First: Sang-Min Author-X-Name-Last: Lee Author-Name: Chan-Hong Kim Author-X-Name-First: Chan-Hong Author-X-Name-Last: Kim Author-Name: Young-Soo Kim Author-X-Name-First: Young-Soo Author-X-Name-Last: Kim Author-Name: Seung-Jae Lee Author-X-Name-First: Seung-Jae Author-X-Name-Last: Lee Author-Name: Kyung-Tea Kim Author-X-Name-First: Kyung-Tea Author-X-Name-Last: Kim Author-Name: Hyung-Jung Kim Author-X-Name-First: Hyung-Jung Author-X-Name-Last: Kim Author-Name: Seung-Keun Park Author-X-Name-First: Seung-Keun Author-X-Name-Last: Park Title: Effect of range resolution in the analysis of X-band sea clutter at low grazing angles Abstract: Analyses of sea spikes are presented for data measured at low grazing angles using a high-resolution X-band radar. To investigate the spikiness of sea clutter at different range resolutions, several analyses and statistical modelling were applied to measured sea clutter data with different resolutions and polarizations. The results show that the spikiness of sea clutter increases as the range resolution becomes finer. Journal: Journal of Electromagnetic Waves and Applications Pages: 2513-2528 Issue: 18 Volume: 33 Year: 2019 Month: 12 X-DOI: 10.1080/09205071.2019.1688690 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1688690 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:18:p:2513-2528 Template-Type: ReDIF-Article 1.0 Author-Name: Rana Sadaf Anwar Author-X-Name-First: Rana Sadaf Author-X-Name-Last: Anwar Author-Name: Yuan Wei Author-X-Name-First: Yuan Author-X-Name-Last: Wei Author-Name: Lingfeng Mao Author-X-Name-First: Lingfeng Author-X-Name-Last: Mao Author-Name: Xijun Li Author-X-Name-First: Xijun Author-X-Name-Last: Li Author-Name: Huansheng Ning Author-X-Name-First: Huansheng Author-X-Name-Last: Ning Title: Novel spoof surface plasmon polaritons on a planar metallic strip with periodic semi-elliptical grooves at microwave frequency Abstract: It is well known that traditional microstrip (MS) transmission lines suffer from high transmission losses at microwave and millimeter wave frequencies. To solve the issue, a novel periodic subwavelength structure is proposed in this work with semi-elliptical grooves (SEGs) on a lateral edge of MS line, for the propagation of spoof surface plasmon polaritons (SSPPs) in the microwave regime. Dispersion relations are analyzed by a numerical method using ANSYS’s HFSS (High-Frequency Structure Simulator), and ability to operate efficiently in primary mode is demonstrated. A comparison with other structures is also accomplished and found that more strong resonant modes are created by the coupling between upper metal strip with textured SEGs and the lower ground layer which are confined near the surface of this grating structure. It has been observed that the cutoff frequency (fc) and the level of field confinement depend on the geometric parameters, and SEG-based SSPPs efficiently minimize the asymptotic frequency by 65% and 12% as compared to MS and Vee-groove structures, respectively. We further investigate a planar and highly efficient, low-pass plasmonic filter with 3 dB cutoff frequency of 11.4 GHz and significantly reduced insertion loss (>−1.9 dB) in the passband. A prototype is fabricated for validation by standard PCB manufacturing process; good agreement between experimental and simulation results confirms the excellent performance of this compact filter in the entire passband with smaller transmission losses. Such a plasmonic metamaterial structure presents a unique and highly unexplored geometry which strongly supports confined SSPPs, therefore, can play a significant role in advanced integrated plasmonics circuitry and applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 125-137 Issue: 2 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1529631 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1529631 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:2:p:125-137 Template-Type: ReDIF-Article 1.0 Author-Name: Amit K. Varshney Author-X-Name-First: Amit K. Author-X-Name-Last: Varshney Author-Name: Raktim Guha Author-X-Name-First: Raktim Author-X-Name-Last: Guha Author-Name: Sushanta Biswas Author-X-Name-First: Sushanta Author-X-Name-Last: Biswas Author-Name: Partha Pratim Sarkar Author-X-Name-First: Partha Pratim Author-X-Name-Last: Sarkar Author-Name: Subrata K. Datta Author-X-Name-First: Subrata K. Author-X-Name-Last: Datta Author-Name: B. N. Basu Author-X-Name-First: B. N. Author-X-Name-Last: Basu Title: Tape-helix model of analysis for the dispersion and interaction impedance characteristics of a helix loaded with a double-negative metamaterial for potential application in vacuum electron devices Abstract: The tape-helix model of analysis of a helix surrounded by a double-negative metamaterial tube in a metal envelope was developed adding a rigor to the earlier analysis that had used the simple sheath-helix model. The analyses using these two models were compared and validated against CST simulation. The structure supporting backward waves opens up the potential application of the structure in backward-wave vacuum electron device. Journal: Journal of Electromagnetic Waves and Applications Pages: 138-150 Issue: 2 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1530614 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1530614 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:2:p:138-150 Template-Type: ReDIF-Article 1.0 Author-Name: Jianxiong Li Author-X-Name-First: Jianxiong Author-X-Name-Last: Li Author-Name: Peiyu Wu Author-X-Name-First: Peiyu Author-X-Name-Last: Wu Author-Name: Haolin Jiang Author-X-Name-First: Haolin Author-X-Name-Last: Jiang Title: The implementation of unconditionally stable higher order PML based on the implicit CNAD-FDTD algorithm Abstract: An unconditionally stable implementation of the higher order complex frequency-shifted perfectly matched layer (CFS-PML) based on the Crank–Nicolson-approximate-decoupling (CNAD) algorithm and the bilinear transform (BT) method is proposed to terminate the finite-difference time-domain (FDTD) lattice. The proposed scheme not only takes advantage of the CNAD algorithm in terms of reducing computational time but also has the advantage of the conventional FDTD algorithm in terms of absorbing performance. Two numerical examples are provided to validate the proposed implementation in the homogenous free space and lossy FDTD domains. The results show that the proposed scheme can overcome the Courant–Friedrich–Levy condition compared with the conventional FDTD method and further enhance the absorbing performance compared with the first order PML implementation. Journal: Journal of Electromagnetic Waves and Applications Pages: 151-164 Issue: 2 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1530615 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1530615 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:2:p:151-164 Template-Type: ReDIF-Article 1.0 Author-Name: J. F. Gómez-Aguilar Author-X-Name-First: J. F. Author-X-Name-Last: Gómez-Aguilar Author-Name: Abdon Atangana Author-X-Name-First: Abdon Author-X-Name-Last: Atangana Title: Time-fractional variable-order telegraph equation involving operators with Mittag-Leffler kernel Abstract: In this paper, we have generalized the time-fractional telegraph equation involving operators with Mittag-Leffler kernel of variable order in Liouville-Caputo sense. The fractional variable-order equation was solved numerically via Crank-Nicholson scheme. We present the existence and uniqueness of the solution. Numerical simulations of the special solutions were done and new behaviors are obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 165-177 Issue: 2 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1531791 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1531791 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:2:p:165-177 Template-Type: ReDIF-Article 1.0 Author-Name: Piotr Kowalczyk Author-X-Name-First: Piotr Author-X-Name-Last: Kowalczyk Author-Name: Rafal Lech Author-X-Name-First: Rafal Author-X-Name-Last: Lech Author-Name: Malgorzata Warecka Author-X-Name-First: Malgorzata Author-X-Name-Last: Warecka Author-Name: Adam Kusiek Author-X-Name-First: Adam Author-X-Name-Last: Kusiek Title: Electromagnetic plane wave scattering from a cylindrical object with an arbitrary cross section using a hybrid technique Abstract: A hybrid technique combining finite-element and mode-matching methods for the analysis of scattering problems in open and closed areas is presented. The main idea of the analysis is based on the utilization of the finite-element method to calculate the post impedance matrix and combine it with external excitation. The discrete analysis, which is the most time- and memory-consuming, is limited here only to the close proximity of the scatterer. Moreover, once the impedance matrix is calculated, any rotation or shifting of the post can be performed without the need for structure recalculation. All the obtained results have been verified by comparison with simulations performed using the hybrid finite-difference-mode-matching method and commercial software. Journal: Journal of Electromagnetic Waves and Applications Pages: 178-192 Issue: 2 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1532323 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1532323 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:2:p:178-192 Template-Type: ReDIF-Article 1.0 Author-Name: E. Holdengreber Author-X-Name-First: E. Author-X-Name-Last: Holdengreber Author-Name: A. G. Moshe Author-X-Name-First: A. G. Author-X-Name-Last: Moshe Author-Name: M. Mizrahi Author-X-Name-First: M. Author-X-Name-Last: Mizrahi Author-Name: V. Khavkin Author-X-Name-First: V. Author-X-Name-Last: Khavkin Author-Name: S. E. Schacham Author-X-Name-First: S. E. Author-X-Name-Last: Schacham Author-Name: E. Farber Author-X-Name-First: E. Author-X-Name-Last: Farber Title: High sensitivity high Tc superconducting Josephson junction antenna for 200 GHz detection Abstract: A high sensitivity rounded bow-tie antenna was optimized based on electromagnetic simulations. The bicrystal Josephson junction detector with a thin layer of YBCO was located exactly at the bicrystal misorientation point at the center of the antenna. The Au antenna was fabricated on an (100) MgO bicrystal substrate. In the presence of 200 GHz RF radiation, a noise equivalent power (NEP) of around 6×10−12 W Hz−1/2 was measured, with a voltage sensitivity, $ {\boldsymbol{\eta}}({\bf V} ) $ η(V), of 30 dB with the detector at 60 K. Even though no coupling lens was used, these results are as good as those reported in systems in which the impinging radiation was focused with lenses over the detectors. Thus, important simplification of the system was obtained without loss of sensitivity. Journal: Journal of Electromagnetic Waves and Applications Pages: 193-203 Issue: 2 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1535333 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1535333 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:2:p:193-203 Template-Type: ReDIF-Article 1.0 Author-Name: Vishal Kesari Author-X-Name-First: Vishal Author-X-Name-Last: Kesari Author-Name: J. P. Keshari Author-X-Name-First: J. P. Author-X-Name-Last: Keshari Title: Hybrid-mode analysis of circular waveguide with chiral dielectric lining for dispersion characteristics for potential application in broadbanding a gyro-traveling-wave tube Abstract: A circular waveguide with chiral dielectric lining was analyzed for hybrid mode dispersion relation. In chiral dielectric lining region, the different radial propagation constants, and in the central free-space region only one radial propagation constant for the left- and right- circularly polarized waves were considered. A method was presented to obtain the hybrid-mode dispersion relation of the proposed structure using the field matching technique. A numerical computer code was developed to solve the hybrid-mode dispersion relation and the solutions were plotted to explore the dispersion characteristics and shaping with the change of material and geometry parameters of the structure. Further, the azimuthal electric field intensity was plotted against radial coordinate to explore the position of field maxima for placing the gyrating electron beam for the potential application of the structure in a gyro-traveling-wave tube. Thus, out of the two modes studied, EH01 and HE01, the later found suitable for the operation of a gyro-traveling-wave tube. Journal: Journal of Electromagnetic Waves and Applications Pages: 204-214 Issue: 2 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1535335 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1535335 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:2:p:204-214 Template-Type: ReDIF-Article 1.0 Author-Name: Qi Zhang Author-X-Name-First: Qi Author-X-Name-Last: Zhang Author-Name: Jie Zhang Author-X-Name-First: Jie Author-X-Name-Last: Zhang Author-Name: Qiang Li Author-X-Name-First: Qiang Author-X-Name-Last: Li Author-Name: Yubing Wang Author-X-Name-First: Yubing Author-X-Name-Last: Wang Author-Name: Wei Dong Author-X-Name-First: Wei Author-X-Name-Last: Dong Author-Name: Xindong Zhang Author-X-Name-First: Xindong Author-X-Name-Last: Zhang Title: Realization of three notch bands in UWB bandpass filter based on stimulated Brillouin scattering Abstract: An Ultra-wideband (UWB) bandpass filter with three notch bands based on multi-tone waveform and Stimulated Brillouin scattering (SBS) is proposed and demonstrated. The phase modulation (PM) and tunable optical bandpass filter (TOBF) of the system are used to implement a single bandpass filter. The SBS attenuation of the multi-pump generates three notch bands and the proposed filter can efficiently reduce the interference from undesired signals at 3.5 GHz in WiMAX, 5.7 GHz in WLAN and 8 GHz in satellite. The rejection ratio of notch bands can be optimized to 36 dB, 38 dB and 35 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 215-225 Issue: 2 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1536563 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1536563 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:2:p:215-225 Template-Type: ReDIF-Article 1.0 Author-Name: Sanaz Zarei Author-X-Name-First: Sanaz Author-X-Name-Last: Zarei Title: Design and analysis of a fiber-optic deep-etched silicon photonic crystal temperature sensor Abstract: A novel silicon fiber-optic temperature sensor based on a 1D photonic crystal is theoretically discussed in this paper. The sensing element consists of a 1D photonic crystal with a central defect at the end of a U-groove that can be created in a silicon substrate by silicon deep etching which facilitates the integration of fiber-optic and sensor in a single silicon die. Temperature variations can be monitored by scanning the shift in wavelength of reflection peak, which is induced by the thermo-optic effect and thermal expansion effect. This sensing configuration shows a nearly linear temperature response over the large temperature range of 0–200°C with a sensitivity of 68 pm/°C that is seven times better than the conventional FBG sensors. Journal: Journal of Electromagnetic Waves and Applications Pages: 226-235 Issue: 2 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1536564 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1536564 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:2:p:226-235 Template-Type: ReDIF-Article 1.0 Author-Name: Kamil Staszek Author-X-Name-First: Kamil Author-X-Name-Last: Staszek Author-Name: Szczepan Odrobina Author-X-Name-First: Szczepan Author-X-Name-Last: Odrobina Author-Name: Krzysztof Wincza Author-X-Name-First: Krzysztof Author-X-Name-Last: Wincza Author-Name: Slawomir Gruszczynski Author-X-Name-First: Slawomir Author-X-Name-Last: Gruszczynski Title: Broadband matrix-type feeding networks for two-beam antennas with constant beamwidth and efficient aperture utilization Abstract: We report a novel approach for the design of a Butler matrix-type feeding network that allows for achieving two-beam antenna arrays in a very broad frequency range. The proposed solution is based on a 2 × 4 frequency-selective beamforming network which changes its frequency characteristics across the bandwidth. The utilized network features three different properties at three different frequencies. Therefore, such a network allows for achieving two-beam radiation pattern with similar beamwidths and beam directions over 3:1 bandwidth in conjunction with four broadband radiating elements. The presented concept has been verified by the design and measurements of a two-beam antenna array operating in 1–3 GHz frequency range. Journal: Journal of Electromagnetic Waves and Applications Pages: 236-248 Issue: 2 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1536565 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1536565 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:2:p:236-248 Template-Type: ReDIF-Article 1.0 Author-Name: Luana M. Silva Author-X-Name-First: Luana M. Author-X-Name-Last: Silva Author-Name: Ana Caroline T. de Carvalho Author-X-Name-First: Ana Caroline T. Author-X-Name-Last: de Carvalho Author-Name: Júlia F. Araujo Author-X-Name-First: Júlia F. Author-X-Name-Last: Araujo Author-Name: Márcio Z. Fortes Author-X-Name-First: Márcio Z. Author-X-Name-Last: Fortes Author-Name: Lorenna B. Oliveira Author-X-Name-First: Lorenna B. Author-X-Name-Last: Oliveira Author-Name: Joacir O. Silva Author-X-Name-First: Joacir O. Author-X-Name-Last: Silva Title: Evaluation of the impact of EMI on Ethernet networks from lighting technologies Abstract: This paper aims to verify the possible influences that lighting technologies can generate in the Ethernet networks through electromagnetic interference (EMI). For the realization of the tests were used twisted-pair cables, category 5 and 6 that were submitted to the influence of seven lighting equipment technologies on 13 samples. The tests were carried out in an armored environment at the LABLUX – UFF facilities using the Iperf3 software. The results of this study showed that although electronic components cause electromagnetic interference in different cable categories, Ethernet networks are not affected by these systems. On the other hands, the protocol for sending the packets may interfere with the efficiency and reliability of data packet traffic. Journal: Journal of Electromagnetic Waves and Applications Pages: 249-259 Issue: 2 Volume: 33 Year: 2019 Month: 1 X-DOI: 10.1080/09205071.2018.1537135 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1537135 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:2:p:249-259 Template-Type: ReDIF-Article 1.0 Author-Name: Jing Cai Author-X-Name-First: Jing Author-X-Name-Last: Cai Author-Name: Yong Jin Zhou Author-X-Name-First: Yong Jin Author-X-Name-Last: Zhou Author-Name: Xin Mi Yang Author-X-Name-First: Xin Mi Author-X-Name-Last: Yang Title: A metamaterials-loaded quarter mode SIW microfluidic sensor for microliter liquid characterization Abstract: In this paper, a two concentric complementary split-ring resonators (CSRRs) loaded quarter mode substrate integrated waveguide (QMSIW) is proposed as a compact microfluidic chemical sensor for liquid characterization, demonstrated by the measurement of distilled (DI) water and ethanol liquid mixtures. The proposed sensor can detect the liquid concentration from the resonance frequency shift caused by the liquid sample flowing inside the microfluidic channel engraved on polydimethylsiloxane (PDMS). Its electrical size is only 0.25λg *0.25λg. The simulated resonant frequency shifts between DI water and 100% ethanol is 1196 MHz (from 2.620 GHz to 3.816 GHz), while less than 6 µL samples are used. The experimental results have validated the possibility of the application of the proposed microfluidic structure as a chemical sensor. Journal: Journal of Electromagnetic Waves and Applications Pages: 261-271 Issue: 3 Volume: 33 Year: 2019 Month: 2 X-DOI: 10.1080/09205071.2018.1543058 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1543058 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:3:p:261-271 Template-Type: ReDIF-Article 1.0 Author-Name: Liangzu Cao Author-X-Name-First: Liangzu Author-X-Name-Last: Cao Author-Name: Lixia Yin Author-X-Name-First: Lixia Author-X-Name-Last: Yin Title: Digital-controlled six-channel switched dielectric filter bank of L-band Abstract: This paper introduces a design of a digital-controlled, six-channel, switched dielectric filter bank of L-band. The physical parameters of a monoblock dielectric filter are optimized by an aggressive space mapping technique. Two HMC252Q24 switches are used for single-pole six throws (SP6T) to realize a 3-bit digital-controlled filter bank. And six filters made of dielectric ceramics are used having advantages of small size and low insertion loss. These six filters and two switches are then fabricated on printed circuit board and measured under 3-bit transistor-transistor logic (TTL) signals. The measured results have shown that (i) 3-bit TTL signals control the path of the filter bank, (ii) six states correspond to six filters and two states are off, and (iii) the isolation between filters exceeds more than 45 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 272-285 Issue: 3 Volume: 33 Year: 2019 Month: 2 X-DOI: 10.1080/09205071.2018.1544510 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1544510 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:3:p:272-285 Template-Type: ReDIF-Article 1.0 Author-Name: Fábio J. F. Gonçalves Author-X-Name-First: Fábio J. F. Author-X-Name-Last: Gonçalves Author-Name: Alfred G. M. Pinto Author-X-Name-First: Alfred G. M. Author-X-Name-Last: Pinto Author-Name: Renato C. Mesquita Author-X-Name-First: Renato C. Author-X-Name-Last: Mesquita Author-Name: Elson J. Silva Author-X-Name-First: Elson J. Author-X-Name-Last: Silva Title: A flexible procedure to avoid the boundary materials singularities in 2D transformation-based cloaks Abstract: An out-of-plane coordinate transformation can avoid singular materials in a two-dimensional electromagnetic cloak. Based on numerical simulations of elliptical cylinders, in this paper we show that the use of two different constants to define the out-of-plane stretching can result in anisotropic materials with lower values and yet with a better scattering reduction for a given incident wave direction. Journal: Journal of Electromagnetic Waves and Applications Pages: 286-295 Issue: 3 Volume: 33 Year: 2019 Month: 2 X-DOI: 10.1080/09205071.2018.1547223 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1547223 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:3:p:286-295 Template-Type: ReDIF-Article 1.0 Author-Name: Hao Zhang Author-X-Name-First: Hao Author-X-Name-Last: Zhang Author-Name: Wei Kang Author-X-Name-First: Wei Author-X-Name-Last: Kang Author-Name: Wen Wu Author-X-Name-First: Wen Author-X-Name-Last: Wu Title: Low phase-noise oscillator based on SIW bandpass filter implementing at the Qsc-peak frequency Abstract: In this paper, a novel low phase-noise oscillator employing an substrate integrated waveguide (SIW) bandpass filter (BPF) embedded with a complementary spiral resonator (CSR) is proposed. The Qsc-peak frequency is chosen for the design of the oscillator to achieve optimal phase noise performance. The CSR exited by TM01 mode has been etched on the top metal of the circular cavity. Three transmission poles and three transmission zeros can be obtained by the proposed SIW BPF which is regarded as the frequency stabilization element. Meanwhile, a short summary about how to obtain a high Qsc-factor to achieve low phase noise performance has been illustrated. A C-band oscillator using a field effect transistor has been designed and experimentally demonstrated at 5.71 GHz with a 147.6 dBc/Hz phase noise at 1 MHz offset frequency. Moreover, the output power is −1.49 dBm with a figure of merit of −209.2 dBc/Hz and less than −32.8 dBm spurious harmonics is obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 296-303 Issue: 3 Volume: 33 Year: 2019 Month: 2 X-DOI: 10.1080/09205071.2018.1549512 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1549512 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:3:p:296-303 Template-Type: ReDIF-Article 1.0 Author-Name: A. A. Kirilenko Author-X-Name-First: A. A. Author-X-Name-Last: Kirilenko Author-Name: S. O. Steshenko Author-X-Name-First: S. O. Author-X-Name-Last: Steshenko Author-Name: V. N. Derkach Author-X-Name-First: V. N. Author-X-Name-Last: Derkach Author-Name: Y. M. Ostrizhnyi Author-X-Name-First: Y. M. Author-X-Name-Last: Ostrizhnyi Title: Comparative analysis of tunable compact rotators Abstract: Three versions of two-layer polarization plane rotators in a circular waveguide based on the internal fringing field interaction are considered. They work on the excitation of unusual eigen-oscillations within the gap between a pair of peculiar four-slot metal irises. The subjects for comparison were the range of rotation angles, the possibility to provide good matching, and the ability of rotators to be tuned by mutual iris-to-iris rotation. The best properties were found in the case of the conjugated planar-chiral irises. Journal: Journal of Electromagnetic Waves and Applications Pages: 304-319 Issue: 3 Volume: 33 Year: 2019 Month: 2 X-DOI: 10.1080/09205071.2018.1550443 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1550443 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:3:p:304-319 Template-Type: ReDIF-Article 1.0 Author-Name: V. V. Atuchin Author-X-Name-First: V. V. Author-X-Name-Last: Atuchin Author-Name: A. P. Gorbachev Author-X-Name-First: A. P. Author-X-Name-Last: Gorbachev Author-Name: V. A. Khrustalev Author-X-Name-First: V. A. Author-X-Name-Last: Khrustalev Author-Name: N. V. Tarasenko Author-X-Name-First: N. V. Author-X-Name-Last: Tarasenko Title: Reentrant wideband quasi-elliptic bandpass filter Abstract: The novel microwave wideband quasi-elliptic bandpass filter, in which the initially uncoupled strip transmission lines are used is considered in the present study. The proposed filter is based on the reentrant structure in which the metallic body with a floating potential is asymmetrical. Generally speaking, the internal and external dielectric fillings must be of unequal relative permittivity. As a result, the additional symmetrical transmission zeros are reached at the lower and upper stop bands of the pass band leading to the quasi-elliptic response function that improves the bandpass filter selectivity. The general TEM circuit model for the proposed filter, in terms of the multi-port series connection, is presented and then used to predict the initial electrical and geometrical quantities. A printed circuit prototype has been manufactured using a common printed circuit board implementation. The measured results are in an acceptable agreement with the simulation-derived ones, and that improves the degree of freedom in the frequency selective unit design. Journal: Journal of Electromagnetic Waves and Applications Pages: 320-334 Issue: 3 Volume: 33 Year: 2019 Month: 2 X-DOI: 10.1080/09205071.2018.1550444 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1550444 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:3:p:320-334 Template-Type: ReDIF-Article 1.0 Author-Name: Hadi Roohani Ghehsareh Author-X-Name-First: Hadi Author-X-Name-Last: Roohani Ghehsareh Author-Name: Maryam Hajisadeghi Esfahani Author-X-Name-First: Maryam Author-X-Name-Last: Hajisadeghi Esfahani Author-Name: Seyed Kamal Etesami Author-X-Name-First: Seyed Author-X-Name-Last: Kamal Etesami Title: Numerical simulation of electromagnetic wave scattering from perfectly conducting cylinders using the local radial point interpolation technique Abstract: This paper is devoted to the investigation of the electromagnetic scattering problems from infinite perfectly conducting cylinders with arbitrary cross-sections. The problems can be mathematically modeled as surface integral equations. Both the electric field integral equation (EFIE), magnetic field integral equation (MFIE) and their combined form are studied. An efficient computational technique based on the local radial point interpolation method is performed to investigate the models. Some test problems with various cross-sections have been analyzed to validate the capability of the proposed technique in calculating the current distribution induced on the scatterer and measuring the Radar Cross Section. Journal: Journal of Electromagnetic Waves and Applications Pages: 335-349 Issue: 3 Volume: 33 Year: 2019 Month: 2 X-DOI: 10.1080/09205071.2018.1551730 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1551730 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:3:p:335-349 Template-Type: ReDIF-Article 1.0 Author-Name: Shuhui Yang Author-X-Name-First: Shuhui Author-X-Name-Last: Yang Author-Name: Yinchao Chen Author-X-Name-First: Yinchao Author-X-Name-Last: Chen Author-Name: Chenyin Yu Author-X-Name-First: Chenyin Author-X-Name-Last: Yu Author-Name: Guizhen Lu Author-X-Name-First: Guizhen Author-X-Name-Last: Lu Author-Name: Bin Li Author-X-Name-First: Bin Author-X-Name-Last: Li Author-Name: Ling Wang Author-X-Name-First: Ling Author-X-Name-Last: Wang Author-Name: Dongdong Zeng Author-X-Name-First: Dongdong Author-X-Name-Last: Zeng Title: Super compact and ultra-wideband bandpass filter with a wide upper stopband based on a SCRLH transmission-line unit-cell and two lumped capacitors Abstract: This paper presents a simplified composite right/left-handed trans-mission-line (SCRLH-TL) unit-cell, which is primarily consisted of a rectangular ring with two grounded vias. Superposing this unit-cell onto a high–low–high step-impedance resonator (SIR) leads to a novel SCRLH-TL multiple-mode resonator (SCRLH-TL MMR). By combining the SCRLH-TL MMR with a cross-shaped defected ground structure (DGS) and using a broadside coupling approach with two lumped capacitors, a highly compact and ultra-wideband bandpass filter was carefully designed and fully investigated. The filter was fabricated by using a conventional PCB process with the substrate of FR4. The measured 3-dB passband ranges from 2.55 through 11.75 GHz with the fractional bandwidth (FBW) of about 129%. The filter exhibits a high selectivity with steep skirt property, and has a wide upper stopband. Its total dimension, including the rectangular substrate with feed lines, occupies only 13.5 mm × 6.0 mm, which is found with the smallest size in comparison to those recently published in the literature. Journal: Journal of Electromagnetic Waves and Applications Pages: 350-366 Issue: 3 Volume: 33 Year: 2019 Month: 2 X-DOI: 10.1080/09205071.2018.1552538 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1552538 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:3:p:350-366 Template-Type: ReDIF-Article 1.0 Author-Name: Nickolay Malyutin Author-X-Name-First: Nickolay Author-X-Name-Last: Malyutin Author-Name: Alexandra Malyutina Author-X-Name-First: Alexandra Author-X-Name-Last: Malyutina Author-Name: Vyacheslav Fedorov Author-X-Name-First: Vyacheslav Author-X-Name-Last: Fedorov Author-Name: Anton Loschilov Author-X-Name-First: Anton Author-X-Name-Last: Loschilov Author-Name: Rakhmatullo Sharabudinov Author-X-Name-First: Rakhmatullo Author-X-Name-Last: Sharabudinov Title: Wave properties of the group delay correctors based on coupled strip-lines with different inphase and antiphase wave phase velocities Abstract: We considered the effect of the imbalance of the inphase and antiphase electromagnetic wave phase velocities on wave properties of group delay time corrector circuits based on contradirectional and transdirectional couplers. We obtained equations for the analysis of the wave dissipation matrix frequency response as a function of the resistance of the elements defining the specified phase frequency response and group delay. In addition, we obtained the group delay time difference as 3 ns under return and minimum insertion losses in the range of 17–20 dB in the 0.35–0.7 GHz bandwidth. We showed that systems based on contradirectional couplers can exhibit a deviation of 20% in the phase velocity ratio of the inphase and antiphase waves without the degradation of the corrector performance. It was found that the increase in the imbalance of phase velocities results in the narrowing of the operating bandwidth, while a transdirectional coupler enables the increase of the passband while maintaining the specified return losses. Journal: Journal of Electromagnetic Waves and Applications Pages: 367-381 Issue: 3 Volume: 33 Year: 2019 Month: 2 X-DOI: 10.1080/09205071.2018.1553688 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1553688 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:3:p:367-381 Template-Type: ReDIF-Article 1.0 Author-Name: Da Lin Author-X-Name-First: Da Author-X-Name-Last: Lin Author-Name: Qi Wan Author-X-Name-First: Qi Author-X-Name-Last: Wan Title: Faulty elements diagnosis of phased array antennas using a generative adversarial learning-based stacked denoising sparse autoencoder Abstract: Diagnosis of faulty elements in a linear phased array antenna is of great importance in the wireless communication field which has been received increasing attention. As a result of element or elements failure in the linear phased array antennas, the whole radiation pattern will suffer from high side lobe levels, wide bandwidth and unexpected nulls. To this end, we suggest a novel approach by combining the generative adversarial learning and the stacked denoising sparse autoencoder to determine the location of the faulty elements in antennas. The suggested approach can learn discriminative features from radiation pattern images adaptively and automatically with less expert knowledge. Meanwhile, the suggested approach is able to overcome the strong noise, the high dimensional size of the radiation pattern and the small fault samples. In this regard, the suggested approach possesses superiority in discriminant capability in contrast to the existing related approaches. Journal: Journal of Electromagnetic Waves and Applications Pages: 382-407 Issue: 3 Volume: 33 Year: 2019 Month: 2 X-DOI: 10.1080/09205071.2018.1553689 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1553689 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:3:p:382-407 Template-Type: ReDIF-Article 1.0 Author-Name: Heng Du Author-X-Name-First: Heng Author-X-Name-Last: Du Author-Name: Xutao Yu Author-X-Name-First: Xutao Author-X-Name-Last: Yu Author-Name: Hui Zhang Author-X-Name-First: Hui Author-X-Name-Last: Zhang Author-Name: Peng Chen Author-X-Name-First: Peng Author-X-Name-Last: Chen Title: A low phase noise oscillator based on substrate integrated coaxial line technology Abstract: In this article, a miniaturized resonator based on substrate integrated coaxial line technology (SICL) is presented. The SICL resonator consists of a hairpin half-wavelength open-ended coaxial line element and two symmetrical parallel coaxial feed lines. The gap between the feed lines and the hairpin element can be adjusted properly to obtain a steep phase change, which can result in a higher group delay peak and achieve a superior phase noise performance. Based on the proposed SICL resonator, an X-band oscillator has been designed and demonstrated by using low-cost printed circuit boards (PCBs). Great consistency between the measured and simulated results is verified. According to the measured results, the oscillation frequency of the SICL oscillator is 10.0625 GHz with −1.81 dBm RF output power, and the phase noise is −138.6 dBc/Hz@1 MHz. The statistic figure of merit (FOM) is −206.1 dBc/Hz@1 MHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 409-418 Issue: 4 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2018.1531728 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1531728 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:4:p:409-418 Template-Type: ReDIF-Article 1.0 Author-Name: Jin-Ho Lee Author-X-Name-First: Jin-Ho Author-X-Name-Last: Lee Author-Name: Jong-Won Yu Author-X-Name-First: Jong-Won Author-X-Name-Last: Yu Title: BLT analysis method for a TWP over ground based on chain scattering parameters Abstract: This paper proposed the Baum–Liu–Tesche (BLT) method using chain scattering parameter to analyze electromagnetic coupling signals to a twisted pair over ground by HEMP. To analyze the various coupling effects between the ground and each twisted wire, Multi-conductor Transmission Line (MTL) analysis method was used. We made a TWP with many non-uniform pitch-lengths the simplified TWP-MTL model to be shown as one MTL, which reduced the calculation time and memory size when it was compared with the conventional BLT method. The results of the proposed method were compared with those of numerical analysis method and good agreements were obtained in both frequency and time domain. Journal: Journal of Electromagnetic Waves and Applications Pages: 419-427 Issue: 4 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2018.1552539 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1552539 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:4:p:419-427 Template-Type: ReDIF-Article 1.0 Author-Name: Manotosh Biswas Author-X-Name-First: Manotosh Author-X-Name-Last: Biswas Author-Name: Mausumi Sen Author-X-Name-First: Mausumi Author-X-Name-Last: Sen Title: Fast and accurate model for a coax-fed rectangular patch antenna with varying aspect ratio, feed location and substrate electrical parameters Abstract: An improved closed-form model based on cavity model and single resonant parallel R-L-C circuit analysis is proposed to predict the resonant frequency, quality factor, bandwidth, gain and input impedance of a coax-fed rectangular patch antenna as a function of aspect ratio, feed location and substrate electrical parameters. The computed values employing the present model are compared with our experimental results and experimental results available in open literature. We have also employed electromagnetic high-frequency structure simulator (HFSS) software to validate the model. The present model shows very close agreements with the experimental and simulation results compared to the other models. This model is very simple, fast and accurate. The present model can be directly applied to CAD program. Journal: Journal of Electromagnetic Waves and Applications Pages: 428-453 Issue: 4 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2018.1554512 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1554512 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:4:p:428-453 Template-Type: ReDIF-Article 1.0 Author-Name: Tao Dong Author-X-Name-First: Tao Author-X-Name-Last: Dong Author-Name: Xiang Zhu Author-X-Name-First: Xiang Author-X-Name-Last: Zhu Author-Name: Mei Li Author-X-Name-First: Mei Author-X-Name-Last: Li Author-Name: Yiman Zhang Author-X-Name-First: Yiman Author-X-Name-Last: Zhang Author-Name: Boya Zhou Author-X-Name-First: Boya Author-X-Name-Last: Zhou Author-Name: Hao Zeng Author-X-Name-First: Hao Author-X-Name-Last: Zeng Author-Name: Ming-Chun Tang Author-X-Name-First: Ming-Chun Author-X-Name-Last: Tang Title: Design of electrically small Hilbert fractal NFRP magnetic monopole antennas Abstract: Electrically small, Hilbert fractal, near-field resonant parasitic (NFRP) antennas are reported and investigated in this paper. This type of electrically small antennas (ESAs) consists of Hilbert fractal curves as the NFRP resonators and small vertical monopoles as the driven elements. By offsetting the driven monopole off the centre position, good impedance matching can be easily realized. The current distributions on the fractal NFRP elements and the driven monopoles manifest that strong electric coupling could excite loop-mode currents along the Hilbert fractal NFRP structures, and thereby horizontal magnetic monopole patterns with broadside radiation property are realized. The results show that the 2nd-step evolution Hilbert fractal NFRP antenna witnesses an electrically size reduction of 25% compared to ka = 0.9622 of the square capacitively loaded loop (CLL) NFRP antenna, while maintaining its original broadside radiation. It is also demonstrated that there is a performance trade-off, i.e. higher fractal iteration orders leading to smaller resonant frequencies, narrower bandwidth and lower radiation efficiencies. Journal: Journal of Electromagnetic Waves and Applications Pages: 454-464 Issue: 4 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2018.1557079 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1557079 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:4:p:454-464 Template-Type: ReDIF-Article 1.0 Author-Name: Sharhabeel Alyones Author-X-Name-First: Sharhabeel Author-X-Name-Last: Alyones Author-Name: Michael Granado Author-X-Name-First: Michael Author-X-Name-Last: Granado Author-Name: Charles. W. Bruce Author-X-Name-First: Charles. W. Author-X-Name-Last: Bruce Title: Optical extinction efficiencies for metallic single wall carbon nanotubes in the infrared spectral region Abstract: The extinction efficiency (mass normalized extinction cross section) of a sample of metallic single wall carbon nanotubes (SWCNTs) has been measured in the infrared spectral region. The tubes were obtained from Nano-Integris Inc. and measured while suspended in propanol. Calculation of the extinction efficiency based on a computational code for fibers of finite length shows good agreement with the experimental results. The computation involved convolution over the SWCNTs’ length and diameter distributions. The results emphasize the potential of SWCNTs as efficient obscurants of electromagnetic radiation in the infrared spectral region. Journal: Journal of Electromagnetic Waves and Applications Pages: 465-473 Issue: 4 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2018.1557080 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1557080 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:4:p:465-473 Template-Type: ReDIF-Article 1.0 Author-Name: Shu-Chuan Chen Author-X-Name-First: Shu-Chuan Author-X-Name-Last: Chen Author-Name: Wun-Siang Cai Author-X-Name-First: Wun-Siang Author-X-Name-Last: Cai Author-Name: Chung-I G. Hsu Author-X-Name-First: Chung-I G. Author-X-Name-Last: Hsu Author-Name: Meng-Kai Wu Author-X-Name-First: Meng-Kai Author-X-Name-Last: Wu Title: Low-profile switchable LTE/WWAN MIMO antenna system Abstract: This study proposes a low-profile switchable LTE/WWAN multi-input and multi-output (MIMO) antenna system for laptops. The main and auxiliary antennas, mirror-imaged of each other, are configured on the left and right sides of the top edge of the display ground plane. The two antennas are each a planar inverted-F antenna (PIFA) having the size of 102 × 5 × 3 mm3. The PIFA structure is matched in impedance with a set of reactive chip elements to increase the antenna operating bandwidth, and is combined with a set of switchable circuits to change the low-frequency resonant path in accordance with the switch status, ON or OFF, thus allowing the low-frequency modes to cover the LTE700 and GSM850/900 bands. Without any isolation element, an isolation of 15 dB or more can be achieved in the MIMO antenna system. The measured realized antenna efficiency is also 48% or greater. Journal: Journal of Electromagnetic Waves and Applications Pages: 474-492 Issue: 4 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2018.1557081 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1557081 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:4:p:474-492 Template-Type: ReDIF-Article 1.0 Author-Name: Tatjana Gric Author-X-Name-First: Tatjana Author-X-Name-Last: Gric Author-Name: Aleksej Trofimov Author-X-Name-First: Aleksej Author-X-Name-Last: Trofimov Author-Name: Ortwin Hess Author-X-Name-First: Ortwin Author-X-Name-Last: Hess Title: Manipulating surface plasmon polaritons with nanostructured TCO metamaterials Abstract: We propose and implement a new concept for three-layered transparent conducting oxides (TCO) based nanostructured metamaterial. It is based on alternating AZO, GZO and PbS layers. In particular, we propose a novel metamaterial for surface plasmon polariton guiding. Specific example of AZO/GZO/PbS metamaterial and its dispersion engineering are studied in details. The general original concept of metamaterials based on inclusions of the additional layers is discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 493-503 Issue: 4 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2018.1557563 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1557563 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:4:p:493-503 Template-Type: ReDIF-Article 1.0 Author-Name: Zhen Meng Author-X-Name-First: Zhen Author-X-Name-Last: Meng Author-Name: Weidong Zhou Author-X-Name-First: Weidong Author-X-Name-Last: Zhou Title: Robust adaptive beamforming using iterative adaptive approach Abstract: The performance of traditional reconstruction-based robust adaptive beamformers may degrade when the array is not well calibrated. This performance degradation is mainly caused by the Capon spectrum estimator which can not estimate the spatial power spectrum accurately. In contrast to existing approaches, we propose two new reconstruction-based robust adaptive beamformers by using the accurate iterative adaptive approach (IAA) spectrum to combat the covariance matrix uncertainties and the steering vector mismatches. The first one employs the low-complexity IAA (IAA-LC) algorithm to obtain the interference power estimates and reconstruct the interference-plus-noise covariance matrix (INCM) with the computational complexity further reduced. The second one reconstructs the INCM by updating the power estimates corresponding to each interference steering vector with the use of knowledge-aided IAA (IAA-KA) algorithm. The desired signal steering vector is corrected by searching for the direction corresponding to the maximum power, which circumvents the use of optimization program. Simulation results show that our proposed beamformers outperform the others and can achieve the robust performance in the cases of array model mismatches. Journal: Journal of Electromagnetic Waves and Applications Pages: 504-519 Issue: 4 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2018.1560366 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1560366 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:4:p:504-519 Template-Type: ReDIF-Article 1.0 Author-Name: Praveen Chaurasia Author-X-Name-First: Praveen Author-X-Name-Last: Chaurasia Author-Name: Binod Kumar Kanaujia Author-X-Name-First: Binod Kumar Author-X-Name-Last: Kanaujia Author-Name: Santanu Dwari Author-X-Name-First: Santanu Author-X-Name-Last: Dwari Author-Name: Mukesh Kumar Khandelwal Author-X-Name-First: Mukesh Kumar Author-X-Name-Last: Khandelwal Title: Metamaterial based circularly polarized hexa-band patch antenna with small frequency ratios for multiple wireless applications Abstract: In this article, a novel shaped hexa-band microstrip patch antenna (MPA) is presented. The proposed antenna offers six frequency bands including 2.4, 3.06, 3.34, 3.54, 4.61, and 5.21 GHz with very small frequency ratio between two consecutive bands of the value of 1.275, 1.091, 1.059, 1.3022 and 1.1301, respectively. The proposed antenna also shows better radiation characteristics at all six bands and circular polarization at two frequency bands from 2.36 to 2.48 GHz and 4.52 to 4.64 GHz. Design steps for achieving all six bands are presented in detail and simulated results are verified with experimental results of the fabricated prototype. Journal: Journal of Electromagnetic Waves and Applications Pages: 520-540 Issue: 4 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2018.1561330 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1561330 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:4:p:520-540 Template-Type: ReDIF-Article 1.0 Author-Name: Scott Ramsey Author-X-Name-First: Scott Author-X-Name-Last: Ramsey Author-Name: Troy Mayo Author-X-Name-First: Troy Author-X-Name-Last: Mayo Author-Name: Christopher A. Howells Author-X-Name-First: Christopher A. Author-X-Name-Last: Howells Author-Name: Andrew Shabaev Author-X-Name-First: Andrew Author-X-Name-Last: Shabaev Author-Name: Samuel G. Lambrakos Author-X-Name-First: Samuel G. Author-X-Name-Last: Lambrakos Title: Modeling apparent camouflage-pattern color using segment-weighted spectra Abstract: Camouflage patterns for military applications, typically upon base materials such as dyed fabrics, consist of highly detailed camouflage patternings that are characterized by combined refectance spectra. The complexity of these camouflage patterns establishes a need for modeling camouflage-pattern reflectance for pattern evaluation as a function of distance. A metric for pattern evaluation is the apparent-camouflage-pattern reflectance spectrum, which is the total reflectance due to all contributions from component segments, within a wavelength range of interest, for light reflected from sufficiently large fabric samples (≥1m2), as a function of standoff distance. This follows in that camouflage patterns tend to lose contributions to the total reflectance from component segments, having less coverage, with increasing standoff distance. Eventually, with increasing distance, reflectance of pattern segments having more coverage combine to produce the “apparent spectrum” of the camouflage pattern at far field. The physical characteristics of camouflage-pattern reflectance spectra are based on far-field and diffuse scattering properties of electromagnetic waves. Accordingly, a modeling approach can be developed to simulate camouflage-pattern spectra using diffuse-reflectance theory, which is based on decomposition of camouflage-pattern reflectance with respect to component segments of camouflage patterns. This paper presents a modeling approach and prototype simulations of camouflage-pattern reflectance within the visible range of wavelengths, which are relevant for evaluating camouflage fabrics with respect to realistic field conditions. A significant aspect of this modeling approach is that it can be extended for simulation of a wide range of factors influencing detection of camouflaged targets. Journal: Journal of Electromagnetic Waves and Applications Pages: 541-556 Issue: 5 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2018.1561331 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1561331 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:5:p:541-556 Template-Type: ReDIF-Article 1.0 Author-Name: Mukesh Kumar Alaria Author-X-Name-First: Mukesh Kumar Author-X-Name-Last: Alaria Author-Name: S. K. Ghosh Author-X-Name-First: S. K. Author-X-Name-Last: Ghosh Title: Backward wave oscillation suppression study of the helix travelling wave tube Abstract: In this paper, the effect of backward wave oscillation (BWO) on helix slow wave structure performance for TWT has been described. In this paper both the cases tapered and untapered helix slow wave structure (SWS) have been analyzed, caused by BWO for high gain helix TWT. In house developed the one-dimensional (SUNRAY-1D) large signal analysis model has been used for stability analysis of the helix SWS. The analysis on backward wave amplifier gain has been carried out as a function of the taper parameter and frequency parameter. The position and nature of tapering also affect the electronic efficiency as well as the start oscillation current. Hence, position and nature of tapering have been optimized. Journal: Journal of Electromagnetic Waves and Applications Pages: 557-563 Issue: 5 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2018.1561332 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1561332 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:5:p:557-563 Template-Type: ReDIF-Article 1.0 Author-Name: Héctor Lorduy G Author-X-Name-First: Héctor Author-X-Name-Last: Lorduy G Author-Name: L. M. Castellanos Author-X-Name-First: L. M. Author-X-Name-Last: Castellanos Title: Electromagnetic waves' self-focusing in metamaterials having both LHM and RHM behavior: an application to filter design Abstract: Self-focusing, also known as Talbot’s effect had been widely studied by the scientific community. In this paper we show self-focusing as a coherence propagation phenomenon, in particular we studied self-focusing for a pulse propagating in a metamaterial with both behaviors: left handed material (LHM) and right handed material (RHM). These dual behaviors allow the construction of frequency filters in the range of frequency in which the metamaterial stops behaving as a LHM (negative refraction index) and begins an RHM behavior (positive refraction index). The coherence length (CL) for pulses propagating in these metamaterials seems to be larger when its frequencies are in the LHM region. Finally, we show that the cell’s size turns out to be critical in designing the filter, and as an example we present here four metamaterial cells. Journal: Journal of Electromagnetic Waves and Applications Pages: 564-571 Issue: 5 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2018.1561333 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1561333 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:5:p:564-571 Template-Type: ReDIF-Article 1.0 Author-Name: Zahra Hamzavi-Zarghani Author-X-Name-First: Zahra Author-X-Name-Last: Hamzavi-Zarghani Author-Name: Alireza Yahaghi Author-X-Name-First: Alireza Author-X-Name-Last: Yahaghi Author-Name: Ladislau Matekovits Author-X-Name-First: Ladislau Author-X-Name-Last: Matekovits Title: Reconfigurable metasurface lens based on graphene split ring resonators using Pancharatnam–Berry phase manipulation Abstract: A reconfigurable graphene based metasurface is presented to controllably focus a circularly polarized incident plane wave. The unit cell of the proposed metasurface consists of split ring resonators on both sides of a dielectric layer. The required phase shift for focusing purpose is achieved by concurrent rotation of the elements to obey to the Pancharatnam–Berry concept. Convergence/Divergence of the transmitted wave can be controlled by handedness of the impinging plane wave and direction of the elements’ rotation. The operating frequency of the designed lens and its focal length can be adjusted by properly exploiting to the unique property of graphene, i.e. by tuning its chemical potential. Journal: Journal of Electromagnetic Waves and Applications Pages: 572-583 Issue: 5 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2018.1563509 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1563509 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:5:p:572-583 Template-Type: ReDIF-Article 1.0 Author-Name: Feng Yang Author-X-Name-First: Feng Author-X-Name-Last: Yang Author-Name: Shiwen Yang Author-X-Name-First: Shiwen Author-X-Name-Last: Yang Author-Name: Yikai Chen Author-X-Name-First: Yikai Author-X-Name-Last: Chen Author-Name: Jixin Guo Author-X-Name-First: Jixin Author-X-Name-Last: Guo Title: An effective hybrid approach for the synthesis of pencil beams and shaped beams through 4D linear antenna arrays with constrained DRR Abstract: In this work, a novel hybrid approach combining differential evolution (DE) algorithm and convex programming (CP) is proposed for the synthesis of four-dimensional (4D) antenna arrays. To achieve ultra-low sidelobe level while suppressing sideband radiations simultaneously, the hybrid approach is applied to optimize static excitation coefficients and switch-on duration time separately. In particular, the hybrid approach fully makes use of the partial convexity of the problem with respect to the static excitation coefficients. CP is used to optimize static excitation coefficients for each set of switch-on duration time generated by the DE algorithm, while the DE algorithm is used to optimize the switch-on duration time only. Consequently, fewer optimization variables are needed and less iterations are required. The approach converges faster as compared to stochastic algorithms including all the optimization variables, especially for large arrays. Several numerical examples of the 4D antenna arrays are presented to demonstrate the effectiveness of the proposed hybrid approach. Journal: Journal of Electromagnetic Waves and Applications Pages: 584-600 Issue: 5 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2018.1564704 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1564704 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:5:p:584-600 Template-Type: ReDIF-Article 1.0 Author-Name: Ender Öztürk Author-X-Name-First: Ender Author-X-Name-Last: Öztürk Author-Name: Birsen Saka Author-X-Name-First: Birsen Author-X-Name-Last: Saka Title: Double orthogonal phase stubs technique for Minkowski fractal reflectarray antenna Abstract: We propose a unit cell consisting of Minkowski fractal with double stubs to attain a broad phase range for the reflectarray antenna. In this study, single stub for Minkowski fractal and double stubs with orthogonal symmetry are simulated using HFSS™ program with Floquet Port incidence. It is observed that the single stub causes higher cross polarization level compared to the double orthogonal stubs. Simulation results are supported by the experimental data obtained from the measurements using waveguide setup. As a result, a broad phase response, better reflection loss, and 10.9% shrinkage in patch size are obtained using double stubs with orthogonal symmetry. Subsequently, the proposed unit cell is used to design and fabricate a full-scale 221 element reflectarray antenna, which may be used, particularly, in aeronautical and space applications. At 10 GHz, simulation results are compared with the measured data, and good agreement is observed. Journal: Journal of Electromagnetic Waves and Applications Pages: 601-611 Issue: 5 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2019.1566027 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1566027 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:5:p:601-611 Template-Type: ReDIF-Article 1.0 Author-Name: Mingye Fu Author-X-Name-First: Mingye Author-X-Name-Last: Fu Author-Name: Qianyin Xiang Author-X-Name-First: Qianyin Author-X-Name-Last: Xiang Author-Name: Quanyuan Feng Author-X-Name-First: Quanyuan Author-X-Name-Last: Feng Title: Minimized reflectionless bandpass filter with four notches and low insertion loss Abstract: A size-minimized low-insertion-loss reflectionless bandpass filter with four notches is presented in this paper. The insertion loss of two quasi-elliptic-type filters is studied and optimized by a new approach based on cascade resonators branches. Parameters extraction procedure for the desired position of notches is illustrated. The inband performance, bandwidth and notch width are studied. This novel approach brings lower insertion loss. It can be extended to reflectionless bandpass filters with arbitrary number of notches. The size of filter is also minimized. This filter is designed, simulated, fabricated and measured. It is centered at 3.481 GHz with a 3-dB bandwidth of 276 MHz. The minimum measured in-band insertion loss, including the loss of SMA interface, is 1.239 dB. Four notches are located at 2.827, 3.238, 3.825 and 4.306 GHz, respectively. S11 of this filter is less than −10 dB during 2–5 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 612-624 Issue: 5 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2019.1566028 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1566028 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:5:p:612-624 Template-Type: ReDIF-Article 1.0 Author-Name: Won-Jun Lee Author-X-Name-First: Won-Jun Author-X-Name-Last: Lee Author-Name: Sang-Min Baek Author-X-Name-First: Sang-Min Author-X-Name-Last: Baek Author-Name: Sang-Yong Kim Author-X-Name-First: Sang-Yong Author-X-Name-Last: Kim Title: Design of electromagnetic wave absorbing sandwich composite for secondary bonding application Abstract: In this study, a novel electromagnetic (EM) wave absorbing composite sandwich structure and its application process are proposed. The composite sandwich can be applied to the outer part of structures as a final surface treatment through a secondary bonding process, and this covers all the surface components that illuminate the incident EM waves. This process improves the structural material properties of the original components and their durability against the environment in contrast to EM wave absorbing paint or patch. With the help of EM wave absorbing characteristics and continuous impedance of the composite sandwich structures, the EM signals from reflection, diffraction, and scatter decrease effectively. The outer skin of the composite sandwich includes a resistive periodic patterned sheet prepared using printed electronics, and a low-dielectric foam is adopted as the core material. This composite is designed based on the equivalent circuit theory and is subsequently fabricated. The EM characteristics are tested after application on an aircraft skin structure through a secondary bonding process. The measurement of reflection loss and image processing of the reflected signal show that this composite and application process decrease the EM wave reflections from the original structure significantly. Journal: Journal of Electromagnetic Waves and Applications Pages: 625-636 Issue: 5 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2019.1567397 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1567397 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:5:p:625-636 Template-Type: ReDIF-Article 1.0 Author-Name: Jacek Gulgowski Author-X-Name-First: Jacek Author-X-Name-Last: Gulgowski Author-Name: Tomasz P. Stefański Author-X-Name-First: Tomasz P. Author-X-Name-Last: Stefański Title: Recurrence scheme for FDTD-compatible discrete Green's function derived based on properties of Gauss hypergeometric function Abstract: In this paper, the formulation of one-dimensional FDTD (Finite-difference time-domain)-compatible discrete Green's function (DGF) is derived based on the Gauss hypergeometric function (GHF). The properties of GHF make it possible to derive the recurrence scheme only in the time domain for the DGF generation. Furthermore, this recurrence scheme is valid for any stable time-step size and can be implemented using standard numerical precision of computations. The proposed derivation is obtained without processing in any symbolic mathematics software and relies on the application of known properties of GHF. The difference between the developed recurrence scheme and the direct FDTD simulation is approximately at the level of numerical noise, which confirms the correctness of our derivation. The results obtained should be useful for the development of computational techniques employing FDTD and the diakoptic approach. Journal: Journal of Electromagnetic Waves and Applications Pages: 637-653 Issue: 5 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2019.1568308 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1568308 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:5:p:637-653 Template-Type: ReDIF-Article 1.0 Author-Name: Ankit Sharma Author-X-Name-First: Ankit Author-X-Name-Last: Sharma Author-Name: Deepak Gangwar Author-X-Name-First: Deepak Author-X-Name-Last: Gangwar Author-Name: Binod Kumar Kanaujia Author-X-Name-First: Binod Kumar Author-X-Name-Last: Kanaujia Author-Name: Santanu Dwari Author-X-Name-First: Santanu Author-X-Name-Last: Dwari Title: Analysis and design of an ultra-thin metamaterial absorber and its application for in-band RCS reduction of antenna Abstract: This paper presents the analysis and design of an ultra-thin metamaterial absorber (MA) for the in-band Radar Cross Section (RCS) reduction of a patch antenna. The proposed MA consists of a periodic array of double square loop structures printed on an FR4 substrate with a thickness of 0.022 λo. A detailed theoretical analysis of the MA unit cell is conducted to investigate the absorbing characteristics of the MA. The simulated and measured results show that MA significantly reduces the RCS of the proposed antenna within its impedance bandwidth and a maximum RCS reduction of 15 dB is achieved at 6.75 GHz. The impedance bandwidth of the proposed antenna is 6.6–7 GHz, which is also improved by the loading of the MA. The results also show that after loading the MA on the patch antenna, the RCS of the proposed antenna is significantly reduced and there is no degradation observed in its radiation properties. Journal: Journal of Electromagnetic Waves and Applications Pages: 654-667 Issue: 5 Volume: 33 Year: 2019 Month: 3 X-DOI: 10.1080/09205071.2019.1571446 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1571446 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:5:p:654-667 Template-Type: ReDIF-Article 1.0 Author-Name: Marco Salucci Author-X-Name-First: Marco Author-X-Name-Last: Salucci Author-Name: Nicola Anselmi Author-X-Name-First: Nicola Author-X-Name-Last: Anselmi Author-Name: Giacomo Oliveri Author-X-Name-First: Giacomo Author-X-Name-Last: Oliveri Author-Name: Paolo Rocca Author-X-Name-First: Paolo Author-X-Name-Last: Rocca Author-Name: Shamim Ahmed Author-X-Name-First: Shamim Author-X-Name-Last: Ahmed Author-Name: Pierre Calmon Author-X-Name-First: Pierre Author-X-Name-Last: Calmon Author-Name: Roberto Miorelli Author-X-Name-First: Roberto Author-X-Name-Last: Miorelli Author-Name: Christophe Reboud Author-X-Name-First: Christophe Author-X-Name-Last: Reboud Author-Name: Andrea Massa Author-X-Name-First: Andrea Author-X-Name-Last: Massa Title: A nonlinear Kernel-based adaptive learning-by-examples method for robust NDT/NDE of conductive tubes Abstract: In this work, the real-time non-destructive testing and evaluation (NDT/NDE) of faulty conductive tubes from eddy current (EC) measurements is addressed and solved in a computationally efficient way by means of an innovative learning-by-examples (LBE) methodology. More specifically, the estimation of the descriptors of a defect embedded within the cylindrical structure under test (SUT) is yielded by combining a non-linear feature extraction technique with an adaptive sampling strategy able to uniformly explore the arising feature space. Predictions are then performed during the on-line testing phase by means of a support vector regression (SVR). Representative results from a numerical/experimental validation are reported to assess the effectiveness of the proposed approach also in comparison with competitive state-of-the-art approaches. Journal: Journal of Electromagnetic Waves and Applications Pages: 669-696 Issue: 6 Volume: 33 Year: 2019 Month: 4 X-DOI: 10.1080/09205071.2019.1572546 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1572546 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:6:p:669-696 Template-Type: ReDIF-Article 1.0 Author-Name: Pourya Rostami Gooran Author-X-Name-First: Pourya Author-X-Name-Last: Rostami Gooran Author-Name: Ali Lalbakhsh Author-X-Name-First: Ali Author-X-Name-Last: Lalbakhsh Author-Name: Hamed Moradi Author-X-Name-First: Hamed Author-X-Name-Last: Moradi Author-Name: Mohammad (Behdad) Jamshidi Author-X-Name-First: Mohammad (Behdad) Author-X-Name-Last: Jamshidi Title: Compact and wideband printed log-periodic dipole array antenna using multi-sigma and multi-Tau techniques Abstract: In this paper, a wideband printed log periodic dipole array antenna (PLPDA) is designed to cover WiMAX (3.3, 3.5, and 5.5 GHz), WLAN (3.657–3.690 GHz, 802.11y), 4.942–4.948 GHz (802.11/a-j), and 5.180–5.825 GHz (802.11/a-n). Three effective techniques including MS (Multi-Sigma), MT (Multi-Tau), and Meander-line techniques for size reduction and bandwidth improvement are employed. The 10 dB return loss bandwidth of the fabricated antenna is 86% (3–7.8 GHz) and the average peak gain and radiation efficiency are 3.7 dB and 90%, respectively. The overall size of the presented antenna is 37 × 52 mm2, (0.37 $ \lambda _0 \times 0.52 \lambda _0 $ λ0×0.52λ0), where $ \lambda _0 $ λ0 is the wavelength at the lowest frequency of the operating band. Journal: Journal of Electromagnetic Waves and Applications Pages: 697-706 Issue: 6 Volume: 33 Year: 2019 Month: 4 X-DOI: 10.1080/09205071.2019.1575286 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1575286 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:6:p:697-706 Template-Type: ReDIF-Article 1.0 Author-Name: Farzad Khajeh-Khalili Author-X-Name-First: Farzad Author-X-Name-Last: Khajeh-Khalili Author-Name: M. Amin Honarvar Author-X-Name-First: M. Amin Author-X-Name-Last: Honarvar Author-Name: Abdolmehdi Dadgarpour Author-X-Name-First: Abdolmehdi Author-X-Name-Last: Dadgarpour Author-Name: Bal S. Virdee Author-X-Name-First: Bal S. Author-X-Name-Last: Virdee Author-Name: Tayeb A. Denidni Author-X-Name-First: Tayeb A. Author-X-Name-Last: Denidni Title: Compact tri-band Wilkinson power divider based on metamaterial structure for Bluetooth, WiMAX, and WLAN applications Abstract: A novel Wilkinson power divider is presented in this paper for triple band operation. It comprises a Π-shaped transmission-line coupled to a rectangular split ring resonator metamaterial structure. The μ-negative feature of the rectangular split ring resonator metamaterial structure is investigated by retrieving its constitutive parameters from the S-parameter response. To demonstrate the versatility of the proposed Wilkinson power divider it was designed to cover Bluetooth (2.4 GHz), WiMAX (3.5 GHz), and WLAN (5.2 GHz). The tri-band Wilkinson power divider was fabricated and its performance measured to verify the design. Good agreement between the measured and simulated data is obtained. Measured results show that the tri-band Wilkinson power divider has fractional bandwidth of 3.86%, 5.82%, and 3.89% at 2.4, 3.5, and 5.2 GHz, respectively. In addition, the rectangular split ring resonator metamaterial Wilkinson power divider has a small physical footprint (14 × 17.9 mm2 or 0.15λg × 0.19λg), which is 60% smaller than conventional designs. Journal: Journal of Electromagnetic Waves and Applications Pages: 707-721 Issue: 6 Volume: 33 Year: 2019 Month: 4 X-DOI: 10.1080/09205071.2019.1575287 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1575287 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:6:p:707-721 Template-Type: ReDIF-Article 1.0 Author-Name: Chunming Tian Author-X-Name-First: Chunming Author-X-Name-Last: Tian Author-Name: Juan Chen Author-X-Name-First: Juan Author-X-Name-Last: Chen Title: Analysis of magnetically biased graphene absorber using anisotropic HIE-FDTD method Abstract: An anisotropic hybrid implicit-explicit finite-difference time-domain scheme is developed to investigate the magnetically biased graphene absorber. The anisotropic conductivity of the graphene is incorporated into the scheme by using the auxiliary difference equations. Numerical examples show that the presented scheme has much higher simulation velocity than the conventional finite-difference time-domain scheme, because the time increment in proposed method is not confined by the fine meshes in graphene sheet. Besides, the results validate that, by controlling the biased magnetic field, the graphene exhibits tunable polarization rotation property at Terahertz spectra and can be used to design magnetically tunable Terahertz absorber effectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 722-733 Issue: 6 Volume: 33 Year: 2019 Month: 4 X-DOI: 10.1080/09205071.2019.1575288 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1575288 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:6:p:722-733 Template-Type: ReDIF-Article 1.0 Author-Name: E. S. Goncharov Author-X-Name-First: E. S. Author-X-Name-Last: Goncharov Author-Name: A. N. Lyakhov Author-X-Name-First: A. N. Author-X-Name-Last: Lyakhov Author-Name: T. V. Loseva Author-X-Name-First: T. V. Author-X-Name-Last: Loseva Title: 3D-FEM simulation model of the Earth-ionosphere cavity Abstract: Radio waves of extremely low frequencies (5–40 Hz) propagate in a special way. Since their wavelengths correspond to the Earth's radius, global resonances are found inside the cavity bounded by the Earth’s surface and the lower ionosphere. These so-called Schumann resonances form a system of standing waves around the planet. They can be a powerful tool for investigating the electrical processes occurring in the lower ionosphere. This paper describes finite element method (FEM) simulations in the frequency domain of Schumann eigenmodes in 3D inhomogeneous Earth-ionosphere cavity. Such an approach provides result independence from source configuration and allows to separate ionosphere configuration influence on Schumann resonances. Also the approach visually reproduces line splitting in the global resonances. The ionosphere was modeled by a simple conventional vertical conductivity profile and by means of a complex 22-species plasmachemical model. Obtained simulation results are compared with the experiment and discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 734-742 Issue: 6 Volume: 33 Year: 2019 Month: 4 X-DOI: 10.1080/09205071.2019.1575289 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1575289 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:6:p:734-742 Template-Type: ReDIF-Article 1.0 Author-Name: Vidyalakshmi M. Ravi Author-X-Name-First: Vidyalakshmi M. Author-X-Name-Last: Ravi Author-Name: Kavitha Arunachalam Author-X-Name-First: Kavitha Author-X-Name-Last: Arunachalam Title: A low noise stable radiometer front-end for passive microwave tissue thermometry Abstract: A low noise, high gain, stable radiometer front-end is presented for non-invasive tissue thermometry using custom designed narrow band low noise amplifiers (LNAs) and band pass filter (BPF) with 1.3 GHz centre frequency and − 20 dB pass band of 332 MHz. The fabricated LNAs have >15 dB gain, unconditional gain stability and noise figure (NF) < 1.45 dB in the pass band. The maximum insertion loss of the BPF is <1 dB over 1.2–1.4 GHz with 50 dB suppression in the surrounding communication bands. The cascaded radiometer front-end has measured gain of 45–50 dB, NF < 1.75 dB in the pass band and > 30 dB suppression in the adjacent personal communication bands. The Allan deviation of the total power radiometer indicates long term system stability and presence of Gaussian thermal noise for integration time, $ \tau \lt 12.8\,{\rm s} $ τ<12.8s. Radiometer measurements of a matched load at room temperature for $ \tau = 3\,{\rm s} $ τ=3s indicate acceptably low influence of external electromagnetic interference (EMI) and system noise equivalent temperature of 145 K. The brightness temperature measured by the total power radiometer using a resonant slot antenna demonstrates the ability to detect a 0.3°C change in the test load temperature with better than 0.1°C accuracy. Journal: Journal of Electromagnetic Waves and Applications Pages: 743-758 Issue: 6 Volume: 33 Year: 2019 Month: 4 X-DOI: 10.1080/09205071.2019.1576063 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1576063 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:6:p:743-758 Template-Type: ReDIF-Article 1.0 Author-Name: Mingye Fu Author-X-Name-First: Mingye Author-X-Name-Last: Fu Author-Name: Qianyin Xiang Author-X-Name-First: Qianyin Author-X-Name-Last: Xiang Author-Name: Quanyuan Feng Author-X-Name-First: Quanyuan Author-X-Name-Last: Feng Author-Name: Zongliang Zheng Author-X-Name-First: Zongliang Author-X-Name-Last: Zheng Author-Name: Zhixiong Di Author-X-Name-First: Zhixiong Author-X-Name-Last: Di Author-Name: Ting Peng Author-X-Name-First: Ting Author-X-Name-Last: Peng Title: Monolithic integrated pseudocombline bandpass filter with pre-designed second to fundamental harmonic ratio Abstract: An integrated 3rd-order pseudocombline bandpass filter with pre-designed second to fundamental harmonic ratio is designed based on 0.25 μm GaAs (Gallium Arsenide) process. λ0/4 microstrip loaded with capacitor is used as the resonator. The second to fundamental harmonic frequency ratio of the resonator is investigated, and the ratio can be controlled by the resonator's capacitor. The coupling coefficients and external quality factor are designed based on coupling matrix. This filter was fabricated with die size of 1050 μm×1556 μm. The measurement shows that the ratio of second to fundamental harmonic is 10.7, the stopband rejection keeps higher than 40 dB from 5.15 to 22.2 GHz, and a transmission zero is generated at 5.7 GHz due to the magnetic cross coupling between the first and third resonator. The −1 dB bandwidth is from 3.05 to 4 GHz, and the minimum insertion loss is 1.5 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 759-770 Issue: 6 Volume: 33 Year: 2019 Month: 4 X-DOI: 10.1080/09205071.2019.1576064 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1576064 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:6:p:759-770 Template-Type: ReDIF-Article 1.0 Author-Name: Yilin Liu Author-X-Name-First: Yilin Author-X-Name-Last: Liu Author-Name: Kama Huang Author-X-Name-First: Kama Author-X-Name-Last: Huang Author-Name: Xiaoping Feng Author-X-Name-First: Xiaoping Author-X-Name-Last: Feng Author-Name: Nouman Rasool Author-X-Name-First: Nouman Author-X-Name-Last: Rasool Title: Light-weight low-profile monopole array antenna with wideband circular polarization on flexible substrate Abstract: A novel 2×2 broadband circularly polarized low-profile monopole array antenna adopting the sequential rotation technique is presented and experimentally studied in this article. The array is very lightweight and is printed on the 0.2 mm flexible substrate. The basal antenna element of the 2×2 arrays is a printed curve-shaped monopole with good bandwidth and circular polarization property. The simulated and measured impedance bandwidth and axial ratio bandwidth are presented. Moreover, radiation patterns are also presented. The advantages of the proposed antenna include low-profile, light-weight, simple structure, and broad working bandwidth. Journal: Journal of Electromagnetic Waves and Applications Pages: 771-781 Issue: 6 Volume: 33 Year: 2019 Month: 4 X-DOI: 10.1080/09205071.2019.1576546 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1576546 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:6:p:771-781 Template-Type: ReDIF-Article 1.0 Author-Name: Xiaoxia He Author-X-Name-First: Xiaoxia Author-X-Name-Last: He Author-Name: Peng Gao Author-X-Name-First: Peng Author-X-Name-Last: Gao Author-Name: Ziqiang Zhu Author-X-Name-First: Ziqiang Author-X-Name-Last: Zhu Author-Name: Sicen You Author-X-Name-First: Sicen Author-X-Name-Last: You Author-Name: Peng Wang Author-X-Name-First: Peng Author-X-Name-Last: Wang Title: A flexible pattern reconfigurable antenna for WLAN wireless systems Abstract: A novel flexible pattern reconfigurable antenna for WLAN wireless system is proposed. The reconfigurable antenna is fed by a microstrip, and consists of a circular monopole patch, three ship-shaped parasitic patches, a planar ground and two parallel symmetrical parasitic branches embedded with two PIN diodes. The antenna achieves two-state pattern reconfigurability by controlling the on and off of two PIN diodes to change the director. The antenna has a bandwidth of 2.40-2.48 GHz and is capable of steering the beam in the direction 30°, 330° in the azimuthal plane. Meanwhile, the antenna works at two states with the same band. Finally, the bending characteristics of the antenna at different bending degrees are analyzed. Measured results are in good agreement with simulations, which denotes that it is suitable for WLAN wireless systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 782-793 Issue: 6 Volume: 33 Year: 2019 Month: 4 X-DOI: 10.1080/09205071.2019.1576547 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1576547 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:6:p:782-793 Template-Type: ReDIF-Article 1.0 Author-Name: P. K. Choudhury Author-X-Name-First: P. K. Author-X-Name-Last: Choudhury Author-Name: M. Abou El-Nasr Author-X-Name-First: M. Author-X-Name-Last: Abou El-Nasr Title: Insight into remote monitoring systems Journal: Journal of Electromagnetic Waves and Applications Pages: 795-798 Issue: 7 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1591057 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1591057 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:7:p:795-798 Template-Type: ReDIF-Article 1.0 Author-Name: Hosam El-Ocla Author-X-Name-First: Hosam Author-X-Name-Last: El-Ocla Title: Accurate remote sensing of conducting objects in random media with plane H-wave polarization Abstract: In this work, a mechanism is proposed to enhance the remote sensing accuracy of conducting objects located within continuous random media. Through our mechanism, operating frequency would be selected properly for preciously radar detection. In this regard, numerical analysis for the influence of medium characteristics on the radar cross section (RCS) is conducted. Illumination region is assumed as partially convex surface while considering targets having large sizes of about four wavelengths. We handle the effect of various parameters such as the medium randomness intensity and scale size, target configuration having curvature and size and incident waves polarization. Waves are backscattering from objects in both free space and random medium while considering horizontal polarization of incident waves. Such polarization generates creeping waves in which they have an extra impact on the backscattering waves where would be avoided through our mechanism. Journal: Journal of Electromagnetic Waves and Applications Pages: 799-810 Issue: 7 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1583609 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1583609 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:7:p:799-810 Template-Type: ReDIF-Article 1.0 Author-Name: Saddek Afifi Author-X-Name-First: Saddek Author-X-Name-Last: Afifi Author-Name: Richard Dusséaux Author-X-Name-First: Richard Author-X-Name-Last: Dusséaux Title: The co- and cross-polarized scattered intensity ratios for 3D layered structures with randomly rough interfaces Abstract: We determine the statistical distributions for the co- and cross-polarized scattered intensity ratios characterizing three-dimensional layered structures with an arbitrary number of rough interfaces illuminated by a plane wave. Within the framework of the first-order small perturbation method, we show for slightly rough interfaces with infinite surface areas and Gaussian height distributions that the intensity ratio is a random variable, the probability law of which is a function of two parameters. For air/clayey soil/rock structures, we analyze the influence of a snow layer upon the probability laws and we validate the closed-form formulae by comparison with Monte-Carlo simulations. Journal: Journal of Electromagnetic Waves and Applications Pages: 811-826 Issue: 7 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2018.1523027 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1523027 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:7:p:811-826 Template-Type: ReDIF-Article 1.0 Author-Name: Wenlong Tang Author-X-Name-First: Wenlong Author-X-Name-Last: Tang Author-Name: Hao Cha Author-X-Name-First: Hao Author-X-Name-Last: Cha Author-Name: Min Wei Author-X-Name-First: Min Author-X-Name-Last: Wei Author-Name: Bin Tian Author-X-Name-First: Bin Author-X-Name-Last: Tian Title: Estimation of surface-based duct parameters from automatic identification system using the Levy flight quantum-behaved particle swarm optimization algorithm Abstract: Atmospheric duct propagation has a significant influence on the performance of wireless communication and radar systems in the maritime environment that makes it essential to master the detailed knowledge of the atmospheric refractivity profile. Automatic identification system (AIS) is a maritime navigation safety communication system that operates in the very high frequency mobile band and the propagation path of AIS signals will be influenced by different atmospheric conditions. In this paper, a new refractivity estimation method based on the AIS signal level is proposed and the Levy flight quantum-behaved particle swarm optimization (LFQPSO) algorithm is presented and applied in the new estimation method to estimate the surface based duct parameters. Numerical simulations demonstrate that the LFQPSO algorithmhas good robustness and the new refractivity estimation method based on the AIS signal level can provide near-real-time estimation ofatmospheric refractivity. Journal: Journal of Electromagnetic Waves and Applications Pages: 827-837 Issue: 7 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2018.1560365 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1560365 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:7:p:827-837 Template-Type: ReDIF-Article 1.0 Author-Name: Thi Duyen Bui Author-X-Name-First: Thi Duyen Author-X-Name-Last: Bui Author-Name: Minh Thuy Le Author-X-Name-First: Minh Thuy Author-X-Name-Last: Le Author-Name: Quoc Cuong Nguyen Author-X-Name-First: Quoc Cuong Author-X-Name-Last: Nguyen Title: Electronically steerable antenna array for indoor positioning system Abstract: This paper presents a 2.4 GHz electronically steerable antenna array (ESAA) using a phase shifter based on the 4×4 Butler matrix which is suitable for the wireless indoor positioning system (WIPS). The low cost and simplicity are advantages of the proposed ESAA. The main beam of the antenna can be steered at four positions in the elevation plane, from −37°, −12°, 12° to + 36° with the narrow beamwidth in order to increase localization accuracy and wide-angle coverage of 240° in the azimuth plane. The ESAA is demonstrated as a base station antenna in a single-anchor indoor localization system experimentation. Two indoor localization algorithms, including fingerprinting and direction-of-arrive (DoA), are implemented and discussed in this paper. The indoor measurement setups and localization results using the proposed ESAA are proven in this paper to have better results than other similar approaches. Journal: Journal of Electromagnetic Waves and Applications Pages: 838-852 Issue: 7 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2018.1555060 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1555060 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:7:p:838-852 Template-Type: ReDIF-Article 1.0 Author-Name: Giovanni Andrea Casula Author-X-Name-First: Giovanni Andrea Author-X-Name-Last: Casula Title: A quarter mode SIW antenna for short-range wireless communications Abstract: A wearable textile antenna based on the fundamental mode of a quarter-mode substrate integrated waveguide is presented for short-range wireless applications. The antenna operates in the UHF frequency band, at 868 MHz, has a compact size, and requires minimal manufacturing complexity and a very low production cost. Moreover, it presents a good isolation from the human body, and a significant robustness with respect to deformation. If compared with its substrate integrate waveguide resonator counterpart, the proposed antenna size has been reduced of 75%, without degrading its performance. The proposed structure has been simulated using CST Microwave Studio, and its gain is around 2 dBi, with a broadside radiation pattern. All these features make it very promising for short-range wireless communications. Journal: Journal of Electromagnetic Waves and Applications Pages: 853-864 Issue: 7 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2018.1537136 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1537136 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:7:p:853-864 Template-Type: ReDIF-Article 1.0 Author-Name: Jian Tan Author-X-Name-First: Jian Author-X-Name-Last: Tan Author-Name: Xiangtao Fan Author-X-Name-First: Xiangtao Author-X-Name-Last: Fan Author-Name: Shenghua Wang Author-X-Name-First: Shenghua Author-X-Name-Last: Wang Author-Name: Yingchao Ren Author-X-Name-First: Yingchao Author-X-Name-Last: Ren Author-Name: Changshun Guo Author-X-Name-First: Changshun Author-X-Name-Last: Guo Author-Name: Jian Liu Author-X-Name-First: Jian Author-X-Name-Last: Liu Author-Name: Jing Li Author-X-Name-First: Jing Author-X-Name-Last: Li Author-Name: Qin Zhan Author-X-Name-First: Qin Author-X-Name-Last: Zhan Title: Target recognition of SAR images by partially matching of target outlines Abstract: A synthetic aperture radar (SAR) automatic target recognition method is proposed based on the matching of the target outlines. The target outline describes the physical sizes and shape of the target thus discriminative for SAR target recognition. The original target outline is segmented into several independent parts. The distance between each part and its counterpart in the corresponding template is measured by the least-trimmed square Hausdorff distance. Afterwards, the results of individual parts are combined to form a similarity measure, which comprehensively considers the possible deformations of the target outline. Based on the similarity measure, the target type is determined to be the class sharing the maximum similarity with the test sample. To evaluate the performance of the proposed method, extensive experiments are conducted on the Moving and Stationary Target Acquisition and Recognition dataset under both the standard operating condition and several typical extended operating conditions. Journal: Journal of Electromagnetic Waves and Applications Pages: 865-881 Issue: 7 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2018.1495580 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1495580 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:7:p:865-881 Template-Type: ReDIF-Article 1.0 Author-Name: Shuguang Miao Author-X-Name-First: Shuguang Author-X-Name-Last: Miao Author-Name: Xiaowen Liu Author-X-Name-First: Xiaowen Author-X-Name-Last: Liu Title: Joint sparse representation of complementary components in SAR images for robust target recognition Abstract: An automatic target recognition (ATR) method of synthetic aperture radar (SAR) images is proposed by joint sparse representation (JSR) of the complementary components from the original SAR image. The shadow and target image are generated from the original image. A simple but effective segmentation algorithm is designed to separate out the shadow region. By replacing the shadow region with randomly selected background pixels in the original image, the target image is generated. Afterwards, the two components together with the original image are jointly classified based on JSR. Due to the extended operating conditions (EOCs) in SAR ATR, the shadow or target region may be corrupted. In this case, the sole use of the original image may bring some interference caused by the corruption. As a remedy, the joint use of the three components can effectively improve the robustness of the ATR method to various EOCs by complementing each other. To quantitatively evaluate the proposed method, experiments are conducted on the moving and stationary target acquisition and recognition dataset under various conditions. The results demonstrate the effectiveness and robustness of the proposed method. Journal: Journal of Electromagnetic Waves and Applications Pages: 882-896 Issue: 7 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2018.1496038 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1496038 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:7:p:882-896 Template-Type: ReDIF-Article 1.0 Author-Name: Xinying Miao Author-X-Name-First: Xinying Author-X-Name-Last: Miao Author-Name: Yupeng Shan Author-X-Name-First: Yupeng Author-X-Name-Last: Shan Title: SAR target recognition via sparse representation of multi-view SAR images with correlation analysis Abstract: This study proposes a synthetic aperture radar (SAR) target recognition method via sparse representation of multi-view images with correlation analysis. The multi-view SAR images are first clustered into several view sets and in each set the included SAR images share high correlations. For the view set with only one SAR image, the sparse representation-based classification (SRC) is used for classification. The joint sparse representation (JSR) is employed to classify the view sets with more than one images in order to exploit their correlations. The decisions from different view sets are then fused based on the Bayesian theory. Therefore, both the independency and inner correlations in the multi-view SAR images can be better exploited to improve the target recognition performance. Experiments are conducted on the moving and stationary target acquisition and recognition (MSTAR) data set. The results show the superiority of the proposed approach over some other methods. Journal: Journal of Electromagnetic Waves and Applications Pages: 897-910 Issue: 7 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1575290 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1575290 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:7:p:897-910 Template-Type: ReDIF-Article 1.0 Author-Name: Yilu Ma Author-X-Name-First: Yilu Author-X-Name-Last: Ma Author-Name: Li Zhu Author-X-Name-First: Li Author-X-Name-Last: Zhu Author-Name: Yuehua Li Author-X-Name-First: Yuehua Author-X-Name-Last: Li Title: HRRP-based target recognition with deep contractive neural network Abstract: One of the radar high resolution range profile (HRRP) target recognition issues is the existence of noise interference, especially for the ground target. The recognition performance of traditional shallow methods degrades as suffering from the limited capability of extracting robust and discriminative features. In this paper, a novel deep neural network called stacked denoising and contractive auto-encoder (SDCAE) is designed for millimeter wave radar HRRP recognition. To enhance the capability of learning robust structure and correlations from corrupted HRRP data, a denoising contractive auto-encoder is designed by combining the advantages of denoising auto-encoder and contractive auto-encoder. As an extension of deep auto-encoders, SDCAE inherits the advantage of enhancing the robustness of features via reducing external noise, retaining local invariance to obtain more discriminative representations of training samples. Experimental results demonstrate the superior performance of the proposed method over traditional methods, especially in noise interference condition and with few training samples. Journal: Journal of Electromagnetic Waves and Applications Pages: 911-928 Issue: 7 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2018.1540309 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1540309 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:7:p:911-928 Template-Type: ReDIF-Article 1.0 Author-Name: Jia Liu Author-X-Name-First: Jia Author-X-Name-Last: Liu Author-Name: Bao Fa Wang Author-X-Name-First: Bao Fa Author-X-Name-Last: Wang Title: Dynamic aircraft identification using HRRP under attitude perturbation interference Abstract: The Automatic Target Recognition (ATR) with target High-Resolution Range Profile (HRRP) is of great research and application significance. Environmental interferences reflect close relevance with target HRRP imaging quality as well as classification performance. The dynamic target attitude perturbation is considered as one of the dominant interference factors. This paper studies its impact on aircraft HRRP through simulation and statistical analysis. HRRP confidence zone and similarity concepts are proposed as qualitative and quantitative tools for HRRP variation description under attitude perturbation. Extracted HRRP variation features provide a novel solution to overcome attitude perturbation interference in target classification while maintaining the accuracy. Classification evaluations over three aircraft models in accuracy and efficiency consolidate the proposed classification method which better suits the practical classification scenario. Journal: Journal of Electromagnetic Waves and Applications Pages: 929-945 Issue: 7 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2018.1555493 File-URL: http://hdl.handle.net/10.1080/09205071.2018.1555493 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:7:p:929-945 Template-Type: ReDIF-Article 1.0 Author-Name: Pengzheng Lei Author-X-Name-First: Pengzheng Author-X-Name-Last: Lei Title: Comprehensive measurement and modeling in foliage environments using UHF UWB ground-based radar Abstract: The precise knowledge of the statistical properties of clutter plays a key role in radar target detection in foliage environments. Owing to a wealth of multiple scattering, the selection of an appropriate model for diverse foliage environments remains a conundrum. Thus the statistical modeling of the foliage clutter in different environments is focused on in this paper. In particular, the primary contribution is to characterize and parameterize the amplitude of the foliage clutter in three typical foliage environments of different densities, including line-of-sight (LOS) forest environment, non line-of-sight (NLOS) forest-penetration environment, and NLOS bush-penetration environment. Based on the real clutter data acquired with an ultra-high frequency (UHF) ultra-wideband (UWB) ground-based radar, the experimental results show that the specific foliage type and configuration has a significant impact on the distribution of foliage clutter. Furthermore, by means of Kullback–Leibler distance (KLD), log-logistic, $ {\mathcal{G}^0} $ G0 and $ \mathcal{G} $ G distributions with estimated parameters are demonstrated to be the best choice to model the clutter in the LOS forest environment, NLOS forest-penetration environment and NLOS bush-penetration environment, respectively. The proposed models are great advantages on understanding and prediction of the clutter in foliage environments. Journal: Journal of Electromagnetic Waves and Applications Pages: 946-958 Issue: 7 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1571445 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1571445 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:7:p:946-958 Template-Type: ReDIF-Article 1.0 Author-Name: Lihang Du Author-X-Name-First: Lihang Author-X-Name-Last: Du Author-Name: Cheng Gao Author-X-Name-First: Cheng Author-X-Name-Last: Gao Author-Name: Qi Zhang Author-X-Name-First: Qi Author-X-Name-Last: Zhang Author-Name: Jianbao Wang Author-X-Name-First: Jianbao Author-X-Name-Last: Wang Author-Name: Rengtang Hong Author-X-Name-First: Rengtang Author-X-Name-Last: Hong Author-Name: Dexin Qu Author-X-Name-First: Dexin Author-X-Name-Last: Qu Title: Simulation and evaluation of leakage electric field of bounded-wave simulator Abstract: This paper presents a detailed analysis on the distribution of the electric field inside and outside the bounded-wave simulator excited by HEMP (early part), and the attenuation law of the leakage electric field is verified by a scale-model experiment. Furthermore, at the basis of the energy spectrum distribution of excitation source, the general public and occupational exposures values at different observation points are calculated, and then, the limits of safety ranges are determined according to the guidelines issued by the ICNCP in 1998. The results provide a guidance for people to effectively defend against electric field radiation derived from a bounded-wave simulator. Journal: Journal of Electromagnetic Waves and Applications Pages: 959-971 Issue: 8 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1577184 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1577184 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:8:p:959-971 Template-Type: ReDIF-Article 1.0 Author-Name: Yong Fang Author-X-Name-First: Yong Author-X-Name-Last: Fang Author-Name: Xueshi Hou Author-X-Name-First: Xueshi Author-X-Name-Last: Hou Author-Name: Haoxuan Sheng Author-X-Name-First: Haoxuan Author-X-Name-Last: Sheng Author-Name: Xiaoling Zhong Author-X-Name-First: Xiaoling Author-X-Name-Last: Zhong Author-Name: Yong Guo Author-X-Name-First: Yong Author-X-Name-Last: Guo Title: Characteristic analysis of microwave multilayer MoS2 and graphene frequency tripler Abstract: In this paper, a multilayer MoS2 frequency tripler (MFT) and a graphene frequency tripler (GFT) are presented. The multilayer MoS2 and graphene have strong nonlinear characteristics. When the input power is about 14 dBm and the input frequency is 0.75–1.1 GHz, the maximum out power of the 3rd harmonic wave of the MFT is −27.1 dBm and it is about 9–13 dB lower than that of the fundamental wave leakage power. Under the same experimental conditions, the maximum output power of the 3rd harmonic wave of the GFT is −13.1dBm, and it is 22–28 dB lower than the fundamental leakage power. At the same time, the even-order harmonic output power values of the two triplers are very small. Therefore, the MFT’s fundamental-wave-leakage power is smaller than that of the GFT, and the conversion loss of the GFT is lower than that of the MFT. Journal: Journal of Electromagnetic Waves and Applications Pages: 972-980 Issue: 8 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1582363 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1582363 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:8:p:972-980 Template-Type: ReDIF-Article 1.0 Author-Name: G. Castorina Author-X-Name-First: G. Author-X-Name-Last: Castorina Author-Name: G. Torrisi Author-X-Name-First: G. Author-X-Name-Last: Torrisi Author-Name: G. Sorbello Author-X-Name-First: G. Author-X-Name-Last: Sorbello Author-Name: L. Celona Author-X-Name-First: L. Author-X-Name-Last: Celona Author-Name: A. Mostacci Author-X-Name-First: A. Author-X-Name-Last: Mostacci Title: Conductor losses calculation in two-dimensional simulations of H-plane rectangular waveguides Abstract: This paper presents a novel numerical approach to simulate H-plane rectangular-waveguide microwave circuits considering a reduced quasi-2D simulation domain with benefits for computational cost and time. With the aim to evaluate the attenuation of the full height 3D component, we propose a modified expression for the waveguide top/bottom wall conductivity. Numerical 2D simulations are validated against results from full wave 3-D commercial electromagnetic simulator. After a benchmark on a simple straight waveguide model, the method has been successfully applied to an asymmetric un-balanced power splitter, where an accurate power loss prediction is mandatory. Simulation time and memory consumption can be reduced by a factor ten and seven respectively, in comparison with complete 3D geometries. Finally, we show that, also for quasi-2D E-bend waveguide, a case where the translational H-plane symmetry is broken, the error on conductor losses computation is mitigated by our approach since the method remains still valid in a first approximation. Journal: Journal of Electromagnetic Waves and Applications Pages: 981-990 Issue: 8 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1583136 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1583136 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:8:p:981-990 Template-Type: ReDIF-Article 1.0 Author-Name: Hao Zhou Author-X-Name-First: Hao Author-X-Name-Last: Zhou Author-Name: Tianming Li Author-X-Name-First: Tianming Author-X-Name-Last: Li Author-Name: Shengen Li Author-X-Name-First: Shengen Author-X-Name-Last: Li Title: L-band dual-frequency recirculating planar magnetron Abstract: Dual-frequency oscillators have been used in many technical disciplines on account of the phase correlation between two output signals or the feasibility of producing beat wave effect. The mechanism to generate two different-frequency microwave outputs from one magnetron was discussed and simulated. Strapping technique and phase velocity modulation were adopted to generate random frequency ratio and adequate output power. The relationship between phase velocity difference and total output power was investigated and the proper variation range of phase velocity difference was discussed. The conclusion above will accelerate the design flow of dual-frequency magnetron in various frequency demand. A method of optimal E/B distribution was also applied to reduce electron recirculating loss and obtained a notable power enhancement. To fulfill the demand of producing two microwave outputs with a desirable 3:4 frequency ratio in L-band, a conventional vacuum electronic device called Dual-Frequency Recirculating Planar Magnetron (DFRPM) was modeled. There was a significant difference between planar magnetron and cylindrical magnetron, one large shared planar cathode provided better thermal stability and separated the cavity into two slow-wave structures (SWSs), consequently, each SWS arose an oscillation at their own operating frequency. The primary frequencies of two output signals were at 1.30 GHz/1.70 GHz and overcame the frequency ratio limitation happened in other design scheme. Journal: Journal of Electromagnetic Waves and Applications Pages: 991-1002 Issue: 8 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1583137 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1583137 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:8:p:991-1002 Template-Type: ReDIF-Article 1.0 Author-Name: Soumik Dey Author-X-Name-First: Soumik Author-X-Name-Last: Dey Author-Name: Santanu Mondal Author-X-Name-First: Santanu Author-X-Name-Last: Mondal Author-Name: Partha Pratim Sarkar Author-X-Name-First: Partha Pratim Author-X-Name-Last: Sarkar Title: Reactive Impedance Surface (RIS) based asymmetric slit patch antenna loaded with complementary split ring resonator (CSRR) for circular polarization Abstract: In this paper a compact patch antenna backed with artificial meta-surface known as reactive impedance surface (RIS) is designed for circular polarization in the ISM band. The antenna consists of an asymmetric diagonal slits with pair of complementary split ring resonators (CSRRs) on patch over the RIS structure. Asymmetric slits and pair of CSRRs are inserted on radiating patch to achieve circular polarization. RIS is used for improving the radiation characteristics of the antenna, while RIS-based patch provides good impedance matching over a broad frequency range. Simulated results are in good agreement with the measured results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1003-1013 Issue: 8 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1583608 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1583608 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:8:p:1003-1013 Template-Type: ReDIF-Article 1.0 Author-Name: U. Saynak Author-X-Name-First: U. Author-X-Name-Last: Saynak Author-Name: A. Kizilay Author-X-Name-First: A. Author-X-Name-Last: Kizilay Title: Scattering from a dielectric cylinder partially buried in a dielectric half space with a periodic height profile by a decomposition method Abstract: A new solution method is applied to solve the problem of electromagnetic scattering partially buried dielectric cylinder at the dielectric rough surface interface. The rough interface is chosen to be infinitely long and periodic with arbitrary profile. Equivalency principle is used to obtain a set of electric field integral equations (EFIEs) for the currents on the scattering object surface and the perturbation currents on a finite portion of interface near the object. The Method of Moments is used to solve the EFIEs in the frequency domain to obtain the scattered field. The method is presented with examples for TM $ _{{\rm z}} $ z polarization. Journal: Journal of Electromagnetic Waves and Applications Pages: 1014-1026 Issue: 8 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1584589 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1584589 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:8:p:1014-1026 Template-Type: ReDIF-Article 1.0 Author-Name: P. C. L. da Silva Author-X-Name-First: P. C. L. Author-X-Name-Last: da Silva Author-Name: J. P. da Silva Author-X-Name-First: J. P. Author-X-Name-Last: da Silva Author-Name: A. R. G. Garcia Author-X-Name-First: A. R. G. Author-X-Name-Last: Garcia Title: Daubechies wavelets as basis functions for the vectorial beam propagation method Abstract: We analyze the propagation of electromagnetic signals in optical waveguides using the Daubechies wavelets as basis functions applied in a mathematical model based in finite element method (FEM). The Daubechies wavelets have the peculiar property of having the compact support, which allows describing the behavior of functions with discontinuities or some abrupt variations of values in frequency and/or time domain. Then, the basis functions and the Galerkin method (GM) are applied together with the vector beam propagation method (VBPM) to develop a new mathematical approach. In order to validate the proposed formulation performance, we analyze a new polished-type optical fiber coupler, for which two cores are curved in a parabolic shape, and between them, a leaky-waveguide with an index-matching liquid layer is included. The distance between cores has variable parameters. Due to the inclusion of the leaky-waveguide, the coupling distance drastically reduces. Journal: Journal of Electromagnetic Waves and Applications Pages: 1027-1041 Issue: 8 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1587319 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1587319 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:8:p:1027-1041 Template-Type: ReDIF-Article 1.0 Author-Name: Haiyan Piao Author-X-Name-First: Haiyan Author-X-Name-Last: Piao Author-Name: Guohui Dong Author-X-Name-First: Guohui Author-X-Name-Last: Dong Author-Name: Longyue Qu Author-X-Name-First: Longyue Author-X-Name-Last: Qu Title: Circularly polarized antenna using ground-mode tuning technique for small-sized IoT devices Abstract: This study focuses on the generation of circular polarization (CP) in a small-sized ground plane by using ground-mode tuning (GMT) technique. The proposed antenna is composed of two branches, so that it can simultaneously excite two orthogonal modes of the ground plane for radiation. Two metal strips at the ends of the ground plane are adopted as GMT structures, and the dominant modes along the length and width of the ground plane can be controlled by tuning the property of the shorting pins, conveniently. Both simulation and measurement results indicate that the proposed technique can achieve a wideband impedance bandwidth and a sufficient AR bandwidth. Furthermore, the proposed CP antenna provides a less directive radiation pattern compared to a linearly-polarized antenna, which can be attractive in receiving performance. Journal: Journal of Electromagnetic Waves and Applications Pages: 1042-1051 Issue: 8 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1588173 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1588173 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:8:p:1042-1051 Template-Type: ReDIF-Article 1.0 Author-Name: Hsuan-Ling Kao Author-X-Name-First: Hsuan-Ling Author-X-Name-Last: Kao Author-Name: Cheng-Lin Cho Author-X-Name-First: Cheng-Lin Author-X-Name-Last: Cho Title: On-chip GaN-on-SiC VCO using a tunable substrate integrated waveguide loaded with complementary split ring resonator Abstract: This paper presents an S-band voltage-controlled oscillator (VCO) using a tunable half-mode substrate integrated waveguide (HMSIW) loaded with complementary split ring resonator (CSRR) in GaN-on-SiC high-electron-mobility transistor technology. A varactor connected to the center of the outer conductor of the HMSIW-CSRR changed the effective capacitance, resulting in a resonance frequency shift but a fixed transmission zero. Therefore, the S-band VCO can be tuned by the HMSIW-CSRR using harmonic suppression. The tunable HMSIW-CSRR VCO exhibited a frequency tuning range of 3.55–3.98 GHz with a varactor voltage of 0–6 V. The maximum output power was 21.1 dBm and rf-to-dc efficiency was 12.8% at 3.98 GHz. The lowest phase noise was −117 dBc/Hz with 1-MHz offset at a 3.56 GHz carrier frequency with 30.55 dBc of harmonic suppression. Journal: Journal of Electromagnetic Waves and Applications Pages: 1052-1059 Issue: 8 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1588790 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1588790 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:8:p:1052-1059 Template-Type: ReDIF-Article 1.0 Author-Name: Jun Qiao Author-X-Name-First: Jun Author-X-Name-Last: Qiao Author-Name: Hang Xu Author-X-Name-First: Hang Author-X-Name-Last: Xu Author-Name: Jianguo Zhang Author-X-Name-First: Jianguo Author-X-Name-Last: Zhang Author-Name: Hong Han Author-X-Name-First: Hong Author-X-Name-Last: Han Author-Name: Bingjie Wang Author-X-Name-First: Bingjie Author-X-Name-Last: Wang Title: High-resolution and anti-jamming chaotic guided radar prototype for perimeter intrusion detection Abstract: We propose a chaotic guided radar for perimeter intrusion detection and experimentally demonstrate the corresponding radar prototype which includes a transmitter, a receiver and two leaky coaxial cables (LCXs). A wideband Boolean-chaos signal is generated in the transmitter and served as the probe signal. An electromagnetic surveillance area is formed between two LCXs which act as transmitting and receiving antennas. The receiver can accurately locate an intruder crossing the LCXs by measuring a variation of correlation traces before and after intrusion. Experimental results demonstrate the proposed radar can realize the simultaneous detection of multiple intruders with 50-cm range resolution and 35-dB dynamic range. Furthermore, the anti-jamming property of the proposed guided radar for radio frequency interferences and noise are also demonstrated experimentally, which makes it perform superbly in the detection environment with multiradar cooperative work and noise. Journal: Journal of Electromagnetic Waves and Applications Pages: 1060-1069 Issue: 8 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1590247 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1590247 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:8:p:1060-1069 Template-Type: ReDIF-Article 1.0 Author-Name: Longzhu Cai Author-X-Name-First: Longzhu Author-X-Name-Last: Cai Author-Name: Daping Chu Author-X-Name-First: Daping Author-X-Name-Last: Chu Title: Highly anisotropic LC material with low dielectric loss for the application of tunable notch filters Abstract: We present here a compact liquid crystal (LC) based tunable notch filter with a narrow 3 dB bandwidth and a high quality factor. The structure of the proposed filter consists of two embedded resonators in serial, with an impedance adaptor and linear taper at each port. The notch filter combines tunable dielectric material LC with inverted microstrip technology, and was designed, fabricated and characterized to deliver a continuously tuned rejection frequency range from 3.545 GHz to 3.731 GHz, together with a narrow 3 dB bandwidth of ∼ 0.8 GHz and a high quality factor of ∼ 4.6. Such a notch filter is both compact (41 mm × 13 mm) and light weight (18.08 grams, including SMA connectors). It is suitable for working in the S band to suppress WiMAX signals that may cause interference in UWB communication systems. The narrow stopband and high quality factor of the device can be further improved at the expense of a certain extent of tuning efficiency, by using a thicker LC layer, and this is verified in experiment. The measured results of the proposed devices confirm the feasibility of using the current LC technology to manufacture tunable notch filters with a narrow bandwidth and a high quality factor. Journal: Journal of Electromagnetic Waves and Applications Pages: 1070-1081 Issue: 8 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1591308 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1591308 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:8:p:1070-1081 Template-Type: ReDIF-Article 1.0 Author-Name: Ashok Bansiwal Author-X-Name-First: Ashok Author-X-Name-Last: Bansiwal Author-Name: Sushil Raina Author-X-Name-First: Sushil Author-X-Name-Last: Raina Author-Name: K. J. Vinoy Author-X-Name-First: K. J. Author-X-Name-Last: Vinoy Author-Name: Subrata Kumar Datta Author-X-Name-First: Subrata Kumar Author-X-Name-Last: Datta Title: A simple method for estimating the quality factor of cylindrical re-entrant cavity of Klystrons Abstract: A simple method for estimation of the unloaded quality factor of single and double re-entrant cylindrical cavities was developed based on Wheeler’s incremental inductance rule. The proposed approach was benchmarked for a Ka-band re-entrant cavity against 3D electromagnetic simulation using CST Studio and also with measurements. The analysis is general and unlike the approach of Fujisawa, it could be extended to analyze the re-entrant cavity comprising dissimilar materials. The effect of surface roughness on the quality factor of the cavity also could be estimated using the present analysis. Journal: Journal of Electromagnetic Waves and Applications Pages: 1082-1091 Issue: 8 Volume: 33 Year: 2019 Month: 5 X-DOI: 10.1080/09205071.2019.1592710 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1592710 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:8:p:1082-1091 Template-Type: ReDIF-Article 1.0 Author-Name: Qinwei Li Author-X-Name-First: Qinwei Author-X-Name-Last: Li Author-Name: Xia Xiao Author-X-Name-First: Xia Author-X-Name-Last: Xiao Author-Name: Takamaro Kikkawa Author-X-Name-First: Takamaro Author-X-Name-Last: Kikkawa Title: Absorption spectrum for non-invasive blood glucose concentration detection by microwave signals Abstract: This paper proposes a blood glucose concentration detection method, which is non-invasive and based on the microwave detection technique. This method is harmless to the patients’ body. And the procedure of this method is fast and convenient. The feasibility of this method is verified by obtaining the relationship between the blood glucose level and the absorption spectrum features of the received signals with the range of blood glucose level 0–500 mg/dl. The validity of this method is testified by establishing a simulation model to test the feasibility of this method. The robustness is also checked by achieving the relationship between the peaks of the received signals at 500 MHz in the experiment earlobe phantom with a group of the human blood glucose level ranges from 0-500 mg/dl with the step of 20 mg/dl. Journal: Journal of Electromagnetic Waves and Applications Pages: 1093-1106 Issue: 9 Volume: 33 Year: 2019 Month: 6 X-DOI: 10.1080/09205071.2019.1596168 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1596168 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:9:p:1093-1106 Template-Type: ReDIF-Article 1.0 Author-Name: Vishal Kesari Author-X-Name-First: Vishal Author-X-Name-Last: Kesari Author-Name: R. Sudhakar Author-X-Name-First: R. Author-X-Name-Last: Sudhakar Author-Name: D. Jayateertha Author-X-Name-First: D. Author-X-Name-Last: Jayateertha Author-Name: P. Srikrishna Author-X-Name-First: P. Author-X-Name-Last: Srikrishna Author-Name: R. Seshadri Author-X-Name-First: R. Author-X-Name-Last: Seshadri Title: Simulation of a depressed collector for millimeter wave gyrotron Abstract: The trajectories of spent electron beam were simulated from the mode converter to the single-stage depressed collector for a W-band gyrotron. The spent beam trajectories and power distribution data obtained from large signal analysis were fed to the simulation model. The collector geometry and the magnetic field were profiled to ensure the landing of the electrons to the wider cylindrical section of the collector electrode for better thermal management, which was ensured with ±5% variation in the magnetic field and no electron interception. The power dissipation and the maximum thermal loading on the collector were 80.55 kW and 0.377 kW/cm2, respectively. The collector efficiency was ∼48% for 120 kW RF generation. The thermal analysis of the collector in pulsed condition with 10 and 40 L per minute flow rates predicted the maximum temperature at the collector electrode as 151.8°C and 133.3°C, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 1107-1118 Issue: 9 Volume: 33 Year: 2019 Month: 6 X-DOI: 10.1080/09205071.2019.1596841 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1596841 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:9:p:1107-1118 Template-Type: ReDIF-Article 1.0 Author-Name: Nezahat Günenç Tuncel Author-X-Name-First: Nezahat Author-X-Name-Last: Günenç Tuncel Title: A comment on the paper: “diffraction of plane waves by an impedance half-plane in cold plasma” Abstract: A comment on the paper “Diffraction of Plane Waves by an Impedance Half-plane in Cold Plasma” is presented. The continuity conditions were written in the case of the surrounding medium that was free space instead of cold plasma. Journal: Journal of Electromagnetic Waves and Applications Pages: 1119-1120 Issue: 9 Volume: 33 Year: 2019 Month: 6 X-DOI: 10.1080/09205071.2019.1596842 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1596842 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:9:p:1119-1120 Template-Type: ReDIF-Article 1.0 Author-Name: Christos Bolakis Author-X-Name-First: Christos Author-X-Name-Last: Bolakis Title: Designing an adjustable THz absorber Abstract: In this paper, a new approach to effective detection of THz radiation is proposed using a configuration of thin metal and thin dielectric films; to this end, the design and performance of an effective composite absorber of THz radiation that can be used as the sensing element of a thermal detector are presented. A composite absorber consists of a set of two double-layered elements of a thin metal layer located on a dielectric material and is designed through a fine-tuning process. The results indicate that the proposed low-cost absorber can be widely tuned based on the metal layer sheet resistance and the thickness of various dielectric media. The development of a proper non-linear system of equations has as input the desired frequency and bandwidth of the absorbed THz radiation and output the required metrics of dielectric refractive index, the dielectric thickness and the metal’s sheet resistance that comprise the absorber. Journal: Journal of Electromagnetic Waves and Applications Pages: 1121-1130 Issue: 9 Volume: 33 Year: 2019 Month: 6 X-DOI: 10.1080/09205071.2019.1598897 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1598897 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:9:p:1121-1130 Template-Type: ReDIF-Article 1.0 Author-Name: Luhang Jiang Author-X-Name-First: Luhang Author-X-Name-Last: Jiang Author-Name: Jianhong Hao Author-X-Name-First: Jianhong Author-X-Name-Last: Hao Author-Name: Yanfei Gong Author-X-Name-First: Yanfei Author-X-Name-Last: Gong Title: Analytical method for electromagnetic coupling to a penetrated transmission line in cascaded multiple enclosures with hybrid apertures Abstract: An efficient analytical model has been developed for predicting the electromagnetic (EM) field coupling to a lossless transmission line (TL) penetrating through cascaded multiple rectangular enclosure with hybrid apertures (apertures with and without conductive sheets coexist) excited by an external plane wave of oblique incidence. First, The EM field in the enclosure through apertures covered by conductive sheets is derived using the dyadic Green’s function and the transfer impedance of the sheet. Then, the EM field in the enclosure through apertures without sheets is derived based on the Bethe’s small holes theory and the mirror procedure. Finally, the electric current induced at the TL terminals is obtained combining the equivalent lumped-pi circuit model of the TL and the Agrawal’s model. The analytical model has been successfully verified by the finite-difference time-domain (FDTD) method over the frequency range of 0.1 ~ 3 GHz, which consumes less time than numerical methods. Journal: Journal of Electromagnetic Waves and Applications Pages: 1131-1144 Issue: 9 Volume: 33 Year: 2019 Month: 6 X-DOI: 10.1080/09205071.2019.1601034 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1601034 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:9:p:1131-1144 Template-Type: ReDIF-Article 1.0 Author-Name: Zion Menachem Author-X-Name-First: Zion Author-X-Name-Last: Menachem Title: A new technique for the analysis of the physical discontinuity in a hollow rectangular waveguide with dielectric inserts of varying profiles Abstract: The main objective of this research is to present an effective technique to solve the problem of hollow rectangular waveguide. The second objective is to examine the influence of the hollow rectangular waveguide with dielectric material between the hollow rectangle and the metal on the output field. The proposed technique is very effective in relation to the analytical methods because it allows to calculate any discontinuous problem in the cross section. The contribution is important in that it is an improvement over the earlier method that was based on the Laplace and Fourier transforms and the inverse Laplace and Fourier transforms and also that it is capable to analyze the physical discontinuity in a hollow rectangular waveguide. A comparison with the known transcendental equation will show in order to examine the validity of the theoretical model. We can predict the waveguide parameters for obtaining the Gaussian behavior of the output field. The application is useful for straight hollow rectangular waveguides with dielectric material between the hollow rectangle and the metal in the microwave regime. The application can be practical in the laboratory by connecting the hollow waveguide to the analyzer spectrum in order to analyze the effect of the dielectric profile on the behavior of the waveguide. Journal: Journal of Electromagnetic Waves and Applications Pages: 1145-1162 Issue: 9 Volume: 33 Year: 2019 Month: 6 X-DOI: 10.1080/09205071.2019.1601035 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1601035 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:9:p:1145-1162 Template-Type: ReDIF-Article 1.0 Author-Name: R. Viger Author-X-Name-First: R. Author-X-Name-Last: Viger Author-Name: S. Ramsey Author-X-Name-First: S. Author-X-Name-Last: Ramsey Author-Name: T. Mayo Author-X-Name-First: T. Author-X-Name-Last: Mayo Author-Name: S. G. Lambrakos Author-X-Name-First: S. G. Author-X-Name-Last: Lambrakos Title: Parametric modeling of reflectance spectra for dyes and their mixtures in fabrics using reference spectra Abstract: This study describes a parametric model of diffuse reflectance that simulates the spectral response of light-absorbing dyes and their mixtures in fabrics for tailoring reflectance spectra of dyed fabrics. This model combines diffuse-reflectance theory with reference spectra for simulating resonant absorption in dyed fabrics. Fabric samples consisting of a cotton blend were used as the test substrate for dyes having characteristic resonant light-absorption. The results of this study demonstrate the application of the parametric model for simulating spectral responses corresponding to variable dye and dye blend concentrations in fabrics. Journal: Journal of Electromagnetic Waves and Applications Pages: 1163-1171 Issue: 9 Volume: 33 Year: 2019 Month: 6 X-DOI: 10.1080/09205071.2019.1604268 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1604268 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:9:p:1163-1171 Template-Type: ReDIF-Article 1.0 Author-Name: You-Feng Cheng Author-X-Name-First: You-Feng Author-X-Name-Last: Cheng Author-Name: Xiao Ding Author-X-Name-First: Xiao Author-X-Name-Last: Ding Author-Name: Wei Shao Author-X-Name-First: Wei Author-X-Name-Last: Shao Author-Name: Cheng Liao Author-X-Name-First: Cheng Author-X-Name-Last: Liao Title: A surface wave-assisted azimuth-pattern reconfigurable antenna with enhanced bandwidth Abstract: A bandwidth-enhanced pattern reconfigurable antenna (PRA) based on surface waves is presented. The PRA consists of a surface-wave guide (SWG), a windmill-shaped feeding network (WSFN) and four groups of parasitic strips. Two resonances are generated by the feeding network and the parasitic strips, and thus the impedance bandwidth is enhanced. Besides, by controlling the feeding network, four endfire radiation patterns in the azimuth plane which benefit from the surface-wave diffraction can be obtained and switched. A fabricated prototype of the designed PRA is simulated and measured, and the measured results show that the PRA can steer its endfire beam in a frequency range from 2.98 to 3.66 GHz (about 20.5 $ \% $ %). Journal: Journal of Electromagnetic Waves and Applications Pages: 1172-1184 Issue: 9 Volume: 33 Year: 2019 Month: 6 X-DOI: 10.1080/09205071.2019.1604269 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1604269 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:9:p:1172-1184 Template-Type: ReDIF-Article 1.0 Author-Name: Abhishek Joshi Author-X-Name-First: Abhishek Author-X-Name-Last: Joshi Author-Name: Rahul Singhal Author-X-Name-First: Rahul Author-X-Name-Last: Singhal Title: Gain enhancement in probe-fed hexagonal ultra wideband antenna using AMC reflector Abstract: UWB antennas are limited to poor gain at higher frequencies due to the presence of higher modes, especially when fed with the probe. This paper demonstrates a method to boost the peak gain of a probe-fed hexagonal UWB antenna. Artificial magnetic conductor (AMC) based reflector is introduced to the antenna that enhances boresight gain to a wider band as well as peak gain for UWB antenna. Average gain improvement is 3.74 and 5.5 dB in peak and antenna boresight, respectively. The boresight gain improves, i.e. becomes positive for around 1 GHz wider band in the presence of AMC-based reflector. The dimension of UWB antenna is 46 × 46 mm2, while with AMC reflector, the total dimension of the antenna becomes 100 × 100 mm2. The proposed antenna structure can provide directional and stable radiation pattern and suits for UWB applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1185-1196 Issue: 9 Volume: 33 Year: 2019 Month: 6 X-DOI: 10.1080/09205071.2019.1605939 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1605939 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:9:p:1185-1196 Template-Type: ReDIF-Article 1.0 Author-Name: Shuhui Yang Author-X-Name-First: Shuhui Author-X-Name-Last: Yang Author-Name: Xiaoyun Yang Author-X-Name-First: Xiaoyun Author-X-Name-Last: Yang Author-Name: Ling Wang Author-X-Name-First: Ling Author-X-Name-Last: Wang Author-Name: Yinchao Chen Author-X-Name-First: Yinchao Author-X-Name-Last: Chen Author-Name: Guizhen Lu Author-X-Name-First: Guizhen Author-X-Name-Last: Lu Author-Name: Bin Li Author-X-Name-First: Bin Author-X-Name-Last: Li Author-Name: Dongdong Zeng Author-X-Name-First: Dongdong Author-X-Name-Last: Zeng Title: Tricyclic nested electromagnetic bandgap structure characterized with broad stopband bandwidth and deep noise suppression Abstract: A novel tricyclic nested electromagnetic bandgap (TN-EBG) structure has been proposed to restrain the simultaneous switching noise (SSN) in high-speed digital systems. The presented TN-EBG structure was fabricated and measured based on the simulated performance of the configuration. It is found that the measured S-parameters are in good agreement with the simulated ones. Also, it is observed that an ultra-wide bandgap has been achieved, which almost ranges from 1 to 27 GHz with the noise suppression at −50 dB. Especially for the stopband width spanning from 1.1 to 21.6 GHz, the suppression depth level reaches up to−60 dB. The derived electric field distribution images have clearly exhibited the operation mechanism of the TN-EBG structure for SSN mitigation within the different frequency regions. Journal: Journal of Electromagnetic Waves and Applications Pages: 1197-1210 Issue: 9 Volume: 33 Year: 2019 Month: 6 X-DOI: 10.1080/09205071.2019.1605940 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1605940 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:9:p:1197-1210 Template-Type: ReDIF-Article 1.0 Author-Name: Maryam Rezapour Author-X-Name-First: Maryam Author-X-Name-Last: Rezapour Author-Name: Jalil A. Rashed-Mohassel Author-X-Name-First: Jalil A. Author-X-Name-Last: Rashed-Mohassel Author-Name: Asghar Keshtkar Author-X-Name-First: Asghar Author-X-Name-Last: Keshtkar Author-Name: Mohammad-Naser Moghadasi Author-X-Name-First: Mohammad-Naser Author-X-Name-Last: Moghadasi Title: Suppression of mutual coupling in rectangular dielectric resonator antenna arrays using Epsilon-Negative metamaterials (ENG) Abstract: A double slotted symmetrical split ring resonator with an inductive stub in its inner ring is presented as a Single Negative Electric (SNG) metamaterial to suppress mutual coupling between two E-plane coupled microstrip line fed rectangular dielectric resonator antenna (RDRA) array. The proposed SRR exhibits two resonant frequencies and wide stop-bands. The -10 dB bandwidth of S21 from 2022MHz to 2720 MHz and from 2187 MHz to 3839 MHz are obtained for the first structure, #1, and the second structure, #2, respectively. By introducing an ENG layer between the two RDRAs, the experimental reduction in mutual coupling is more than 23 dB with a small frequency shift (∼ 20 MHz), while the impedance matching is improved. The radiation efficiency and total efficiency are increased while the far-field pattern in the E-plane is not disturbed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1211-1223 Issue: 9 Volume: 33 Year: 2019 Month: 6 X-DOI: 10.1080/09205071.2019.1605941 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1605941 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:9:p:1211-1223 Template-Type: ReDIF-Article 1.0 Author-Name: Jin-Jin Mao Author-X-Name-First: Jin-Jin Author-X-Name-Last: Mao Author-Name: Shou-Fu Tian Author-X-Name-First: Shou-Fu Author-X-Name-Last: Tian Author-Name: Li Zou Author-X-Name-First: Li Author-X-Name-Last: Zou Author-Name: Tian-Tian Zhang Author-X-Name-First: Tian-Tian Author-X-Name-Last: Zhang Title: Stability analysis, optical solitons and complexitons of the two-dimensional complex Ginzburg-Landau equation Abstract: In this paper, the two-dimensional complex Ginzburg-Landau equation is investigated, which describes phase transitions in superconductors near their critical temperature in the field of electromagnetic behavior dynamics and in the study of external magnetic fields. We employ the hypothetical method to find the bright soliton, dark soliton and complexitons of the equation. We also find its power series solution with its convergence analysis. Moreover, some constraint conditions are provided which can guarantee the existence of solitons. By use of the Hamiltonian description, we analyze the modulation instability and stable solutions. In order to further understand the dynamic behavior, the graphics analysis is provided of these solutions. Journal: Journal of Electromagnetic Waves and Applications Pages: 1224-1238 Issue: 9 Volume: 33 Year: 2019 Month: 6 X-DOI: 10.1080/09205071.2019.1606736 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1606736 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:9:p:1224-1238 Template-Type: ReDIF-Article 1.0 Author-Name: Mohsen Yousefian Author-X-Name-First: Mohsen Author-X-Name-Last: Yousefian Author-Name: Seyed Jalil Hosseini Author-X-Name-First: Seyed Jalil Author-X-Name-Last: Hosseini Author-Name: Masoud Dahmardeh Author-X-Name-First: Masoud Author-X-Name-Last: Dahmardeh Title: Compact broadband coaxial to rectangular waveguide transition Abstract: Coaxial to waveguide transitions play an important role in high frequency systems. The excitation signal to be employed for the calibration of high-power systems and microwave components is typically in the form of standard 50 Ω coaxial port. Therefore, it is necessary to provide a transition medium to inject the coaxial signal into the waveguide medium. This article presents a simple yet effective coaxial to waveguide transition. A cone-shaped transition including a cone-shaped impedance match section is proposed. Simulation and measurement results are presented. The insertion loss of better than 10 dB is achieved for the operating bandwidth of 2.2–4.6 GHz, which shows superior performance, considering other transition units. Moreover, the simplicity of the design and structure makes is feasible to be employed for other waveguides. The proposed broadband transition design is suitable to be employed as the feed of broadband horn antennas, as well as the TE $_{11} $11 mode launcher feed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1239-1247 Issue: 9 Volume: 33 Year: 2019 Month: 6 X-DOI: 10.1080/09205071.2019.1606737 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1606737 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:33:y:2019:i:9:p:1239-1247 Template-Type: ReDIF-Article 1.0 Author-Name: Krishnaswamy Sankaran Author-X-Name-First: Krishnaswamy Author-X-Name-Last: Sankaran Title: Spaceborne radar remote sensing of ocean surfaces: electromagnetic modelling and applications Abstract: Spaceborne synthetic aperture radars are powerful tools for monitoring ocean surfaces. Various environmental conditions prevailing on the ocean surfaces strongly influence the quality of detection and monitoring using spaceborne imaging radars. In this paper, we discussed the electromagnetic modelling and applications of spaceborne polarimetric synthetic aperture radar for oil spill monitoring on ocean surface. Starting with the physics of electromagnetic wave scattering by ocean surfaces, we have introduced different concepts of polarimetric radar backscattering. These concepts are later used to develop different detection algorithms for enhanced identification of oil spills on ocean surfaces. We discussed two advanced schemes for post-processing fully polarimetric radar data for accurately detecting oil spills under varying ocean conditions. In doing so, we highlighted the challenges and advantages of single and half polarimetric spaceborne missions. Finally, we demonstrated how optimal combination of different channel information further improves the detection of oil spills and reduces false alarms. Journal: Journal of Electromagnetic Waves and Applications Pages: 1-34 Issue: 1 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1696237 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1696237 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:1:p:1-34 Template-Type: ReDIF-Article 1.0 Author-Name: H. Razmjoo Author-X-Name-First: H. Author-X-Name-Last: Razmjoo Author-Name: H. Abiri Author-X-Name-First: H. Author-X-Name-Last: Abiri Author-Name: A. Yahaghi Author-X-Name-First: A. Author-X-Name-Last: Yahaghi Title: A novel dual band patch design for electrical steerable reflectarray antennas Abstract: Reflectarray antennas do not necessarily exhibit a better antenna efficiency compared to ordinary reflector antennas. However, flat structure, multiband design capability, and specially, possibility of electrical beam scanning of this type of antenna are attractive to the antenna designers and researchers. By using elements with electrically tunable reflection phases, it is possible to design an electrically steerable beam reflectarray. In this paper, a novel dual band element is presented for which the reflection phase within each band can be controlled independently. Therefore, the reflectarray arranged by this element can perform the functions of two electrically steerable antennas simultaneously. An aperture coupled element and a miniaturized diplexer are used in the proposed structure. The reflection phase of the designed element can be controlled by changing the lengths of the output lines of the diplexer. It is possible to electrically change this line length using MEM switches. As a result, a dual band reflectarray with independent electrical beam scanning capabilities in each of its frequency bands is obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 35-50 Issue: 1 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1688198 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1688198 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:1:p:35-50 Template-Type: ReDIF-Article 1.0 Author-Name: Varikuntla Krushna Kanth Author-X-Name-First: Varikuntla Author-X-Name-Last: Krushna Kanth Author-Name: Singaravelu Raghavan Author-X-Name-First: Singaravelu Author-X-Name-Last: Raghavan Title: Design and optimization of complementary frequency selective surface using equivalent circuit model for wideband EMI shielding Abstract: The electromagnetic interference (EMI) caused by microwave sources leads to the malfunction and faulty readings of many real-time systems. Hence it is essential to provide EMI shielding for sensitive electronic devices and chambers. An array of periodic elements offers advantages such as transparency and opacity at selected frequencies with a lower weight. In this regard, two closely coupled periodic complementary conducting elements; popularly known as complementary frequency selective surfaces (CFSS) has been analysed for wideband EMI shielding application. A simple equivalent circuit (EC) in conjunction with the transmission line (TL) model is used to analyse the response of the presented element. Further, an extensive parametric study of CFSS aimed at their EC model optimization is presented. The CFSS exhibits a highly stable response with two controllable passbands for normal and oblique incidences. The validity of the proposed method is verified with the full-wave simulations and measured results of the fabricated prototype in a free space measurement setup. Journal: Journal of Electromagnetic Waves and Applications Pages: 51-69 Issue: 1 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1688691 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1688691 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:1:p:51-69 Template-Type: ReDIF-Article 1.0 Author-Name: Konstantin V. Kobrin Author-X-Name-First: Konstantin V. Author-X-Name-Last: Kobrin Author-Name: Mikhail B. Manuilov Author-X-Name-First: Mikhail B. Author-X-Name-Last: Manuilov Title: Fast full-wave technique for CAD of polarizers based on double-ridge waveguide sections Abstract: Full-wave technique for a computer-aided design (CAD) of a wide class of square waveguide 90-degree polarizers based on double-ridge sections is presented. The proposed hybrid full-wave technique for analysis of polarizers is based on the Galerkin method with taking into account the edge condition, mode-matching technique and generalized scattering matrix method. The weighted Gegenbauer polynomials are used as the basis functions taking into account the field asymptotic at the edges when solving the eigenvalue problem for a ridge waveguide. Compact Ku-band waveguide 90-degree polarizers are designed for operation within frequency bands 12–12.5/14–14.5 GHz and 12.1–12.5/17.7–18.1 GHz. VSWR within two operational bands of polarizers is less than 1.04, differential phase shift is about 90° ± 0.5° and 90° ± 1.5°, respectively. The length of polarizers is reduced at a factor about 2 in comparison with the known corrugated square waveguide polarizers. Journal: Journal of Electromagnetic Waves and Applications Pages: 70-85 Issue: 1 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1688692 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1688692 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:1:p:70-85 Template-Type: ReDIF-Article 1.0 Author-Name: Priyanka Das Author-X-Name-First: Priyanka Author-X-Name-Last: Das Author-Name: Kaushik Mandal Author-X-Name-First: Kaushik Author-X-Name-Last: Mandal Author-Name: Ali Lalbakhsh Author-X-Name-First: Ali Author-X-Name-Last: Lalbakhsh Title: Single-layer polarization-insensitive frequency selective surface for beam reconfigurability of monopole antennas Abstract: In this paper, a miniaturized single band-stop frequency selective surface (FSS) with higher order of angular stability and polarization insensitivity is utilized to reconfigure the radiation patterns of a monopole antenna, forming end-fire-like radiation patterns at 5.2 GHz. A mathematical analysis based on pattern multiplication is presented to suggest the arrangement of the FSS to achieve the end-fire-like radiation patterns from the monopole antenna. According to this analysis, the monopole radiator needs to be shielded from three sides, two parallel vertical sides and the top of the antenna. The FSS shows great angular stability with the incidence angle ranging from 0° to 80° for both TE and TM polarizations, resulting in stable end-fire-like radiation patterns when it is used with the monopole antenna. The monopole antenna along with the FSSs were fabricated and tested successfully, thus verifying the functionality of the FSSs in shaping the beam of the antenna. Journal: Journal of Electromagnetic Waves and Applications Pages: 86-102 Issue: 1 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1688693 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1688693 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:1:p:86-102 Template-Type: ReDIF-Article 1.0 Author-Name: Min-Hang Weng Author-X-Name-First: Min-Hang Author-X-Name-Last: Weng Author-Name: Che-Wei Hsu Author-X-Name-First: Che-Wei Author-X-Name-Last: Hsu Author-Name: Yuanmo Lin Author-X-Name-First: Yuanmo Author-X-Name-Last: Lin Author-Name: Chin-Yi Tsai Author-X-Name-First: Chin-Yi Author-X-Name-Last: Tsai Author-Name: Ru-Yuan Yang Author-X-Name-First: Ru-Yuan Author-X-Name-Last: Yang Title: A simple method to design a tri-bandpass filter using open-loop uniform impedance resonators Abstract: The paper presents a simple method to design a tri-band bandpass filter (BPF) using only two pairs of open-loop uniform impedance resonators (OLUIRs). The three passbands can be designed independently by selecting the lengths of two pairs of the OLUIRs. The design procedure is described in this paper. A tri-bandpass filter example is designed at 1.93, 2.6 and 3.9 GHz that can be applied to digital enhanced cordless telecommunications (DECT) and worldwide interoperability for microwave access (WiMAX). By means of the cross-coupling effect with different coupling paths, several transmission zeros appear near the passbands, thus enhancing the selectivity of the passbands. The measured results of the fabricated tri-BPF match the simulated results and confirm the design concept. Journal: Journal of Electromagnetic Waves and Applications Pages: 103-115 Issue: 1 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1689181 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1689181 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:1:p:103-115 Template-Type: ReDIF-Article 1.0 Author-Name: Satyabrat Hota Author-X-Name-First: Satyabrat Author-X-Name-Last: Hota Author-Name: Sudeep Baudha Author-X-Name-First: Sudeep Author-X-Name-Last: Baudha Author-Name: B. B. Mangaraj Author-X-Name-First: B. B. Author-X-Name-Last: Mangaraj Author-Name: Manish Varun Yadav Author-X-Name-First: Manish Author-X-Name-Last: Varun Yadav Title: A novel compact planar antenna for ultra-wideband application Abstract: A novel compact antenna for ultra-wideband application is investigated and presented. The proposed structure consists of a modified patch with rectangular parasitic elements at the top, whereas a defective ground plane is etched on the flame retardant FR-4 substrate at the bottom with a 50 Ω feed line. The magnitude of S11 < −10 dB of the structure is 2.7–11 GHz which accounts for the fractional bandwidth of 121.1%. The overall volume of the structure has a compact dimension of 20 × 20 × 1.6 mm3. The gain and antenna efficiency of the structure are 3.34 dB and 79.8%, respectively. The structure exhibits stable radiations across the band of operation. Measured and simulated results of co and cross(X)-polarization are in relatively good agreement. All these properties suggest that the proposed structure finds its applications in WiMAX-band 3.5 and 5.5 GHz, WLAN-band 5.2 and 5.8 GHz, data links to satellites along with various other applications in the wireless communication field. Journal: Journal of Electromagnetic Waves and Applications Pages: 116-128 Issue: 1 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1689854 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1689854 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:1:p:116-128 Template-Type: ReDIF-Article 1.0 Author-Name: Xiaoxu Yu Author-X-Name-First: Xiaoxu Author-X-Name-Last: Yu Author-Name: Dechun Li Author-X-Name-First: Dechun Author-X-Name-Last: Li Author-Name: Liuge Du Author-X-Name-First: Liuge Author-X-Name-Last: Du Author-Name: Hongwei Chu Author-X-Name-First: Hongwei Author-X-Name-Last: Chu Title: The signal-to-noise ratio analysis of coronal plane microwave correlation imaging based on azimuth one-dimensional array Abstract: Microwave correlation imaging is developed on the basis of the traditional radar imaging. It gets rid of the dependence of the traditional radar imaging on Doppler frequency, providing a new solution for the stationary or quasi-stationary target imaging. In this paper, the coronal plane microwave correlation imaging based on azimuth one-dimensional (1D) array was proposed. The resolution of the two-dimensional (2D) coronal plane along azimuth and elevation directions can be achieved by distributing the array in only one dimension without the synthetic aperture scanning in another dimension. By simulating the detection signals in the coronal plane region, it is determined this imaging method has the imaging resolution capability that is not available in the traditional SAR imaging in the coronal plane. The effectiveness of this imaging method was verified by the image reconstruction with three imaging algorithms. Moreover, the imaging performance including the signal-to-noise ratio was compared and analyzed. Journal: Journal of Electromagnetic Waves and Applications Pages: 129-139 Issue: 1 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1690588 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1690588 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:1:p:129-139 Template-Type: ReDIF-Article 1.0 Author-Name: P.K. Choudhury Author-X-Name-First: P.K. Author-X-Name-Last: Choudhury Author-Name: M. Abou El-Nasr Author-X-Name-First: M. Abou Author-X-Name-Last: El-Nasr Title: Waves in resonant metasurfaces Journal: Journal of Electromagnetic Waves and Applications Pages: 1309-1313 Issue: 10 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2020.1790141 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1790141 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:10:p:1309-1313 Template-Type: ReDIF-Article 1.0 Author-Name: Sabyasachi Banerjee Author-X-Name-First: Sabyasachi Author-X-Name-Last: Banerjee Author-Name: Bishnu P. Pal Author-X-Name-First: Bishnu P. Author-X-Name-Last: Pal Author-Name: Dibakar Roy Chowdhury Author-X-Name-First: Dibakar Author-X-Name-Last: Roy Chowdhury Title: Resonance phenomena in electromagnetic metamaterials for the terahertz domain: a review Abstract: Most electromagnetic phenomena pertaining to metamaterials are observed at the resonance positions. In this review, we have collated and analyze the most prevalent forms of resonance-based phenomena observed in metamaterials to serve as a ready reference for future researchers. Our focus will be on metamaterials operating at the terahertz frequency domain. Starting with the origin and evolution of fundamental LC resonances in metamaterials, we would explain occurrence of typical even and odd higher order resonance modes. We have also discussed Fano resonances in asymmetric gap resonators-based metamaterials. Further, quantum phenomena analogues, such as, electromagnetically induced transparency (EIT) or Plasmon Induced Transparency (PIT), which can significantly influence the metamaterials resonances are also discussed. Thereafter, origins to ultra-sharp resonances in toroidal metamaterials, along with chiral metamaterials and resonance mode hybridization effects in the context of terahertz metamaterials are described. This review should be useful for undertaking. Journal: Journal of Electromagnetic Waves and Applications Pages: 1314-1337 Issue: 10 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2020.1713227 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1713227 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:10:p:1314-1337 Template-Type: ReDIF-Article 1.0 Author-Name: J. Y. Rhee Author-X-Name-First: J. Y. Author-X-Name-Last: Rhee Author-Name: Y. J. Kim Author-X-Name-First: Y. J. Author-X-Name-Last: Kim Author-Name: C. Yi Author-X-Name-First: C. Author-X-Name-Last: Yi Author-Name: J. S. Hwang Author-X-Name-First: J. S. Author-X-Name-Last: Hwang Author-Name: Y. P. Lee Author-X-Name-First: Y. P. Author-X-Name-Last: Lee Title: Recent progress in perfect absorbers by utilizing metamaterials Abstract: This paper reviews recent progress in perfect absorbers of electromagnetic waves that utilize metamaterials (MMs). Various numerical techniques that are inevitable for the research on MMs, along with their pros and cons, are commented on and discussed. Abandoning the conventional periodic-boundary conditions is crucial for understanding the discrepancy between simulation and experiments for certain MMs. Broadband perfect absorption can be realized by using multiple resonances and/or multiple units with different sizes in a unit cell, or by utilizing bad Q-factors by incorporating the electrically resistive components, in addition to the ordinary metallic elements. The classical analogue of electromagnetically-induced transparency can be utilized to realize perfect absorption, by employing either structural asymmetry, or near-field interactions. Perspectives and suggestions for further study are discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1338-1371 Issue: 10 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2019.1668865 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1668865 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:10:p:1338-1371 Template-Type: ReDIF-Article 1.0 Author-Name: Alireza Shabani Author-X-Name-First: Alireza Author-X-Name-Last: Shabani Author-Name: Neda Rahmani Author-X-Name-First: Neda Author-X-Name-Last: Rahmani Author-Name: Mehdi Khazaei Nezhad Author-X-Name-First: Mehdi Author-X-Name-Last: Khazaei Nezhad Title: Impact of material characteristics on the general optical behavior of perforated surface plasmon system Abstract: In this paper, we studied the impact of material characteristics on the optical response of a perforated surface plasmon system as a general trend by employing dielectric function of metallic film. To this end, different artificial materials were modeled based on a single interband transition peak in the form of a Lorentzian function in the imaginary part of dielectric function ${\varepsilon _2} $ε2 as well as a Drude term for free electron feature. The impact of place, strength and broadening of interband peak of metallic film were evaluated on the optical transmission spectrum. Our results revealed that these peaks affect the excited modes in the form of a decrease in the intensity of transmitted beam at corresponding frequencies. This decrease was proportional to the strength and width of the peak, and interpreted as an optical dissipation coming from material specifics. The present study provides a better insight into how the optical transmission response of such systems can be tuned for a particular goal or application using material characteristics. Journal: Journal of Electromagnetic Waves and Applications Pages: 1372-1385 Issue: 10 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2019.1654931 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1654931 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:10:p:1372-1385 Template-Type: ReDIF-Article 1.0 Author-Name: M. S. Bisht Author-X-Name-First: M. S. Author-X-Name-Last: Bisht Author-Name: Vadher Pratik Vinubhai Author-X-Name-First: Vadher Pratik Author-X-Name-Last: Vinubhai Author-Name: Kumar Vaibhav Srivastava Author-X-Name-First: Kumar Vaibhav Author-X-Name-Last: Srivastava Title: Analysis and realization of a wideband mantle cloak with improved cloaking performance Abstract: An approach for improving the invisibility performance of mantle cloak is proposed. It is based on an interesting observation that the cloaking performance of mantle cloak can be significantly enhanced if the cloak is operated under tilted conditions with respect to the incident radiation (such that the wave is incident obliquely onto the cloak). The mantle cloak is thus designed by judiciously choosing the value of surface impedance corresponding to the tilt angle. It is because the optimum value of surface impedance changes with the tilt angle. An analytical method is devised for the calculation of optimum surface impedance under tilted conditions and subsequently verified with Ansys HFSS simulations. It is also shown that by deliberately tilting the mantle cloak, numerous advantages over normal incidence scenario, are obtained, such as (a) significant reduction in total scattering width, (b) considerable enhancement in bandwidth, and (c) increase in performance robustness with respect to the dispersion of surface impedance. These advantages of operating under tilted conditions are well elucidated by comparing it with that for normal incidence scenario previously presented in various literatures. The metasurface cloak is subsequently realized using I-shaped unit cell structure and varactor diodes, and cloaking performance is analyzed using HFSS simulations. Journal: Journal of Electromagnetic Waves and Applications Pages: 1386-1399 Issue: 10 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2020.1726213 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1726213 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:10:p:1386-1399 Template-Type: ReDIF-Article 1.0 Author-Name: Guanxia Yu Author-X-Name-First: Guanxia Author-X-Name-Last: Yu Author-Name: Huizhou Yang Author-X-Name-First: Huizhou Author-X-Name-Last: Yang Author-Name: Jingjing Fu Author-X-Name-First: Jingjing Author-X-Name-Last: Fu Author-Name: Xiaomeng Zhang Author-X-Name-First: Xiaomeng Author-X-Name-Last: Zhang Author-Name: Ruoyu Cao Author-X-Name-First: Ruoyu Author-X-Name-Last: Cao Title: Nonreciprocal transmission using a multilayer magneto-optical dispersive material with defect Abstract: A one-dimensional nonreciprocal structure comprising two asymmetric multilayers filled with magneto-optical dispersive media and a defect layer is designed. The nonreciprocal optical Tamm states (OTSs) are excited at the interface of the two asymmetric multilayer structure with an opposing external magnetic field. With the excitation of the nonreciprocal OTSs, the numerical results show that the waves can be transmitted and be reflected in one way. These nonreciprocal properties are affected by the layers thickness of the defect layer, the angles of incidence, and the externally applied magnetic fields. Owing to the inherent dispersive property of the magneto-optical media, our investigations show promising potential for the practical application of nonreciprocal structures. Journal: Journal of Electromagnetic Waves and Applications Pages: 1400-1409 Issue: 10 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2019.1696712 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1696712 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:10:p:1400-1409 Template-Type: ReDIF-Article 1.0 Author-Name: Jia-Ying Feng Author-X-Name-First: Jia-Ying Author-X-Name-Last: Feng Author-Name: Liang-Pei Wu Author-X-Name-First: Liang-Pei Author-X-Name-Last: Wu Author-Name: Sheng-Yuan Shi Author-X-Name-First: Sheng-Yuan Author-X-Name-Last: Shi Author-Name: Min-Hua Li Author-X-Name-First: Min-Hua Author-X-Name-Last: Li Author-Name: Jian-Feng Dong Author-X-Name-First: Jian-Feng Author-X-Name-Last: Dong Title: Asymmetric transmission of circularly polarized waves in a bi-layered extrinsic chiral metamaterial Abstract: In this paper, a kind of bi-layer extrinsic chiral metamaterial is proposed to realize asymmetric transmission (AT) of circularly polarized waves in the microwave region. We have studied numerically and experimentally the transmission properties of the proposed structure. The results show that under oblique incident wave the asymmetric transmission effect occurs with a 1.5 GHz operation band. The maximum value of AT parameter reaches up to 0.68 at the resonant frequency, which is larger than those in the extrinsic chiral metamaterials previously reported. This AT phenomenon is illustrated by the surface current distribution in detail. The transmission properties of the incident waves can be dynamically regulated by tuning the incident angles θ and ϕ. This metamaterial is potential in the polarization control applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1410-1419 Issue: 10 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2019.1699169 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1699169 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:10:p:1410-1419 Template-Type: ReDIF-Article 1.0 Author-Name: Bao-qin Lin Author-X-Name-First: Bao-qin Author-X-Name-Last: Lin Author-Name: Lintao Lv Author-X-Name-First: Lintao Author-X-Name-Last: Lv Author-Name: Jianxin Guo Author-X-Name-First: Jianxin Author-X-Name-Last: Guo Author-Name: Yanwen Wang Author-X-Name-First: Yanwen Author-X-Name-Last: Wang Author-Name: Zuliang Wang Author-X-Name-First: Zuliang Author-X-Name-Last: Wang Author-Name: Rui Zhu Author-X-Name-First: Rui Author-X-Name-Last: Zhu Title: Ultra-wideband circular polarization-maintaining reflection realized by an anisotropic metasurface Abstract: In this paper, an ultra-wideband circular polarization (CP) maintaining reflector is proposed based on an anisotropic metasurface, which is an orthogonal anisotropic structure with a pair of symmetrical axes u and v perpendicular to each other. The simulated results show that the reflector can realized CP-maintaining reflection under both right-handed and left-handed CP (RHCP and LHCP) incidences in the frequency band between 8.79 and 27.09 GHz, the fractional bandwidth is up to 102%. In addition, the physical mechanism of the CP-maintaining reflection has been analyzed in detail, and one useful formula has been derived, which can be used to calculate the cross- and co-polarization reflection coefficients under CP incidence according to the phase differences between the two reflection coefficients under u and v-polarized incidences. Finally, one effective experimental validation was carried out. Journal: Journal of Electromagnetic Waves and Applications Pages: 1420-1429 Issue: 10 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2020.1738964 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1738964 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:10:p:1420-1429 Template-Type: ReDIF-Article 1.0 Author-Name: Chetan Barde Author-X-Name-First: Chetan Author-X-Name-Last: Barde Author-Name: Arvind Choubey Author-X-Name-First: Arvind Author-X-Name-Last: Choubey Author-Name: Rashmi Sinha Author-X-Name-First: Rashmi Author-X-Name-Last: Sinha Title: A set square design metamaterial absorber for X-band applications Abstract: This paper presents a set square design which serves as a wideband Metamaterial Absorber (MA) for X-band applications. The simulation results show that the absorber has $-8 $−8 dB absorption bandwidth of 2.51 GHz (8.36–10.87 GHz) and the Full Width Half Maximum (FWHM) bandwidth of 3.55 GHz (7.47–11.02 GHz). MA proposed in this paper uses $FR_{4} $FR4 as a substrate having thickness of 1.6 mm and overall dimensions of 10 mm × 10 mm with center frequency at 9.61 GHz. The absorption mechanism which depends on effective permittivity ( $\epsilon _{{\rm eff}} $ϵeff) and effective permeability ( $\mu _{{\rm eff}} $μeff) is explained and plotted. Journal: Journal of Electromagnetic Waves and Applications Pages: 1430-1443 Issue: 10 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2019.1654930 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1654930 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:10:p:1430-1443 Template-Type: ReDIF-Article 1.0 Author-Name: Dhruba Jyoti Gogoi Author-X-Name-First: Dhruba Jyoti Author-X-Name-Last: Gogoi Title: Microwave absorber based on encapsulated expanded graphite-silicone composite as meta-“atom” for X-band application Abstract: In this work, a wideband microwave resonating-type absorber is investigated in terms of metal backed metamaterial absorber (MMA). Expanded graphite-silicone (EG-Si) composite is encapsulated in the flexible silicone rubber matrix to build periodic unit cell of the MMA. Microwave material characterization of the EG-Si composites with different weight percentages (1, 3, 5, 7, 9 and 11 wt. %) is carried out at X-band frequency range. CST simulation is performed to optimize the unit cell parameters i.e. a wideband absorption with at least −10 dB absorption bandwidth (BW) throughout the X-band is obtained. Simulation is also carried out to check the polarization and incident angle dependency of the absorber’s absorption performance. The resonance and absorption mechanism of the absorber are investigated with the help of simulated electric field, magnetic field and current density inside the unit cell. The absorption of the prototype absorbers is experimentally measured by waveguide measurement technique. Journal: Journal of Electromagnetic Waves and Applications Pages: 1444-1459 Issue: 10 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2020.1761458 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1761458 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:10:p:1444-1459 Template-Type: ReDIF-Article 1.0 Author-Name: Xiaojie Lu Author-X-Name-First: Xiaojie Author-X-Name-Last: Lu Author-Name: Zhongyin Xiao Author-X-Name-First: Zhongyin Author-X-Name-Last: Xiao Author-Name: Mingming Chen Author-X-Name-First: Mingming Author-X-Name-Last: Chen Title: Perfect metamaterial absorber based on the circular or elliptical cavity with one side open in the terahertz region Abstract: In this work, we present the analysis and design of a perfect metamaterial absorber (MA) based on the circular cavity with one side open in the terahertz region. This structure consists of a metal plate where one circular cavity with one side open is vertically placed on. Based on the circular-cavity-theory, a formula can be used to calculate the resonant frequency. In terms of normal incidence, the simulated results show that the MA has one resonance point on 6.674 THz, which is consistent with the calculated results. What’s more, we present the distribution of E-field, surface current distribution and power loss density distribution in the cavity, and use the standing wave theory and electric dipole to prove the physical mechanism of the perfect absorption. Finally, an MA based on elliptical cavity with one side open is also studied. These results verify the application of resonant cavities in the field of MA. Journal: Journal of Electromagnetic Waves and Applications Pages: 1460-1470 Issue: 10 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2019.1676831 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1676831 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:10:p:1460-1470 Template-Type: ReDIF-Article 1.0 Author-Name: Narinder Sharma Author-X-Name-First: Narinder Author-X-Name-Last: Sharma Author-Name: Sumeet Singh Bhatia Author-X-Name-First: Sumeet Singh Author-X-Name-Last: Bhatia Title: Metamaterial inspired fidget spinner-shaped antenna based on parasitic split ring resonator for multi-standard wireless applications Abstract: This paper presents the design of fidget spinner-shaped antenna (FSSA) loaded with parasitic EC-SRR (edge coupled-split ring resonator) for multi-standard wireless applications. Parasitic EC-SRR element-loaded antenna helps to improve the impedance matching and bandwidth of antenna in comparison to the unloaded FSSA. The 50 Ω microstrip line fed has been applied to the structure of proposed antenna to obtain the distinct performance parameters such as reflection coefficient, gain, radiation pattern and efficiency. Comparison of the proposed antenna with and without SRR is made and found that the later case exhibits better results in terms of reflection coefficient and bandwidth. Bandwidth is increased by 21.61% at first two resonance points, 57.57% at third and 32.76% at fourth resonance point. A prototype of the proposed FSSA has also been fabricated and tested for validation of simulated results with measured results, and found in good agreement with each other. The overall dimensions of the proposed FSSA are 30 mm × 30 mm and can be used for different wireless applications in the frequency range 1.88–7.0 GHz, 7.81–8.85 GHz and 9.6–14.3 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1471-1490 Issue: 10 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2019.1654412 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1654412 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:10:p:1471-1490 Template-Type: ReDIF-Article 1.0 Author-Name: Zhengyi Yang Author-X-Name-First: Zhengyi Author-X-Name-Last: Yang Author-Name: Shixing Yu Author-X-Name-First: Shixing Author-X-Name-Last: Yu Author-Name: Na Kou Author-X-Name-First: Na Author-X-Name-Last: Kou Author-Name: Fei Long Author-X-Name-First: Fei Author-X-Name-Last: Long Author-Name: Zhao Ding Author-X-Name-First: Zhao Author-X-Name-Last: Ding Author-Name: Zhengping Zhang Author-X-Name-First: Zhengping Author-X-Name-Last: Zhang Title: Ultrathin tri-band reflective cross-polarization artificial electromagnetic metasurface Abstract: A high-efficiency tri-band artificial electromagnetic (EM) polarization manipulating metasurface is proposed, which is employing two metal rectangle rings composed of a single-layer reflectance surface. There are three frequency bands generated by the artificial EM polarization manipulating metasurfaces, with 3-dB bandwidth at 9.10–12.40, 15.55–23.80 and 24.71–30.00 GHz, and the relative bandwidth is 30.7%, 41.9% and 19.4%, respectively. The polarization converter ratio of the polarization manipulating metasurfaces is great than 90% at 9.8–12.2, 19–22.6, and 24.9–29.5 GHz, respectively. There are five resonance frequencies at 10.5, 11.8, 20.9, 25.7 and 28.3 GHz, where the polarization converter ratio is almost reached 100%. Equivalent circuit and surface current distributions reveal that the coupling results from the strong electric and magnetic resonances between the top surface and bottom ground. Experimental results of the prototype are basically consistent with the simulation results, which clearly show that the metasurfaces have multiband characteristics and higher efficiency. Journal: Journal of Electromagnetic Waves and Applications Pages: 1491-1501 Issue: 10 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2020.1787232 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1787232 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:10:p:1491-1501 Template-Type: ReDIF-Article 1.0 Author-Name: Guilherme L. F. Brandão Author-X-Name-First: Guilherme L. F. Author-X-Name-Last: Brandão Author-Name: Elson J. Silva Author-X-Name-First: Elson J. Author-X-Name-Last: Silva Author-Name: Ursula C. Resende Author-X-Name-First: Ursula C. Author-X-Name-Last: Resende Author-Name: Icaro V. Soares Author-X-Name-First: Icaro V. Author-X-Name-Last: Soares Author-Name: Welyson T. S. Ramos Author-X-Name-First: Welyson T. S. Author-X-Name-Last: Ramos Title: Design of artificial magnetic conductor metasurfaces using generalized boundary conditions Abstract: In this work, a design method for artificial magnetic conductor metasurfaces based on generalized boundary conditions is proposed as an alternative to analytic expressions and to conventional optimization approaches. First, the required surface susceptibility is analytically obtained by using generalized boundary conditions and the equivalent circuit model. Then, the geometry of the PEC scatterers is optimized to achieve the required transmission coefficient. The detailed design procedure is presented and its applicability is demonstrated through numerical examples. The proposed method is compared to analytical expressions and to standard optimization methods, showing better results in terms of flexibility and computational cost. Metasurfaces based on square patch, square loop and Jerusalem cross scatterers, mounted on different commercial dielectric substrates are studied for ISM band applications. The results have shown good agreement with the design requirements. Journal: Journal of Electromagnetic Waves and Applications Pages: 1502-1512 Issue: 10 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2020.1748523 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1748523 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:10:p:1502-1512 Template-Type: ReDIF-Article 1.0 Author-Name: Oleg Rybin Author-X-Name-First: Oleg Author-X-Name-Last: Rybin Author-Name: Sergey Shulga Author-X-Name-First: Sergey Author-X-Name-Last: Shulga Title: Generalized broad-band Effective Medium Theory of two-component metamaterials including magnetic ones: a review Abstract: This review is dedicated to the Effective Medium Theory of two-component metamaterials in the broad frequency range from microwaves to visible region. The metamaterials are unbounded periodic 2-D lattice of infinitely long cylinders of circular cross section or unbounded periodic 3-D lattice of spherical particles embedded in a homogeneous isotropic host dielectric. Three types of inclusions are considered: 1) non-magnetic metal inclusions; 2) ferric inclusions; 3) ferromagnetic inclusions. It is assumed that ferric and ferromagnetic inclusions can be fully or partially magnetized by an external dc bias magnetic field. Two directions of wave propagation are considered for magnetized inclusions: 1) the direction of the bias field; 2) the direction transversal to the direction of magnetization. It has been shown that the metamaterials can exhibit the different properties depending on the material constituent and the direction of wave propagation. Antenna substrate application of the metamaterials is discussed in the review. Journal: Journal of Electromagnetic Waves and Applications Pages: 1513-1549 Issue: 11 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2020.1787234 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1787234 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:11:p:1513-1549 Template-Type: ReDIF-Article 1.0 Author-Name: Anurag Srivastava Author-X-Name-First: Anurag Author-X-Name-Last: Srivastava Title: Design and simulation of ring-bar slow-wave structure TWT at Ku-band with power over 1200 watts Abstract: This paper presents the electrical design of a high power ring-bar TWT amplifier at Ku-band. The design parameters of Slow-wave structure (SWS) were synthesized theoretically. Further, the design was optimized using a computer simulation technology (CST). The dispersion and interaction impedance characteristics were simulated using the eigenmode simulation (EMS) technique at a beam voltage of 14.5 kV. The sever and attenuators were incorporated in the designed two-section TWT for obtaining the device gain of more than 30 dB. The particle-in-cell (PIC) simulation was predicted the power of 61.5 dBm (1412 watts), the gain of 34.5 dB, and electronic efficiency of 17.5% at operating center frequency of 15.15 GHz for beam voltage of 14.5 kV and current of 0.55 A. The gain fluctuation value was obtained less than 1 dB for any 80 MHz bandwidth for the interest of frequency band of 14.9 to 15.4 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1550-1562 Issue: 11 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2020.1769504 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1769504 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:11:p:1550-1562 Template-Type: ReDIF-Article 1.0 Author-Name: David Zeppettella Author-X-Name-First: David Author-X-Name-Last: Zeppettella Author-Name: Mohammod Ali Author-X-Name-First: Mohammod Author-X-Name-Last: Ali Title: A broadband directional circularly polarized spiral antenna on EBG structure Abstract: A new low profile broadband directional spiral antenna design on a planar EBG structure is introduced which is suitable for aircraft structural integration. The proposed antenna has the (greater than 4 dBiC) gain and axial ratio (less than 3-dB) bandwidth of 400–800 MHz (except for a narrow frequency range of 505–530 MHz) within a total thickness of one tenth of the wavelength. Meausured peak gain is 7.5 dBiC while gain at 400 and 500 MHz are 6 and 7.2 dBiC, respectively.Abbreviations: EBG: Electromagnetic Bandgap; HIS: High Impedance Surface; SATCOM: Satellite Communications; UHF: Ultra High Frequency; CP: Circularly Polarized; BW: Bandwidth; AR: Axial Ratio Journal: Journal of Electromagnetic Waves and Applications Pages: 1563-1585 Issue: 11 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2020.1774927 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1774927 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:11:p:1563-1585 Template-Type: ReDIF-Article 1.0 Author-Name: W. Y. Song Author-X-Name-First: W. Y. Author-X-Name-Last: Song Author-Name: Y. D. Kim Author-X-Name-First: Y. D. Author-X-Name-Last: Kim Author-Name: J. H. Lee Author-X-Name-First: J. H. Author-X-Name-Last: Lee Author-Name: H. J. Kim Author-X-Name-First: H. J. Author-X-Name-Last: Kim Author-Name: J. W. Yu Author-X-Name-First: J. W. Author-X-Name-Last: Yu Title: Automatic design of slanted wall anechoic chamber using 3D deterministic ray tube method Abstract: In order to make an anechoic chamber operate similarly to ideal OATS, various design methods of the anechoic chamber have been studied. Without changing of RAM and major structural design of the rectangle anechoic chamber, we propose a method of automatically designing the shape of a slanted wall anechoic chamber by applying the PSO to 3D deterministic ray tube method. The 3D Deterministic Ray Tube method enables efficient and fast calculation of the electric field in any slanted wall anechoic chamber. The optimized slanted wall anechoic chamber has very good performance for NSA, sVSWR compared to the general rectangle chamber. Journal: Journal of Electromagnetic Waves and Applications Pages: 1586-1600 Issue: 11 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2020.1775135 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1775135 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:11:p:1586-1600 Template-Type: ReDIF-Article 1.0 Author-Name: Ekta Thakur Author-X-Name-First: Ekta Author-X-Name-Last: Thakur Author-Name: Naveen Jaglan Author-X-Name-First: Naveen Author-X-Name-Last: Jaglan Author-Name: Samir Dev Gupta Author-X-Name-First: Samir Dev Author-X-Name-Last: Gupta Title: Design of compact triple band-notched UWB MIMO antenna with TVC-EBG structure Abstract: In this editorial, a compact two element Ultra Wide Band Multiple Input Multiple Output (UWB MIMO) antenna with triple-band notch characteristics is presented. A single Two Via Compact Electromagnetic Band Gap (TVC-EBG) structure is used to achieve triple-band notches at WiMAX, WLAN, and X Band. An inverse L-shaped stub is inserted in the ground plane of the antenna to diminish mutual coupling amid antenna elements. Isolation and Envelope Correlation Coefficient (ECC) is less than −15 dB and 0.015, respectively. The diversity properties like Total Active Reflection Coefficient (TARC), Diversity Gain (DG) are less than −10 dB and greater than 9.95 dB respectively. The proposed antenna is designed using a low-cost FR4 substrate with overall dimensions of 21 × 36 × 1.6 mm3. Journal: Journal of Electromagnetic Waves and Applications Pages: 1601-1615 Issue: 11 Volume: 34 Year: 2020 Month: 7 X-DOI: 10.1080/09205071.2020.1775136 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1775136 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:11:p:1601-1615 Template-Type: ReDIF-Article 1.0 Author-Name: Arya Kari Author-X-Name-First: Arya Author-X-Name-Last: Kari Author-Name: Abolghasem Zeidaabadi Nezhad Author-X-Name-First: Abolghasem Author-X-Name-Last: Zeidaabadi Nezhad Author-Name: Ahmad Bakhtafrouz Author-X-Name-First: Ahmad Author-X-Name-Last: Bakhtafrouz Title: Removal of scan blindness of phased array antenna using fourth-order Hilbert curved EBG structure Abstract: It has been shown that the Hilbert curved electromagnetic band gap (HC-EBG) structure effectively reduces the surface wave excitation in the substrate. This paper investigates the performance of HC-EBG structure for probe-fed microstrip patch phased array antenna. The results show that not only the mutual coupling between two elements is reduced about 20 dB, but also the blind angle is removed. Based on the proposed method, a probe-fed microstrip patch antenna phased array 9 × 7 elements are designed and simulated that shows the blind angle has been eliminated without increasing the dimensions of the antenna. Simulation results show improvement in the active reflection coefficient of center element and gain of the array. Journal: Journal of Electromagnetic Waves and Applications Pages: 1617-1630 Issue: 12 Volume: 34 Year: 2020 Month: 8 X-DOI: 10.1080/09205071.2020.1775713 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1775713 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:12:p:1617-1630 Template-Type: ReDIF-Article 1.0 Author-Name: Zhong Du Author-X-Name-First: Zhong Author-X-Name-Last: Du Author-Name: Quanyuan Feng Author-X-Name-First: Quanyuan Author-X-Name-Last: Feng Title: A wideband folded magnetoelectric dipole antenna with miniaturized integration for 5G applications Abstract: A 3-layer substrate integrated folded magnetoelectric dipole antenna is presented in this paper. The folded metal vias are proposed to broaden bandwidth and miniaturized antenna. Furthermore, the double-arc-edged patch, the single-arc-edged metal plane, side wall and removing shorted end are designed to improve the impedance matching and reduce the operating frequencies. The structure and parameters of the antenna are analyzed, especially the bandwidth blending and the current paths. A prototype was fabricated and measured. The presented antenna obtains a wide impedance bandwidth of 34.2% for VSWR≤2 from 4.88 to 6.89 GHz and a stable gain ranging from 6.0 to 7.5 dBi. Moreover, nearly identical unidirectional radiation patterns, low cross-polarization and low back radiation are achieved. The parameter of ds even can realize a lower operating frequency. The presented antenna is suitable for mass production with low cost by the printed circuit board technology, and promising for 5th Generation (5G) applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1631-1646 Issue: 12 Volume: 34 Year: 2020 Month: 8 X-DOI: 10.1080/09205071.2020.1776162 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1776162 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:12:p:1631-1646 Template-Type: ReDIF-Article 1.0 Author-Name: Aicha Mchbal Author-X-Name-First: Aicha Author-X-Name-Last: Mchbal Author-Name: Naima Amar Touhami Author-X-Name-First: Naima Author-X-Name-Last: Amar Touhami Author-Name: Hanae Elftouh Author-X-Name-First: Hanae Author-X-Name-Last: Elftouh Author-Name: Aziz Dkiouak Author-X-Name-First: Aziz Author-X-Name-Last: Dkiouak Title: Coupling reduction using a novel circular ripple-shaped decoupling mechanism in a four-element UWB MIMO antenna design Abstract: A 4*4 multiple-input multiple-output (MIMO) antenna with compact size and good isolation is presented for UWB applications. The concept of polarization diversity is here discussed and employed to satisfy contemporary wireless communication systems requirements. In the proposed antenna, the utilization of a novel circular ripple-shaped decoupling structure and a matching structure are presented to minimize mutual coupling of the inter-elements and enhance adaptation. Experimental results show a bandwidth range from 2.96 to 11.4 GHz with a good reflection coefficient which is S11 < −12 dB, high isolation S21 and S31 < −20 dB, good Envelope Correlation Coefficients ECC21 and ECC31 < 0.03, Diversity Gain DG21 and DG31 equal to 8.75, and a Total Active Reflection Coefficient (TARC) less than −12 dB. The antenna also exhibits a maximum gain of about 4 dBi with a maximum efficiency of 70% which proves that this antenna is a potential candidate for UWB applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1647-1666 Issue: 12 Volume: 34 Year: 2020 Month: 8 X-DOI: 10.1080/09205071.2020.1780160 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1780160 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:12:p:1647-1666 Template-Type: ReDIF-Article 1.0 Author-Name: Alexandr A. Shmat’ko Author-X-Name-First: Alexandr A. Author-X-Name-Last: Shmat’ko Author-Name: Victoria N. Mizernik Author-X-Name-First: Victoria N. Author-X-Name-Last: Mizernik Author-Name: Eugene N. Odarenko Author-X-Name-First: Eugene N. Author-X-Name-Last: Odarenko Title: Floquet-Bloch waves in magnetophotonic crystals with transverse magnetic field Abstract: We solved the problem of Floquet-Bloch waves propagation in the one-dimensional gyrotropic magnetophotonic crystal with transverse magnetic field. New fundamental solutions of the Hill’s equation in crystal layers based on the Floquet theory for a third boundary value problem are obtained in the analytical form. The dispersion equation is found through fundamental solutions. The analysis of the dispersion properties of the structures depending on the material parameters was carried out and extraordinary surface waves inherent only in gyrotropic magnetophotonic crystals have been discovered. Journal: Journal of Electromagnetic Waves and Applications Pages: 1667-1679 Issue: 12 Volume: 34 Year: 2020 Month: 8 X-DOI: 10.1080/09205071.2020.1780955 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1780955 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:12:p:1667-1679 Template-Type: ReDIF-Article 1.0 Author-Name: Eugene Smolkin Author-X-Name-First: Eugene Author-X-Name-Last: Smolkin Author-Name: Yury Smirnov Author-X-Name-First: Yury Author-X-Name-Last: Smirnov Author-Name: Maxim Snegur Author-X-Name-First: Maxim Author-X-Name-Last: Snegur Title: Leaky waves in a nonlinear metamaterial rod Abstract: We consider propagation of leaky TE waves in a rod filled with nonlinear metamaterial medium. The problem is reduced to the analysis of a nonlinear integral equation with a kernel in the form of the Green function of an auxiliary boundary value problem on an interval. The existence of propagating nonlinear leaky TE waves for the chosen nonlinearity (Kerr law) is proved using the method of contraction. For the numerical solution, a method based on solving an auxiliary Cauchy problem (a version of the shooting method) is proposed. New propagation regimes are discovered. Journal: Journal of Electromagnetic Waves and Applications Pages: 1680-1690 Issue: 12 Volume: 34 Year: 2020 Month: 8 X-DOI: 10.1080/09205071.2020.1781696 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1781696 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:12:p:1680-1690 Template-Type: ReDIF-Article 1.0 Author-Name: Wontaek Lee Author-X-Name-First: Wontaek Author-X-Name-Last: Lee Author-Name: Mingook Jung Author-X-Name-First: Mingook Author-X-Name-Last: Jung Author-Name: Tae-Hyung Kim Author-X-Name-First: Tae-Hyung Author-X-Name-Last: Kim Author-Name: Jong-Gwan Yook Author-X-Name-First: Jong-Gwan Author-X-Name-Last: Yook Author-Name: Jeonghoon Yoo Author-X-Name-First: Jeonghoon Author-X-Name-Last: Yoo Title: Patch antenna design using the gA and the binary method for dual-band applications Abstract: This study proposes an innovative patch antenna design for multi-band operation and high radiation efficiency. The design target is the structural shape of a patch and a ground plane. The operating range of patch antenna is set to both the 5G band (3.4−3.7 GHz) and the Bluetooth range (2.4−2.48 GHz). The design process follows two steps, the genetic algorithm (GA) and the binary method. Although the GA has been widely used for patch antenna design, however, it is hard to improve the performance only using the GA due to its restriction on design constraints. Therefore, this study proposes the successive application of the binary method after the GA to derive a unique topological shape of a patch antenna. The application of the binary method enables the design constraint for bandwidth enhancement. Design results are verified through experimental measurements using fabricated antennas. Journal: Journal of Electromagnetic Waves and Applications Pages: 1691-1704 Issue: 12 Volume: 34 Year: 2020 Month: 8 X-DOI: 10.1080/09205071.2020.1781697 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1781697 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:12:p:1691-1704 Template-Type: ReDIF-Article 1.0 Author-Name: R. F. Abreu Author-X-Name-First: R. F. Author-X-Name-Last: Abreu Author-Name: S. O. Saturno Author-X-Name-First: S. O. Author-X-Name-Last: Saturno Author-Name: J. P. C. do Nascimento Author-X-Name-First: J. P. C. Author-X-Name-Last: do Nascimento Author-Name: E. O. Sancho Author-X-Name-First: E. O. Author-X-Name-Last: Sancho Author-Name: J. E. V. de Morais Author-X-Name-First: J. E. V. Author-X-Name-Last: de Morais Author-Name: J. C. Sales Author-X-Name-First: J. C. Author-X-Name-Last: Sales Author-Name: D. X. Gouveia Author-X-Name-First: D. X. Author-X-Name-Last: Gouveia Author-Name: H. D. de Andrade Author-X-Name-First: H. D. Author-X-Name-Last: de Andrade Author-Name: I. S. Queiroz Júnior Author-X-Name-First: I. S. Author-X-Name-Last: Queiroz Júnior Author-Name: A. S. B. Sombra Author-X-Name-First: A. S. B. Author-X-Name-Last: Sombra Title: Dielectric characterisation and numerical investigation of SrBi2Nb2O9–Bi2O3 composites for applications in microwave range Abstract: We present a study of the dielectric properties and behaviour of dielectric resonator antennas (DRAs) based on SrBi2Nb2O9 (SBN)-Bi2O3 composites. X-ray diffraction is used for structural characterisation of the samples and it indicates the formation of a new phase after the addition of Bi2O3. The temperature coefficient of resonant frequency (τf) is measured and the results demonstrate that the increment of Bi2O3 improves the thermal stability of the composites from −345.62 to −235.02 ppm/°C. For the dielectric properties, it is observed that Bi2O3 additions cause the formation of new phases, which present higher dielectric ϵ’ than SBN. Our numerical simulations show that the materials operate as DRAs and that SBN-Bi2O3 composites could be potential candidates for DRAs operating in the S band. Journal: Journal of Electromagnetic Waves and Applications Pages: 1705-1718 Issue: 12 Volume: 34 Year: 2020 Month: 8 X-DOI: 10.1080/09205071.2020.1787231 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1787231 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:12:p:1705-1718 Template-Type: ReDIF-Article 1.0 Author-Name: Lionel Pichon Author-X-Name-First: Lionel Author-X-Name-Last: Pichon Title: Electromagnetic analysis and simulation aspects of wireless power transfer in the domain of inductive power transmission technology Abstract: Wireless power transfer (WPT) technologies have now reached a commercial stage in applications going from consumer electronics, biomedical implants and domestic applications. For electrical cars, WPT offers some new opportunities compared to classical wired charging. Although there exist some commercial cars equipped with wireless charging system, improving design procedures needs to address various domains including power electronics, components and electromagnetics. The magnetic coupling system is a key component of wireless power transfer: the coils and surrounding materials have a great impact on the efficiency of the transfer as well as the level of the stray field near the system. The paper aims to present three essential features regarding the inductive power transfer dedicated to electric vehicles. The first one addresses the topology and efficiency of the coupling system, the second one underlines the human exposure considerations and the third one deals with the impact of uncertainties regarding system parameters. Journal: Journal of Electromagnetic Waves and Applications Pages: 1719-1755 Issue: 13 Volume: 34 Year: 2020 Month: 9 X-DOI: 10.1080/09205071.2020.1799870 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1799870 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:13:p:1719-1755 Template-Type: ReDIF-Article 1.0 Author-Name: Maimoona Naheed Author-X-Name-First: Maimoona Author-X-Name-Last: Naheed Author-Name: Muhammad Faryad Author-X-Name-First: Muhammad Author-X-Name-Last: Faryad Title: Surface plasmon-polariton waves guided by an interface of a metal and an obliquely mounted uniaxially chiral, bianisotropic material Abstract: The excitation of surface plasmon-polariton (SPP) waves was delineated for an interface of a metal and an obliquely mounted uniaxially chiral, bianisotropic material with optic axis making an arbitrary angle with the interface plane. Such a material can be fabricated as a parallel assembly of hellixes with the axis of the hellixes making an arbitrary tilt angle with the metallic substrate. The canonical boundary-value problem as well as the two prism-coupled configurations were investigated. The direction of propagation of SPP waves was restricted to be in the morphologically significant plane of the bianisotropic material that contains titled hellixes. It was found that the chirality parameter of the bianisotropic material has to have a magnitude smaller than a threshold in order for SPP waves to exist for all tilt angles. Also, the SPP wave can be excited in both prism-coupled configurations only by p-polarized plane waves. Journal: Journal of Electromagnetic Waves and Applications Pages: 1756-1770 Issue: 13 Volume: 34 Year: 2020 Month: 9 X-DOI: 10.1080/09205071.2020.1787233 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1787233 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:13:p:1756-1770 Template-Type: ReDIF-Article 1.0 Author-Name: Akbar Babaeihaselghobi Author-X-Name-First: Akbar Author-X-Name-Last: Babaeihaselghobi Author-Name: Habib Badri Ghavifekr Author-X-Name-First: Habib Author-X-Name-Last: Badri Ghavifekr Title: Development of a planar helix slow-wave structure based on ball-grid array technology Abstract: The fabrication process for a planar helix slow-wave structure (SWS) based on ball-grid array (BGA) technology is developed to be used in the traveling wave tube (TWT). The planar helix layers are structured on two printed circuit boards and the solder ball is used to connect each other upside down. The material properties of the used substrate and also the solder ball connection for being used by TWT are described. Additional to previous work, filled via paths are applied inner side of the RF-substrate as an enhancement of thermal management. A typical planar helix is modeled, and the parameters of the cold and hot tests are calculated in CST microwave studio. The simulation results show that the proposed structure has high interaction impedance and wide bandwidth. The fundamental space harmonic mode overlaps with a 5.5 kV electron beam in the dispersion diagram. The scattering parameters are reported for 100 periods of the proposed structure that 1−15 GHz frequency range has a minimum reflection. The maximum gain of 22 dB is achieved at 10 GHz frequency. Journal: Journal of Electromagnetic Waves and Applications Pages: 1771-1781 Issue: 13 Volume: 34 Year: 2020 Month: 9 X-DOI: 10.1080/09205071.2020.1787235 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1787235 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:13:p:1771-1781 Template-Type: ReDIF-Article 1.0 Author-Name: Yu-Jen Chi Author-X-Name-First: Yu-Jen Author-X-Name-Last: Chi Author-Name: Chih-His Lin Author-X-Name-First: Chih-His Author-X-Name-Last: Lin Author-Name: Chien-Wen Chiu Author-X-Name-First: Chien-Wen Author-X-Name-Last: Chiu Title: Design and modeling of a wearable textile rectenna array implemented on Cordura fabric for batteryless applications Abstract: This paper presents a wearable rectenna array fabricated using Cordura textile material for harvesting low-power radio frequency (RF) energy. The dielectric properties of the textile were thoroughly investigated for circuit and antenna design. The rectenna element comprises a linearly polarized patch antenna and a single-stage full-wave Greinacher rectifier. The proposed stack topology helps reduce the size of the elements in the rectenna array. An RF choke is added to the array to prevent impedance mismatch due to changes in load impedance, and a foam with a shielding ground is inserted between the rectifier circuit and the human body to eliminate the body-proximity effect. A maximum output voltage of 1.05 V is achieved when the 2 × 2 rectenna array attached to a human body and 150 cm from the indoor Wi-Fi access point whose output power is 20 dBm and the antenna gain is 5 dBi. Journal: Journal of Electromagnetic Waves and Applications Pages: 1782-1796 Issue: 13 Volume: 34 Year: 2020 Month: 9 X-DOI: 10.1080/09205071.2020.1787869 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1787869 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:13:p:1782-1796 Template-Type: ReDIF-Article 1.0 Author-Name: Yongqiang Wang Author-X-Name-First: Yongqiang Author-X-Name-Last: Wang Author-Name: Changhui Feng Author-X-Name-First: Changhui Author-X-Name-Last: Feng Author-Name: Jie Guan Author-X-Name-First: Jie Author-X-Name-Last: Guan Title: UHF LS Peano fractal antenna for PD GIS detection Abstract: An LS Peano fractal antenna, which integrates the self-similarity and spatial filling features of fractal technology, was designed for detecting the ultra-high frequency (UHF) signals generated by gas-insulated switchgear (GIS) partial discharge (PD). Firstly, we used ANSYS HFSS to simulate and design the LS Peano fractal antenna. Then we made the antenna object according to the optimised simulation results. Finally, PD trials involving a metal protrusion defect are conducted therewith. The test results show that: the LS Peano fractal antenna has ellipsoidal directivity; the measured results indicate that the voltage standing wave ratio (VSWR) of this antenna is less than 4.5 in the range from 300 MHz to 3 GHz, which has better PD monitoring ability; the VSWR of this antenna is less than 2 in the range from 1.1 GHz MHz to 3 GHz, which has a higher density of monitoring PD. Journal: Journal of Electromagnetic Waves and Applications Pages: 1797-1811 Issue: 13 Volume: 34 Year: 2020 Month: 9 X-DOI: 10.1080/09205071.2020.1790430 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1790430 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:13:p:1797-1811 Template-Type: ReDIF-Article 1.0 Author-Name: A. Alakhras Author-X-Name-First: A. Author-X-Name-Last: Alakhras Author-Name: D. A. McNamara Author-X-Name-First: D. A. Author-X-Name-Last: McNamara Title: Sub-structure characteristic mode computation utilising field-based MM/GTD hybrid methods Abstract: It is pointed out how the (sub-structure) characteristic modes of a perfect electrically conducting (PEC) object, in the presence of an electrically very large second PEC object, can be computed using a field-based hybrid method that combines the method of moments (MM) and the geometrical theory of diffraction (GTD). An example is provided to demonstrate this. This possibility has not yet been explicitly stated elsewhere (and so perhaps not realised), nor example computations provided. We believe this realisation might widen the scope of application of characteristic mode analysis. Journal: Journal of Electromagnetic Waves and Applications Pages: 1812-1821 Issue: 13 Volume: 34 Year: 2020 Month: 9 X-DOI: 10.1080/09205071.2020.1791258 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1791258 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:13:p:1812-1821 Template-Type: ReDIF-Article 1.0 Author-Name: H.F. Contopanagos Author-X-Name-First: H.F. Author-X-Name-Last: Contopanagos Title: A broadband polarized artificial magnetic conductor metasurface Abstract: We present an artificial metasurface comprised of a metallic monolayer having a designed functionality of an Artificial Magnetic Conductor (AMC). The metasurface is designed to operate as a broadband AMC for incident electromagnetic waves polarized in a specific direction, while it works as a pass-band filter for waves orthogonally polarized to the previous direction. Hence the design presents a dual polarization-specific functionality, that of a broadband AMC, or that of a transparent dielectric. In this paper we have selected design parameters scaling the AMC behavior at mm-wave frequencies, but the design can be scaled in other frequency bands of choice. A metasurface sample has been fabricated and characterized via Ka-band waveguide measurements which have validated the approach. Applications on antenna substrates have also been demonstrated through full-wave electromagnetic simulations. Journal: Journal of Electromagnetic Waves and Applications Pages: 1823-1841 Issue: 14 Volume: 34 Year: 2020 Month: 9 X-DOI: 10.1080/09205071.2020.1791259 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1791259 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:14:p:1823-1841 Template-Type: ReDIF-Article 1.0 Author-Name: Héctor Lorduy G Author-X-Name-First: Héctor Author-X-Name-Last: Lorduy G Author-Name: L. M. Castellanos Author-X-Name-First: L. M. Author-X-Name-Last: Castellanos Title: Negative electrical permittivity in metamaterials for a wire of rectangular cross-sectional: an application to antennas design Abstract: In this article, we propose a model to obtain negative electrical permittivity in metamaterials using a conductor wire of rectangular cross-sectional geometry. Plasma frequency in the GHz range is determined in terms of the wire geometry. This new composite dielectric, which has the property of negative electrical permittivity below the plasma frequency, opens new possibilities for GHz devices. Finally, we show a unitary metamaterial cell where the refractive index takes negative values over a wide frequency range. Journal: Journal of Electromagnetic Waves and Applications Pages: 1842-1848 Issue: 14 Volume: 34 Year: 2020 Month: 9 X-DOI: 10.1080/09205071.2020.1791739 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1791739 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:14:p:1842-1848 Template-Type: ReDIF-Article 1.0 Author-Name: Lili Wu Author-X-Name-First: Lili Author-X-Name-Last: Wu Author-Name: Fayu Wan Author-X-Name-First: Fayu Author-X-Name-Last: Wan Author-Name: Wenceslas Rahajandraibe Author-X-Name-First: Wenceslas Author-X-Name-Last: Rahajandraibe Author-Name: Sébastien Lalléchère Author-X-Name-First: Sébastien Author-X-Name-Last: Lalléchère Author-Name: Blaise Ravelo Author-X-Name-First: Blaise Author-X-Name-Last: Ravelo Title: On the investigation of contactless bandpass NGD control with microstrip patch-based circuit Abstract: This paper presents an investigation on innovative bandpass negative group delay (NGD) control. The bandpass NGD theory is elaborated with patch antenna-based circuit input impedance. The S-matrix and group delay (GD) models are expressed in function of the circuit geometrical parameters. To validate the no-contact electromagnetic coupling bandpass NGD control, proof of concept is designed, fabricated and tested. The bandpass NGD behavior is in good agreement between theoretical model, EM full wave simulation and measurement, which shows NGD center frequency, 2.2 GHz, value, −0.67 ns and insertion loss, −2.93 dB, and reflection loss, −11.39 dB. It is also demonstrated that the NGD parameters vary in function of the metallic sheet-patch distance increased progressively from 0 to 26 cm. Journal: Journal of Electromagnetic Waves and Applications Pages: 1849-1857 Issue: 14 Volume: 34 Year: 2020 Month: 9 X-DOI: 10.1080/09205071.2020.1791740 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1791740 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:14:p:1849-1857 Template-Type: ReDIF-Article 1.0 Author-Name: Dawei Tang Author-X-Name-First: Dawei Author-X-Name-Last: Tang Author-Name: Qianyin Xiang Author-X-Name-First: Qianyin Author-X-Name-Last: Xiang Author-Name: Dengyao Tian Author-X-Name-First: Dengyao Author-X-Name-Last: Tian Author-Name: Mingye Fu Author-X-Name-First: Mingye Author-X-Name-Last: Fu Author-Name: Xiaoguo Huang Author-X-Name-First: Xiaoguo Author-X-Name-Last: Huang Author-Name: Quanyuan Feng Author-X-Name-First: Quanyuan Author-X-Name-Last: Feng Title: Analysis and modeling of magnetic-free broadband circulator based on three switched reflection delay lines Abstract: Magnetic-free broadband circulator structure based on three switched reflection type delay lines with a total electrical length of 180-degree at the switching frequency is investigated. The nonreciprocal transmission property is modeled and simulated, the impedance mismatching property and reconfigurable direction are studied. A prototype magnetic-free circulator circuit is designed and fabricated using coaxial cables and switches driving by switching frequency of 7.94 MHz with tolerance of ±10%. The nonreciprocal scatter parameters are measured in 300kHz ∼ 100 MHz. It shows that the circulator direction can be reconfigured by changing the switching frequency, and the maximum operating bandwidth equals 1.5fs which is limited by clock feedthrough and spectrum aliasing. Journal: Journal of Electromagnetic Waves and Applications Pages: 1858-1869 Issue: 14 Volume: 34 Year: 2020 Month: 9 X-DOI: 10.1080/09205071.2020.1792354 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1792354 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:14:p:1858-1869 Template-Type: ReDIF-Article 1.0 Author-Name: Franco Fiorini Author-X-Name-First: Franco Author-X-Name-Last: Fiorini Author-Name: Leonardo Morbidel Author-X-Name-First: Leonardo Author-X-Name-Last: Morbidel Author-Name: Pablo A. Costanzo Caso Author-X-Name-First: Pablo A. Author-X-Name-Last: Costanzo Caso Title: A new approach to nearly constant input impedance of self-complementary antennas Abstract: Conformal techniques, based on the covariance of Maxwell's electrodynamics under the full conformal group in four spacetime dimensions, are discussed in relation with the constant input impedance properties of frequency-independent antennas. In particular, we show that by applying suitable conformal transformations to existing self-complementary planar structures like logarithmic spirals, the constant input impedance property is considerably improved, especially in the low-frequency domain, where it usually fails due to the large wavelength involved. This procedure enables to perform a more intelligent truncation with the aim to capture some of the properties left behind in the cutting and to design realistic ultra wideband antennas with a more controlled value of the input impedance in the whole operation range. Journal: Journal of Electromagnetic Waves and Applications Pages: 1870-1887 Issue: 14 Volume: 34 Year: 2020 Month: 9 X-DOI: 10.1080/09205071.2020.1794985 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1794985 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:14:p:1870-1887 Template-Type: ReDIF-Article 1.0 Author-Name: Pradeep Bhatia Author-X-Name-First: Pradeep Author-X-Name-Last: Bhatia Author-Name: S.S. Verma Author-X-Name-First: S.S. Author-X-Name-Last: Verma Author-Name: M.M. Sinha Author-X-Name-First: M.M. Author-X-Name-Last: Sinha Title: Tunable optical response of Fe-Ag nanoparticles in core-Shell nanostructures Abstract: The core-shell nanoparticles have received much attention due to their potential applications in biomedicine, molecular detection, catalyst, and cancer therapy. In this work, the optical properties of Fe-Ag nanoparticles in core-shell configuration are studied by using the discrete dipole approximation (DDA) method. The Fe-core is coated with varying Ag-shell thicknesses for different shapes and sizes of nanoparticles. The absorption localized surface plasmon resonance (LSPR) peak at the maximum wavelength (λmax.) of Fe@Ag core-shell nanoparticles (NPs) is found in the range of 335–387 nm & 382–749 nm wavelengths for sphere & prolate nanostructures respectively. It is observed that the LSPR peaks are blue-shifted with increasing core-sizes and red-shifted with the increasing shell thickness as well as the aspect ratio. Furthermore, prolate nanostructure shows the shifting of LSPR peaks at λmax towards the longer wavelength regime as compared to spherical shape nanostructures. The 30 nm core-size and aspect ratio of 3 is optimized for high sensitivity and figure of merit (FOM). The calculated results suggest that different Fe-core sizes, Ag-shell thickness, and shapes in core-shell configuration Fe@Ag NPs influence the tunning and enhancement of absorption spectra. These findings can be utilized as basic knowledge for the development of synthesis methods to obtain suitable Fe@Ag core-shell NPs for future applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1888-1898 Issue: 14 Volume: 34 Year: 2020 Month: 9 X-DOI: 10.1080/09205071.2020.1794986 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1794986 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:14:p:1888-1898 Template-Type: ReDIF-Article 1.0 Author-Name: Biplab Bag Author-X-Name-First: Biplab Author-X-Name-Last: Bag Author-Name: Rahul Mondal Author-X-Name-First: Rahul Author-X-Name-Last: Mondal Author-Name: Sushanta Biswas Author-X-Name-First: Sushanta Author-X-Name-Last: Biswas Author-Name: Partha Pratim Sarkar Author-X-Name-First: Partha Pratim Author-X-Name-Last: Sarkar Title: Application-based evolution of microstrip antenna: presenting wide-bandwidth circular polarization and multi-resonating characteristics Abstract: Impedance bandwidth, multi-band, gain, and circular polarization (CP) are important characteristics of the microstrip antenna. In this paper, these characteristics have been highlighted by designing three different antenna structures. The proposed modified ground plane antenna consists of tilted G-shaped radiator (TGSR), which acts as a radiating element. The overall volume of the proposed antenna is 0.25λ0 × 0.2λ0 × 0.008λ0 (where λ0 is the free space wavelength of 1.5 GHz). The substrate used for fabricating the antennas is FR4. The Ant.I has multiband characteristics with four distinct frequency bands. However, Ant.II provides wide impedance bandwidth and also it has a single CP band, which covers the upper band of WLAN and WiMAX. Moreover, Ant.III (TGSR) exhibits two wide impedance bandwidths as well as two wide CP bands, supporting for WLAN, WiMAX, and X-band for satellite communication. The peak gains of Ant.I, Ant.II and Ant.III are about 5.5dBi, 6.6dBi, and 6.5dBic, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 1899-1917 Issue: 14 Volume: 34 Year: 2020 Month: 9 X-DOI: 10.1080/09205071.2020.1796823 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1796823 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:14:p:1899-1917 Template-Type: ReDIF-Article 1.0 Author-Name: Saeed Fakhte Author-X-Name-First: Saeed Author-X-Name-Last: Fakhte Author-Name: Iman Aryanian Author-X-Name-First: Iman Author-X-Name-Last: Aryanian Author-Name: Ladislau Matekovits Author-X-Name-First: Ladislau Author-X-Name-Last: Matekovits Title: A helical shaped broadband circularly polarized dielectric resonator antenna Abstract: By modifying the shape of a rectangular dielectric resonator antenna (DRA), a wideband circularly polarized (CP) radiator is introduced. The modified structure is composed of two L-shaped dielectric pieces stacked onto each other. The resulting geometry is similar to a two-turn helix with a rectangular cross section. Placing a coaxial probe adjacent to the sidewall of the DRA excites multiple orthogonal modes in the antenna which in sequence leads to a wideband CP DRA. The special geometry of the DRA provides the required quadrature phase difference between the orthogonal components of the electric fields. The measured input scattering parameter, $| {{S_{11}}} | $|S11|, is below −10 dB from 3 to 4.6 GHz (42%). Also, the frequency band in which axial ratio (AR) is lower than 3 dB extends from 3.1 to 3.83 GHz (21.07%), which is suitable for WIMAX applications. The measured results of the fabricated prototype are presented to verify the simulations. Journal: Journal of Electromagnetic Waves and Applications Pages: 1918-1929 Issue: 14 Volume: 34 Year: 2020 Month: 9 X-DOI: 10.1080/09205071.2020.1796824 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1796824 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:14:p:1918-1929 Template-Type: ReDIF-Article 1.0 Author-Name: Rolf Ole R. Jenssen Author-X-Name-First: Rolf Ole R. Author-X-Name-Last: Jenssen Author-Name: Svein Jacobsen Author-X-Name-First: Svein Author-X-Name-Last: Jacobsen Title: Drone-mounted UWB snow radar: technical improvements and field results Abstract: Drone borne radar systems have seen considerable advances over recent years, and the application of drone-mounted continuous wave (CW) radars for remote sensing of snow properties has great potential. Regardless, major challenges remain in antenna design for which both low weight and small size combined with high gain and bandwidth are important design parameters. Additional limiting factors for CW radars include range ambiguities and antenna isolation. To solve these problems, we have developed an ultra-wideband snow sounder (UWiBaSS), specifically designed for drone-mounted measurements of snow properties. In this paper, we present the next iteration of this prototype radar system, including a novel antenna configuration and useful processing techniques for drone borne radar. Finally, we present results from a field campaign on Svalbard aimed to measure snow depth distribution. This radar system is capable of measuring snow depth with a correlation coefficient of 0.97 compared to in situ depth probing. Journal: Journal of Electromagnetic Waves and Applications Pages: 1930-1954 Issue: 14 Volume: 34 Year: 2020 Month: 9 X-DOI: 10.1080/09205071.2020.1799871 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1799871 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:14:p:1930-1954 Template-Type: ReDIF-Article 1.0 Author-Name: Tomasz P. Stefański Author-X-Name-First: Tomasz P. Author-X-Name-Last: Stefański Author-Name: Jacek Gulgowski Author-X-Name-First: Jacek Author-X-Name-Last: Gulgowski Title: Fundamental properties of solutions to fractional-order Maxwell's equations Abstract: In this paper, fundamental properties of solutions to fractional-order (FO) Maxwell's equations are analysed. As a starting point, FO Maxwell's equations are introduced in both time and frequency domains. Then, we introduce and prove the fundamental properties of electromagnetic field in FO electromagnetics, i.e. energy conservation, uniqueness of solutions, and reciprocity. Furthermore, the algorithm of the plane wave simulation is developed and implemented in software, which allows us to demonstrate the general properties of electromagnetic field in the media described by FO models (FOMs). The differences in interpretation of the fundamental theorems of electromagnetics (i.e. Poynting's theorem, the uniqueness theorem and the Lorentz reciprocity theorem) in comparison to integer-order electromagnetics are analysed. It is demonstrated that all the properties of electromagnetic field, related to these fundamental theorems are preserved when time derivatives are generalized towards FO in Maxwell's equations. Journal: Journal of Electromagnetic Waves and Applications Pages: 1955-1976 Issue: 15 Volume: 34 Year: 2020 Month: 10 X-DOI: 10.1080/09205071.2020.1801520 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1801520 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:15:p:1955-1976 Template-Type: ReDIF-Article 1.0 Author-Name: G. M. Battaglia Author-X-Name-First: G. M. Author-X-Name-Last: Battaglia Author-Name: A. F. Morabito Author-X-Name-First: A. F. Author-X-Name-Last: Morabito Author-Name: R. Palmeri Author-X-Name-First: R. Author-X-Name-Last: Palmeri Author-Name: T. Isernia Author-X-Name-First: T. Author-X-Name-Last: Isernia Title: Constrained focusing of vector fields intensity in near zone and/or complex scenarios as a low-dimensional global optimization Abstract: A hybrid effective approach is proposed to focus the intensity of a vector field generated by an arbitrary fixed-geometry array antenna into a target point and keep it bounded elsewhere. To overcome the complexity of the underlying non-convex problem involving a possibly large number of unknowns, we show how the space of possible polarizations can be regarded as a 5-sphere and introduce a nested procedure which jointly relies on an (external) global optimization of the field polarization on the target point plus an (internal) convex optimization of the array excitations. The approach can deal with both the cases of near-field (NF) and far-field (FF) focusing as well as with complex inhomogeneous 3-D media. The high-performance results achieved through full-wave simulations of realistic scenarios confirm the actual feasibility of tackling the problem as a low-dimensional global optimization, so that the best possible focusing can be hopefully realized. Journal: Journal of Electromagnetic Waves and Applications Pages: 1977-1989 Issue: 15 Volume: 34 Year: 2020 Month: 10 X-DOI: 10.1080/09205071.2020.1801521 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1801521 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:15:p:1977-1989 Template-Type: ReDIF-Article 1.0 Author-Name: Ajay Kumar Dwivedi Author-X-Name-First: Ajay Kumar Author-X-Name-Last: Dwivedi Author-Name: Anand Sharma Author-X-Name-First: Anand Author-X-Name-Last: Sharma Author-Name: Ashutosh Kumar Singh Author-X-Name-First: Ashutosh Kumar Author-X-Name-Last: Singh Author-Name: Vivek Singh Author-X-Name-First: Vivek Author-X-Name-Last: Singh Title: Design of dual band four port circularly polarized MIMO DRA for WLAN/WiMAX applications Abstract: This article presents a circularly polarized 4-port Multiple Inputs Multiple Outputs dielectric resonator-based antenna with two resonating bands for WLAN (5.0 GHz) and WiMAX (3.5 GHz) applications. Important attributes of proposed MIMO-DRA are: (i) Bandwidth enhancement is observed due to the use of ring-shaped ceramic material radiator; (ii) Incorporation of rectangular aperture lead to excite the dual hybrid mode in ring DRA, which helps to support dual-frequency range (iii) Circular polarization is achieved in both operating bands by conversion of rectangular to Z-shaped slot; and (iv) mutual coupling among port <−18 dB due to the use of space diversity. The fabricated prototype of the MIMO radiator is measured experimentally, which confirms the dual impedance bandwidth of 3.35 – 3.82 GHz and 5.09 – 5.41 GHz. The proposed antenna is right-handed circularly polarized (RHCP) within the frequency range of 3.54 – 3.72 GHz & 5.04 – 5.16 GHz respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 1990-2009 Issue: 15 Volume: 34 Year: 2020 Month: 10 X-DOI: 10.1080/09205071.2020.1801522 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1801522 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:15:p:1990-2009 Template-Type: ReDIF-Article 1.0 Author-Name: Partha Pratim Shome Author-X-Name-First: Partha Pratim Author-X-Name-Last: Shome Author-Name: Taimoor Khan Author-X-Name-First: Taimoor Author-X-Name-Last: Khan Title: Switchable triple band-notched UWB antenna modelling for interference rejection from dual WiMAX bands and satellite C-band service Abstract: A triple band-notched monopole antenna with reconfigurable characteristics is designed and investigated in this study for implementation in ultra-wideband (UWB) systems. A conventional rectangular monopole antenna is intended first to accomplish UWB performance characteristics. Further, to obtain triple notched characteristics, three U-shaped slots are etched on the rectangular radiating surface of the antenna. A wide frequency bandwidth ranging from 2.13 GHz to 10.50 GHz with three notched bands operating at 2.65 GHz (2.49–2.82 GHz), 3.43 GHz (3.18–3.68 GHz), and 4.08 GHz (3.93–4.22 GHz) have been successfully realized. By integrating three PIN diode switches, total eight reconfigurable states of operations have been realized in the UWB spectrum. A thorough analytical investigation along with the comparison of simulated and measured performances for the proposed antenna has been presented to manifest the applicability in practical systems. The antenna structure can be successfully implemented for rejecting interferences from dual WiMAX bands along with C-band fixed satellite communication systems, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 2010-2029 Issue: 15 Volume: 34 Year: 2020 Month: 10 X-DOI: 10.1080/09205071.2020.1806115 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1806115 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:15:p:2010-2029 Template-Type: ReDIF-Article 1.0 Author-Name: Y. Ben-Ali Author-X-Name-First: Y. Author-X-Name-Last: Ben-Ali Author-Name: F. Z. Elamri Author-X-Name-First: F. Z. Author-X-Name-Last: Elamri Author-Name: A. Ouariach Author-X-Name-First: A. Author-X-Name-Last: Ouariach Author-Name: F. Falyouni Author-X-Name-First: F. Author-X-Name-Last: Falyouni Author-Name: Z. Tahri Author-X-Name-First: Z. Author-X-Name-Last: Tahri Author-Name: D. Bria Author-X-Name-First: D. Author-X-Name-Last: Bria Title: A high sensitivity hydrostatic pressure and temperature based on a defective 1D photonic crystal Abstract: We study the transmission spectrum and the band structure of a one-dimensional photonic crystal, made of alternating layers of SiO2 and TiO2 with a GaAs defect layer. The relative permittivity of the GaAs depends on the hydrostatic pressure and the temperature, while its thickness depends only on the pressure. The objective of this work is to apply an external pressure and temperature on the GaAs and study the behavior of the defect mode. The insertion of the GaAs layer inside the perfect structure creates defect mode in the gaps with higher quality factor $Q\ (Q = 65858) $Q (Q=65858) and important transmission rate $T\ (T = 88\%) $T (T=88%). The results show that our structure is sensitive to pressure and temperature variations of approximately P = 50 bar and Θ = 5°K, with a frequency shift of 0.05THz and 0.108THz, respectively. So, our proposed structure is a good candidate for the hydrostatic pressure and temperature sensor design. Journal: Journal of Electromagnetic Waves and Applications Pages: 2030-2050 Issue: 15 Volume: 34 Year: 2020 Month: 10 X-DOI: 10.1080/09205071.2020.1806116 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1806116 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:15:p:2030-2050 Template-Type: ReDIF-Article 1.0 Author-Name: M. Wasif Niaz Author-X-Name-First: M. Author-X-Name-Last: Wasif Niaz Author-Name: S. H. H. Mashhadi Author-X-Name-First: S. H. H. Author-X-Name-Last: Mashhadi Author-Name: Zhao Zhou Author-X-Name-First: Zhao Author-X-Name-Last: Zhou Author-Name: Yingzeng Yin Author-X-Name-First: Yingzeng Author-X-Name-Last: Yin Title: Enhanced bandwidth, low sidelobe resonant cavity antenna using tapered complementary FSS layers Abstract: A novel resonant cavity antenna (RCA) with low sidelobe levels over an enhanced bandwidth is presented. Radiation bandwidth of the antenna is increased by using a pair of complementary FSS layers, giving a positive reflection phase over a wide frequency range, as the proposed PRS. Low sidelobes are achieved by lowering the reflection amplitude of the PRS along its length while keeping reflection phase almost the same throughout the operating band. The performance of the proposed PRS is validated by creating a circular aperture RCA and measuring its radiation characteristics. The cavity is excited by an aperture coupled patch antenna having a broad impedance bandwidth. Prototype RCA gives a peak realized gain of 16.1 dBi and a 3-dB gain bandwidth of 8.6% ranging from 14.5 to 15.8 GHz. Measured sidelobe levels are reduced, respectively, to less than −17 dB and −23 dB in the E- and H-plane of the prototype antenna. Journal: Journal of Electromagnetic Waves and Applications Pages: 2051-2064 Issue: 15 Volume: 34 Year: 2020 Month: 10 X-DOI: 10.1080/09205071.2020.1806738 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1806738 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:15:p:2051-2064 Template-Type: ReDIF-Article 1.0 Author-Name: Pankaj Kumar Author-X-Name-First: Pankaj Author-X-Name-Last: Kumar Author-Name: Akhlesh Lakhtakia Author-X-Name-First: Akhlesh Author-X-Name-Last: Lakhtakia Author-Name: Pradip Kumar Jain Author-X-Name-First: Pradip Author-X-Name-Last: Kumar Jain Title: Tricontrollable pixelated metasurface for stopband for terahertz radiation Abstract: Transmission of a normally incident plane wave through a pixelated metasurface with meta-atoms made up of graphene-patched and InSb-patched pixels on a silicon substrate was simulated using CST Microwave StudioTM2019 software. This metasurface is electrically controllable due to the graphene-patched pixels, and it is magnetically as well as thermally controllable due to the InSb-patched pixels. A tricontrollable stopband with minimum transmittance as low as 0.05 can be achieved for operation in the terahertz gap. Journal: Journal of Electromagnetic Waves and Applications Pages: 2065-2078 Issue: 15 Volume: 34 Year: 2020 Month: 10 X-DOI: 10.1080/09205071.2020.1796825 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1796825 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:15:p:2065-2078 Template-Type: ReDIF-Article 1.0 Author-Name: Huayan Jin Author-X-Name-First: Huayan Author-X-Name-Last: Jin Author-Name: Chiao-Yi Chien Author-X-Name-First: Chiao-Yi Author-X-Name-Last: Chien Author-Name: Eric S. Li Author-X-Name-First: Eric S. Author-X-Name-Last: Li Author-Name: Chung-Yi Li Author-X-Name-First: Chung-Yi Author-X-Name-Last: Li Author-Name: Kuo-Sheng Chin Author-X-Name-First: Kuo-Sheng Author-X-Name-Last: Chin Title: Design of wideband CPW bandpass filters using phase comparison method and oblique air bridges Abstract: This work presents two wideband coplanar-waveguide bandpass filters using open-circuited stubs (Design 1) and short-circuited stubs (Design 2), respectively. The electrical lengths of stubs were accurately determined by a phase comparison method. In Design 1, a spurious resonance was found at the high band edge of the passband. The problem was solved by introducing oblique air bridges to ruin the undesired resonance path for the suppression of the spurious resonance. Design 1 achieves bandwidth of 38.1% and low insertion loss of 0.7 dB. Another CPW filter, Design 2, was constructed with short-circuited stubs for compact size, which can achieve a very wide bandwidth of 70.8% and insertion loss of 0.9 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 2079-2093 Issue: 16 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1807414 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1807414 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:16:p:2079-2093 Template-Type: ReDIF-Article 1.0 Author-Name: Li Zhu Author-X-Name-First: Li Author-X-Name-Last: Zhu Author-Name: Min Liu Author-X-Name-First: Min Author-X-Name-Last: Liu Author-Name: Wen Hao Shao Author-X-Name-First: Wen Hao Author-X-Name-Last: Shao Title: MMW compressed sensing target reconstruction based on AMPSO search algorithm Abstract: Introducing compressed sensing theory into the millimeter-wave near-field holographic imaging algorithm, it can break the Nyquist sampling limit, reconstruct the compressed echo signal, and invert the target image. In the reconstruction process, there are defects such as missing target key information, excessive invalid search volume and so on. Aiming at this problem, an adaptive multi-extreme particle swarm optimization (AMPSO) algorithm is proposed. Its advantages are that it can retain more target information, search for more extreme values, and improve the convergence speed. At the same time, the search probability in the strong scattering area is also increased, the search time is avoided in the noise area, and the number of extreme points is adjusted on a global scale. The effectiveness of the algorithm is verified by simulation and actual measurement of multiple types of targets under different experimental conditions. Journal: Journal of Electromagnetic Waves and Applications Pages: 2094-2106 Issue: 16 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1809018 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1809018 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:16:p:2094-2106 Template-Type: ReDIF-Article 1.0 Author-Name: Janaki Pakalapati Author-X-Name-First: Janaki Author-X-Name-Last: Pakalapati Author-Name: Karthick Nagaraj Author-X-Name-First: Karthick Author-X-Name-Last: Nagaraj Author-Name: Gundavarapu Venkata Nagesh Kumar Author-X-Name-First: Gundavarapu Venkata Author-X-Name-Last: Nagesh Kumar Title: Study of electrostatic field effect in a three-phase gas-insulated busduct with FGM spacer under the effect of protrusion Abstract: Recently, the defects in Gas-Insulated Busduct (GIB) affect the electric field distribution badly over the spacer length and de-energies the GIB leading to huge loss economically. In this paper, a post type spacer with Functionally Graded Material (FGM) has been designed for a three-phase GIB under protrusion and further electric field stress is minimized by inserting metal inserts. Functionally graded materials are spatially distributed with several filler materials by doping them with different permittivity values to achieve uniform electric field stress. Simulation is carried out with the designed spacer for different voltages and also for different types of FGM gradings. The protrusion effect on the electric field stress is studied with different sizes and the results obtained are presented and analyzed. Journal: Journal of Electromagnetic Waves and Applications Pages: 2107-2129 Issue: 16 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1809019 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1809019 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:16:p:2107-2129 Template-Type: ReDIF-Article 1.0 Author-Name: Gabriel Ángel Jiménez-Guzmán Author-X-Name-First: Gabriel Ángel Author-X-Name-Last: Jiménez-Guzmán Author-Name: José Alfredo Tirado-Mendez Author-X-Name-First: José Alfredo Author-X-Name-Last: Tirado-Mendez Author-Name: Arturo Rangel-Merino Author-X-Name-First: Arturo Author-X-Name-Last: Rangel-Merino Author-Name: Luis Alberto Vasquez-Toledo Author-X-Name-First: Luis Alberto Author-X-Name-Last: Vasquez-Toledo Author-Name: Ricardo Marcelin-Jimenez Author-X-Name-First: Ricardo Author-X-Name-Last: Marcelin-Jimenez Title: Improving the performance of a patch antenna array by using photonic bandgap structures at X-band Abstract: A proposed three-layered patch antenna array combined with Uniplanar Compact Photonic Bandgap structures (UC-PBG) is presented to avoid non-desired radiations from the feeding structure and to mitigate the surface propagation modes, increasing the radiation efficiency, and reducing the parasitic lobes. The array is fed by electromagnetic proximity, implemented by a stripline network below the radiators. The array is designed to operate at of 10 GHz and is surrounded by UC-PBG structures. This configuration also helps to increase the bandwidth by keeping the electric field and the surface current stable around the radiators, reducing the variations of the impedance on a wider bandwidth. Also, the UC-PBG structures attenuate the surface propagation modes, lowering the parasitic lobes by almost 7 dB and reaching measured radiation efficiency higher than 80%. The patch array gets an operational bandwidth of 2.5 GHz, with a measured gain of 24 dB. The fractional bandwidth is 25%. Journal: Journal of Electromagnetic Waves and Applications Pages: 2130-2146 Issue: 16 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1809020 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1809020 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:16:p:2130-2146 Template-Type: ReDIF-Article 1.0 Author-Name: Yanfei Gong Author-X-Name-First: Yanfei Author-X-Name-Last: Gong Author-Name: Xingtong Chen Author-X-Name-First: Xingtong Author-X-Name-Last: Chen Author-Name: Yujie Li Author-X-Name-First: Yujie Author-X-Name-Last: Li Title: Research and application of finite-element time-domain method for transient response of buried cable excited by an electromagnetic wave Abstract: To analyze electromagnetic (EM) transient responses of a buried cable, an accurate and reliable time-domain method is proposed in this paper. The approach is based on the transmission line (TL) second-order telegrapher’s current equation, and the expressions of ground impedance and admittance at higher frequencies are used to obtain the discrete finite-element time-domain (FETD) equations for the cable. Finally, transient responses at termination loads of the buried cable are obtained based on the global FETD equation, which is assembled using discrete FETD equations on all intervals. The accuracy and effectiveness of the proposed FETD method are demonstrated by comparing numerical results to those of the finite-difference time-domain (FDTD) method. The proposed method is also employed to investigate the effects of numerous parameters on transient currents of the buried cable, including the soil conductivity, buried cable depth, and incident and polarization angles of the external EM wave. Journal: Journal of Electromagnetic Waves and Applications Pages: 2147-2167 Issue: 16 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1809530 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1809530 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:16:p:2147-2167 Template-Type: ReDIF-Article 1.0 Author-Name: Saif ur Rehman Author-X-Name-First: Saif Author-X-Name-Last: ur Rehman Author-Name: Muhammad Arshad Fiaz Author-X-Name-First: Muhammad Arshad Author-X-Name-Last: Fiaz Author-Name: Muhammad Aqueel Ashraf Author-X-Name-First: Muhammad Aqueel Author-X-Name-Last: Ashraf Title: Scattering from a grounded chiral slab with rough interface using perturbation theory Abstract: Scattering from a grounded chiral slab with rough interface is studied using perturbation theory. A system of equations for zeroth and higher order solution is written, which can be solved to get co and cross polarized scattered and transmitted field components. The zeroth-order coefficients provide the results for the flat case, while the higher order coefficients provide the solution with perturbation involved. Upon substituting the value of chirality of the medium to zero, we get the results for the dielectric slab to highlight the effect of chirality. Moreover, the parameters related to sinusoidal and Gaussian rough surfaces such as period and correlation length are changed to check their effects on the scattering pattern. Journal: Journal of Electromagnetic Waves and Applications Pages: 2168-2180 Issue: 16 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1809531 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1809531 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:16:p:2168-2180 Template-Type: ReDIF-Article 1.0 Author-Name: Sinan Aksimsek Author-X-Name-First: Sinan Author-X-Name-Last: Aksimsek Title: Design of an ultra-thin, multiband, micro-slot based terahertz metamaterial absorber Abstract: An ultra-thin, multiband, micro-slot based metamaterial absorber is presented in this paper. The proposed unit cell is compact which is in the form of single-layer gold patch-gallium arsenide-ground package, involving four identical micro-slots. Using the micro-slots, the fundamental circular patch gains a multiband resonation skill, and the absorber operates at 1.16, 2.73, and 4.57 THz bands with near-perfect absorptivity. The absorption mechanism is discussed based on the electric and surface current distributions, and all outcomes are also validated by the effective medium approach. The proposed absorber is ultra-thin with a thickness of 2.6 µm, corresponding to ∼λ/100 at its lowest operation frequency. The unit cell indicates polarization-independent, and wide incident angle absorption spectra up to 40°, hence, the proposed absorber is a promising candidate as an absorbing platform for THz band imaging and sensing applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 2181-2193 Issue: 16 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1809532 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1809532 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:16:p:2181-2193 Template-Type: ReDIF-Article 1.0 Author-Name: Arashpreet K. Sohi Author-X-Name-First: Arashpreet K. Author-X-Name-Last: Sohi Author-Name: Amanpreet Kaur Author-X-Name-First: Amanpreet Author-X-Name-Last: Kaur Title: Hexa-band suppression characteristics from a fork-shaped UWB-MIMO antenna loaded with complementary split-ring resonator and slots Abstract: In the present article, a fork-shaped UWB-MIMO antenna is designed and experimentally tested to achieve hexa-band rejection characteristics. Initially, the proposed array consists of two fork-shaped radiators and a reduced ground with a vertical stub, designed to cover a large bandwidth from 3.64–12.2 GHz and high port-to-port isolation. Furthermore, each fork-shaped radiator is defected with two U-shaped slots, inverted U-shaped slot, complementary SRR and a pair of Z-shaped slots to eliminate the interfering frequency bands at 3.95 GHz (downlink C-band), 4.8 GHz (INSAT), 5.35 GHz (WLAN), 6.19 GHz (uplink C-band) and 8.4 GHz (ITU-8) respectively. The reduced ground is loaded with two G-shaped slots to suppress the interfering amateur radio band (10.01–11.27 GHz). The total volume occupied by the proposed array is 21.5 × 57 × 1.64 mm3. The diversity performance of the proposed array is characterized by low ECC, high DG, high MEG, low CCL and stable TARC characteristics. A close resemblance is achieved between the simulated and experimental results. Journal: Journal of Electromagnetic Waves and Applications Pages: 2194-2219 Issue: 16 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1809533 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1809533 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:16:p:2194-2219 Template-Type: ReDIF-Article 1.0 Author-Name: Mohsen Eslami Nazari Author-X-Name-First: Mohsen Author-X-Name-Last: Eslami Nazari Author-Name: Weimin Huang Author-X-Name-First: Weimin Author-X-Name-Last: Huang Author-Name: Zahraalsadat Alavizadeh Author-X-Name-First: Zahraalsadat Author-X-Name-Last: Alavizadeh Title: Return loss-bandwidth evaluation for electrically small microstrip antennas Abstract: A method incorporating Bode–Fano integrals is proposed in this paper to evaluate the potential bandwidth of small antennas and provide a particular strategy for bandwidth improvement. The Bode–Fano theory is applied to the equivalent circuit of small microstrip antennas to calculate the maximum achievable return loss-bandwidth. Results of applying this theory to three types of microstrip antennas in $TM_{01} $TM01 mode of propagation with defected ground structure (DGS) and defected microstrip structure (DMS) indicate that creating slots on the microstrip patch or ground structure despite their advantages can decrease the potential bandwidth of the antenna. Fano integrals reveal the invariant relation between maximum achievable return loss-bandwidth and overall volume of the antenna validated using the quality factor (Q factor) analysis. Journal: Journal of Electromagnetic Waves and Applications Pages: 2220-2235 Issue: 16 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1809534 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1809534 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:16:p:2220-2235 Template-Type: ReDIF-Article 1.0 Author-Name: Yang Dong Author-X-Name-First: Yang Author-X-Name-Last: Dong Author-Name: Zijun Chen Author-X-Name-First: Zijun Author-X-Name-Last: Chen Author-Name: Xinyi Li Author-X-Name-First: Xinyi Author-X-Name-Last: Li Author-Name: Hexin Wang Author-X-Name-First: Hexin Author-X-Name-Last: Wang Author-Name: Zhanliang Wang Author-X-Name-First: Zhanliang Author-X-Name-Last: Wang Author-Name: Shaomeng Wang Author-X-Name-First: Shaomeng Author-X-Name-Last: Wang Author-Name: Zhigang Lu Author-X-Name-First: Zhigang Author-X-Name-Last: Lu Author-Name: Huarong Gong Author-X-Name-First: Huarong Author-X-Name-Last: Gong Author-Name: Zhaoyun Duan Author-X-Name-First: Zhaoyun Author-X-Name-Last: Duan Author-Name: Jinjun Feng Author-X-Name-First: Jinjun Author-X-Name-Last: Feng Author-Name: Yubin Gong Author-X-Name-First: Yubin Author-X-Name-Last: Gong Title: Ka-band dual sheet beam traveling wave tube using supported planar ring-bar slow wave structure Abstract: A dual-beam planar slow wave structure (SWS), named dielectric supported ring-bar SWS is proposed in this paper. The planar SWS is supported by two dielectric rods at the side edges, making it fit for dual sheet beam operation. The high frequency and transmission characteristics of the proposed SWS are investigated. The backward-wave oscillation and higher harmonic waves are effectively suppressed by setting two cathodes in the same plane parallel to the SWS and negative phase-velocity jumping. The hot performance of the proposed SWS is carried out by using particle-in-cell (PIC) simulation, in which two sheet electron beams (9.7 kV, 0.2 A) are employed to provide direct current power. With an input power of 1W, the output power is 180 W at 38 GHz and the corresponding gain is 22.6 dB. Besides, after adding dielectric rods to the output part, the entire structure dissipates heat well by thermal analysis. Journal: Journal of Electromagnetic Waves and Applications Pages: 2236-2250 Issue: 16 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1807413 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1807413 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:16:p:2236-2250 Template-Type: ReDIF-Article 1.0 Author-Name: Do Thuy Chi Author-X-Name-First: Do Thuy Author-X-Name-Last: Chi Author-Name: Bui Xuan Khuyen Author-X-Name-First: Bui Xuan Author-X-Name-Last: Khuyen Author-Name: Bui Son Tung Author-X-Name-First: Bui Son Author-X-Name-Last: Tung Author-Name: Vu Dinh Lam Author-X-Name-First: Vu Dinh Author-X-Name-Last: Lam Author-Name: Liang Yao Chen Author-X-Name-First: Liang Yao Author-X-Name-Last: Chen Author-Name: YoungPak Lee Author-X-Name-First: YoungPak Author-X-Name-Last: Lee Title: Progresses in metamaterials for advanced low-frequency perfect absorbers: a brief review Abstract: In recent years, the exotic capability of metamaterials to absorb perfectly electromagnetic wave has induced potentially many practical purposes, especially, the rapid growth of 5G/6G telecommunication systems. Therefore, the perfect metamaterial absorbers have been reduced in a fast way to several hundred times smaller than the working wavelength. However, it is still a big obstacle to obtain the real low-frequency perfect absorbers (LFPAs), since the absorption frequency and the physical size are two conflicting requirements. To overcome this limitation, we review rather briefly the existing optimization strategies for LFPAs, by which the merits of geometrical optimization and the hybridization with parasitic elements will be highlighted. In addition, to be more feasible in electronic devices, the studies on flexible LFPA are also mentioned. Especially, we focus on recent investigations, which use inkjet-printing as an advanced fabrication technique to create the cost-efficient, printable and flexible LFPA. Journal: Journal of Electromagnetic Waves and Applications Pages: 2251-2265 Issue: 17 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1820385 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1820385 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:17:p:2251-2265 Template-Type: ReDIF-Article 1.0 Author-Name: K. Paul Author-X-Name-First: K. Author-X-Name-Last: Paul Author-Name: B. Mukhopadhyay Author-X-Name-First: B. Author-X-Name-Last: Mukhopadhyay Title: Electromagnetic, thermal and diffusive wave analysis on a two-temperature generalized thermo-elastic problem in a semi-infinite solid with cylindrical cavity subject to thermal loads Abstract: Our present work is concerned with the study of a semi-infinitely long, conducting solid with a cavity in cylindrical form in the context of magneto-thermo-elastic diffusion with two-temperature and three-phase-lag effect. The medium we have considered here is supposed to be initially quiescent. The material is assumed to be made of an isotropic homogeneous thermo-elastic material and put in a magnetic field which is uniform and acted in the direction of the axis of the cylindrical cavity. The solution to the problem is done in Laplace transform domain. Inversion process is applied to obtain the solution in space time domain and finally illustrated graphically. Journal: Journal of Electromagnetic Waves and Applications Pages: 2266-2288 Issue: 17 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1769505 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1769505 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:17:p:2266-2288 Template-Type: ReDIF-Article 1.0 Author-Name: Robab Kazemi Author-X-Name-First: Robab Author-X-Name-Last: Kazemi Author-Name: Ali Hassanpour Author-X-Name-First: Ali Author-X-Name-Last: Hassanpour Title: Design procedure for a wideband high power multi-way SIW radial divider/combiner Abstract: In this paper, a wideband 12-way high power radial power divider/combiner is designed based on substrate integrated waveguide (SIW) technology. Broadband performance is achieved by using a stepped-core coaxial line at the central port and wideband SIW-to-grounded coplanar waveguide transitions at the radial ports. Due to the high power-handling capability of this structure, it is suitable for both power combining and power dividing applications. A prototype of the proposed combiner at X-band was designed, fabricated and tested. The measured insertion loss at output ports is approximately 10.7 ± 0.5 dB and the phase imbalance is ±1.8°. The isolation between the adjacent ports is better than 12.6 dB all over the X-band (40% bandwidth) and it can handle input power in the multi hundred-KW range (>266 KW), which is a huge advantage. Journal: Journal of Electromagnetic Waves and Applications Pages: 2289-2303 Issue: 17 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1811164 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1811164 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:17:p:2289-2303 Template-Type: ReDIF-Article 1.0 Author-Name: A. A. Kirilenko Author-X-Name-First: A. A. Author-X-Name-Last: Kirilenko Author-Name: S. O. Steshenko Author-X-Name-First: S. O. Author-X-Name-Last: Steshenko Author-Name: V.N. Derkach Author-X-Name-First: V.N. Author-X-Name-Last: Derkach Author-Name: Ye. M. Ostrizhnyi Author-X-Name-First: Ye. M. Author-X-Name-Last: Ostrizhnyi Author-Name: L. P. Mospan Author-X-Name-First: L. P. Author-X-Name-Last: Mospan Title: Tunable polarization rotator on a pair of grooved flanges Abstract: The polarization plane rotators located outside the transmission line volume are presented. Their work is based on the excitation of special (‘dihedral') eigen-oscillations in a waveguide object formed by two corrugated flanges with rotational symmetry. Such a topology provides 3D chirality of the composite object at an azimuthal shift of the flanges and rotation of the polarization plane by an arbitrary angle in the band of a few percent with minimal return loss. In circular and coaxial waveguides, a mechanical or electronic rearrangement of the PP by mutual rotation of the flanges or by the placement of controlled elements (media) into the object cavity is possible. Journal: Journal of Electromagnetic Waves and Applications Pages: 2304-2316 Issue: 17 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1812442 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1812442 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:17:p:2304-2316 Template-Type: ReDIF-Article 1.0 Author-Name: Arashpreet K. Sohi Author-X-Name-First: Arashpreet K. Author-X-Name-Last: Sohi Author-Name: Amanpreet Kaur Author-X-Name-First: Amanpreet Author-X-Name-Last: Kaur Title: UWB aperture coupled circular fractal MIMO antenna with a complementary rectangular spiral defected ground structure (DGS) for 4G/WLAN/radar/satellite/international space station (ISS) communication systems Abstract: In this article, a dual-port aperture-coupled circular fractal antenna array is designed, developed and tested for its usage in 4G, WLAN, radar, satellite and ISS communication systems, covering C-band, X-band and Ku-band of frequencies. The proposed array is designed on two FR-4 substrates (with overall dimensions of 34 × 68.7 × 3.245 mm3) where the upper and lower substrate consists of circular fractal radiators (2nd order of iteration) and a feed network respectively. The aperture slots in the ground are transformed into complementary rectangular spiral slots with a tree-shaped DGS, to achieve the desired operational band (4.6–16.8 GHz) with improved matching performance. It provides a maximum gain of 4.57 dB (at 6.6 GHz) and high port-to-port isolation (S21 ≤ −19 dB) performance. The implementation of the proposed array in MIMO systems is validated by various diversity parameters like low ECC, high DG, high MEG, low CCL and stable TARC attributes. An acceptable agreement is achieved between the simulated and experimental results. Journal: Journal of Electromagnetic Waves and Applications Pages: 2317-2338 Issue: 17 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1813638 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1813638 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:17:p:2317-2338 Template-Type: ReDIF-Article 1.0 Author-Name: Aymen Hlali Author-X-Name-First: Aymen Author-X-Name-Last: Hlali Author-Name: Hassen Zairi Author-X-Name-First: Hassen Author-X-Name-Last: Zairi Title: Terahertz microstrip circulator based on graphene Abstract: In this paper, we present an improved wave concept iterative process (WCIP) algorithm for the analysis of anisotropic graphene. Then, we use it to investigate a novel type of terahertz microstrip circulator based on graphene. In this algorithm, we propose a new technique for modeling of magnetized graphene layers, which consists of redefining the boundary conditions of graphene in terms of waves and integrating the surface conductivity without involving volumetric discretization. Numerical examples are presented to verify the efficiency of the proposed algorithm. The numerical simulations demonstrate that the performances of the circulator can be adjusted by applying an electric or magnetic field bias. Journal: Journal of Electromagnetic Waves and Applications Pages: 2339-2348 Issue: 17 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1813639 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1813639 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:17:p:2339-2348 Template-Type: ReDIF-Article 1.0 Author-Name: N. Anselmi Author-X-Name-First: N. Author-X-Name-Last: Anselmi Author-Name: A. Polo Author-X-Name-First: A. Author-X-Name-Last: Polo Author-Name: M. A. Hannan Author-X-Name-First: M. A. Author-X-Name-Last: Hannan Author-Name: M. Salucci Author-X-Name-First: M. Author-X-Name-Last: Salucci Author-Name: P. Rocca Author-X-Name-First: P. Author-X-Name-Last: Rocca Title: Maximum BCE synthesis of domino-tiled planar arrays for far-field wireless power transmission Abstract: The design of transmitting antenna arrays with a modular aperiodic architecture for far-field wireless power transmission (WPT) is addressed in this work. The synthesis of the subarray layout and of the subarrays weights is carried out to maximize the power transmission efficiency, while guaranteeing the full aperture coverage with simple domino-shaped tiles. Two design methodologies, one enumerative and one optimization-based, customized to the synthesis of small and larger apertures are presented. The best tiled array configuration is obtained through the maximization of the beam collection efficiency (BCE) for a given collection area where the receiving rectenna system is assumed. A set of representative numerical examples, including both ideal and real antenna models, is shown to prove the effectiveness of the proposed architectural solution as well as of the clustering methods. Analyses considering different array dimensions and sizes of the collection area, when scanning the beam off-boresight also along diagonal directions, are given to assess the performance of the proposed solutions. Journal: Journal of Electromagnetic Waves and Applications Pages: 2349-2370 Issue: 17 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1814166 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1814166 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:17:p:2349-2370 Template-Type: ReDIF-Article 1.0 Author-Name: Lijun Zhu Author-X-Name-First: Lijun Author-X-Name-Last: Zhu Author-Name: Zhen Liu Author-X-Name-First: Zhen Author-X-Name-Last: Liu Author-Name: Huimin Gao Author-X-Name-First: Huimin Author-X-Name-Last: Gao Title: Two-stage sparse representation of NSCT features with application to SAR target classification Abstract: To improve synthetic aperture radar (SAR) target classification performance, both the feature extraction and classification algorithms are considered. The nonsubsampled contourlet transform (NSCT) is employed to decompose SAR images to generate multi-layer components, which provide more discriminative descriptions for the targets. During the classification, the two-stage sparse representations are developed. Each NSCT component is classified using the sparse representation-based classification (SRC). Afterwards, the joint sparse representation (JSR) is adopted to represent the selected NSCT components from the first stage, which are assumed to be highly discriminative. Based on the two decisions, the target label of the test sample is determined. In the experiment, the moving and stationary target acquisition and recognition (MSTAR) dataset is used to set up scenarios for performance evaluation including the standard operating condition (SOC) and several extended operating conditions (EOCs). The results show the superior performance of the proposed methodover some current methods. Journal: Journal of Electromagnetic Waves and Applications Pages: 2371-2384 Issue: 17 Volume: 34 Year: 2020 Month: 11 X-DOI: 10.1080/09205071.2020.1814167 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1814167 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:17:p:2371-2384 Template-Type: ReDIF-Article 1.0 Author-Name: Yabin Zhang Author-X-Name-First: Yabin Author-X-Name-Last: Zhang Title: Theoretical research on branch-guide energy coupler for wide bandwidth terahertz relativistic sheet electron beam TWTs Abstract: Branch-guide energy couplers can be used in the terahertz relativistic sheet electron beam traveling wave tubes (THz-RSBTWT) for high and high frequency microwave radiations. To analyze this type of coupler, a new method based on the phase superposition principle was put forward in this paper. A physical model was developed, which is applicable no matter the coupler width is large or small. The general distance relationship between the branches was derived and a rapid design formula was obtained, which can help design energy coupler with arbitrary coupling coefficient. Journal: Journal of Electromagnetic Waves and Applications Pages: 2385-2396 Issue: 18 Volume: 34 Year: 2020 Month: 12 X-DOI: 10.1080/09205071.2020.1815594 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1815594 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:18:p:2385-2396 Template-Type: ReDIF-Article 1.0 Author-Name: Tharani Duraisamy Author-X-Name-First: Tharani Author-X-Name-Last: Duraisamy Author-Name: Rusan Kumar Barik Author-X-Name-First: Rusan Kumar Author-X-Name-Last: Barik Author-Name: Qingsha S. Cheng Author-X-Name-First: Qingsha S. Author-X-Name-Last: Cheng Author-Name: Selvajyothi Kamakshy Author-X-Name-First: Selvajyothi Author-X-Name-Last: Kamakshy Author-Name: Karthikeyan Sholampettai Subramanian Author-X-Name-First: Karthikeyan Author-X-Name-Last: Sholampettai Subramanian Title: Miniaturized SIW filter using D-shaped resonators with wide out-of-band rejection for 5G applications Abstract: In this article, substrate integrated waveguide (SIW) filter with compact size and wide out-of-band rejection is designed for 5G (sub-6 GHz) applications. To achieve the proposed filter responses, D-shaped resonators oriented face-to-face are etched out on the top layer of SIW. Due to the resonators loading, the filter provides a passband below the cut-off frequency of SIW. This decrease in the operating frequency of the filter allows us to achieve size miniaturization. To enhance the frequency responses, a double-stage SIW filter is proposed and investigated. The equivalent electrical-circuits are developed to validate the transmission responses. To support our claim, single- and double-stage SIW filters are designed, fabricated and tested. The filter prototypes achieve size miniaturization, low insertion loss and wide out-of-band responses. The measured responses are very similar to the full-wave simulation responses. Journal: Journal of Electromagnetic Waves and Applications Pages: 2397-2409 Issue: 18 Volume: 34 Year: 2020 Month: 12 X-DOI: 10.1080/09205071.2020.1816219 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1816219 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:18:p:2397-2409 Template-Type: ReDIF-Article 1.0 Author-Name: Lyda-Vanessa Herrera-Sepulveda Author-X-Name-First: Lyda-Vanessa Author-X-Name-Last: Herrera-Sepulveda Author-Name: Jose-Luis Olvera-Cervantes Author-X-Name-First: Jose-Luis Author-X-Name-Last: Olvera-Cervantes Author-Name: Alonso Corona-Chavez Author-X-Name-First: Alonso Author-X-Name-Last: Corona-Chavez Author-Name: Tejinder Kaur Author-X-Name-First: Tejinder Author-X-Name-Last: Kaur Title: New methodology to determine the loss tangent of dielectric planar samples by using electrically coupled resonators Abstract: A new methodology to determine the loss tangent of dielectric planar samples by using electrically coupled resonators is presented. The coupling between the resonators is disrupted by the sample under test (SUT). The proposed methodology is based on the analysis of the equivalent circuit of the sensor in differential and common modes. This work demonstrates that the total quality factor of the electric wall is suitable to determine the losses of the SUT for a wide range of loss tangent values. Additionally, the methodology was experimentally tested with a microstrip sensor and planar samples whose loss tangent values are between 0.000303 and 0.02. The results show that the proposed method achieves an accuracy higher than 97.74%. Journal: Journal of Electromagnetic Waves and Applications Pages: 2410-2418 Issue: 18 Volume: 34 Year: 2020 Month: 12 X-DOI: 10.1080/09205071.2020.1816502 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1816502 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:18:p:2410-2418 Template-Type: ReDIF-Article 1.0 Author-Name: F. Etesami Author-X-Name-First: F. Author-X-Name-Last: Etesami Author-Name: H. Abiri Author-X-Name-First: H. Author-X-Name-Last: Abiri Author-Name: S. Khorshidi Author-X-Name-First: S. Author-X-Name-Last: Khorshidi Title: Design of a broadband single-layer reflectarray antenna using double hexagonal rings and a hexapole Abstract: This paper proposes a novel subwavelength single-layer reflectarray antenna unit cell operating in X-band, composed of double hexagonal rings and a hexapole. This new cell is not sensitive to TE and TM polarizations. Infinite array approach has been used to determine the reflection phase curve. The proposed element has more than 575° linear phase range in 8.5–11 GHz frequency band by varying the radius of the outer ring. The scattering parameters of an infinite reflectarray using the proposed element are measured by the waveguide simulator which takes into account the effects of the mutual coupling. A 277-element center-fed reflectarray antenna using this cell is designed, fabricated and measured to verify the broadband property of the proposed element. The measurement results show about 27.5% 3-dB gain bandwidth and 22.8 dB maximum gain at 10 GHz, which is equivalent to about 32% aperture efficiency. Journal: Journal of Electromagnetic Waves and Applications Pages: 2419-2432 Issue: 18 Volume: 34 Year: 2020 Month: 12 X-DOI: 10.1080/09205071.2020.1817798 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1817798 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:18:p:2419-2432 Template-Type: ReDIF-Article 1.0 Author-Name: N. M. Murad Author-X-Name-First: N. M. Author-X-Name-Last: Murad Author-Name: L. Rajaoarisoa Author-X-Name-First: L. Author-X-Name-Last: Rajaoarisoa Author-Name: S. Lalléchère Author-X-Name-First: S. Author-X-Name-Last: Lalléchère Author-Name: G. Fontgalland Author-X-Name-First: G. Author-X-Name-Last: Fontgalland Author-Name: B. Ravelo Author-X-Name-First: B. Author-X-Name-Last: Ravelo Title: Analysis of microstrip coupled line based data signal and energy hybrid receiver Abstract: This paper develops an original circuit theory of energy and data transition. The modelling of signal and energy hybrid receiver (SEHR) is developed. The SEHR topology is described in function of the constituting coupled line (CL) and a transmission line (TL) performed with unfamiliar and arbitrary load values. The equivalent S-matrix versus electrical parameters is established. The analysis of the S-matrix enables to predict the transmitted power and also the optimal condition of zero reflection in function of the terminal loads. The validity of the SEHR analytical model is verified with commercial tool simulations with a microstrip structure proof-of-concept. A configuration of electromagnetic (EM) environment operating at 2.45 GHz with input power of about 0 dBm is considered. The prediction of detected average energy and transmitted data-signal voltage amplitude in function of SEHR electrical and geometrical parameters is discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 2433-2454 Issue: 18 Volume: 34 Year: 2020 Month: 12 X-DOI: 10.1080/09205071.2020.1819443 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1819443 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:18:p:2433-2454 Template-Type: ReDIF-Article 1.0 Author-Name: L. Dinia Author-X-Name-First: L. Author-X-Name-Last: Dinia Author-Name: F. Mangini Author-X-Name-First: F. Author-X-Name-Last: Mangini Author-Name: F. Frezza Author-X-Name-First: F. Author-X-Name-Last: Frezza Title: Electromagnetic scattering between an elliptically inhomogeneous plane wave and a multilayered cylinder Abstract: The interaction of a stratified cylinder with an elliptically inhomogeneous plane wave is introduced and also determined through a rigorous theoretical approach. The scattered electromagnetic field by a multilayered cylinder is investigated through an application of the generalized Vector Cylinder Harmonics (VCH) expansion. The exact mathematical model to represent this scenario considers the so-called complex-angle formalism reaching a superposition of Vectorial Cylindrical-Harmonics and the T-matrix formulation to contemplate the multi-scattering process between the cylinders. The validation of the procedure was accomplished with a comparison between the numerical results obtained with the Finite Element Method (FEM) in Comsol Multiphysics environment and a homemade Matlab code. Journal: Journal of Electromagnetic Waves and Applications Pages: 2455-2466 Issue: 18 Volume: 34 Year: 2020 Month: 12 X-DOI: 10.1080/09205071.2020.1820384 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1820384 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:18:p:2455-2466 Template-Type: ReDIF-Article 1.0 Author-Name: Lamyaa F. A. AL-Barram Author-X-Name-First: Lamyaa F. A. Author-X-Name-Last: AL-Barram Author-Name: Selma M. H. AL-Jawad Author-X-Name-First: Selma M. H. Author-X-Name-Last: AL-Jawad Author-Name: Ali A. Taha Author-X-Name-First: Ali A. Author-X-Name-Last: Taha Author-Name: Natheer Jamal Imran Author-X-Name-First: Natheer Jamal Author-X-Name-Last: Imran Title: Photothermal therapy of cancer cells enhanced by glutathione (GSH) modified small-sized gold nanoparticles Abstract: Small-sized gold nanoparticles (∼3nm) coated with Glutathione (GSH) ligand have designed as an active agent in photothermal therapy (PTT). GSH is pH-sensitive surface that have a fast response property to the variation in pH conditions, especially between normal (∼7.4) and cancer cell (6–6.5), that help the evaluation of the target and toxic effect of the cancer rather than normal cells. Results revealed considerable toxic effects of GSH-AuNPs accumulation in cancer cells for both green and NIR laser irradiation. The GSH-AuNPs represent promising agents for developing the safety issues of photothermal cancer treatment by; the selective targeting of the cancer rather than normal cells, reducing the NPs toxicity by their size overlapping with the renal clearance barrier of kidney filtration (~5.5 nm), and promoting the photothermal performance in the NIR region, in which light penetration into deep cancer regions are more interested. Journal: Journal of Electromagnetic Waves and Applications Pages: 2467-2487 Issue: 18 Volume: 34 Year: 2020 Month: 12 X-DOI: 10.1080/09205071.2020.1822759 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1822759 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:18:p:2467-2487 Template-Type: ReDIF-Article 1.0 Author-Name: Şekip Dalgaç Author-X-Name-First: Şekip Author-X-Name-Last: Dalgaç Author-Name: Murat Furat Author-X-Name-First: Murat Author-X-Name-Last: Furat Author-Name: Muharrem Karaaslan Author-X-Name-First: Muharrem Author-X-Name-Last: Karaaslan Author-Name: Oğuzhan Akgöl Author-X-Name-First: Oğuzhan Author-X-Name-Last: Akgöl Author-Name: Faruk Karadağ Author-X-Name-First: Faruk Author-X-Name-Last: Karadağ Author-Name: Mehmet Zile Author-X-Name-First: Mehmet Author-X-Name-Last: Zile Author-Name: Mehmet Bakir Author-X-Name-First: Mehmet Author-X-Name-Last: Bakir Title: Grease oil humidity sensor by using metamaterial Abstract: Interaction between water and lubrication grease oil is not desirable, but it is not inevitable. The operational life of the machine component is influenced by humid grease oil. Metameterial-based transmission line sensor application is proposed and its operation is validated both numerically and experimentally by inserting grease oil samples in the sample holder. The proposed sensor structure is able to determine the humidity ratio of grease oil samples. The proposed structure shifts resonance frequency to react to the grease oil’s dielectric constant. The frequency shift of grease oil samples is monitored as about 300 MHz’s. Linearity characteristic between resonant frequency and dielectric constant value is validated. The novelty of this article is that no such study has been conducted by employing non-destructive methods which provide long-term stability of the sensor structure. Journal: Journal of Electromagnetic Waves and Applications Pages: 2488-2498 Issue: 18 Volume: 34 Year: 2020 Month: 12 X-DOI: 10.1080/09205071.2020.1824690 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1824690 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:18:p:2488-2498 Template-Type: ReDIF-Article 1.0 Author-Name: Nilesh K. Tiwari Author-X-Name-First: Nilesh K. Author-X-Name-Last: Tiwari Author-Name: S. P. Singh Author-X-Name-First: S. P. Author-X-Name-Last: Singh Author-Name: M. Jaleel Akhtar Author-X-Name-First: M. Jaleel Author-X-Name-Last: Akhtar Title: Novel substrate integrated waveguide cavity-based unified multiband permittivity and permeability estimation approach Abstract: A novel approach of multiband real permittivity and permeability estimation of the magnetic composites using a modified under coupled multimodal (TE10p) substrate integrated waveguide (SIW) cavity is presented. The proposed schemes allow the accurate wideband microwave characterization of the magneto-dielectric composites by using the higher-order modes of the designed SIW cavity. The analytical closed-form modified formulation is developed to calculate the permittivity and permeability over the wide frequency range, 10–20 GHz. Consequently, a unified empirical formulation is also developed, which can be used to generate the approximate prior values of multimodal permittivity and permeability for the synthesized magnetic composites, which is usually not known in advance. The proposed analytical and empirical approaches are validated numerically and experimentally, corresponding to various test samples. The estimated parameters using the proposed analytical approach are found to be in quite close agreement, error <5%, with the corresponding reference values and empirically generated values. Journal: Journal of Electromagnetic Waves and Applications Pages: 2499-2513 Issue: 18 Volume: 34 Year: 2020 Month: 12 X-DOI: 10.1080/09205071.2020.1825995 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1825995 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:18:p:2499-2513 Template-Type: ReDIF-Article 1.0 Author-Name: Ghulam Fatima Kakepoto Author-X-Name-First: Ghulam Fatima Author-X-Name-Last: Kakepoto Author-Name: Shao-Qiu Xiao Author-X-Name-First: Shao-Qiu Author-X-Name-Last: Xiao Author-Name: Farman Ali Mangi Author-X-Name-First: Farman Ali Author-X-Name-Last: Mangi Title: Circularly polarized scanning phased array antenna based on circular polarizer Abstract: A circularly polarized (CP) scanning phased array antenna based on circular polarizer is proposed. An efficient technique is developed to introduce the novel scheme of the designed patch antenna and circular polarizer, which are coupled with a small gap. The new approach of fission transmission of electromagnetic (FTEM) wave is developed to transform linear-to-circularly polarized waves. The designed structure is composed of a 2×8 double-layer array with a small gap, which enhances the wide-angle beam scanning capability of ± 20° with high gain at distinct frequencies. The axial ratio (AR) is below 3 dB and exhibits a 4.80% bandwidth from 5.14 GHz to 5.36 GHz with a 13 dBic maximum gain. This new concept is theoretically and experimentally investigated to evaluate the performance of the proposed structure. The proposed structure shows promising potential for applications in radar and satellite communication systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 2514-2526 Issue: 18 Volume: 34 Year: 2020 Month: 12 X-DOI: 10.1080/09205071.2020.1828180 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1828180 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:18:p:2514-2526 Template-Type: ReDIF-Article 1.0 Author-Name: Zahra Bahrami Author-X-Name-First: Zahra Author-X-Name-Last: Bahrami Author-Name: Asghar Keshtkar Author-X-Name-First: Asghar Author-X-Name-Last: Keshtkar Author-Name: Ayaz Ghorbani Author-X-Name-First: Ayaz Author-X-Name-Last: Ghorbani Author-Name: Hector Esteban Author-X-Name-First: Hector Author-X-Name-Last: Esteban Title: Efficient analysis of metal and dielectric rods in rectangular waveguide with ferrite magnetized transversely Abstract: This paper presents a new analytical method based on mode matching technique for a waveguide full of anisotropic material with rods. It is proved that mode matching technique is applicable for the waveguide with anisotropic materials. The problem is considered as a 2D electromagnetic problem assuming no field variation normal to the waveguide length. Incident and scattered fields from circular cylinder rods in ferrite medium are expanded with cylindrical modes, and the fields in the waveguide ports are expanded using progressive and regressive modal summations. In both regions, extraordinary wave number is considered for the fields. Finally, the hybrid mode matching between guided and cylindrical modes is done by projecting continuity equations in the circular boundary containing the rod. The fast Fourier transform is used to solve the matching in the presented method. It is shown, that the new method runs faster than commercial software packages, with very good accuracy. Journal: Journal of Electromagnetic Waves and Applications Pages: 141-153 Issue: 2 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1690589 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1690589 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:2:p:141-153 Template-Type: ReDIF-Article 1.0 Author-Name: Sahar Saleh Author-X-Name-First: Sahar Author-X-Name-Last: Saleh Author-Name: Widad Ismail Author-X-Name-First: Widad Author-X-Name-Last: Ismail Author-Name: Intan Sorfina Zainal Abidin Author-X-Name-First: Intan Sorfina Author-X-Name-Last: Zainal Abidin Author-Name: Mohd Haizal Jamaluddin Author-X-Name-First: Mohd Haizal Author-X-Name-Last: Jamaluddin Author-Name: Samir Ahmed Al-Gailani Author-X-Name-First: Samir Ahmed Author-X-Name-Last: Al-Gailani Author-Name: Asem S. Alzoubi Author-X-Name-First: Asem S. Author-X-Name-Last: Alzoubi Author-Name: Mohammed Hussein Bataineh Author-X-Name-First: Mohammed Hussein Author-X-Name-Last: Bataineh Title: Nonuniform compact Ultra-Wide Band Wilkinson power divider with different unequal split ratios Abstract: A compact Ultra-Wide Band (UWB) Wilkinson power divider with different unequal split ratios of 2:1 and 3:1 using three optimized resistors is analyzed, designed and fabricated in this study. A 31.1% size reduction in each λ/4 uniform transmission line (UTL) of the divider is achieved by applying non-uniform transmission lines (NTLs) theory. The proposed divider is contributed to be suitable as a feeder to currently used wireless communication networks such as cognitive radios (CR), resulting in good impedance matching to its entire ports. In addition, the optimized resistors used provided good isolation between the output ports. The simulation is carried out in this study uses High Frequency Structure Simulator (HFSS) software. The simulation results are compared with the hardware measurements to validate the results. It was observed that there was approximately 5% of the difference between simulated and hardware measurements which is within the acceptable limit. Journal: Journal of Electromagnetic Waves and Applications Pages: 154-167 Issue: 2 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1691944 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1691944 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:2:p:154-167 Template-Type: ReDIF-Article 1.0 Author-Name: Hager Shawky Fouda Author-X-Name-First: Hager Shawky Author-X-Name-Last: Fouda Author-Name: Amr Hussein Hussein Abdullah Author-X-Name-First: Amr Hussein Hussein Author-X-Name-Last: Abdullah Title: Practical implementation of real-time cognitive radio energy detector using frequency reconfigurable filtenna Abstract: In this paper, a new design of cognitive radio (CR) system based on a reconfigurable filtenna, RF power detector, and Raspberry pi is proposed. It provides a fast and cheap solution to efficiently detect the spectrum holes over the frequency range from 2.37 to 3.69 GHz. The frequency scanning is performed by using a compact narrow bandwidth filtenna. The electrical frequency reconfiguration is achieved by incorporating a varactor diode into the filtenna structure. Under the control of Raspberry pi, the frequency tuning is done by varying the voltage across the varactor from 0 to 30 Volts. Followed by the filtenna, an RF power detector circuit is utilized to monitor the primary user (PU) existence. Different scenarios of measurements are carried out to verify the reliability and successfulness of the proposed prototype. Journal: Journal of Electromagnetic Waves and Applications Pages: 168-182 Issue: 2 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1692699 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1692699 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:2:p:168-182 Template-Type: ReDIF-Article 1.0 Author-Name: Zhengdong Qi Author-X-Name-First: Zhengdong Author-X-Name-Last: Qi Author-Name: Yechao Bai Author-X-Name-First: Yechao Author-X-Name-Last: Bai Author-Name: Qiong Wang Author-X-Name-First: Qiong Author-X-Name-Last: Wang Author-Name: Xinggan Zhang Author-X-Name-First: Xinggan Author-X-Name-Last: Zhang Author-Name: Hao Chen Author-X-Name-First: Hao Author-X-Name-Last: Chen Title: Synthesis of pattern reconfigurable sparse arrays via sequential convex optimizations for monopulse radar applications Abstract: In this paper, a new array synthesis approach is developed for the design of reconfigurable sparse arrays radiating sum and difference patterns. The proposed approach provides a significant reduction in the complexity of the beam forming network, which is fulfilled by reducing the number of antenna elements in the array and sharing some excitation weights for the sum and difference channels. An iterative scheme is used where the prescribed pattern response in the mainlobe is cast as a multi-convex problem at each step that the nonconvex lower bound constraint is relaxed while including a reweighted $l_{1} $l1-norm minimization based on the magnitudes of the elements. Thus a better performance of beam pattern (e.g. narrower 3-dB beamwidth, lower maximum sidelobe levels) and a smaller number of elements can be obtained compared with the case of uniformly spaced array. The practical array imperfections are also compensated in the optimization stage by using worst-case performance optimization technique. Numerical tests are presented and discussed to validate the versatility and effectiveness of the proposed approach. Journal: Journal of Electromagnetic Waves and Applications Pages: 183-200 Issue: 2 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1693910 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1693910 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:2:p:183-200 Template-Type: ReDIF-Article 1.0 Author-Name: Ashok Bansiwal Author-X-Name-First: Ashok Author-X-Name-Last: Bansiwal Author-Name: Sushil Raina Author-X-Name-First: Sushil Author-X-Name-Last: Raina Author-Name: K. J. Vinoy Author-X-Name-First: K. J. Author-X-Name-Last: Vinoy Author-Name: Subrata Kumar Datta Author-X-Name-First: Subrata Kumar Author-X-Name-Last: Datta Title: Analysis for unloaded quality factor of a rectangular double-reentrant cavity with circular cylindrical ferrule for klystron using Wheeler’s incremental inductance rule Abstract: Closed-form formulation for the estimation of equivalent circuit capacitance and inductance of a rectangular double-reentrant klystron cavity with circular cylindrical ferrules was developed and used for arriving at the resonant frequency of the cavity. The closed-form expression for the cavity inductance and resonant frequency were subsequently used for estimating unloaded quality factor of the cavity using Wheeler’s incremental inductance rule. The proposed analysis was validated against 3D electromagnetic analysis and measurements for a typical rectangular klystron cavity operating in C-X-bands. Journal: Journal of Electromagnetic Waves and Applications Pages: 201-212 Issue: 2 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1694449 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1694449 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:2:p:201-212 Template-Type: ReDIF-Article 1.0 Author-Name: Wenyi Shao Author-X-Name-First: Wenyi Author-X-Name-Last: Shao Author-Name: Beibei Zhou Author-X-Name-First: Beibei Author-X-Name-Last: Zhou Title: 3-D experimental UWB microwave imaging in dispersive media Abstract: Three-dimensional (3D) microwave imaging in very dispersive media using a phase shift and sum (PSAS) algorithm is presented. The phase shift and amplitude attenuation within the dispersive media are compensated individually for each frequency component and then integrated to calculate the pixel values in the region of interest (ROI). Therefore, the multi-speed and multipath issue when an ultra-wide band (UWB) signal propagates in the dispersive media is overcome. The current approach is validated by lab-collected data using our self-developed 3-D UWB microwave measurement system. Image results are compared with prior arts at the end of this paper. Journal: Journal of Electromagnetic Waves and Applications Pages: 213-223 Issue: 2 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1696713 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1696713 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:2:p:213-223 Template-Type: ReDIF-Article 1.0 Author-Name: V. Zemlyakov Author-X-Name-First: V. Author-X-Name-Last: Zemlyakov Author-Name: M. Tyaglov Author-X-Name-First: M. Author-X-Name-Last: Tyaglov Author-Name: V. Shevchenko Author-X-Name-First: V. Author-X-Name-Last: Shevchenko Title: Compact quasi-elliptic waveguide filters on contoured resonant diaphragms Abstract: We present a new type of waveguide bandpass quasi-elliptic filter whose resonators are implemented by thin transverse resonant diaphragms with an aperture in the form of a rectangular window with two metal L-shaped ridges. It is shown that the amplitude–frequency characteristics of such contoured diaphragms demonstrate the frequencies of parallel and series resonances simultaneously. We also construct equivalent circuits of the third and fifth-order elliptic filters and provide a computer simulation of the diaphragms satisfying the amplitude–frequency characteristics of each resonator. It is shown that for waveguide elliptic filters, some resonators can be located on one resonant diaphragm, which further reduces the length of the filter. The synthesis results of compact quasi-elliptic filters for WR137 rectangular waveguide with the central frequency of 6.5 GHz and bandwidth of 7.5% are presented. The total length of the filters is 34 mm for third order and 64 mm for fifth order, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 224-234 Issue: 2 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1697379 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1697379 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:2:p:224-234 Template-Type: ReDIF-Article 1.0 Author-Name: Pranita Manish Potey Author-X-Name-First: Pranita Manish Author-X-Name-Last: Potey Author-Name: Kushal Tuckley Author-X-Name-First: Kushal Author-X-Name-Last: Tuckley Title: Design of wearable textile antenna for low back radiation Abstract: In this paper, the back radiation incident on-body tissue due to wearable antennas is investigated. The research is directed toward reducing the “Main lobe to back lobe power ratio” for the wearable antennas. The radiated power of the wearable antenna is being increased to achieve communication over longer distances. It is important to keep the back radiation well below the SAR for human safety. The paper presents a representative case of an antenna operating at 2.45 GHz (ISM band) and illustrates design improvisations to reduce the back radiation. The experimental results are substantiated by computing the SAR impact with two “human body tissue models” for human upper arm (humerus) and the back. The results are compared with advanced techniques like EBG. Journal: Journal of Electromagnetic Waves and Applications Pages: 235-245 Issue: 2 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1699170 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1699170 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:2:p:235-245 Template-Type: ReDIF-Article 1.0 Author-Name: Alexandra Marsenić Author-X-Name-First: Alexandra Author-X-Name-Last: Marsenić Title: Understanding 1D magnetotelluric apparent resistivity and phase Abstract: A novel approach is applied on 1D magnetotelluric problem, based purely on physical considerations of processes on a layered half-space. Relations for apparent resistivity and impedance phase as functions of frequency were derived on grounds of knowledge of a given model. These are considered to be the best benefit coming from the analysis. Two different systems of a layered half-space were examined theoretically and the results were compared with those gained by the traditionally used recursion formula. The obtained dependences faithfully reflect all prescribed physical features. Understanding of these behaviours can significantly contribute to correct interpretation of measured data. Inflection points of the impedance phase appeared to be the proper diagnostic tool for detection of transitions in conductivity. They provide the pairs frequency – apparent resistivity as an input for inversion. It relies on the derived formulas and for well localized changes gives output in the form of layers' thicknesses and their resistivities. Journal: Journal of Electromagnetic Waves and Applications Pages: 246-258 Issue: 2 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1699452 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1699452 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:2:p:246-258 Template-Type: ReDIF-Article 1.0 Author-Name: G. Gopikrishnan Author-X-Name-First: G. Author-X-Name-Last: Gopikrishnan Author-Name: Z. Akhter Author-X-Name-First: Z. Author-X-Name-Last: Akhter Author-Name: Vikesh S. Bhadouria Author-X-Name-First: Vikesh S. Author-X-Name-Last: Bhadouria Author-Name: M. J. Akhtar Author-X-Name-First: M. J. Author-X-Name-Last: Akhtar Title: Microwave imaging of hidden crevasse in glacier terrain using metamaterial loaded eight-slot Vivaldi antenna Abstract: In this paper, a novel microwave imaging methodology based on the simplified experimental setup for identifying hidden crevasse in a glacier or polar terrain is proposed. For scanning the glacier terrain, a new eight-slot Vivaldi antenna (ESVA) with high directivity (16 dBi) and wide bandwidth is proposed. The proposed antenna is designed for the wide frequency range of 1.5–10.5 GHz in order to achieve the improved spatial resolution for the detection of the hidden crevasse. To improve the lower frequency response (1.5–6 GHz), a novel anisotropic zero-index metamaterial (AZIM) cell is introduced. By placing the AZIM cells on the proposed ESVA, a further 2 dB increase in the directivity is achieved. The proposed antenna is designed and simulated using the CST Microwave studio, and its various parameters are optimized for better performance. The designed antenna is then fabricated on the FR-4 substrate, and its matching performance and the far-field characteristics are measured. Later, the designed antenna along with the associated microwave components is used to image the glacier-like situation in the laboratory environment. The glacier terrain in the present situation is emulated using the hard-plastic plates denoting the ice, buried inside fine sand particles representing the snow. It is found that the designed antenna, along with the simple imaging methodology proposed in this work, can conveniently be used to locate hidden crevasse in the glacier terrain. Journal: Journal of Electromagnetic Waves and Applications Pages: 259-274 Issue: 2 Volume: 34 Year: 2020 Month: 1 X-DOI: 10.1080/09205071.2019.1699451 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1699451 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:2:p:259-274 Template-Type: ReDIF-Article 1.0 Author-Name: Arun Kumar Author-X-Name-First: Arun Author-X-Name-Last: Kumar Author-Name: Mohammad S. Hashmi Author-X-Name-First: Mohammad S. Author-X-Name-Last: Hashmi Author-Name: Abdul Q. Ansari Author-X-Name-First: Abdul Q. Author-X-Name-Last: Ansari Author-Name: Sultangali Arzykulov Author-X-Name-First: Sultangali Author-X-Name-Last: Arzykulov Title: Haar wavelet based algorithm for solution of second order electromagnetic problems in time and space domains Abstract: In this paper, a novel wavelet algorithm has been proposed for solving second order electromagnetic problems both in time and space domains. The algorithm has been used to solve four different problems, i.e. the transmission line problem, the problems associated with electromagnetic waves travelling in different media, the problem related to uniform plane wave in lossy dielectric and problem associated with the telegrapher's equation. The comparison between the results obtained using the proposed approach and the conventional numerical techniques demonstrate that the proposed technique exhibits better time complexity. In essence, the proposed algorithm possesses complexity of order $O(n) $O(n) whereas the conventional technique possesses complexity order of $O(n^2) $O(n2). Furthermore, the memory requirement of the proposed algorithm is significantly lower when compared to the conventional technique. Journal: Journal of Electromagnetic Waves and Applications Pages: 362-374 Issue: 3 Volume: 34 Year: 2020 Month: 2 X-DOI: 10.1080/09205071.2020.1713225 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1713225 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:3:p:362-374 Template-Type: ReDIF-Article 1.0 Author-Name: Jakob W. Kunzler Author-X-Name-First: Jakob W. Author-X-Name-Last: Kunzler Author-Name: Jacob M. Bartschi Author-X-Name-First: Jacob M. Author-X-Name-Last: Bartschi Author-Name: Karl F. Warnick Author-X-Name-First: Karl F. Author-X-Name-Last: Warnick Title: Compact structure with high TX-RX isolation for frequency domain duplexing on printed circuit boards Abstract: When developing compact and lightweight antenna systems for unmanned aerial systems, achieving high isolation between transmit and receive signal paths is challenging. To address this issue, we demonstrate a prototype isolation design on a printed circuit board for a frequency division duplexed X band antenna system. Key components include a microstrip defected ground plane notch filter and a copper grating barrier that provides 20 dB higher isolation than free space separation between the transmit and receive antennas. The hardware provides at least 105 dB of transmit isolation into the receiver low noise amplifier in the transmit band. The proposed design is lighter and more compact than traditional machined metal waveguide isolation techniques used for ground-based systems yet achieves similar isolation performance. Journal: Journal of Electromagnetic Waves and Applications Pages: 390-395 Issue: 3 Volume: 34 Year: 2020 Month: 2 X-DOI: 10.1080/09205071.2020.1715267 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1715267 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:3:p:390-395 Template-Type: ReDIF-Article 1.0 Author-Name: Rafael Julius Author-X-Name-First: Rafael Author-X-Name-Last: Julius Author-Name: Mansoor Zahirzai Author-X-Name-First: Mansoor Author-X-Name-Last: Zahirzai Author-Name: Abdel-Baset M. A. Ibrahim Author-X-Name-First: Abdel-Baset M. A. Author-X-Name-Last: Ibrahim Author-Name: Hichem Eleuch Author-X-Name-First: Hichem Author-X-Name-Last: Eleuch Author-Name: Pankaj K. Choudhury Author-X-Name-First: Pankaj K. Author-X-Name-Last: Choudhury Title: Single- and compound-mode squeezing in nonlinear coupler with frequency mismatch Abstract: The properties of squeezing, in relation to the different interaction frequencies of the input modes in three-mode Kerr nonlinear coupler consisting of two linearly-coupled Kerr waveguides, were explored. Utilizing the exact representation of a set of noisy-stochastic equations, an investigation was made of the first-order properties of squeezing for two- and three-mode interactions with frequency mismatch. It was observed that enhanced squeezing could be obtained under certain conditions of interactions. Journal: Journal of Electromagnetic Waves and Applications Pages: 301-315 Issue: 3 Volume: 34 Year: 2020 Month: 2 X-DOI: 10.1080/09205071.2019.1702591 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1702591 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:3:p:301-315 Template-Type: ReDIF-Article 1.0 Author-Name: S. H. H. Mashhadi Author-X-Name-First: S. H. H. Author-X-Name-Last: Mashhadi Author-Name: Yong-Chang Jiao Author-X-Name-First: Yong-Chang Author-X-Name-Last: Jiao Author-Name: Jingdong Chen Author-X-Name-First: Jingdong Author-X-Name-Last: Chen Title: Wide 3-dB beamwidth step-walled rectangular dielectric resonator antenna Abstract: Wide angular coverage antennas despite being a requirement for many recent safety applications are a design challenge. Applications like Automotive Radars, GPS and telemetry all need an antenna with wide half-power beamwidths in both principal planes. A novel broadbeam aperture-coupled step-walled rectangular dielectric resonator antenna is proposed. The antenna consists of a central widest ceramic plate with two plates on each side with decreased widths creating stepped or staircase like walls. The dielectric resonator is centered over the feed slot. Two modes $TE^x_{111} $TE111x and $TE^x_{113} $TE113x are simultaneously excited. The antenna is shown to yield broadbeam radiation patterns at frequencies between Mode-I and Mode-III resonances. To validate the principal, a prototype is fabricated and measured. The antenna has measured operating frequency band ranging from 5.75 GHz to 7.23 GHz with broadbeam frequency band from 6.1 to 6.6 GHz. The measured xoz and yoz beamwidths range from $120^{\circ } $120∘ to $132^{\circ } $132∘ with measured gain from 4.5 dB to 5.5 dB in the broadbeam band. Journal: Journal of Electromagnetic Waves and Applications Pages: 349-361 Issue: 3 Volume: 34 Year: 2020 Month: 2 X-DOI: 10.1080/09205071.2020.1713224 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1713224 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:3:p:349-361 Template-Type: ReDIF-Article 1.0 Author-Name: Deepika Singh Author-X-Name-First: Deepika Author-X-Name-Last: Singh Author-Name: Rana Pratap Yadav Author-X-Name-First: Rana Pratap Author-X-Name-Last: Yadav Title: A 3-D printed square loop frequency selective surface for harmonic radar applications Abstract: This paper presents a 3-D printed frequency selective surface (FSS) for harmonic radar applications. The proposed FSS design consists of a square loop printed on the cost-effective acrylonitrile butadiene styrene (ABS) plastic material to pass the signals at 5 GHz resonant frequency band. The proposed FSS is tested for various oblique angles up to 45° and even for different polarization modes. A prototype of the proposed design FSS is fabricated. The results demonstrate a good agreement of simulated results with experimental ones. The 3-D printing technique provides a simple and low-cost method to fabricate FSS and make it suitable for future FSS mass production. Journal: Journal of Electromagnetic Waves and Applications Pages: 396-406 Issue: 3 Volume: 34 Year: 2020 Month: 2 X-DOI: 10.1080/09205071.2020.1719213 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1719213 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:3:p:396-406 Template-Type: ReDIF-Article 1.0 Author-Name: Cheng Zhang Author-X-Name-First: Cheng Author-X-Name-Last: Zhang Author-Name: Mengde Cao Author-X-Name-First: Mengde Author-X-Name-Last: Cao Author-Name: Yang Li Author-X-Name-First: Yang Author-X-Name-Last: Li Author-Name: Yuqin Gong Author-X-Name-First: Yuqin Author-X-Name-Last: Gong Author-Name: Yongming Huang Author-X-Name-First: Yongming Author-X-Name-Last: Huang Title: Velocity ambiguity resolution for wideband automotive millimeter wave radar: a carrier frequency multiplexing framework Abstract: Wideband millimeter-wave (mmWave) radars perform sensing for automotive applications. For the velocity ambiguity in automotive mmWave radars, a resolution scheme is proposed via exploiting carrier frequency multiplexing. Compared with conventional auxiliary signal-based schemes, the proposed scheme only needs one set of main frequency modulated continuous wave (FMCW) signal. After collecting a part of the main signal as the sub-signal, the ambiguity is resolved via using the carrier-frequency difference between these two signals, resulting in higher time utilization efficiency. Meanwhile, the target information from the main signal is utilized to calculate the discrete Fourier transform (DFT) coefficient and a two-dimensional DFT is performed on the sub-signal for the ambiguity resolution. Thus, the procedures including fast Fourier transform (FFT), detection and estimation for the auxiliary signal in conventional schemes are avoided, which reduces the computational complexity. Simulations verify the effectiveness of the proposed scheme. Journal: Journal of Electromagnetic Waves and Applications Pages: 375-389 Issue: 3 Volume: 34 Year: 2020 Month: 2 X-DOI: 10.1080/09205071.2020.1713226 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1713226 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:3:p:375-389 Template-Type: ReDIF-Article 1.0 Author-Name: Changsheng Liu Author-X-Name-First: Changsheng Author-X-Name-Last: Liu Author-Name: Ming Zhang Author-X-Name-First: Ming Author-X-Name-Last: Zhang Author-Name: Jinfa Ma Author-X-Name-First: Jinfa Author-X-Name-Last: Ma Author-Name: Haigen Zhou Author-X-Name-First: Haigen Author-X-Name-Last: Zhou Author-Name: Jie Liang Author-X-Name-First: Jie Author-X-Name-Last: Liang Author-Name: Jun Lin Author-X-Name-First: Jun Author-X-Name-Last: Lin Title: Divergence of tipper vector imaging for ground–airborne frequency-domain electromagnetic method with orthogonal sources Abstract: The ground–airborne frequency–domain electromagnetic (GAFDEM) method is a recently developed rapid detection approach for underground structures. However, the conventional apparent resistivity imaging in this method cannot meet the requirements of high precision and high efficiency detection for 3D targets. Therefore, we introduce the divergence of tipper vector (DTV) imaging to solve this problem with two orthogonal sources. First, we define DTV for the GAFDEM method, and then, we analyze the characteristics, advantages, and detection principles of DTV imaging using 3D models. Incorporating DTV imaging into the GAFDEM method allows us to directly distinguish the resistivity properties, position, and direction of an anomalous body more clearly and in less computing time, relative to apparent resistivity imaging. Thus, DTV imaging provides a fast detection method with high detection precision for a 3D anomalous body. This may effectively promote the development and application of the GAFDEM method and systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 316-329 Issue: 3 Volume: 34 Year: 2020 Month: 2 X-DOI: 10.1080/09205071.2019.1704890 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1704890 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:3:p:316-329 Template-Type: ReDIF-Article 1.0 Author-Name: N. Mabrouk Author-X-Name-First: N. Author-X-Name-Last: Mabrouk Author-Name: Moh’d Yasein Author-X-Name-First: Moh’d Author-X-Name-Last: Yasein Author-Name: K. Lotfy Author-X-Name-First: K. Author-X-Name-Last: Lotfy Author-Name: A.A. El-Bary Author-X-Name-First: A.A. Author-X-Name-Last: El-Bary Title: Effect of magneto-rotator-diffusive waves on the photothermal excitation medium of a dual-phase-lag model and variable thermal conductivity Abstract: The thermal variable conductivity of a rotator semiconductor elastic medium is investigated. The medium is exposed to beams of light and an initial external magnetic field during a diffusion process. The governing equations cover the overlapping between the wave propagations of mechanical, thermal, plasma and mass diffusion distributions. The reflection wave will be obtained in the context of the thermoelasticity theory and photothermal theory. The harmonic wave analysis is used to obtain the coefficient ratios of reflection analytically of the incident wave (CI) and incident rotational wave. On the free surface of the semiconductor medium, some mechanical, plasma and thermal loads are applied to observe the physical quantities of this phenomenon. The different values of the amplitude of reflection coefficient ratios and the incidence angle are obtained numerically and shown graphically. The comparisons between the obtained results will be studied under the influence of the magnetic field, the variable thermal conductivity and rotation. Journal: Journal of Electromagnetic Waves and Applications Pages: 330-348 Issue: 3 Volume: 34 Year: 2020 Month: 2 X-DOI: 10.1080/09205071.2019.1708813 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1708813 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:3:p:330-348 Template-Type: ReDIF-Article 1.0 Author-Name: Jianchun Xu Author-X-Name-First: Jianchun Author-X-Name-Last: Xu Author-Name: Yaxian Guo Author-X-Name-First: Yaxian Author-X-Name-Last: Guo Author-Name: Puyu Yang Author-X-Name-First: Puyu Author-X-Name-Last: Yang Author-Name: Ru Zhang Author-X-Name-First: Ru Author-X-Name-Last: Zhang Author-Name: Xiaojun Zhai Author-X-Name-First: Xiaojun Author-X-Name-Last: Zhai Author-Name: Shanguo Huang Author-X-Name-First: Shanguo Author-X-Name-Last: Huang Author-Name: Ke Bi Author-X-Name-First: Ke Author-X-Name-Last: Bi Title: Recent progress on RF orbital angular momentum antennas Abstract: In the last five years or so, there has been a great interest in RF OAM to address the contradiction between the lack of wireless spectrum resources and the continually growing demands of the bandwidth. Recent developments and technological advancements in antenna design, material science, and integrated circuits have enabled miniaturized, multiple modes, tunable in radio frequency (RF) orbital angular momentum (OAM) antenna designs. From conventional methods such as spiral phase plate and reflector antenna to antenna array and metasurface, the working principle and structures are introduced. To improve the performance of RF OAM antennas, several innovative physical concepts have been explored for the designs of RF OAM antenna designs. In this paper, we present an up-to-date survey on the development of RF OAM antenna technologies. Open issues and development trends are explored as a source of inspiration towards the future better outcome of RF OAM antenna designs. Journal: Journal of Electromagnetic Waves and Applications Pages: 275-300 Issue: 3 Volume: 34 Year: 2020 Month: 2 X-DOI: 10.1080/09205071.2019.1708814 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1708814 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:3:p:275-300 Template-Type: ReDIF-Article 1.0 Author-Name: Prabhat Thakur Author-X-Name-First: Prabhat Author-X-Name-Last: Thakur Author-Name: G. Singh Author-X-Name-First: G. Author-X-Name-Last: Singh Title: Power management for spectrum sharing in cognitive radio communication system: a comprehensive survey Abstract: The underlay spectrum access is a very prominent technique in cognitive radio (CR) communication systems in which the primary users (PUs) share the spectrum with the cognitive users (CUs), simultaneously. However, the PU communication is protected by constraining the CUs' transmission power in such a way that the interference power introduced at the PU receiver is under the tolerable limits. In this comprehensive survey, we have presented the general framework of CR communication technology and emphasized on the spectrum accessing and sharing techniques. Various approaches of the optimal power allocation to CUs, namely, the game theory, price auction, convex optimization and iterative water-filling are presented. Moreover, to address the random nature of channel, the performance metrics analysis with the perfect and imperfect channel state information is also illustrated. Finally, the potential issues and research challenges for power management in the CR communication systems are presented which need to be explored. Journal: Journal of Electromagnetic Waves and Applications Pages: 407-461 Issue: 4 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1716858 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1716858 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:4:p:407-461 Template-Type: ReDIF-Article 1.0 Author-Name: Saeed Ur Rahman Author-X-Name-First: Saeed Author-X-Name-Last: Ur Rahman Author-Name: Faisal Amin Author-X-Name-First: Faisal Author-X-Name-Last: Amin Author-Name: Afzal Ahmed Author-X-Name-First: Afzal Author-X-Name-Last: Ahmed Author-Name: Wang Yi Author-X-Name-First: Wang Author-X-Name-Last: Yi Author-Name: Qunsheng Cao Author-X-Name-First: Qunsheng Author-X-Name-Last: Cao Title: Comment on “A novel ultrathin wideband metamaterial absorber for X-band applications” Abstract: Recently, Ranjan et al. [A novel ultrathin wideband metamaterial absorber for X-band applications. J Electromagn Waves Appl. 2019;33:2341–2353. DOI:10.1080/09205071.2019.1681299] have designed a wideband metamaterial absorber for X-band applications. In this comment, we demonstrate that a linear reflective polarization converter is erroneously interpreted as a wideband metamaterial absorber by Ranjan et al. They have shown that the proposed structure is a metamaterial absorber due to the ignorance of cross-polarized component of the reflected wave. Furthermore, we have shown that due to anisotropic geometry and high cross-polarization of the reflected wave, the proposed design is a cross-polarization converter. Journal: Journal of Electromagnetic Waves and Applications Pages: 462-467 Issue: 4 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1719214 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1719214 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:4:p:462-467 Template-Type: ReDIF-Article 1.0 Author-Name: Yunnan Jin Author-X-Name-First: Yunnan Author-X-Name-Last: Jin Author-Name: Jaehoon Choi Author-X-Name-First: Jaehoon Author-X-Name-Last: Choi Title: Gain-enhanced PEC reflector backed slot-loop antenna Abstract: This paper proposes a low-cost, gain-enhanced, wideband, perfect electric conductor (PEC) reflector backed antenna. The proposed antenna consists of a rectangular loop with an internal inset-fed rectangular patch, a pair of symmetrical L-shaped interdigitated radiating branches, and a PEC reflector. The antenna has compact dimensions of 36 mm × 17.5 mm × 7.2 mm. The proposed antenna satisfies a −10 dB reflection coefficient bandwidth from 7.94 GHz to 14.45 GHz. To understand the operating principle of the proposed antenna, this paper presents a modal analysis. The gain performance is improved by using the constructive superposition of in-phase electromagnetic energy from the side edges of the rectangular loop and the two vertical edges of the radiating branches. In addition, the experimental and simulated results of the proposed antenna are in good agreement. Journal: Journal of Electromagnetic Waves and Applications Pages: 468-482 Issue: 4 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1721336 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1721336 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:4:p:468-482 Template-Type: ReDIF-Article 1.0 Author-Name: Fedir O. Yevtushenko Author-X-Name-First: Fedir O. Author-X-Name-Last: Yevtushenko Author-Name: Sergii V. Dukhopelnykov Author-X-Name-First: Sergii V. Author-X-Name-Last: Dukhopelnykov Author-Name: Alexander I. Nosich Author-X-Name-First: Alexander I. Author-X-Name-Last: Nosich Title: H-polarized plane-wave scattering by a PEC strip grating on top of a dielectric substrate: analytical regularization based on the Riemann-Hilbert Problem solution Abstract: We consider the H-polarized plane wave scattering from an infinite flat grating of perfectly electrically conducting strips, placed on the interface of a dielectric slab. We reduce this problem to a dual series equation for the complex amplitudes of the Floquet spatial harmonics. Then, we perform analytical regularization of this equation, based on the inversion of the static part of the problem with the aid of the Riemann-Hilbert Problem. This yields a Fredholm second-kind infinite matrix equation, numerical solution of which has a guaranteed convergence. Numerical results obtained demonstrate how the rate of convergence depends on the geometrical parameters and then concentrate on the resonance effects in the reflection and transmission. We reveal and discuss ultra-high-Q resonances on the lattice modes of such a composite grating, overlooked in earlier studies. Journal: Journal of Electromagnetic Waves and Applications Pages: 483-499 Issue: 4 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1722258 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1722258 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:4:p:483-499 Template-Type: ReDIF-Article 1.0 Author-Name: Zhijun Tang Author-X-Name-First: Zhijun Author-X-Name-Last: Tang Author-Name: Jie Zhan Author-X-Name-First: Jie Author-X-Name-Last: Zhan Author-Name: Xiaofeng Wu Author-X-Name-First: Xiaofeng Author-X-Name-Last: Wu Author-Name: Zaifang Xi Author-X-Name-First: Zaifang Author-X-Name-Last: Xi Author-Name: Long Chen Author-X-Name-First: Long Author-X-Name-Last: Chen Author-Name: Shigang Hu Author-X-Name-First: Shigang Author-X-Name-Last: Hu Title: Design of a compact UWB-MIMO antenna with high isolation and dual band-notched characteristics Abstract: A compact UWB-MIMO antenna with dual band-notched behaviors is proposed. The bending and E-shaped meander structures are introduced to broaden the bandwidth. Two circular patches are placed orthogonally and dual U-shaped branches are added for reducing the mutual couplings. Dual notches are achieved by embedding two L-shaped slots in the elements. The simulated and measured results show that the antenna has the wider impedance bandwidths of 2.68–12.50 GHz (Element 1) and 2.82–11.20 GHz (Element 2) except two notched bands. The notched bands of 5.12–5.81 GHz and 7.06–8.03 GHz are achieved for the element 1. The notched bands of 5.08–5.83 GHz and 7.02–7.98 GHz are achieved for the element 2. These notched bands accurately cover the WLAN band and X-band. Furthermore, the antenna obtains higher isolation, smaller envelope correlation coefficient, higher radiating efficiency, acceptable peak realized gain, and stable radiation patterns. Therefore, the antenna is suitable for building the UWB-MIMO communication systems with good performance. Journal: Journal of Electromagnetic Waves and Applications Pages: 500-513 Issue: 4 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1724200 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1724200 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:4:p:500-513 Template-Type: ReDIF-Article 1.0 Author-Name: Viktor Timofeev Author-X-Name-First: Viktor Author-X-Name-Last: Timofeev Author-Name: Eduard Vinter Author-X-Name-First: Eduard Author-X-Name-Last: Vinter Author-Name: Anatolii Gulyashinov Author-X-Name-First: Anatolii Author-X-Name-Last: Gulyashinov Title: Plane electromagnetic wave propagation of pulsed periodic field in conductive half-space Abstract: Nowadays, application of pulsed periodic fields in various technological devices is of interest, in particular for the influencing on a conductive media. In this paper solution of the problem of the propagation of a plane electromagnetic wave of pulsed periodic field created by a planar inductor, in the conductive half-space is presented. The solution is obtained in the form of Fourier series as a function of a complex argument. The differential and integral characteristics of the “inductor-conductive half-space” system for different values of the inductor time constant are determined. A comparative analysis of the obtained results with the electromagnetic characteristics of plane sinusoidal electromagnetic wave propagation process in conductive half-space is made. Journal: Journal of Electromagnetic Waves and Applications Pages: 514-523 Issue: 4 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1724570 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1724570 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:4:p:514-523 Template-Type: ReDIF-Article 1.0 Author-Name: Prabhakar Tripathi Author-X-Name-First: Prabhakar Author-X-Name-Last: Tripathi Author-Name: Arjun Kumar Author-X-Name-First: Arjun Author-X-Name-Last: Kumar Author-Name: Smrity Dwivedi Author-X-Name-First: Smrity Author-X-Name-Last: Dwivedi Author-Name: P. K. Jain Author-X-Name-First: P. K. Author-X-Name-Last: Jain Title: Electromagnetic analysis for the side-coupled cavity-type interaction structure for the linear accelerators Abstract: The side-coupled cavity (SCC) structure is widely used in Linac, and also finds its application in the high-power microwave tubes. The SCC structure operating under the slow-wave regime, for the π/2 mode in transverse magnetic mode operation, has been electromagnetically analyzed using field-matching technique for the dispersion and interaction impedance characteristics. Furthermore, the effect of different structural parameters on the dispersion and interaction characteristics has been studied. To validate the developed dispersion and interaction relation, the SCC is simulated using commercially available electromagnetic simulation tools. The results obtained through the developed analytical expression are compared with the simulated results, and it is found to be in agreement within 3%. This analysis will help the design engineer to select the approximate accurate parameters before performing the simulation or experimental design. Also, it helps to develop a better understanding about the SCC’s behavior with respect to structural parameter before the simulation. Journal: Journal of Electromagnetic Waves and Applications Pages: 524-538 Issue: 4 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1724571 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1724571 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:4:p:524-538 Template-Type: ReDIF-Article 1.0 Author-Name: Y. Ben-Ali Author-X-Name-First: Y. Author-X-Name-Last: Ben-Ali Author-Name: A. Ghadban Author-X-Name-First: A. Author-X-Name-Last: Ghadban Author-Name: Z. Tahri Author-X-Name-First: Z. Author-X-Name-Last: Tahri Author-Name: K. Ghoumid Author-X-Name-First: K. Author-X-Name-Last: Ghoumid Author-Name: D. Bria Author-X-Name-First: D. Author-X-Name-Last: Bria Title: Accordable filters by defect modes in single and double negative star waveguides grafted dedicated to electromagnetic communications applications Abstract: In the framework of the Green Function approach, we determine the transmission spectrum and the band structure of detective one-dimensional photonic star waveguides. This structure is composed of backbones’ periodicity that is characterized by negative magnetic permeability μ and positive dielectric permittivity ϵ, grafted in each site by resonators of negative permittivity and positive magnetic permeability. In the middle of the structure, we consider geometrical or/and material defect at the backbone level. The presence of such defect in this structure creates inside the photonic band gaps of the perfect structure, very narrow filtered frequencies (defect modes) with a significant quality factor Q and a very high transmission coefficient. The frequencies of the defect modes are strongly sensitive to the variation of the length and the relative permittivity of the defect. These electromagnetic characteristics of the considered structure provide good information for the design of adjustable wide gap filters. Journal: Journal of Electromagnetic Waves and Applications Pages: 539-558 Issue: 4 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1724830 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1724830 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:4:p:539-558 Template-Type: ReDIF-Article 1.0 Author-Name: Chien-Yuan Pan Author-X-Name-First: Chien-Yuan Author-X-Name-Last: Pan Author-Name: Chum-Chieh Su Author-X-Name-First: Chum-Chieh Author-X-Name-Last: Su Title: CPW-fed modified rhombus slot antenna with circularly polarized radiation for UHF RFID fixed reader application Abstract: A modified rhombus slot antenna using coplanar waveguide (CPW)-fed is presented. The proposed antenna has circularly polarized (CP) radiation in ultra-high frequency band for radio frequency identification fixed reader application. The antenna comprises a straight strip, a modified rhombus slot with a pair of L-shaped grounded strips and a pair of inverted L-shaped extended slots for exciting CP radiation. In this design, the use of the grounded strip and the extended slot were found an effective approach for exciting two resonant modes as well as achieving CP radiation. The experiment results exhibited the broadband CP characteristics including an impedance bandwidth of 34.7% (694–986 MHz) for 10 dB return loss, a CP bandwidth of 26.3% (860–1120 MHz) for 3 dB axial ratio and maximum gain of 5.4 dBic at 860–960 MHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 559-569 Issue: 4 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1724831 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1724831 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:4:p:559-569 Template-Type: ReDIF-Article 1.0 Author-Name: Jingyu Cui Author-X-Name-First: Jingyu Author-X-Name-Last: Cui Author-Name: Anxue Zhang Author-X-Name-First: Anxue Author-X-Name-Last: Zhang Author-Name: Zixian Wu Author-X-Name-First: Zixian Author-X-Name-Last: Wu Author-Name: Sen Yan Author-X-Name-First: Sen Author-X-Name-Last: Yan Title: A frequency reconfigurable filtering antenna based on stepped impedance resonator Abstract: In this paper, a novel frequency reconfigurable filtering antenna is proposed for modern wireless communication systems. The feed network is composed of a stepped impedance resonator filter and a 50-Ω microstrip line. PIN diodes are used to switch the antenna to operate at either an ultra-wideband state or a dual-band state. For the dual-band state, the antenna operates at both 3.35 and 5.2 GHz. The measured results on tuning range, radiation patterns, and realized gains are provided, which show a good agreement with the numerical simulations. Journal: Journal of Electromagnetic Waves and Applications Pages: 571-580 Issue: 5 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1719212 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1719212 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:5:p:571-580 Template-Type: ReDIF-Article 1.0 Author-Name: L. T. P. Bui Author-X-Name-First: L. T. P. Author-X-Name-Last: Bui Author-Name: N. Anselmi Author-X-Name-First: N. Author-X-Name-Last: Anselmi Author-Name: T. Isernia Author-X-Name-First: T. Author-X-Name-Last: Isernia Author-Name: P. Rocca Author-X-Name-First: P. Author-X-Name-Last: Rocca Author-Name: A. F. Morabito Author-X-Name-First: A. F. Author-X-Name-Last: Morabito Title: On bandwidth maximization of fixed-geometry arrays through convex programming Abstract: We propose a new approach to solve the problem of optimal power synthesis of array antennas, so that maximum possible bandwidth can be granted to fixed sidelobe-level performances. The proposed approach can be applied to any kind of fixed-geometry array that radiates pencil beams and to linear equispaced arrays that generate shaped patterns. The designing problem is cast as a sequence of Convex Programming optimizations. Numerous numerical experiments, including full-wave synthesis of realistic antennas, were carried out and their results discussed here to assess the array antennas’ capability of achieving ultra-wideband performances. Journal: Journal of Electromagnetic Waves and Applications Pages: 581-600 Issue: 5 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1724832 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1724832 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:5:p:581-600 Template-Type: ReDIF-Article 1.0 Author-Name: Lyudmila P. Mospan Author-X-Name-First: Lyudmila P. Author-X-Name-Last: Mospan Title: Tri-post resonator in a rectangular waveguide Abstract: A novel three-in-one waveguide resonator is proposed in the paper. The resonator is composed of three rectangular partial-height posts inserted along a rectangular waveguide cross-section. A pair of posts is mounted symmetrically whereas the third antipodal post is centered. The resonator provides a bandstop response if all the posts are of equal height. Both singlet-type and pseudoelliptic characteristics are achieved if one of the posts differs by its height. Both symmetric and asymmetric configurations are considered. Besides, it is demonstrated that the asymmetric resonator acts as a switching waveguide filter providing the ON and the OFF states to allow/block the signal propagation in a narrow vicinity of a given frequency. A parametric numerical study is performed in order to demonstrate a transformation of the response Measurement data are presented for a single-standing resonator and a two-section pseudoelliptic filter in WR90 waveguide. Journal: Journal of Electromagnetic Waves and Applications Pages: 601-611 Issue: 5 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1728392 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1728392 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:5:p:601-611 Template-Type: ReDIF-Article 1.0 Author-Name: Parul Mathur Author-X-Name-First: Parul Author-X-Name-Last: Mathur Author-Name: Amrita Thakur Author-X-Name-First: Amrita Author-X-Name-Last: Thakur Author-Name: Dhanesh G. Kurup Author-X-Name-First: Dhanesh G. Author-X-Name-Last: Kurup Title: An artificial neural network-based non-destructive microwave technique for monitoring fluoride contamination in water Abstract: This article presents a novel non-destructive microwave technique for predicting fluoride contamination in pure water. The proposed microwave-based sensing technique uses an open-ended coaxial probe (OECP) microwave sensor for monitoring fluoride concentration in water. The sensor output is the input of Artificial Neural Network (ANN) for predicting the complex dielectric constant of contaminated water, which has direct correlation with fluoride contamination in water. The ANN is trained through analytically generated sensor output for various lossy liquid materials and tested for experimental data obtained through laboratory prepared samples. Hence, the proposed technique has the capability to compute the amount of fluoride contamination faster, when compared to analysis only method. The results shows that a well-trained ANN is computationally efficient and capable of predicting the amount of fluoride level in the pure water. The results also has good agreement with the data published in the literature at room temperature. Journal: Journal of Electromagnetic Waves and Applications Pages: 612-622 Issue: 5 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1729253 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1729253 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:5:p:612-622 Template-Type: ReDIF-Article 1.0 Author-Name: Youcef Hadj Aissa Fekhar Author-X-Name-First: Youcef Author-X-Name-Last: Hadj Aissa Fekhar Author-Name: Faouzi Salah-Belkhodja Author-X-Name-First: Faouzi Author-X-Name-Last: Salah-Belkhodja Author-Name: Didier Vincent Author-X-Name-First: Didier Author-X-Name-Last: Vincent Author-Name: Enrique Bronchalo Author-X-Name-First: Enrique Author-X-Name-Last: Bronchalo Author-Name: Wassila Tebboune Author-X-Name-First: Wassila Author-X-Name-Last: Tebboune Author-Name: Rafah Naoum Author-X-Name-First: Rafah Author-X-Name-Last: Naoum Title: Microwave non-reciprocal coplanar directional coupler based on ferrite materials Abstract: Magnetized ferrites are anisotropic materials used in passive non-reciprocal components. One of the main applications of ferrites at microwave frequencies is the isolation effect. In this work, the non-reciprocal propagation in a ferrite coplanar coupler is studied from simulation results. The proposed structure exhibits a low insertion loss less than 1 dB, and return loss better than 20 dB, with significant non-reciprocal behavior for through propagation. The design of the non-reciprocal coplanar coupler, based on a magnetized transversally ferrite as substrate dielectric material, is presented. The numerical study allows to describe the component physical behavior. As results, a miniature coupler at 12.50 GHz with a non-reciprocal effect in direct access is better than 35 dB has been designed and simulated. Journal: Journal of Electromagnetic Waves and Applications Pages: 623-633 Issue: 5 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1733102 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1733102 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:5:p:623-633 Template-Type: ReDIF-Article 1.0 Author-Name: H. Helali Author-X-Name-First: H. Author-X-Name-Last: Helali Author-Name: M. Aidi Author-X-Name-First: M. Author-X-Name-Last: Aidi Author-Name: T. Aguili Author-X-Name-First: T. Author-X-Name-Last: Aguili Title: Electromagnetic modelling of multiband frequency reconfigurable antenna for wireless communications Abstract: The present work aims to propose a new formulation by combining the moment method and generalized equivalent circuit's method (MOM-GEC) to study the performance of a frequency reconfigurable antenna commanded by a PIN diode(s) as switching component(s). This method makes it possible to reduce the 3D problems to an alleviate calculation in the discontinuity plane using the admittance operators. The antenna structure is excited by a localized voltage source and the PIN diode is introduced in the mathematical formulation by a surface impedance model. A parametric study is made to achieve a good approximation of PIN diodes longitudinal dimension ensuring the switch operation. Then we focus on the analysis of reconfigurable antennas controlled by one and two PIN diodes. The simulation results are in good agreement with those obtained by software simulation and they show that it is possible to shift the resonant frequency depending on the PIN diode state. Journal: Journal of Electromagnetic Waves and Applications Pages: 634-654 Issue: 5 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1736186 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1736186 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:5:p:634-654 Template-Type: ReDIF-Article 1.0 Author-Name: Lu Yin Author-X-Name-First: Lu Author-X-Name-Last: Yin Author-Name: Peng Yang Author-X-Name-First: Peng Author-X-Name-Last: Yang Author-Name: Yu-yi Gan Author-X-Name-First: Yu-yi Author-X-Name-Last: Gan Title: Microstrip array antenna in-band RCS reduction using polarization reconfigurable elements Abstract: An efficient approach for in-band radar cross section (RCS) reduction of microstrip patch array antenna without employing extra-low RCS artificial materials is proposed and analysed. The element of the array has a simple structure, consisting of a corner-cut square patch and two tiny perturbation elements. By controlling two independently biased PIN diodes, it can produce linear polarization (LP), left- and right-handed circular polarization (LHCP/RHCP) radiation waves. The backscattering RCS reduction of the array can be achieved by changing the polarization status of array elements. For verification, the performance of a $\textrm{7} \times \textrm{7} $7×7 polarization reconfigurable microstrip array with different polarization modes is designed, compared and analysed. From the simulation and measurement results, the peak RCS of the array can be reduced by more than 7 dB without affecting its radiation performance. Journal: Journal of Electromagnetic Waves and Applications Pages: 655-667 Issue: 5 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1736187 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1736187 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:5:p:655-667 Template-Type: ReDIF-Article 1.0 Author-Name: Nguyen Quoc Dinh Author-X-Name-First: Nguyen Quoc Author-X-Name-Last: Dinh Author-Name: Nguyen Thanh Binh Author-X-Name-First: Nguyen Thanh Author-X-Name-Last: Binh Author-Name: Yoshihide Yamada Author-X-Name-First: Yoshihide Author-X-Name-Last: Yamada Author-Name: Naobumi Michishita Author-X-Name-First: Naobumi Author-X-Name-Last: Michishita Title: Proof of the density tapering concept of an unequally spaced array by electric field distributions of electromagnetic simulations Abstract: The design method of an unequally spaced array was based on the density tapering in the textbook “Antenna theory” in 1969. The effects on grating lobe reductions were shown by radiation pattern calculations. However, no proof for the achievement of density tapering was shown. In this paper, through direct comparisons of the objective amplitude distribution with electric field distributions by electromagnetic simulation, density tapering is examined. A log-periodic dipole antenna operating from 900MHz to 2500MHz is designed for the array element. The unequally spaced 31-element array antenna is used for calculation. At many kinds of density tapering and many frequencies, calculated electric field distributions in a near-field region of the array antenna agree with the given density tapering distributions. The paper results show that the density tapering is achieved from 900MHz to 2000MHz and the effects of grating lobe reductions are ensured from 900MHz to 2500MHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 668-681 Issue: 5 Volume: 34 Year: 2020 Month: 3 X-DOI: 10.1080/09205071.2020.1736185 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1736185 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:5:p:668-681 Template-Type: ReDIF-Article 1.0 Author-Name: Susmita Biswas Author-X-Name-First: Susmita Author-X-Name-Last: Biswas Author-Name: Chandan Kumar Ghosh Author-X-Name-First: Chandan Kumar Author-X-Name-Last: Ghosh Author-Name: Soumen Banerjee Author-X-Name-First: Soumen Author-X-Name-Last: Banerjee Author-Name: Santimoy Mandal Author-X-Name-First: Santimoy Author-X-Name-Last: Mandal Author-Name: Durbadal Mandal Author-X-Name-First: Durbadal Author-X-Name-Last: Mandal Title: High port isolation of a dual polarized microstrip antenna array using DGS Abstract: In this paper, high port isolation in dual feed orthogonally polarized square patch antenna array is achieved by the use of Defected Ground Structure (DGS). A simple rectangular-headed cross DGS is implanted in the ground plane underneath the square patch in order to achieve high port isolation between two orthogonal ports at 2.95 GHz. The proposed design offers 58.55 dB port isolation between ports of single element patch and 45 dB that for two-element arrays. The port isolation of microstrip antenna with and without DGS has been studied and the result indicates better port isolation of the array with high cross polarization for two orthogonal polarizations owing to the effect of DGS. Finally, the two-element array is considered for MIMO application and mutual coupling between them is investigated. The simulated results of the proposed antennas are found to be in close agreement with the experimentally measured ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 683-696 Issue: 6 Volume: 34 Year: 2020 Month: 4 X-DOI: 10.1080/09205071.2020.1736647 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1736647 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:6:p:683-696 Template-Type: ReDIF-Article 1.0 Author-Name: S. Smirani Author-X-Name-First: S. Author-X-Name-Last: Smirani Author-Name: M. Aidi Author-X-Name-First: M. Author-X-Name-Last: Aidi Author-Name: S. Mili Author-X-Name-First: S. Author-X-Name-Last: Mili Author-Name: T. Aguili Author-X-Name-First: T. Author-X-Name-Last: Aguili Title: Electromagnetic modeling of rectenna based on the hybrid MoM–GEC combined to the harmonic balance method for wireless power transmission Abstract: Rectennas are key contributors in wireless power transmission. Such prominent technology requires intensive works to gain a better performance thus a reliable energy source. In this paper, we present an electromagnetic model of rectenna using nonlinear resolution approach. This was achieved by a hybrid MoM-GEC (the Moments method combined to the generalized equivalent circuit) and the Harmonic balance method. The structure presenting the rectenna was given in a network form making it a flexible and reconfigurable model. The proposed method was demonstrated using a patch antenna and a Schottky diode as a rectifier circuit. The given current density and field distributions validated using HFSS software proves the accuracy of the obtained solutions. Moreover, a study of the RF-DC conversion efficiency is presented to discuss the performance of the rectenna. Finally, results show that this is a simple but effective technique to study the rectifying antenna for different topologies and technologies. Journal: Journal of Electromagnetic Waves and Applications Pages: 697-714 Issue: 6 Volume: 34 Year: 2020 Month: 4 X-DOI: 10.1080/09205071.2020.1739566 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1739566 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:6:p:697-714 Template-Type: ReDIF-Article 1.0 Author-Name: Shu-Chuan Chen Author-X-Name-First: Shu-Chuan Author-X-Name-Last: Chen Author-Name: Chong-Wei Liou Author-X-Name-First: Chong-Wei Author-X-Name-Last: Liou Author-Name: Chung-I. G. Hsu Author-X-Name-First: Chung-I. G. Author-X-Name-Last: Hsu Author-Name: Ming-Chan Hsu Author-X-Name-First: Ming-Chan Author-X-Name-Last: Hsu Title: Integrated planar inverted-F antenna on laptop computer’s hinge for 2.4/5.2/5.8-GHz WLAN operation Abstract: A compact planar inverted-F antenna (PIFA) placed on one of the two hinges of a laptop computer is proposed for wireless local-area network (WLAN) operation. The aim of this design is to integrate the PIFA’s metal surroundings as part of the radiating structure. When the PIFA is fed, resonant modes in the hinge slot bounded by the two hinges, display ground plane, and keyboard ground plane can in turn be excited. Since the 200 × 5 mm2 slot is much larger than the 10 × 5 mm2 PIFA itself, the latter, although compact and structurally simple, can be made efficiently radiating with the help of the former. Measured efficiencies are all over 50% in the desired three WLAN bands Journal: Journal of Electromagnetic Waves and Applications Pages: 715-725 Issue: 6 Volume: 34 Year: 2020 Month: 4 X-DOI: 10.1080/09205071.2020.1745096 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1745096 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:6:p:715-725 Template-Type: ReDIF-Article 1.0 Author-Name: Zhu Hong Lin Author-X-Name-First: Zhu Hong Author-X-Name-Last: Lin Author-Name: Zhen Ting Chen Author-X-Name-First: Zhen Ting Author-X-Name-Last: Chen Author-Name: Kai Li Author-X-Name-First: Kai Author-X-Name-Last: Li Title: Radiation patterns of a horizontal electric dipole in a four-layered region and applications for microstrip antennas Abstract: The present work focuses on the radiation field excited by a horizontal electric dipole (HED) in a four-layered region composed of a perfect conductor covered with two dielectrics and the air above. Analytical expressions for the radiation field are derived for the case of both the source and the observation point being on or near the air-dielectric boundary. The propagation characteristics of the interference phenomenon are investigated. The radiation field components undergo sharp interference as the relative permittivities and dielectric layer thicknesses increase. When the observation angle $\Theta \geq 88^{\circ } $Θ≥88∘, the trapped surface wave predominates in the total field. Otherwise, the total field is determined primarily by the lateral wave. Due to the useful applications for microstrip antennas, radiation patterns of a patch antenna with specific current distributions are investigated. Some special cases of interest are discussed. The proposed formulas offer the potential to develop planar four-layered circuit structures. Journal: Journal of Electromagnetic Waves and Applications Pages: 726-743 Issue: 6 Volume: 34 Year: 2020 Month: 4 X-DOI: 10.1080/09205071.2020.1748120 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1748120 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:6:p:726-743 Template-Type: ReDIF-Article 1.0 Author-Name: Rajanish Kumar Singh Author-X-Name-First: Rajanish Kumar Author-X-Name-Last: Singh Author-Name: Akash Author-X-Name-First: Author-X-Name-Last: Akash Author-Name: M. Thottappan Author-X-Name-First: M. Author-X-Name-Last: Thottappan Title: Design and simulation investigations of high-power millimeter-wave gyrotron Abstract: In this paper, a high power millimeter wave gyrotron cavity was modelled and studied for its beam-wave interaction, beam-misalignment, and thermal issues. The sub-assemblies including the magnetron injection gun (MIG), RF output window, and electron beam collector were investigated. The MIG has produced an annular electron beam with transverse velocity spread less than ∼4%. The Particle–In–Cell simulation predicted an RF output of  470 kW in TE10,4 mode at ∼139.52 GHz for a DC drive of 80 kV, 20 A. The temperature on the inner, outer surfaces of the cavity and the corresponding average radial expansion of the cavity were calculated. Due to the radial expansion of the cavity, the resonant frequency and RF output power has changed to ∼0.514 GHz and ∼50 kW, respectively. Finally, the overall efficiency of the present gyrotron was improved from ∼29% to ∼47% by using a single–stage depressed collector. Journal: Journal of Electromagnetic Waves and Applications Pages: 744-758 Issue: 6 Volume: 34 Year: 2020 Month: 4 X-DOI: 10.1080/09205071.2020.1750974 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1750974 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:6:p:744-758 Template-Type: ReDIF-Article 1.0 Author-Name: Abdulaziz H. Haddab Author-X-Name-First: Abdulaziz H. Author-X-Name-Last: Haddab Author-Name: Edward F. Kuester Author-X-Name-First: Edward F. Author-X-Name-Last: Kuester Title: The effect of inhomogeneous dielectric loading on transmission through a slot in an infinite thick metallic shield Abstract: Transmission through a slot in a an infinite metallic shield of finite thickness, inhomogeneously loaded with dielectric material, is modeled using an analytical approximation based on the slot being small compared to a free space wavelength. Resonances of relatively broad bandwidth (Fabry-Perot) as well as of very narrow bandwidth (Fano) are found. We show that by introducing a gap of different dielectric constant within the slot, we can control the separation between the broad bandwidth resonances, and the locations and magnitudes of the very narrow bandwidth resonances. The influence of grooves on both kinds of resonances is considered using the same analytical model. The effect of losses in the dielectric slot is also considered, using data for commercially available dielectrics. Journal: Journal of Electromagnetic Waves and Applications Pages: 759-773 Issue: 6 Volume: 34 Year: 2020 Month: 4 X-DOI: 10.1080/09205071.2020.1751733 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1751733 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:6:p:759-773 Template-Type: ReDIF-Article 1.0 Author-Name: GuoHua Lin Author-X-Name-First: GuoHua Author-X-Name-Last: Lin Author-Name: YongJian Zhi Author-X-Name-First: YongJian Author-X-Name-Last: Zhi Author-Name: XiaoQi Yin Author-X-Name-First: XiaoQi Author-X-Name-Last: Yin Author-Name: SiWei Ren Author-X-Name-First: SiWei Author-X-Name-Last: Ren Author-Name: Tong He Author-X-Name-First: Tong Author-X-Name-Last: He Title: Electromagnetic fields of a horizontal infinitely long wire buried in three-layered medium Abstract: In this paper, the electromagnetic fields of a horizontal infinitely long wire source buried in a three-layered medium are studied. The source and the observation points are located in the middle region. The expressions of the electromagnetic waves are more complex because of the multiple reflections from the up and down boundaries. The electromagnetic field components between the two boundaries are given, and the trapped surface waves and lateral waves along the two boundaries are computed. The analysis and computations have some practical applications in the line sources buried in the earth or cements. Journal: Journal of Electromagnetic Waves and Applications Pages: 774-788 Issue: 6 Volume: 34 Year: 2020 Month: 4 X-DOI: 10.1080/09205071.2020.1752311 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1752311 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:6:p:774-788 Template-Type: ReDIF-Article 1.0 Author-Name: Min Zhong Author-X-Name-First: Min Author-X-Name-Last: Zhong Title: Realization of a tunable double-fishnet metamaterial structure based on the plasmon-induced transparency Abstract: A high transmission tunable metamaterial structure is proposed and manufactured experimentally in the THz range. A transmission peak is achieved at resonance frequency 5.97THz based on the bright-bright modes coupling effect. The transmission peak can be controlled by changing the periodicity P of the unit cell or the diameter D increasing. Moreover, the transmission peak can also be controlled by changing the temperature. The effect of three gases (carbon dioxide, carbon monoxide, and nitric oxide) on the transmission peak is also measured. The effect of liquids is also measured in experiments. Journal: Journal of Electromagnetic Waves and Applications Pages: 789-801 Issue: 6 Volume: 34 Year: 2020 Month: 4 X-DOI: 10.1080/09205071.2020.1757515 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1757515 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:6:p:789-801 Template-Type: ReDIF-Article 1.0 Author-Name: Z. E. Eremenko Author-X-Name-First: Z. E. Author-X-Name-Last: Eremenko Author-Name: Yu. V. Tarasov Author-X-Name-First: Yu. V. Author-X-Name-Last: Tarasov Author-Name: I. N. Volovichev Author-X-Name-First: I. N. Author-X-Name-Last: Volovichev Title: A method of effective potentials for calculating the frequency spectrum of eccentrically layered spherical cavity resonators Abstract: A novel method for the calculation of eigenfrequencies of non-uniformly filled spherical cavity resonators is developed. The spectrum is determined through the introduction of effective “dynamic” potentials which encode the infill inhomogeneity. For angularly symmetric cavity, regardless of its radial non-uniformity, the set of modes is shown to be a superposition of TE and TM oscillations which can be described in terms of a single scalar function independently of each other. The violation of polar symmetry in the infill dielectric properties, the azimuthal symmetry being preserved, suppresses all azimuthally non-uniform modes of TM oscillations. In the absence of angular symmetry of both electric and magnetic properties of the infill, only azimuthally uniform distribution of both TM and TE fields is expected to occur in the resonator. The method is quite efficient for computational complex algorithms for solving different spectral problems, including those for studying the chaotic properties of systems' spectra. Journal: Journal of Electromagnetic Waves and Applications Pages: 802-824 Issue: 6 Volume: 34 Year: 2020 Month: 4 X-DOI: 10.1080/09205071.2020.1758220 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1758220 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:6:p:802-824 Template-Type: ReDIF-Article 1.0 Author-Name: Shivangi Mishra Author-X-Name-First: Shivangi Author-X-Name-Last: Mishra Author-Name: J. Shanmuga Sundari Author-X-Name-First: J. Author-X-Name-Last: Shanmuga Sundari Author-Name: B. Channabasava Author-X-Name-First: B. Author-X-Name-Last: Channabasava Author-Name: V. K. Anandan Author-X-Name-First: V. K. Author-X-Name-Last: Anandan Title: First indigenously developed polarimetric C-band Doppler weather radar in India and its first hand validation results Abstract: As a first of its kind in India, indigenous development of dual-polarization C-Band Doppler weather radar (DWR) is discussed in the manuscript. Radar Development Area (RDA) of ISRO Telemetry Tracking and Command Network (ISTRAC) have developed the system and the DWR is installed at Thumba Equatorial Rocket Launch Station (TERLS) of Vikram Sarabhai Space Centre (VSSC) which is a centre of Indian Space Research Organization (ISRO) in the Kerala state of India. Till now, the DWRs available in India were either imported or were working on single polarization. The purpose of this DWR is to establish the technology based on polarimetric observation for meteorological and hydrological applications like intense weather monitoring and cyclone detection. The current paper mainly aims to show the DWR system-level details and the calibration approaches adopted. Some first cut data validation results are also presented for various events captured by the DWR. Journal: Journal of Electromagnetic Waves and Applications Pages: 825-840 Issue: 6 Volume: 34 Year: 2020 Month: 4 X-DOI: 10.1080/09205071.2020.1742798 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1742798 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:6:p:825-840 Template-Type: ReDIF-Article 1.0 Author-Name: J. L. Valdez-Garcia Author-X-Name-First: J. L. Author-X-Name-Last: Valdez-Garcia Author-Name: J. L. Overa-Cervantes Author-X-Name-First: J. L. Author-X-Name-Last: Overa-Cervantes Author-Name: T. K. Kataria Author-X-Name-First: T. K. Author-X-Name-Last: Kataria Author-Name: A. Corona-Chavez Author-X-Name-First: A. Author-X-Name-Last: Corona-Chavez Title: Water-based frequency selective surface for green electronics applications Abstract: In this paper, a water based All Dielectric Frequency Selective Surface (ADFSS) is presented made of renewable materials. This surface is based on a modified dielectric resonator incorporating air holes inside the water to increase its Q factor. The ADFSS shows a low pass response with a cutoff frequency of 3.7 GHz. The surface is simulated and measured giving reasonable results. Journal: Journal of Electromagnetic Waves and Applications Pages: 841-848 Issue: 6 Volume: 34 Year: 2020 Month: 4 X-DOI: 10.1080/09205071.2020.1750490 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1750490 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:6:p:841-848 Template-Type: ReDIF-Article 1.0 Author-Name: Abhishek Kumar Author-X-Name-First: Abhishek Author-X-Name-Last: Kumar Author-Name: Dileep Kumar Upadhyay Author-X-Name-First: Dileep Kumar Author-X-Name-Last: Upadhyay Author-Name: Srikanta Pal Author-X-Name-First: Srikanta Author-X-Name-Last: Pal Title: Design of the quasi-0 dB backward wave-coupled line coupler using CRLH-TL based on stepped-impedance open stub-loaded dual-mode resonator Abstract: This paper demonstrates symmetric backward wave quasi-0 dB coupled line coupler (CLC) based on the globe shaped composite right/left-handed transmission line (GS-CRLH-TL). The proposed CLC shows quasi-0 dB backward wave coupling with measured maximum backward coupling level of −0.72 dB at 3.07 GHz. −3 dB bandwidth of the backward coupling region is from 2.75 GHz to 3.34 GHz, corresponding to fractional bandwidth (FBW) of 19.16%. The designed CLC shows good isolation of more than 43 dB in the backward coupling region in −3 dB frequency range from 2.75 GHz to 3.34 GHz. The measured value of return loss, at the center frequency 3.07 GHz, is more than 26.4 dB. Overall size of the fabricated CLC including 50 Ω feedline is 0.631λg × 0.455λg where λg is the guided wavelength at 3.07 GHz. Good concurrence is obtained between the simulated results, equivalent LC circuit model results and the measured results. Journal: Journal of Electromagnetic Waves and Applications Pages: 849-868 Issue: 7 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1758221 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1758221 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:7:p:849-868 Template-Type: ReDIF-Article 1.0 Author-Name: Husnu Deniz Basdemir Author-X-Name-First: Husnu Deniz Author-X-Name-Last: Basdemir Title: Diffraction by a right angle impedance wedge between left- and right-handed media Abstract: An analytical solution for the diffraction of plane waves by a right angle impedance wedge which is lying between double negative and positive materials is investigated. In order to satisfy the boundary conditions and shifted shadow boundary, the diffracted fields are divided to subfields. As a result, an anomalous shift of shadow boundary is observed towards to lower surface of the wedge. In addition, geometric optics fields are determined by using the geometry of the problem. Also, the behavior of the fields is investigated numerically. Journal: Journal of Electromagnetic Waves and Applications Pages: 869-880 Issue: 7 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1759460 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1759460 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:7:p:869-880 Template-Type: ReDIF-Article 1.0 Author-Name: Vasil Tabatadze Author-X-Name-First: Vasil Author-X-Name-Last: Tabatadze Author-Name: Kamil Karaçuha Author-X-Name-First: Kamil Author-X-Name-Last: Karaçuha Author-Name: Eldar I. Veliyev Author-X-Name-First: Eldar I. Author-X-Name-Last: Veliyev Title: The solution of the plane wave diffraction problem by two strips with different fractional boundary conditions Abstract: In this article, the plane wave diffraction by two strips is studied. Fractional boundary condition is required on strips when the fractional order for each strip is different. The goal of the paper is to investigate the resonant properties of such structures. The mathematical apparatus for the solution of the problem is given. The frequency dependency on the total radar cross-section is constructed for the different combinations of the fractional order. At the resonant frequencies, the near and the far-field distributions are presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 881-893 Issue: 7 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1759461 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1759461 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:7:p:881-893 Template-Type: ReDIF-Article 1.0 Author-Name: Priyanka Tiwari Author-X-Name-First: Priyanka Author-X-Name-Last: Tiwari Author-Name: Surya Kumar Pathak Author-X-Name-First: Surya Kumar Author-X-Name-Last: Pathak Author-Name: Anitha V. p. Author-X-Name-First: Anitha Author-X-Name-Last: V. p. Author-Name: Varsha Siju Author-X-Name-First: Varsha Author-X-Name-Last: Siju Author-Name: Abhishek Sinha Author-X-Name-First: Abhishek Author-X-Name-Last: Sinha Title: X-band Γ-shaped anisotropic metasurface-based perfect cross-polarizer for RCS reduction Abstract: In this paper, an X-band perfect cross-polarization convertor (CPC) that consists of Γ-shaped metal patch imprinted on a metal-backed FR-4 dielectric substrate is designed, analyzed, and characterized. The unit cell dimensions of the developed structure are optimized to achieve more than 99.9% polarization conversion ratio (PCR) for a frequency range of 8–12 GHz (X-band) at normal incidence angle. The performance of device exhibits 80% PCR value as a function of angle of incidence up to 40°. The analytical finding and experimental characteristics of the designed structure agree well with the simulated results. In addition, the developed device has been thoroughly analyzed numerically for radar cross-section (RCS) reduction using phase cancellation techniques which exhibits 10-dB mono-static RCS reduction over a frequency band 7.7 GHz to 13.7 GHz. The developed device is highly suitable for radar stealth applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 894-906 Issue: 7 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1759462 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1759462 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:7:p:894-906 Template-Type: ReDIF-Article 1.0 Author-Name: Tanmoy Sarkar Author-X-Name-First: Tanmoy Author-X-Name-Last: Sarkar Author-Name: Abhijyoti Ghosh Author-X-Name-First: Abhijyoti Author-X-Name-Last: Ghosh Author-Name: Subhradeep Chakraborty Author-X-Name-First: Subhradeep Author-X-Name-Last: Chakraborty Author-Name: L. L. K. Singh Author-X-Name-First: L. L. K. Author-X-Name-Last: Singh Author-Name: Sudipta Chattopadhyay Author-X-Name-First: Sudipta Author-X-Name-Last: Chattopadhyay Title: Employment of mixed mode in single-layer microstrip antenna for ISM/WiMAX/WLAN/4G/Sub 6 GHz 5G mobile communication Abstract: The design and development of multiband antenna for useful operating bands are the current state-of-the-art research in the field of antenna research. A simple and single-layer printed multiband radiation structure eliminates the packaging complexity of modern communication devices. The present investigation proposes such simple and single-layer multiband antenna for ISM 2.5 GHz/WiMax 3.5 GHz/WLAN 5.2 GHz/ISM 5.8 GHz wireless application for 4G LTE and sub 6 GHz 5G spectrum. The proposed antenna can completely cover the required frequencies with good radiation characteristics at the broadside direction. The design has been carried out using the RT duroid 5870 substrate (ϵr = 2.33, height h = 1.575 mm) for simulation and measurements. In the proposed patch antenna, the slots have been judiciously used to employ mixed modal behaviour which capitulates multiple useful bands with proper bore-sight radiation. Journal: Journal of Electromagnetic Waves and Applications Pages: 907-925 Issue: 7 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1759463 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1759463 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:7:p:907-925 Template-Type: ReDIF-Article 1.0 Author-Name: Daniel Hernandez Author-X-Name-First: Daniel Author-X-Name-Last: Hernandez Author-Name: Kyoung-Nam Kim Author-X-Name-First: Kyoung-Nam Author-X-Name-Last: Kim Title: Computational evaluation for improving the |B1+ field in deep brain and cerebellum using a combination of a birdcage coil and a dipole antenna array Abstract: The use of strong magnetic fields for brain imaging has shown that increased SNR and resolution can be obtained. Such MRI systems are prone to field non-uniformities that are more likely to appear in deep brain structures making high-quality imaging of deep brain regions a challenge. We investigate the combination of a dipole antenna and Birdcage coil to generate a uniform magnetic field with high intensity in the deep brain. Magnetic fields |B1|, were computed from a human brain model and statistical analysis was done specifically on the tissues of interest. The geometry of the Birdcage coil and eight Dipole antenna array was selected after performing simulations by varying its dimensions, and evaluating  the |B1| field intensity and uniformity on the deep brain area. The proposed combination of birdcage coil and dipole array shows to have an improvement on the field intensity and uniformity on the deep brain and cerebellum area in comparison to only using the birdcage coil. Journal: Journal of Electromagnetic Waves and Applications Pages: 926-939 Issue: 7 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1760148 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1760148 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:7:p:926-939 Template-Type: ReDIF-Article 1.0 Author-Name: Hridesh Kumar Verma Author-X-Name-First: Hridesh Kumar Author-X-Name-Last: Verma Author-Name: Mithilesh Kumar Author-X-Name-First: Mithilesh Author-X-Name-Last: Kumar Author-Name: R. S. Meena Author-X-Name-First: R. S. Author-X-Name-Last: Meena Author-Name: Satya P. Singh Author-X-Name-First: Satya P. Author-X-Name-Last: Singh Title: A low RCS wideband high gain CP slot antenna loaded with frequency selective surface Abstract: In this paper, a compact wideband circularly polarized slot antenna consisting of two L-shaped resonators is proposed. The slot antenna is loaded with a band-stop frequency selective surface (FSS) reflector to improve the gain of the antenna and to reduce the profile of the antenna. The radiation and scattering characteristics of FSS loaded slot antenna are compared with the metallic reflector loaded slot antenna, and the proposed antenna shows improved impedance bandwidth of 1.75–2.65 GHz. The measured results show that the peak gain of the slot antenna with FSS is enhanced by 4 dB. The proposed antenna with FSS also exhibits 3-dB ARBW of 2.2–2.65 GHz, and the scattering performance shows an average RCS reduction of 7.34 dB is achieved by slot antenna with FSS as compared to slot antenna with metallic reflector with peak RCS reduction of 24 dB at 1.2 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 940-959 Issue: 7 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1761459 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1761459 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:7:p:940-959 Template-Type: ReDIF-Article 1.0 Author-Name: R. K. Barik Author-X-Name-First: R. K. Author-X-Name-Last: Barik Author-Name: Q. S. Cheng Author-X-Name-First: Q. S. Author-X-Name-Last: Cheng Author-Name: S. K. K. Dash Author-X-Name-First: S. K. K. Author-X-Name-Last: Dash Author-Name: N. C. Pradhan Author-X-Name-First: N. C. Author-X-Name-Last: Pradhan Author-Name: S. S. Karthikeyan Author-X-Name-First: S. S. Author-X-Name-Last: Karthikeyan Title: Compact high-isolation self-diplexing antenna based on SIW for C-band applications Abstract: This paper presents a novel compact high-isolation cavity-backed inverted U-shaped slot antenna using substrate-integrated waveguide (SIW) for C-band applications. The SIW cavity is loaded by an inverted U-shaped slot that produces two fictitious aperture for radiation at two distinct frequency bands and to exhibit self-diplexing antenna (SDA) characteristics. Two orthogonal microstrip feed lines are applied for excitation of fundamental mode ( $TE_{110} $TE110) and two degenerated modes ( $TE_{120} $TE120 and $TE_{210} $TE210). The perturbation of these modes due to slot loading allows to achieve size miniaturization. Compared with conventional SIW cavity without slot, the proposed SDA allows a size reduction of 56%. High isolation is achieved due to the transmission zeros produced by these modes and orthogonal feed lines. This isolation is further improved (>40.5 and >32.8 dB) due to off-centered input ports that creates very weak cross-coupling path between them. The resonating frequencies of the proposed SDA can be designed individually. Finally, an SDA working at 4.29 and 7.52 GHz is fabricated for validation of simulated performances. The measured gains of the fabricated SDA are 5.38 and 5.82 dBi at the resonating frequencies of 4.29 and 7.52 GHz, respectively. A good consistency is found between measured and simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 960-974 Issue: 7 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1763859 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1763859 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:7:p:960-974 Template-Type: ReDIF-Article 1.0 Author-Name: Muhammad Sajid Hanif Author-X-Name-First: Muhammad Sajid Author-X-Name-Last: Hanif Author-Name: Muhammad Arshad Fiaz Author-X-Name-First: Muhammad Arshad Author-X-Name-Last: Fiaz Title: Effect of surface states on scattering from a slab made of topological insulator material with rough interface Abstract: Using the perturbation theory (PT), reflected field both in specular and non specular directions from a slab made of topological insulator (TI) material with rough interface is studied. The specular reflections are described by zeroth order terms of the perturbation series while non specular reflections are associated with higher order terms. To describe the surface states on the TI, γ-model characterized by the surface admittance is utilized. It is observed that the co-polarized specular reflection increases for large values of surface admittance which results in vanishing transmission. The main objective is to pronounce distinctions between the results for a dielectric slab and TI slab. It is observed that the co polarized diffraction efficiency of the sinusoidal grating is enhanced for p-polarization as the surface admittance increases. Moreover, the scattering behavior of the TI slab with Gaussian rough interface as a function of surface admittance differs significantly from that of the dielectric slab. Journal: Journal of Electromagnetic Waves and Applications Pages: 975-987 Issue: 7 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1769506 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1769506 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:7:p:975-987 Template-Type: ReDIF-Article 1.0 Author-Name: Hui Liu Author-X-Name-First: Hui Author-X-Name-Last: Liu Author-Name: Cheng Liu Author-X-Name-First: Cheng Author-X-Name-Last: Liu Author-Name: Qingchong Liu Author-X-Name-First: Qingchong Author-X-Name-Last: Liu Author-Name: Yuefeng Lu Author-X-Name-First: Yuefeng Author-X-Name-Last: Lu Author-Name: Sailing He Author-X-Name-First: Sailing Author-X-Name-Last: He Title: Compact broadband circularly polarized UHF RFID tag antenna for metallic mounting Abstract: We report a broadband ultra-high frequency (UHF) radio frequency identification (RFID) tag antenna of compact size mounted on a metallic object in a near field communication (NFC) RFID system. One half of the square radiation patch has a semi-annular strip feedline embedded inside a semicircle-shaped slot to improve the antenna bandwidth and gain, and the other half of the radiation patch has an L-shaped slot and a shorting pin to increase the circular polarization (CP) bandwidth and reduce the antenna size. The resonant input impedance of the tag antenna can be tuned easily by varying the length of the semi-annular feedline, and the gap between the feedline and the etched semicircular slot. The proposed tag antenna has a wide measured impedance bandwidth (−10-dB |Γ|) covering the whole operating frequency range of 181 MHz (from 790 to 971 MHz) for a UHF RFID system. The measured 3-dB axis ratio (AR) bandwidth is 43 MHz (from 895 to 938 MHz), which is much larger than those of the CP tag antennas reported in the literature for metallic objects. Further experiment has shown that the proposed tag antenna can provide a stable reading range when mounted on metal plates of various sizes. Journal: Journal of Electromagnetic Waves and Applications Pages: 989-1001 Issue: 8 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1767702 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1767702 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:8:p:989-1001 Template-Type: ReDIF-Article 1.0 Author-Name: Mendil Samir Author-X-Name-First: Mendil Author-X-Name-Last: Samir Author-Name: Aguili Taoufik Author-X-Name-First: Aguili Author-X-Name-Last: Taoufik Title: The electromagnetic scattering modelization of metallic object in rectangular waveguide by hybrid method (MOM–PO–GTD) Abstract: This article deals with a new hybrid approach combining a Moment Method (MOM), with the Geometrical Theory of Diffraction (GTD), this approach evaluates the currents surface on the microstrip antenna placed in the rectangular Electric Magnetic Electric Magnetic(EMEM) Waveguides. The incident field is taken as a TEM polarized plane wave in the principal plane. The new hybrid current function based on the Geometrical Theory of Diffraction (GTD), consists in approximating the total current on a homogenous metallic pattern on two steps; in the inside of the metal is dominated by the Physical Optic (PO) method, and the edges, tips effects are described by the GTD method. A set of test functions (sinusoidal or triangular or others) used in the MoM method is replaced by one and unique test function, to get a rapid convergence and less computation time. The new hybrid method can be applied to different structures to calculate scattering for validation proposes. The result of this new method electromagnetic variables current and filed distributions are in agreement with those given by the MoM method. An accurate gain in precision and time, memory resources are obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 1002-1014 Issue: 8 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1769502 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1769502 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:8:p:1002-1014 Template-Type: ReDIF-Article 1.0 Author-Name: Chien Ching Chiu Author-X-Name-First: Chien Ching Author-X-Name-Last: Chiu Author-Name: Bo Jie Hong Author-X-Name-First: Bo Jie Author-X-Name-Last: Hong Author-Name: Jiang Hao Author-X-Name-First: Jiang Author-X-Name-Last: Hao Title: Inverse scattering of a periodic inhomogeneous dielectric scatterer Abstract: This paper is to reconstruct the periodic inhomogeneous dielectric distribution of the scatterer buried in the rough surface. In order to explore the dielectric coefficient distribution of the unknown dielectric object under the rough surface, we emit electromagnetic wave to the object and measure the scattered electromagnetic wave above the rough surface. Base on Green's identity and the induced current concepts, the nonlinear integral equation can be derived and solved by the method of moments. Next, the inverse scattering problem is converted into an optimization problem. We use Self-Adaptive Dynamic Differential Evolution (SADDE) and Asynchronous Particle Swarm Optimization (APSO) to find the extreme value of the problem. With the regularization technique, the reconstruction is good. When the noise is less than 1%, the dielectric constant can also be achieved successfully. Numerical results show that SADDE can reduce the error for the permittivities of the object better than the APSO. Journal: Journal of Electromagnetic Waves and Applications Pages: 1015-1028 Issue: 8 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1769503 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1769503 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:8:p:1015-1028 Template-Type: ReDIF-Article 1.0 Author-Name: Shahid Ullah Author-X-Name-First: Shahid Author-X-Name-Last: Ullah Author-Name: Cunjun Ruan Author-X-Name-First: Cunjun Author-X-Name-Last: Ruan Author-Name: Muhammad Shahzad Sadiq Author-X-Name-First: Muhammad Shahzad Author-X-Name-Last: Sadiq Author-Name: Tanveer Ul Haq Author-X-Name-First: Tanveer Ul Author-X-Name-Last: Haq Author-Name: Wenlong He Author-X-Name-First: Wenlong Author-X-Name-Last: He Title: Microstrip system on-chip circular polarized (CP) slotted antenna for THz communication application Abstract: This paper is presenting two different microstrip antennas (LHCP and RHCP antennas). It can explain the effects of S-shape and Z-shape slots for left-hand circular polarization and right-hand circular polarization respectively. Both types of slots are used to convert linear polarized antenna into the circularly polarized antenna. It is simulated with the help of CST-2015 and HFSS2018 design software. The antenna is designed into two steps. At first step, a simple linear microstrip antenna is designed and with second step, slots are used for circular polarization. The operating simulated frequency in both types of software’s is 0.258 THz to 0.355 THz and having 11 % operating bandwidth with the axial ratio at 3 dB. All the results of both antennas are the same but only radiation patterns results are opposite in polarization. The paper also presents the parametric study of copper material thickness and substrate thickness of the antenna. Journal: Journal of Electromagnetic Waves and Applications Pages: 1029-1038 Issue: 8 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1770130 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1770130 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:8:p:1029-1038 Template-Type: ReDIF-Article 1.0 Author-Name: Goker Sener Author-X-Name-First: Goker Author-X-Name-Last: Sener Title: High-gain low-profile rectangular microstrip patch antenna with Yagi elements Abstract: This paper presents a novel high gain rectangular microstrip patch antenna (RMSA) with vertically placed Yagi elements. The antenna is fed by a coaxial probe to excite TM01 fundamental waves at 2.4GHz, which is suitable for wireless local area network (WLAN) applications. In order to increase the antenna gain, Yagi elements are placed in groups of 5, on each side of the substrate in order to serveas directors for the radiating slots as well as the ground reflections. The proposed antenna offers 1.3dB gain improvement and %3 .1 impedance bandwidth increase in comparison to the plain rectangular microstrip antenna with the same specifications. The advantage of this antenna is to provide an easy and cost effective solution to increase microstrip antenna gain, particularly in 8-10dB range, without disruptingits planar structure. Journal: Journal of Electromagnetic Waves and Applications Pages: 1039-1046 Issue: 8 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1772124 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1772124 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:8:p:1039-1046 Template-Type: ReDIF-Article 1.0 Author-Name: Cong Du Author-X-Name-First: Cong Author-X-Name-Last: Du Author-Name: Fangming Liu Author-X-Name-First: Fangming Author-X-Name-Last: Liu Author-Name: Yujiao Ding Author-X-Name-First: Yujiao Author-X-Name-Last: Ding Author-Name: Kai Wu Author-X-Name-First: Kai Author-X-Name-Last: Wu Author-Name: Baohua Li Author-X-Name-First: Baohua Author-X-Name-Last: Li Author-Name: Wei Dong Author-X-Name-First: Wei Author-X-Name-Last: Dong Title: Ultra-wideband doublet signal generation with tunable notch band based on delay-line filter Abstract: A novel and simple scheme to generate Ultra-wideband (UWB) doublet signal with tunable notch band based on a tunable delay-line filter is presented. The first-order differentiation is realized by a dual-drive Mach–Zehnder modulator (DD-MZM), which differentiates the Gaussian pulses to the monocycle pulses. Subsequently, the UWB monocycle pulses are transmitted to an optical delay-line filter implemented by a balanced photo-detector and a tunable delay line for both differentiation and photodetection. Consequently, the desired UWB doublet signal can be obtained with a 10-dB bandwidth of 8.75 GHz. Besides, the polarity reversibility of the generated doublet signal is demonstrated by changing the bias voltage of the DD-MZM. Moreover, the desired notch can be introduced in the generated frequency spectrum to eliminate the interference between the existing narrowband systems and the UWB systems. And the tunability of the band-notched position is implemented by simply adjusting the delay time of the delay-line filter. The feasibility of the presented scheme is investigated by mathematical models and simulations. Journal: Journal of Electromagnetic Waves and Applications Pages: 1047-1056 Issue: 8 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1772889 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1772889 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:8:p:1047-1056 Template-Type: ReDIF-Article 1.0 Author-Name: Yanfei Gong Author-X-Name-First: Yanfei Author-X-Name-Last: Gong Author-Name: Bo Wang Author-X-Name-First: Bo Author-X-Name-Last: Wang Title: An efficient method for predicting the shielding effectiveness of an enclosure with multiple apertures Abstract: An efficient analytical method has been proposed for predicting the shielding effectiveness (SE) and resonances of a metallic enclosure with multiple apertures against an external incident plane wave. First, the electromagnetic (EM) field distribution within the enclosure through multiple apertures is represented by the equivalent electric and magnetic dipole moments based on the Bethe’s theory for small aperture coupling. Then, the EM fields in the enclosure can be obtained by using the scalar wave functions, where the unknown coefficients in the functions are related to the equivalent dipole moments. Finally, the analytical method is applied to handle the enclosure with multiple apertures, and corresponding inclusions about the SE and resonances can be obtained. Compared with the full-wave simulation software CST over the frequency range of 0–2.5 GHz, the analytical method is proved to be accurate and effective, which consumes less time than the conventional numerical methods. Journal: Journal of Electromagnetic Waves and Applications Pages: 1057-1072 Issue: 8 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1773935 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1773935 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:8:p:1057-1072 Template-Type: ReDIF-Article 1.0 Author-Name: Mengping Yu Author-X-Name-First: Mengping Author-X-Name-Last: Yu Author-Name: Dagang Wu Author-X-Name-First: Dagang Author-X-Name-Last: Wu Author-Name: Yanjun Chen Author-X-Name-First: Yanjun Author-X-Name-Last: Chen Author-Name: Hanming Wang Author-X-Name-First: Hanming Author-X-Name-Last: Wang Author-Name: Ji Chen Author-X-Name-First: Ji Author-X-Name-Last: Chen Title: Electromagnetic rock properties’ characterization and modeling using 3D micro-CT rock images Abstract: This paper mainly focuses on the electromagnetic modeling aspect of the digital rock physics to understand the relationship between the micro-structures and contents within the structure to their electrical properties. This is achieved by using the 3D rock micro-CT images and performing electromagnetic modeling using the 3D numerical mixing law (finite difference method based), which is a robust numerical method with high efficiency. Based on the results of this investigation, one can establish the relationship between the rock structure/porous space-filling materials and the buck electrical properties, such as the permittivity and the conductivity. Two different 3D rock (sandstone and dacite) images with different image reconstruction processes were used to demonstrate the accuracy and efficiency of this method. Additionally, single-pole Debye model was also used to be compared with our results to further validate our proposed numerical method and also provide a potential approach to predict the oil saturation for future research study. Journal: Journal of Electromagnetic Waves and Applications Pages: 1073-1089 Issue: 8 Volume: 34 Year: 2020 Month: 5 X-DOI: 10.1080/09205071.2020.1775134 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1775134 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:8:p:1073-1089 Template-Type: ReDIF-Article 1.0 Author-Name: P. K. Choudhury Author-X-Name-First: P. K. Author-X-Name-Last: Choudhury Author-Name: M. Abou El-Nasr Author-X-Name-First: M. Author-X-Name-Last: Abou El-Nasr Title: Massive MIMO toward 5G Journal: Journal of Electromagnetic Waves and Applications Pages: 1091-1094 Issue: 9 Volume: 34 Year: 2020 Month: 6 X-DOI: 10.1080/09205071.2020.1783825 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1783825 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:9:p:1091-1094 Template-Type: ReDIF-Article 1.0 Author-Name: Biswajeet Mukherjee Author-X-Name-First: Biswajeet Author-X-Name-Last: Mukherjee Author-Name: Pragati Patel Author-X-Name-First: Pragati Author-X-Name-Last: Patel Author-Name: Jayanta Mukherjee Author-X-Name-First: Jayanta Author-X-Name-Last: Mukherjee Title: A review of the recent advances in dielectric resonator antennas Abstract: This paper presents a comprehensive review of the state of art techniques and geometries which have been explored in the areas of Dielectric Resonator Antennas (DRA). With the evolution of first rectangular geometry to the current investigations, the basic aims of research in this field of electrical size miniaturization, retrofitting bandwidth as per commercial needs and radiation pattern stability by controlling the modes in the DRA still persist. Various techniques to miniaturize the physical and electrical size, mode excitation through varied mechanisms like probe, microstrip, slot, etc., improving bandwidth and radiation characteristics by various researchers have been included. The novel geometries and concept of fractals as introduced to the DRAs have also been addressed in this paper. Journal: Journal of Electromagnetic Waves and Applications Pages: 1095-1158 Issue: 9 Volume: 34 Year: 2020 Month: 6 X-DOI: 10.1080/09205071.2020.1744484 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1744484 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:9:p:1095-1158 Template-Type: ReDIF-Article 1.0 Author-Name: José Alfredo Tirado-Méndez Author-X-Name-First: José Alfredo Author-X-Name-Last: Tirado-Méndez Author-Name: Hildeberto Jardón-Aguilar Author-X-Name-First: Hildeberto Author-X-Name-Last: Jardón-Aguilar Author-Name: Arturo Rangel-Merino Author-X-Name-First: Arturo Author-X-Name-Last: Rangel-Merino Author-Name: Luis Alberto Vasquez-Toledo Author-X-Name-First: Luis Alberto Author-X-Name-Last: Vasquez-Toledo Author-Name: Ricardo Gómez-Villanueva Author-X-Name-First: Ricardo Author-X-Name-Last: Gómez-Villanueva Title: Four ports wideband drop-shaped slot antenna for MIMO applications Abstract: In this paper, a proposal of a four-port antenna for MIMO applications is presented with high interport isolation. The isolation among elements is implemented by limiting the surface current distribution of each radiator by placing them on different substrate layers, leading to a size optimization. The array is implemented by four drop-shaped slot radiators. The antenna performs from 1.7 to 7.2 GHz, presents a very low Envelope Correlation Coefficient (ECC), reaching values of 0.0025 tops, and a stable Total Active Reflection Coefficient (TARC) over the entire operational bandwidth. These parameters demonstrate the feasibility of the antenna for MIMO systems. The peak average gain is 5 dB, and the port isolation between adjacent radiators, S12 and S14, and opposite radiators, S13 and S24 are below −20 dB, reaching values even less than −30 dB in some bands without adding extra structures, avoiding an increment in the total area. Journal: Journal of Electromagnetic Waves and Applications Pages: 1159-1179 Issue: 9 Volume: 34 Year: 2020 Month: 6 X-DOI: 10.1080/09205071.2019.1710578 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1710578 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:9:p:1159-1179 Template-Type: ReDIF-Article 1.0 Author-Name: S. S. Singhwal Author-X-Name-First: S. S. Author-X-Name-Last: Singhwal Author-Name: B. K. Kanaujia Author-X-Name-First: B. K. Author-X-Name-Last: Kanaujia Author-Name: A. Singh Author-X-Name-First: A. Author-X-Name-Last: Singh Author-Name: J. Kishor Author-X-Name-First: J. Author-X-Name-Last: Kishor Author-Name: L. Matekovits Author-X-Name-First: L. Author-X-Name-Last: Matekovits Title: Multiple input multiple output dielectric resonator antenna with circular polarized adaptability for 5G applications Abstract: In this paper, the concept of the circularly polarized agile, multiple-input multiple-output (MIMO) dielectric resonator antenna (DRA) structure for fifth generation (5G) new radio application in mobile terminal is presented. Two prototypes have been fabricated, namely one with cylindrical DRA (CDRA) referred as A1 and a second one with ring DRA (RDRA) named as A2. These practical realizations of dual-port MIMO antennas have been mounted on a Rogers 5870 substrate of octagonal shape with proper ground architecture. The proposed dual-port MIMO antennas have been excited with conformal probes and L-type feed network aiming to achieve circular polarization (CP). Measured impedance bandwidth of A1 and A2 are 21.2% (3.15–3.9 GHz) and 22.2% (3.12–3.9 GHz), respectively. Moreover, for both antennas low mutual coupling between ports with minimum isolation of $-20 $−20 dB over entire impedance bandwidth has been obtained by using triangular head slots in the ground plane. Measured axial ratio bandwidths in broadside direction $(\theta =0) $(θ=0) are 5.66% (3.26–3.45 GHz) and 4.25% (3.45–3.6 GHz), respectively. Maximum gains are 7.3 and 7.2 dBi, in that order. MIMO antenna parameters such as envelope correction coefficient, diversity gain (DG), mean effective gain and total active reflection coefficient are also calculated to verify MIMO performance parameters. The proposed antennas also demonstrate CP agility with insertion of concentric cylindrical shells of different radii. Journal: Journal of Electromagnetic Waves and Applications Pages: 1180-1194 Issue: 9 Volume: 34 Year: 2020 Month: 6 X-DOI: 10.1080/09205071.2020.1730984 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1730984 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:9:p:1180-1194 Template-Type: ReDIF-Article 1.0 Author-Name: Shu-Chuan Chen Author-X-Name-First: Shu-Chuan Author-X-Name-Last: Chen Author-Name: Meng-Kai Wu Author-X-Name-First: Meng-Kai Author-X-Name-Last: Wu Author-Name: Cheng-Wei Chiang Author-X-Name-First: Cheng-Wei Author-X-Name-Last: Chiang Author-Name: Ming-Shing Lin Author-X-Name-First: Ming-Shing Author-X-Name-Last: Lin Title: 3.5-GHz four-element MIMO antenna system for 5G laptops with a large screen-to-body ratio Abstract: This paper proposes a 3.5-GHz four-element multi-input multi-output (MIMO) antenna system for fifth-generation (5G) laptops. The four antennas are configured into two dual-antenna units, measuring 26 × 3 × 2 mm3 each and separated by a distance of 6 mm, the latter of which accounts for the isolation between the two units. The two antennas in each unit are located on the two sides of the same substrate and are both three-dimensional inverted-F antennas (IFAs) of the same size, but are deployed to be skew-symmetric with respect to the top edge of the display ground. With a decoupling neutralization line connecting the two antennas in the same unit, the simulated isolation between them is enhanced by up to 8 dB. Within the operating frequency band, its measured isolation exceeds 12 dB, the simulated electric field ECC (envelope correlation coefficient) is smaller than 0.15, and the measured realized radiation efficiency is more than 40%. Journal: Journal of Electromagnetic Waves and Applications Pages: 1195-1209 Issue: 9 Volume: 34 Year: 2020 Month: 6 X-DOI: 10.1080/09205071.2019.1693911 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1693911 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:9:p:1195-1209 Template-Type: ReDIF-Article 1.0 Author-Name: Muhammad Mateen Hassan Author-X-Name-First: Muhammad Mateen Author-X-Name-Last: Hassan Author-Name: Zeeshan Zahid Author-X-Name-First: Zeeshan Author-X-Name-Last: Zahid Author-Name: Adnan Ahmed Khan Author-X-Name-First: Adnan Ahmed Author-X-Name-Last: Khan Author-Name: Imran Rashid Author-X-Name-First: Imran Author-X-Name-Last: Rashid Author-Name: Abdul Rauf Author-X-Name-First: Abdul Author-X-Name-Last: Rauf Author-Name: Moazam Maqsood Author-X-Name-First: Moazam Author-X-Name-Last: Maqsood Author-Name: Farooq Ahmed Bhatti Author-X-Name-First: Farooq Ahmed Author-X-Name-Last: Bhatti Title: Two element MIMO antenna with frequency reconfigurable characteristics utilizing RF MEMS for 5G applications Abstract: This paper presents a novel two-element multiple input multiple output (MIMO) reconfigurable antenna that can be switched among 600 MHz, 1.8, 2.4, 3.5, and 5.5 GHz bands. The proposed antenna consists of two semi-circular ring-shaped strip-lines and a rectangular slot on the top conducting layer of the substrate and a U-shaped slot, etched on the bottom side of the substrate. Frequency reconfigurable characteristics have been achieved using single pole four throw radio frequency micro-electro-mechanical system switch. The switch has been installed in the ground slot. The dimensions of the proposed MIMO antenna are 32 × 98 × 1 mm3. Measured isolation greater than 15 dB has been achieved in the operating bands. The calculated envelop correlation coefficient is less than 0.04 and the diversity gain in the operating bands is greater than 9.8 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 1210-1224 Issue: 9 Volume: 34 Year: 2020 Month: 6 X-DOI: 10.1080/09205071.2020.1765883 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1765883 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:9:p:1210-1224 Template-Type: ReDIF-Article 1.0 Author-Name: Muhammad Mateen Hassan Author-X-Name-First: Muhammad Mateen Author-X-Name-Last: Hassan Author-Name: Maryam Rasool Author-X-Name-First: Maryam Author-X-Name-Last: Rasool Author-Name: Muhammad Umair Asghar Author-X-Name-First: Muhammad Umair Author-X-Name-Last: Asghar Author-Name: Zeeshan Zahid Author-X-Name-First: Zeeshan Author-X-Name-Last: Zahid Author-Name: Adnan Ahmed Khan Author-X-Name-First: Adnan Ahmed Author-X-Name-Last: Khan Author-Name: Imran Rashid Author-X-Name-First: Imran Author-X-Name-Last: Rashid Author-Name: Abdul Rauf Author-X-Name-First: Abdul Author-X-Name-Last: Rauf Author-Name: Farooq Ahmed Bhatti Author-X-Name-First: Farooq Ahmed Author-X-Name-Last: Bhatti Title: A novel UWB MIMO antenna array with band notch characteristics using parasitic decoupler Abstract: This paper presents a 4 × 4 multiple-input–multiple-output (MIMO) antenna array for ultra-wide band (UWB) applications with 5.5 GHz wireless local area network (WLAN) band rejection characteristics. The single UWB antenna element consists of modified patch antenna with partial ground plane. WLAN band has been rejected by etching a U-shaped slot in the antenna element. The antenna elements have been arranged in a planar geometry where each element is orthogonal to its adjacent element. A fan-shaped parasitic decoupler, that consists of four strip lines connected with a central square-shaped conductor, is placed among the antenna elements. The dimensions of the antenna array are 67 × 67 × 1.6 mm3. Full wave simulations and experiments have been conducted where measured peak gain and average isolation were 8.1 and −20 dB, respectively. The calculated envelop correction coefficient was less than 0.01. Journal: Journal of Electromagnetic Waves and Applications Pages: 1225-1238 Issue: 9 Volume: 34 Year: 2020 Month: 6 X-DOI: 10.1080/09205071.2019.1682063 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1682063 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:9:p:1225-1238 Template-Type: ReDIF-Article 1.0 Author-Name: Rakesh N. Tiwari Author-X-Name-First: Rakesh N. Author-X-Name-Last: Tiwari Author-Name: Prabhakar Singh Author-X-Name-First: Prabhakar Author-X-Name-Last: Singh Author-Name: Binod Kumar Kanaujia Author-X-Name-First: Binod Kumar Author-X-Name-Last: Kanaujia Author-Name: Sachin Kumar Author-X-Name-First: Sachin Author-X-Name-Last: Kumar Author-Name: Surendra Kumar Gupta Author-X-Name-First: Surendra Kumar Author-X-Name-Last: Gupta Title: A low profile dual band MIMO antenna for LTE/Bluetooth/Wi-Fi/WLAN applications Abstract: In the present endeavor, a CPW-fed dome-shaped monopole radiating elements with 2 × 2 MIMO configuration is presented. The dual-band response of the antenna is obtained by embedding a pair of comb-shaped slots in the ground plane. The measured dual frequency bands of 2.11–4.19 GHz (lower) and 4.98–6.81 GHz (upper) effectively cover LTE, Wi-Fi/WLAN, Bluetooth, and Wi-MAX applications. A T-shaped stub is integrated with the ground plane to obtain high isolation (>21 dB). The measured antenna gain varies in the range of 2.75–4.19 dBi and its radiation efficiency is found greater than 70% in both the resonating bands. The overall size of the proposed antenna is 20 × 34 × 1.6 mm3. The antenna is fabricated and measured results are validated with the results obtained by CST Microwave Studio. Finally, various diversity parameters are evaluated for the antenna and the results are satisfactory for MIMO applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1239-1253 Issue: 9 Volume: 34 Year: 2020 Month: 6 X-DOI: 10.1080/09205071.2020.1716859 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1716859 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:9:p:1239-1253 Template-Type: ReDIF-Article 1.0 Author-Name: Aziz Dkiouak Author-X-Name-First: Aziz Author-X-Name-Last: Dkiouak Author-Name: Alia Zakriti Author-X-Name-First: Alia Author-X-Name-Last: Zakriti Author-Name: Mohssine El Ouahabi Author-X-Name-First: Mohssine Author-X-Name-Last: El Ouahabi Title: Design of a compact dual-band MIMO antenna with high isolation for WLAN and X-band satellite by using orthogonal polarization Abstract: This paper presents a new design of a compact dual-band Multiple Input Multiple Output (MIMO) antenna with high isolation for WLAN and X-band satellite applications. The proposed antenna is realized using three slots: the first slot is used on the upper layer to create the second resonance frequency at 5.3 GHz and two symmetrical slots are etched on the bottom layer to enhance the impedance bandwidth of the two operating bands. In order to obtain a low mutual coupling, the two antenna elements have an orthogonal polarization. The simulated results show that the MIMO antenna has a high isolation (S21 ≤−22.5 dB) at the two desired bands with impedance bandwidths are about 4.15% (5.19–5.41 GHz) and 4.81% (7.30–7.66 GHz). In addition, the MIMO parameters like envelope correlation coefficient (ECC), diversity gain (DG), Total Active Reflection Coefficient (TARC), realized gain and efficiency are also analyzed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1254-1267 Issue: 9 Volume: 34 Year: 2020 Month: 6 X-DOI: 10.1080/09205071.2019.1657504 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1657504 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:9:p:1254-1267 Template-Type: ReDIF-Article 1.0 Author-Name: Aziz Dkiouak Author-X-Name-First: Aziz Author-X-Name-Last: Dkiouak Author-Name: Alia Zakriti Author-X-Name-First: Alia Author-X-Name-Last: Zakriti Author-Name: Mohssine El Ouahabi Author-X-Name-First: Mohssine Author-X-Name-Last: El Ouahabi Author-Name: Aicha Mchbal Author-X-Name-First: Aicha Author-X-Name-Last: Mchbal Title: Design of two element Wi-MAX/WLAN MIMO antenna with improved isolation using a short stub-loaded resonator (SSLR) Abstract: In this paper, we design a compact MIMO antenna with high isolation. The antenna covers 2.5/5.8 GHz frequency bands, which are allocated for Wi-MAX / WLAN applications. The suggested MIMO antenna consists of two identical F-shaped monopole antenna elements, which are symmetrically positioned on the top side of an FR-4 substrate. To increase the isolation between the two radiating elements, a T-shaped junction is added which acts as a short stub-loaded resonator (SSLR). To improve the impedance matching, different forms are engraved on the bottom. The measured results show that the proposed antenna has impedance bandwidths of 16.23% (2.32–2.73 GHz) and10.07% (5.56–6.15 GHz), with a mutual coupling of less than –19 dB. Also, the proposed design exhibits high diversity performance in terms of ECC (9.81 dB) on the entire operating band. Furthermore, the MIMO parameters like TARC and efficiency are also studied. Journal: Journal of Electromagnetic Waves and Applications Pages: 1268-1282 Issue: 9 Volume: 34 Year: 2020 Month: 6 X-DOI: 10.1080/09205071.2020.1756927 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1756927 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:9:p:1268-1282 Template-Type: ReDIF-Article 1.0 Author-Name: Amit Birwal Author-X-Name-First: Amit Author-X-Name-Last: Birwal Author-Name: Sanjeev Singh Author-X-Name-First: Sanjeev Author-X-Name-Last: Singh Author-Name: Binod Kumar Kanaujia Author-X-Name-First: Binod Kumar Author-X-Name-Last: Kanaujia Author-Name: Sachin Kumar Author-X-Name-First: Sachin Author-X-Name-Last: Kumar Title: Low-profile 2.4/5.8 GHz MIMO/diversity antenna for WLAN applications Abstract: A low-profile multi-input-multi-output (MIMO)/diversity antenna suitable for wireless local area network (WLAN) applications is presented. In the proposed antenna, two identical elements (each of size 20 × 47 mm2) are designed to operate at 2.4 GHz and other two identical elements (each of size 20.5 × 20 mm2) at 5.8 GHz. All elements of the proposed diversity antenna are printed on 1.6 mm thick FR-4 substrate in a coplanar configuration. By optimizing the distance between the antenna elements (in horizontal and vertical directions), optimal isolation and diversity performance are achieved. Compared to a single feed dual-band antenna, the MIMO/diversity antenna has the ability to transmit or receive the 2.4 and 5.8 GHz signals simultaneously, without any external switching circuit between the module and the proposed antenna. Journal: Journal of Electromagnetic Waves and Applications Pages: 1283-1299 Issue: 9 Volume: 34 Year: 2020 Month: 6 X-DOI: 10.1080/09205071.2020.1757516 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1757516 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:9:p:1283-1299 Template-Type: ReDIF-Article 1.0 Author-Name: Kamil Staszek Author-X-Name-First: Kamil Author-X-Name-Last: Staszek Author-Name: Slawomir Gruszczynski Author-X-Name-First: Slawomir Author-X-Name-Last: Gruszczynski Author-Name: Krzysztof Wincza Author-X-Name-First: Krzysztof Author-X-Name-Last: Wincza Title: Broadband feeding networks based on directional filters for two-beam antenna arrays Abstract: An alternative approach for the design of feeding networks designated for two-beam antenna arrays that ensure similar radiation patterns in a very broad frequency range has been proposed. The presented concept is based on directional filters that are utilized for smooth change of excitation signals of two broadband radiating elements and a broadband directional coupler used for ensuring quadrature excitations between two identical parts of the antenna arrays. The proposed concept has been confirmed by measurements of two-beams antenna arrays operating in frequency ratio fH/fL ≈ 2:1 and 3:1. Journal: Journal of Electromagnetic Waves and Applications Pages: 1300-1307 Issue: 9 Volume: 34 Year: 2020 Month: 6 X-DOI: 10.1080/09205071.2019.1657964 File-URL: http://hdl.handle.net/10.1080/09205071.2019.1657964 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:34:y:2020:i:9:p:1300-1307 Template-Type: ReDIF-Article 1.0 Author-Name: Tong Van Luyen Author-X-Name-First: Tong Van Author-X-Name-Last: Luyen Author-Name: Hoang Manh Kha Author-X-Name-First: Hoang Manh Author-X-Name-Last: Kha Author-Name: Nguyen Viet Tuyen Author-X-Name-First: Nguyen Viet Author-X-Name-Last: Tuyen Author-Name: Truong Vu Bang Giang Author-X-Name-First: Truong Vu Bang Author-X-Name-Last: Giang Title: An efficient ULA pattern nulling approach in the presence of unknown interference Abstract: In this study, an adaptive pattern nulling approach of half-wave dipole uniform linear arrays (DULA), inspired by binary bat algorithm (BBA)-based beamformers and the phase-only control of array excitation weights, has been proposed. This helps suppress interference with unknown directions in the sidelobe region. Several scenarios have been conducted to investigate the performance of the proposal including operation speed and adaptive pattern nulling with or without the effect of mutual coupling. The simulation results show that the proposed approach is a potential solution to precisely place nulls at any direction of unknown interferences while maintaining the main lobe and suppressing the sidelobes. In addition, regarding the pattern nulling, the approach proposed in this study demonstrates greater efficiency and higher speed than those using binary particle swarm optimization (BPSO). Journal: Journal of Electromagnetic Waves and Applications Pages: 1-18 Issue: 1 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1819442 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1819442 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:1:p:1-18 Template-Type: ReDIF-Article 1.0 Author-Name: Vladimir L. Bakunin Author-X-Name-First: Vladimir L. Author-X-Name-Last: Bakunin Author-Name: Mikhail Yu. Glyavin Author-X-Name-First: Mikhail Yu. Author-X-Name-Last: Glyavin Author-Name: Gregory G Denisov Author-X-Name-First: Gregory G Author-X-Name-Last: Denisov Author-Name: Yulia V. Novozhilova Author-X-Name-First: Yulia V. Author-X-Name-Last: Novozhilova Title: Investigation of mode interaction for a gyrotron with dense mode spectrum Abstract: Influence of the density of mode spectrum in the gyrotron cavity on the possibility of stable single-mode operation has been investigated for high-order modes. Interaction of the operating mode with its two neighboring satellites, symmetrically spaced in frequency, is analyzed. Some threshold value of mode spectrum density dependent on the beam current is found. Journal: Journal of Electromagnetic Waves and Applications Pages: 19-26 Issue: 1 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1821790 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1821790 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:1:p:19-26 Template-Type: ReDIF-Article 1.0 Author-Name: Chao Gu Author-X-Name-First: Chao Author-X-Name-Last: Gu Author-Name: Vincent Fusco Author-X-Name-First: Vincent Author-X-Name-Last: Fusco Title: PCB prism absorber design and characterisation Abstract: This article presents a stack of metal/dielectric lamination absorber shaped as a doubly periodic array of truncated prism. We show how the EM absorption characteristics can be modified through simple changes to the geometric structure of the unit cell. The resultant absorber can be designed to exhibit broadband performance, i.e. 10 dB return loss from 8.2 to 14.2 GHz. We then discuss the angular TE, TM incidence absorption characteristics of a doubly periodic arrangement of square truncated prism array. Through EM simulation, we demonstrate the possibility for optical imaging through the absorber by introducing perforations into it. Finally, we show how to use a waveguide simulator method to experimentally verify the absorption performance of the basic structure. Journal: Journal of Electromagnetic Waves and Applications Pages: 27-38 Issue: 1 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1824691 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1824691 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:1:p:27-38 Template-Type: ReDIF-Article 1.0 Author-Name: K. P. Prajosh Author-X-Name-First: K. P. Author-X-Name-Last: Prajosh Author-Name: Uday K. Khankhoje Author-X-Name-First: Uday K. Author-X-Name-Last: Khankhoje Author-Name: Francesco Ferranti Author-X-Name-First: Francesco Author-X-Name-Last: Ferranti Title: Element excitation optimization for phased array fault diagnosis Abstract: We present techniques for solving the problem of detecting element failures in phased array antennas by using a combination of a single fixed probe and an optimization of element excitations using principles derived from compressive sensing. This departs significantly from conventional techniques where the excitations are held constant and probes are instead moved spatially to collect measurements. Doing so helps us to accomplish two objectives with regards to successful fault diagnosis. First, we achieve a reduction in the number of measurements required compared to the state of the art; this reduction is particularly significant in the case of high-noise measurements where existing methods fail. Second, our techniques solve the problem of fault diagnosis in the case of real valued measurements (i.e. intensity measurement along with phase detection instead of phase measurement), which leads to simpler measurement hardware. We use nonconvex optimization algorithms to generate numerical results in support of our conclusions. Journal: Journal of Electromagnetic Waves and Applications Pages: 39-50 Issue: 1 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1825123 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1825123 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:1:p:39-50 Template-Type: ReDIF-Article 1.0 Author-Name: Z. Seifi Author-X-Name-First: Z. Author-X-Name-Last: Seifi Author-Name: A. Ghorbani Author-X-Name-First: A. Author-X-Name-Last: Ghorbani Author-Name: A. Abdipour Author-X-Name-First: A. Author-X-Name-Last: Abdipour Title: Time-domain analysis and experimental investigation of electromagnetic wave coupling to RF/microwave nonlinear circuits Abstract: This paper presents an efficient time-domain analysis of RF/microwave nonlinear circuits in the presence of the incident uniform plane wave. In this paper, a set of differential equations, including the linear equations due to incident field coupling and nonlinear state equations for the active part of the circuit, are derived and simultaneously solved using the finite difference time domain (FDTD) method. Moreover, a numerical approach with global convergence is used to guarantee the stability of the proposed algorithm. Furthermore, for validation of the proposed method, the theoretical and experimental studies using a measurement setup, including a transverse electromagnetic (TEM) cell, are carried out for performance analysis of a low noise amplifier illuminated by the high-power incident plane wave. By comparison with measurement results, satisfactory accuracy is obtained, which indicates the ability of the proposed method in dealing with the radiated susceptibility of RF/microwave circuits, involving the electromagnetic interference (EMI) problem. Journal: Journal of Electromagnetic Waves and Applications Pages: 51-70 Issue: 1 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1825994 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1825994 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:1:p:51-70 Template-Type: ReDIF-Article 1.0 Author-Name: Deniz Ustun Author-X-Name-First: Deniz Author-X-Name-Last: Ustun Author-Name: Feyza Toktas Author-X-Name-First: Feyza Author-X-Name-Last: Toktas Title: Surrogate-based computational analysis and design for H-shaped microstrip antenna Abstract: A conceptual Kriging surrogate model (KSM) for the computational analysis and design of H-shaped microstrip antennas (HMAs) is proposed in this study. A dataset contains 216 simulated HMAs with different physical/electrical parameters of the HMAs and the respective resonant frequency (RF) values are employed in construction and test processes of the KSM. The performance of the KSM is tested and verified through 20 and 13 HMAs by an extensive comparison with the state-of-the-art models. The results illustrate that KSM computes the most accurate RF values of 20 and 13 HMAs with absolute percent error (APE) of 0.48% and 0.76%, respectively. Moreover, a miniaturized HMA is optimally designed through the KSM as 27% smaller than the smallest design in the dataset for operating at about 2.40 GHz. Therefore, the performance of the proposed method is validated by means of the fabrication of the miniaturized HMA. Journal: Journal of Electromagnetic Waves and Applications Pages: 71-82 Issue: 1 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1828181 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1828181 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:1:p:71-82 Template-Type: ReDIF-Article 1.0 Author-Name: Zi-Kai Yang Author-X-Name-First: Zi-Kai Author-X-Name-Last: Yang Author-Name: Zhao Li Author-X-Name-First: Zhao Author-X-Name-Last: Li Author-Name: Sheng Zhao Author-X-Name-First: Sheng Author-X-Name-Last: Zhao Author-Name: Xiang-Dong Huang Author-X-Name-First: Xiang-Dong Author-X-Name-Last: Huang Title: A simple microwave method to assess the uniformity of steel fiber distribution in the SFRC Abstract: This paper presents a simple microwave non-destructive method to assess the uniformity of fiber distribution in the steel fiber reinforced concrete (SFRC). To simplify the assessment, only the amplitude attenuation information is needed, but no phase information is required. The assessment can be achieved by means of the relationship between the attenuation constant and the quantity of steel fibers per unit volume in the SFRC, which is deduced based on the Maxwell–Garnett mixing rule and the Clausius–Mossotti formulation. A measurement system based on two horn antennas in a transmission arrangement is built to analyze a real building wall for the verification of the proposed method. In addition, the cosine similarity index is proposed to confirm the validity of the experiment. The obtained results imply that the presented method is effective and simple to assess the uniformity of fiber distribution. Journal: Journal of Electromagnetic Waves and Applications Pages: 83-94 Issue: 1 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1828182 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1828182 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:1:p:83-94 Template-Type: ReDIF-Article 1.0 Author-Name: A. Mercy Latha Author-X-Name-First: A. Author-X-Name-Last: Mercy Latha Author-Name: S. K. Ghosh Author-X-Name-First: S. K. Author-X-Name-Last: Ghosh Title: A comprehensive review of depressed collectors of slow-wave devices Abstract: Collectors are an indispensable part of any vacuum microwave devices where the electron beam – so-called spent electron beam emerged from interaction structure – is collected. Although the first publication on depressed collectors dates back to 1940s, several evolving researches are still being carried out on collectors till date. The incessant publications from researchers all over the globe reveal the fact that this field has much more potential and vigor to be explored. The outcome of such intensive and diversified research has been in achieving several novel design variants in the geometry, different computer-aided modeling and design optimization techniques, innovative methods to counter/suppress secondary electrons. This comprehensive review has been intended to cover all the major research findings consolidating them at one place so that it could be beneficial to any new reader in this field, thereby further research progress may be accelerated. Journal: Journal of Electromagnetic Waves and Applications Pages: 95-137 Issue: 1 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1823895 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1823895 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:1:p:95-137 Template-Type: ReDIF-Article 1.0 Author-Name: Kanishka Katoch Author-X-Name-First: Kanishka Author-X-Name-Last: Katoch Author-Name: Naveen Jaglan Author-X-Name-First: Naveen Author-X-Name-Last: Jaglan Author-Name: Samir Dev Gupta Author-X-Name-First: Samir Dev Author-X-Name-Last: Gupta Title: Analysis and design of a simple and compact bandstop Frequency Selective Surface at mobile WiMAX and satellite communication X-band Abstract: This article presents a dual notched Frequency Selective Surface (FSS) using a compact structure. Four sub-cell square split ring resonators (SSRRs) are imprinted over 8×8 mm2 FR-4 substrate in a 90° clockwise rotational symmetric manner. Dual resonant bands are obtained at 3.08 GHz ranging from 2.5 to 3.6 GHz and 10.2 GHz ranging from 7.95 GHz to 12.3 GHz. The proposed FSS covers the WiMAX band ranging from 2.5 to 2.7 GHz and 3.3 to 3.6 GHz and entire X-band ranging from 8 to 12 GHz. The structure presents a good angular response for both TE and TM incident polarized wave for normal and oblique angles. The pass band from 4.3 GHz to 5 GHz frequency with resonant dip at 4.6 GHz is obtained. The maximum relative deviation in between transmission zero frequency and angularly incident frequency is 1.2% and 4.2% at 70° TM and TE polarized wave, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 1321-1336 Issue: 10 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1888319 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1888319 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:10:p:1321-1336 Template-Type: ReDIF-Article 1.0 Author-Name: R. M. H. Bilal Author-X-Name-First: R. M. H. Author-X-Name-Last: Bilal Author-Name: M. A. Naveed Author-X-Name-First: M. A. Author-X-Name-Last: Naveed Title: A comment: a set square design metamaterial absorber for X-band applications Abstract: Recently, Barde C, Choubey A, Sinha R. [A set square design metamaterial absorber for X-band applications. J Electromagn Waves Appl. 2020;34:1430–1443.] have demonstrated the metamaterial absorber for X-band applications. In the present communication, we numerically investigated that a cross-polarizer is mistakenly reported as a wideband metamaterial absorber. Authors ignored the cross-polarized reflection component in the calculation of the absorption. Moreover, it is proved that the anisotropic geometry of the unit cell provides poor absorption and it is suitable for the polarization conversion. Journal: Journal of Electromagnetic Waves and Applications Pages: 1354-1358 Issue: 10 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1888809 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1888809 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:10:p:1354-1358 Template-Type: ReDIF-Article 1.0 Author-Name: Sol Kim Author-X-Name-First: Sol Author-X-Name-Last: Kim Author-Name: Jeong-Wook Kim Author-X-Name-First: Jeong-Wook Author-X-Name-Last: Kim Author-Name: Hyunyoung Cho Author-X-Name-First: Hyunyoung Author-X-Name-Last: Cho Author-Name: ByungKuon Ahn Author-X-Name-First: ByungKuon Author-X-Name-Last: Ahn Author-Name: Kwang-Seok Kim Author-X-Name-First: Kwang-Seok Author-X-Name-Last: Kim Author-Name: Jong-Won Yu Author-X-Name-First: Jong-Won Author-X-Name-Last: Yu Title: Squint-less arc array for near-field focusing in wideband systems Abstract: In this paper, the arc array for squint-less near-field focusing is used, theoretically analyzed, and verified. The arc array is designed to overcome the squint phenomenon in the near-field and transfers the maximum power at a focused distance. The implemented transmitter is composed of $ 16\times 1 $ 16×1 vivaldi antennas with a $ 0.7\lambda $ 0.7λ spacing and operates at a frequency of 5.8 GHz. In addition, the design method of the arc array is proposed, considering the focused distances. In the experiments, the bending degree of the arc array is $ 4.14^{\circ } $ 4.14∘ when the focused distance is 0.5 m. At a fractional bandwidth of 27.5%, the focus position is shifted 32%. On the other hand, in the arc array, the focus position is not shifted. Experimental results from the implemented arc array show good agreement with the proposed theory. Journal: Journal of Electromagnetic Waves and Applications Pages: 1378-1387 Issue: 10 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1890642 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1890642 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:10:p:1378-1387 Template-Type: ReDIF-Article 1.0 Author-Name: Fangzhou Guo Author-X-Name-First: Fangzhou Author-X-Name-Last: Guo Author-Name: Qingzhi Wu Author-X-Name-First: Qingzhi Author-X-Name-Last: Wu Title: Mode matching analysis of a novel transmission line with two centrosymmetric longitudinal slots Abstract: In this paper, the mode matching (MM) method is applied to analyze the dispersion of the newly proposed transmission line (TL), centrosymmetric double-slotted line (CSDSL). For simplicity, the lateral metallic vias are replaced with the electric walls (EWs). Furthermore, four magnetic walls (MWs) are added to guarantee the boundary condition (BC) of MM. The proposed method is compared with the 3D electromagnetic field analysis (HFSS). The result shows a good agreement between the dispersions of the dominant mode obtained using MM method and HFSS. Additionally, the dispersions of the higher modes of CSDSL are also provided using the proposed method with convergent results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1310-1320 Issue: 10 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1887000 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1887000 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:10:p:1310-1320 Template-Type: ReDIF-Article 1.0 Author-Name: Konstantin Kobrin Author-X-Name-First: Konstantin Author-X-Name-Last: Kobrin Author-Name: Vyacheslav Rudakov Author-X-Name-First: Vyacheslav Author-X-Name-Last: Rudakov Author-Name: Zimeng Li Author-X-Name-First: Zimeng Author-X-Name-Last: Li Author-Name: Mikhail Manuilov Author-X-Name-First: Mikhail Author-X-Name-Last: Manuilov Title: A novel high-performance diplexer for mobile communication base stations Abstract: In this paper, a novel design of a diplexer for mobile communication base station is proposed, theoretically investigated and successfully tested. The proposed design of the diplexer is implemented on the base of interdigital filters. Successfully fabricated and tested diplexer operates within frequency bands 2.3–2.4/2.49–2.69 GHz and shows high performances: reflection loss within pass bands is less −20 dB, insertion loss is −0.15 dB, isolation is −30 dB and intermodulation is −124 dBm.Computer-aided design of the diplexer is carried out on the basis of combined technique, which includes filter synthesis using coupling matrices, eigenvalue problem solution for single resonator, interresonator coupling calculation and final full wave simulation and optimization of diplexer. The suggested design is a promising candidate for the implementation of diplexers with narrow, moderate and wide bandwidths for standard mobile communication frequency bands. Journal: Journal of Electromagnetic Waves and Applications Pages: 1273-1289 Issue: 10 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1886998 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1886998 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:10:p:1273-1289 Template-Type: ReDIF-Article 1.0 Author-Name: Yanfei Gong Author-X-Name-First: Yanfei Author-X-Name-Last: Gong Author-Name: Jianhong Hao Author-X-Name-First: Jianhong Author-X-Name-Last: Hao Author-Name: Jian Sun Author-X-Name-First: Jian Author-X-Name-Last: Sun Author-Name: Chaofei Gao Author-X-Name-First: Chaofei Author-X-Name-Last: Gao Author-Name: Xingtong Chen Author-X-Name-First: Xingtong Author-X-Name-Last: Chen Title: Fast prediction of the shielding effectiveness and resonances of the heterotypic metallic enclosure with a built-in dielectric plate Abstract: On the basis of the characteristics of the heterotypic metallic enclosure with a built-in dielectric plate, this paper proposes an analytical method to evaluate the shielding performance of an apertured enclosure with convex or stepped structure under the plane wave illumination. First, the heterotypic enclosure is modeled based on the electromagnetic topology (EMT) theory, where the scattering parameter matrix at the discontinuous position can be derived according to the theory of microwave circuit. Then, the expressions of total voltage components can be obtained by using the extended Baum-Liu-Tesche (BLT) equation, which are convenient to calculate the SE at the monitor point. Finally, the effectiveness and accuracy of the proposed method in predicting the shielding effectiveness (SE) and resonances of heterotypic enclosure are verified by the computer simulation technology (CST) through several cases. Compared with the CST simulation, the proposed method is more efficient and takes up less memory. Journal: Journal of Electromagnetic Waves and Applications Pages: 1290-1309 Issue: 10 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1886999 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1886999 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:10:p:1290-1309 Template-Type: ReDIF-Article 1.0 Author-Name: Asutosh Mohanty Author-X-Name-First: Asutosh Author-X-Name-Last: Mohanty Author-Name: Sudhakar Sahu Author-X-Name-First: Sudhakar Author-X-Name-Last: Sahu Title: Integration of coupling resonator as port-isolator and MMLC-Minkowiski fractal loop for Wi-Max rejection in 4-port compact UWB MIMO antenna Abstract: This paper presents a 4-port compact UWB MIMO antenna. It has 45 $ ^{0} $ 0 tilted offset feed for better impedance matching and connected to cornered cut-out quad-radiators. Radially symmetric resonators are provided for impedance matching and isolation improvements. A miniaturized magnetic LC (MMLC) Minkowiski fractal loop acts as a magnetic shield between electric walls of feed and resonator for Wi-max band rejection. The contra-rotational symmetry of resonator and rotationally asymmetric strips in ground enhances isolation. To validate, a prototype antenna is fabricated and measured which shows good agreements. The proposed antenna has a compact dimension 31 mm × 31 mm, operates from 2.27 to 11.7 GHz and reject bands at 3.0–4.2 GHz. The average gain is > 4 dBi with ECC < 0.16 in the operating band. An equivalent circuit topology is also modelled which validates the design. The multi-port antenna system can be used for microwave imaging, RF-sensing and radar applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1359-1377 Issue: 10 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1890232 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1890232 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:10:p:1359-1377 Template-Type: ReDIF-Article 1.0 Author-Name: Fedir O. Yevtushenko Author-X-Name-First: Fedir O. Author-X-Name-Last: Yevtushenko Author-Name: Sergii V. Dukhopelnykov Author-X-Name-First: Sergii V. Author-X-Name-Last: Dukhopelnykov Author-Name: Tatiana L. Zinenko Author-X-Name-First: Tatiana L. Author-X-Name-Last: Zinenko Title: E-polarized plane-wave scattering from a PEC strip grating on a dielectric substrate: analytical regularization and lattice-mode resonances Abstract: We consider a plane E-polarized wave scattering from an infinite flat grating of slots cut in a perfect electrically conducting plane, backed with a dielectric slab. At first, we reduce this problem to a dual series equation for the complex amplitudes of the Floquet spatial harmonics. Then we perform its analytical regularization, based on the inversion of the main part with the aid of the Riemann-Hilbert Problem. This yields a Fredholm second-kind infinite matrix equation, numerical solution of which has a guaranteed convergence. We perform numerical experiments demonstrating how the rate of convergence depends on the thickness and dielectric permittivity of the slab. Our computations demonstrate the Fano-shape resonances on the so-called lattice modes, responsible for the phased array blindness. Their frequencies lay near to the Rayleigh anomalies and, if the slots or strips are narrow and the slab is thin, may have ultrahigh Q-factors. Journal: Journal of Electromagnetic Waves and Applications Pages: 1388-1405 Issue: 10 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1887001 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1887001 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:10:p:1388-1405 Template-Type: ReDIF-Article 1.0 Author-Name: Sourav Roy Author-X-Name-First: Sourav Author-X-Name-Last: Roy Author-Name: Ashim Kumar Biswas Author-X-Name-First: Ashim Kumar Author-X-Name-Last: Biswas Author-Name: Soumendu Ghosh Author-X-Name-First: Soumendu Author-X-Name-Last: Ghosh Author-Name: Ujjal Chakraborty Author-X-Name-First: Ujjal Author-X-Name-Last: Chakraborty Author-Name: Abhishek Sarkhel Author-X-Name-First: Abhishek Author-X-Name-Last: Sarkhel Title: Isolation improvement of dual-/quad-element textile MIMO antenna for 5G application Abstract: A compact wideband dual-/quad-element multiple input multiple output (MIMO) antenna, using jeans textile material for WiMAX (IEEE 802.16d) and 5G application band, is proposed. The wideband nature of basic single element antenna with a frequency span of 2.74 to 4.41 GHz (47%) is analyzed in detail by using circuit model representation. Thereafter, in order to resolve different practical issues, such as multipath fading, shadowing and scattering of electromagnetic waves as well as human body effect, wideband compact quad-element MIMO antenna is presented. To improve isolation characteristics, meander line structures are integrated in-between the antenna elements. Isolation is achieved greater than 19dB over the whole application band. The diversity parameters such as envelope correlation coefficient (ECC < 0.2), diversity gain (DG > 9.6) and mean effective gain (MEG = ±0.3dB) are found within the satisfactory ranges. Measured outcomes are also good enough to confirm the antenna as a suitable contender for wearable scenarios. Journal: Journal of Electromagnetic Waves and Applications Pages: 1337-1353 Issue: 10 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1888808 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1888808 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:10:p:1337-1353 Template-Type: ReDIF-Article 1.0 Author-Name: Zhong-Liang Zhou Author-X-Name-First: Zhong-Liang Author-X-Name-Last: Zhou Author-Name: Cong Wang Author-X-Name-First: Cong Author-X-Name-Last: Wang Author-Name: Alok Kumar Author-X-Name-First: Alok Author-X-Name-Last: Kumar Author-Name: Dan-Qing Zou Author-X-Name-First: Dan-Qing Author-X-Name-Last: Zou Author-Name: Yu-Chen Wei Author-X-Name-First: Yu-Chen Author-X-Name-Last: Wei Author-Name: Luqman Ali Author-X-Name-First: Luqman Author-X-Name-Last: Ali Author-Name: Meng Zhao Author-X-Name-First: Meng Author-X-Name-Last: Zhao Title: Coding DGS resonator sensor for ultra-high Q-factor dielectric thickness detection Abstract: In this paper, a high Q-factor-based defective ground structure (DGS) etched microwave resonator is demonstrated to identify the unknown thickness of non-destructive monolayer dielectric material. The proposed structure consists of coupled sharp-edged split-square resonator (CS-SSR), a high-impedance microstrip line, and symmetrically coded DGS optimized by adaptive genetic algorithm (AGA), which is evaluated through simulation and experiment assessment. AGA is applied to obtain ultra-high quality factor (Q-factor) using a robust calculation model with rapid convergence speed. The high Q-factor leads to high sensitivity, better accuracy, and enhanced resolution of the microwave sensor. Furthermore, the comparison of the results between the codeless, asymmetrical, and symmetrical DGS resonator illustrates that the symmetrical coding DGS resonator with higher sensitivity and better performance for dielectric material thickness detection sensors. Journal: Journal of Electromagnetic Waves and Applications Pages: 1464-1476 Issue: 11 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1895896 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1895896 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:11:p:1464-1476 Template-Type: ReDIF-Article 1.0 Author-Name: Sangin Kim Author-X-Name-First: Sangin Author-X-Name-Last: Kim Author-Name: Hyunjae Lee Author-X-Name-First: Hyunjae Author-X-Name-Last: Lee Author-Name: Yeong-Hoon Noh Author-X-Name-First: Yeong-Hoon Author-X-Name-Last: Noh Author-Name: Jong-Gwan Yook Author-X-Name-First: Jong-Gwan Author-X-Name-Last: Yook Title: Polarimetric micro-doppler signature measurement of a small drone and its resonance phenomena Abstract: This study presents the micro-Doppler signature (MDS) of small drones based on resonance phenomena. The MDS analysis of a drone is conducted for various detection conditions. The Doppler frequencies due to the rotation of rotor blades, characterized by different materials and dimensions, are extracted at specific angular frequencies. It is confirmed that the resonance phenomenon caused by the copper-coated conducting rotor blade significantly affects the Doppler frequency. As the rotor blade dimension increases, the resonance effect moves to a lower frequency band. It is interesting to note that the resonance effect of horizontal to horizontal (HH) polarization occurs in a lower frequency band compared to vertical to vertical (VV) polarization. Additionally, it is performed in a monostatic and bistatic radar environment to analyze the resonance effect. The theoretical analysis based on full-wave simulation is confirmed via measurements with frequency-modulation continuous wave (FMCW) radar. Journal: Journal of Electromagnetic Waves and Applications Pages: 1493-1510 Issue: 11 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1898480 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1898480 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:11:p:1493-1510 Template-Type: ReDIF-Article 1.0 Author-Name: Luilly A. G. Ortiz Author-X-Name-First: Luilly A. Author-X-Name-Last: G. Ortiz Author-Name: Renato C. Mesquita Author-X-Name-First: Renato Author-X-Name-Last: C. Mesquita Author-Name: Naísses Z. Lima Author-X-Name-First: Naísses Author-X-Name-Last: Z. Lima Title: Creating higher order vector shape functions based on H(curl) for the edge meshless method Abstract: The goal of this work is to extend the Edge Meshless Method (EMM) presenting a new way to build the vector shape functions based on the H(curl) space. These vector shape functions allow the use of four, five and six edges in the support domain. For this, the basis functions polynomial order is increased. The new EMM vector shape functions are applied to eigenvalues problems with different media. The numerical solution is not corrupted by spurious modes, field singularities generated by corners are correctly overcome and the continuity of tangential components across the interface between two different media is satisfied. The shape function with six edges in the support domain present the best results, where the majority of the eigenvalues double their convergence rate. Also, approximations of different polynomial orders can be used in the same problem. Journal: Journal of Electromagnetic Waves and Applications Pages: 1511-1528 Issue: 11 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1901787 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1901787 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:11:p:1511-1528 Template-Type: ReDIF-Article 1.0 Author-Name: Elena A. Velichko Author-X-Name-First: Elena A. Author-X-Name-Last: Velichko Title: Comparative analysis of exact and approximate solutions of the plane electromagnetic wave scattering from a discrete parabolic reflector made of parallel circular PEC wires Abstract: Numerical analysis of the scattering of a plane monochromatic electromagnetic wave from a discrete parabolic reflector made of parallel cylinders (wires) with perfect electric conductivity is carried out in the exact and approximate formulations, the latter neglecting all interactions between the wires. Both the TE and the TM polarizations of the incident field are considered. It is shown that the difference between the exact and approximate solutions strongly depends on the frequency of the incident wave and that the TM-polarized plane wave is focused better by the discrete reflector than the TE-polarized wave. The field in the vicinity of the geometrical focus is investigated. It is found that the focusing ability, oscillating, gradually decreases with frequency. This behavior is in stark contrast to a solid perfectly electrically conducting parabolic reflector. Journal: Journal of Electromagnetic Waves and Applications Pages: 1529-1540 Issue: 11 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1903344 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1903344 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:11:p:1529-1540 Template-Type: ReDIF-Article 1.0 Author-Name: Sarah Clendinning Author-X-Name-First: Sarah Author-X-Name-Last: Clendinning Author-Name: R. Cahill Author-X-Name-First: R. Author-X-Name-Last: Cahill Author-Name: D. Zelenchuk Author-X-Name-First: D. Author-X-Name-Last: Zelenchuk Author-Name: V. Fusco Author-X-Name-First: V. Author-X-Name-Last: Fusco Title: Single screen cross slot polarization convertors with enhanced bandwidth and frequency selective filtering performance Abstract: This paper describes a new design strategy which is used to obtain a fivefold increase in the 3 dB axial ratio bandwidth of linear to circular polarization convertors based on anisotropic frequency selective surfaces composed of single screens of cross slots. The performance improvement is obtained by employing stratified dielectric media to carefully tailor the shape of the TE and TM spectral transmission responses. We demonstrate that a bandwidth of 24.5% can be achieved at a center operating frequency of 10.6 GHz using an array of unequal length cross-slots embedded centrally between two 2.25 mm thick dielectric slabs (εr = 9.0). Moreover it is shown that the inherent self-filtering behavior of the structure provides greater rejection of unwanted signals than designs embedded in lower permittivity material. Computed and experimental axial ratio results are compared to verify the new design methodology. Journal: Journal of Electromagnetic Waves and Applications Pages: 1420-1432 Issue: 11 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1893832 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1893832 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:11:p:1420-1432 Template-Type: ReDIF-Article 1.0 Author-Name: Khalid Saeed Lateef Al-badri Author-X-Name-First: Khalid Saeed Lateef Author-X-Name-Last: Al-badri Author-Name: Yadgar I. Abdulkarim Author-X-Name-First: Yadgar I. Author-X-Name-Last: Abdulkarim Author-Name: Fatih Özkan Alkurt Author-X-Name-First: Fatih Özkan Author-X-Name-Last: Alkurt Author-Name: Muharrem Karaaslan Author-X-Name-First: Muharrem Author-X-Name-Last: Karaaslan Title: Simulated and experimental verification of the microwave dual-band metamaterial perfect absorber based on square patch with a 450 diagonal slot structure Abstract: In this paper, we designed a dual band metamaterial perfect absorber (MPA) for Ku band applications. The overall ultrathin layer of proposed absorber consists of square patch with 450 diagonal slot structure within a copper square patch which loaded on both sides of dielectric thickness 1.6 mm FR-4 substrate. The results show that designed MPA gives two absorption bands at 12.45 and 14.18 GHz and absorption rates are 99.73% and 99.87% respectively. The proposed dual-band absorber has a polarization sensitive characteristic, the absorption performance is almost changing with different polarization angles. Furthermore, resonance centres of two absorption bands can be adjusted by changing related parameters. The novelties of proposed structure are simple, easy fabricate, low cost, durable, suitable for real-time applications and long-term stability considering the fabrication technique and non-destructive measurement method. The dualband absorber can be used in practical applications such as bolometer, EM wave spatial filter and satellite communications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1541-1552 Issue: 11 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1905560 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1905560 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:11:p:1541-1552 Template-Type: ReDIF-Article 1.0 Author-Name: Shu-Chuan Chen Author-X-Name-First: Shu-Chuan Author-X-Name-Last: Chen Author-Name: Jo-Yen Nieh Author-X-Name-First: Jo-Yen Author-X-Name-Last: Nieh Author-Name: Wei-Hsiang Liao Author-X-Name-First: Wei-Hsiang Author-X-Name-Last: Liao Author-Name: Sheng-Min Li Author-X-Name-First: Sheng-Min Author-X-Name-Last: Li Title: DTV/LTE antennas with no physical structure for laptop computers Abstract: This paper proposes a DTV/LTE antenna design without physical structure for laptop computers. By changing the laptop’s right revolving axis to a non-conductor material and exciting several dipoles and loop paths formed by the display, keyboard ground plane and metal revolving axis using a feed matching circuit at an appropriate position of the slot on the hinge to cover the frequency bands for DTV (470–862 MHz) and LTE (698–960 MHz, 1710–2690 MHz). The feed matching circuit is fitted to the keyboard ground plane adjacent to the hinge. It consists of a 3.6 nH chip inductor and a 0.2 pF chip capacitor to improve the high frequency matching and increase the high frequency bandwidth. The antenna can cover the frequency bands required by DTV and LTE, and the measured antenna efficiency in the operational frequency band is also better than 50%. Journal: Journal of Electromagnetic Waves and Applications Pages: 1448-1463 Issue: 11 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1895895 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1895895 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:11:p:1448-1463 Template-Type: ReDIF-Article 1.0 Author-Name: Murat Ozturk Author-X-Name-First: Murat Author-X-Name-Last: Ozturk Author-Name: D. D. L. Chung Author-X-Name-First: D. D. L. Author-X-Name-Last: Chung Title: Radio-wave shielding behavior of steel structures Abstract: The shielding of radio wave by steel-containing structures is desirable for electronics protection but undesirable for telecommunication signal reception. This work investigates the shielding behavior of steel structures consisting of members in various configurations, with the practical aim of determining how the configuration can be exploited to control the shielding. Differently oriented continuous steel reinforcement (stranded/unstranded wires in the unidirectional, crossply and planar coil configurations) are evaluated for electromagnetic interference (EMI) shielding at 600–2000 MHz, using unpolarized radiation. The absorption loss SEA dominates the reflection loss SER. The crossply configuration gives the highest SEA, SEA/thickness and SEA/SET (SET = total loss); the planar coil configuration gives the lowest values. The SEA, SEA/thickness and SEA/SET are moderately higher for the crossply configuration than the unidirectional configuration, because steel’s electrical isotropy allows the 0° electric field to interact with the 90° wire. The SEA/SET is comparable for the stranded and unstranded wires. Journal: Journal of Electromagnetic Waves and Applications Pages: 1407-1419 Issue: 11 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1891975 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1891975 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:11:p:1407-1419 Template-Type: ReDIF-Article 1.0 Author-Name: Mstislav E. Kaliberda Author-X-Name-First: Mstislav E. Author-X-Name-Last: Kaliberda Author-Name: Leonid M. Lytvynenko Author-X-Name-First: Leonid M. Author-X-Name-Last: Lytvynenko Author-Name: Sergey A. Pogarsky Author-X-Name-First: Sergey A. Author-X-Name-Last: Pogarsky Title: Method of singular integral equations in scattering by double-layer infinite strip grating with several strips removed in every layer Abstract: The H-polarized plane wave scattering by the infinite double-layer strip grating with several strips removed in every layer is considered. The scattered field is represented as a sum of the field of currents on the ideally periodic double-layer grating and field of correction currents excited due to the absence of strips. The Fourier amplitudes of these fields are obtained from the singular integral equation with additional conditions. The solution is rigorous. Numerical results for the near and far fields are presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 1433-1447 Issue: 11 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1893833 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1893833 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:11:p:1433-1447 Template-Type: ReDIF-Article 1.0 Author-Name: Shu-Chuan Chen Author-X-Name-First: Shu-Chuan Author-X-Name-Last: Chen Author-Name: Sheng-Min Li Author-X-Name-First: Sheng-Min Author-X-Name-Last: Li Title: Reconfigurable narrow open-slot LTE MIMO antennas for metal-rimmed smartphone applications Abstract: This paper presents a ‘reconfigurable narrow open-slot LTE MIMO antennas for metal-rimmed smartphone applications,’ which consist of two structurally identical L-shaped slot antennas combined with a metal rim with a 1 mm wide opening. The slots are 3 mm wide and 90 mm long, and are placed diagonally on the upper left and lower right corners of the mobile phone in a mirror-symmetrical manner to achieve good isolation. The 1 mm wide opening divides the L-slot structure into a longer open-slot and a shorter open-slot, and two different feed monopoles are designed to couple and excite the resonance modes of the slot by switching between the two different feed monopoles to cover LTE700/GSM850/900 and GSM1800/1900/UMTS/LTE2300/2500, respectively. The measured isolation is better than 11 dB, the measured antenna efficiency is better than 40%, and the calculated ECCs from measured radiation patterns are lower than 0.3. Journal: Journal of Electromagnetic Waves and Applications Pages: 1477-1492 Issue: 11 Volume: 35 Year: 2021 Month: 07 X-DOI: 10.1080/09205071.2021.1897689 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1897689 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:11:p:1477-1492 Template-Type: ReDIF-Article 1.0 Author-Name: M. M. Couto Author-X-Name-First: M. M. Author-X-Name-Last: Couto Author-Name: M. W. B. Silva Author-X-Name-First: M. W. B. Author-X-Name-Last: Silva Author-Name: A. L. P. S. Campos Author-X-Name-First: A. L. P. S. Author-X-Name-Last: Campos Title: A novel ultra-wideband reflective cross-polarization converter based on anisotropic metasurface Abstract: An ultra-thin and ultra-wideband anisotropic metasurface, acting as a linear polarization converter through reflection is designed and simulated in this research. The operation frequency range covers almost completely the Ku-band and the entire K- and Ka-band. The unit cell of the proposed metasurface is composed of a arrangement of concentric square metallic loops on a grounded dielectric substrate, in which a diagonal split is made, providing properties of an anisotropic material. Simulation results show that an efficient cross-polarization conversion, both for normal as well as for oblique incidence, is achieved with $ -10 $ −10 dB fractional bandwidth of 98.7% from 13.8 GHz to 40.7 GHz and with an average polarization conversion ratio of 97.5%. The ultra-wideband of the proposed structure results from multiple plasmonic resonances occurring at three neighboring frequencies (15.2 GHz, 25.9 GHz, and 38 GHz) resulting in a significant expansion of the operating frequency range. Journal: Journal of Electromagnetic Waves and Applications Pages: 1652-1662 Issue: 12 Volume: 35 Year: 2021 Month: 08 X-DOI: 10.1080/09205071.2021.1914742 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1914742 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:12:p:1652-1662 Template-Type: ReDIF-Article 1.0 Author-Name: F. Ponti Author-X-Name-First: F. Author-X-Name-Last: Ponti Author-Name: F. Barbuto Author-X-Name-First: F. Author-X-Name-Last: Barbuto Author-Name: P. P. Di Gregorio Author-X-Name-First: P. P. Author-X-Name-Last: Di Gregorio Author-Name: F. Frezza Author-X-Name-First: F. Author-X-Name-Last: Frezza Author-Name: F. Mangini Author-X-Name-First: F. Author-X-Name-Last: Mangini Author-Name: R. Parisi Author-X-Name-First: R. Author-X-Name-Last: Parisi Author-Name: P. Simeoni Author-X-Name-First: P. Author-X-Name-Last: Simeoni Author-Name: M. Troiano Author-X-Name-First: M. Author-X-Name-Last: Troiano Title: GPR radargrams analysis through machine learning approach Abstract: This work proposes a Machine Learning (ML) approach for the analysis and classification of Ground Penetrating Radar (GPR) given a limited number of B-scan images. Specifically, we consider both a custom Convolutional Neural Network (CNN) and a wellestablished Deep Learning (DL) architecture, DenseNet, that is opportunely scaled down to take into account the small dataset. Those networks are then employed to classify B-scan simulations from buried cylinders in order to retrieve the host media permittivity, the cylinder depth respect to surface, and cylinders radius. A prediction based on the mean-square error (MSE) is applied. The main aim of the proposed work is to test the applicability of a scaled-down version of DenseNet architecture to the analysis of B-scan images and compare the performance respect to a classical CNN. The architecture chosen has shown interesting results in retrieving information from a limited data set. Limitations of the considered approach are also discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1678-1686 Issue: 12 Volume: 35 Year: 2021 Month: 08 X-DOI: 10.1080/09205071.2021.1906329 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1906329 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:12:p:1678-1686 Template-Type: ReDIF-Article 1.0 Author-Name: Shiyun Zhou Author-X-Name-First: Shiyun Author-X-Name-Last: Zhou Author-Name: Tianwu Li Author-X-Name-First: Tianwu Author-X-Name-Last: Li Author-Name: Erping Li Author-X-Name-First: Erping Author-X-Name-Last: Li Title: Design of resistor-loaded coding metasurface for independent amplitude and phase control Abstract: Due to their subwavelength thickness, light weight and easy fabrication, metasurfaces show obvious advantages over 3D metamaterials. Among this, a new concept so-called digital coding metasurfaces which are described in a direct manner by quantized reflection or refraction phases was proposed. This paper proposes a scheme to achieve simultaneous and independent control of phase and amplitude responses via a reflective coding metasurface as it would be beneficial for full control of propagation of electromagnetic waves. The deflection of the reflected beam is dominated by designed coding patterns of digital unit cells while the amplitude adjustment depends on tuning values of loaded resistances on the unit cells. The simulation and experimental results confirm the function of the metasurface proposed above. The independent control of both phase and amplitude profiles of EM waves implies the potential application in beam shaping and high-quality holography. Journal: Journal of Electromagnetic Waves and Applications Pages: 1575-1586 Issue: 12 Volume: 35 Year: 2021 Month: 08 X-DOI: 10.1080/09205071.2021.1908916 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1908916 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:12:p:1575-1586 Template-Type: ReDIF-Article 1.0 Author-Name: Arun Kumar Author-X-Name-First: Arun Author-X-Name-Last: Kumar Author-Name: Santanu Dwari Author-X-Name-First: Santanu Author-X-Name-Last: Dwari Author-Name: Ganga Prasad Pandey Author-X-Name-First: Ganga Prasad Author-X-Name-Last: Pandey Title: A dual-band high-gain microstrip antenna with a defective frequency selective surface for wireless applications Abstract: A dual-band high-gain linearly polarized antenna for wideband operation using a defective frequency selective surface (DFSS) is proposed and demonstrated experimentally. The designed antenna consists of radiating patch, truncated ground with a half-inverted L-shaped rectangular ring and frequency selective surface (FSS) with a defective ground plane. The dimensions are optimized to achieve dual band with a 10-dB impedance bandwidth of 7.72% from 2.37 to 2.56 GHz and 46.75% from 4.60 to 7.41 GHz. The antenna gain is enhanced by 8.8 dBi at lower band and 4.5 dBi at upper wideband. The maximum gain achieved using this technique is 8.8 dBi at 2.4 GHz. The measured and simulated results of the proposed antenna are well-matched in terms of gain, reflection coefficient (S11) and radiation patterns. The Proposed antenna is easy to implement, low cost, low profile and can be used in wireless services like Wi-Fi, Wi-MAX and C band applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1637-1651 Issue: 12 Volume: 35 Year: 2021 Month: 08 X-DOI: 10.1080/09205071.2021.1914195 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1914195 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:12:p:1637-1651 Template-Type: ReDIF-Article 1.0 Author-Name: Chuanbao Du Author-X-Name-First: Chuanbao Author-X-Name-Last: Du Author-Name: Zheng Liu Author-X-Name-First: Zheng Author-X-Name-Last: Liu Author-Name: Congguang Mao Author-X-Name-First: Congguang Author-X-Name-Last: Mao Author-Name: Zhitong Cui Author-X-Name-First: Zhitong Author-X-Name-Last: Cui Author-Name: Dongyang Sun Author-X-Name-First: Dongyang Author-X-Name-Last: Sun Author-Name: Feng Qin Author-X-Name-First: Feng Author-X-Name-Last: Qin Title: Statistical analysis comparison of HEMP transient response of monopole antenna from facility and burst views Abstract: The existing literatures, concentrating on the statistical analysis of transient response of antennas, radiated by high-altitude electromagnetic pulse, always choose an area-based method to calculate the statistics from the perspective of explosion. However, it may be more suitable to analyze from the view of the affected facility position. In this paper, we demonstrate a statistical analysis comparison of multiple norms of the transient response from both viewpoints. Distinguished from the burst view, the location of the affected facility is set as the observer location, and the formulas of uncertain factors, involved in the HEMP coupling calculation of monopole antenna, are derived. An efficient statistical method, based on Polynomial Chaos and Moment of Method, is applied to compute the statistical results of monopole antenna in a finite conductive plane. The statistical comparison reveals several primarily interesting conclusions in the end, which will be beneficial for system-level HEMP vulnerability assessment. Journal: Journal of Electromagnetic Waves and Applications Pages: 1663-1677 Issue: 12 Volume: 35 Year: 2021 Month: 08 X-DOI: 10.1080/09205071.2021.1915186 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1915186 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:12:p:1663-1677 Template-Type: ReDIF-Article 1.0 Author-Name: H. Chen Author-X-Name-First: H. Author-X-Name-Last: Chen Author-Name: G.-X. Liu Author-X-Name-First: G.-X. Author-X-Name-Last: Liu Author-Name: F. Zhu Author-X-Name-First: F. Author-X-Name-Last: Zhu Author-Name: M.-T. Han Author-X-Name-First: M.-T. Author-X-Name-Last: Han Author-Name: D. Jiang Author-X-Name-First: D. Author-X-Name-Last: Jiang Title: Design of dual-band power amplifier based on tri-band impedance matching circuit Abstract: In this paper, a dual-band power amplifier based on tri-band impedance matching circuit is proposed. This amplifier uses reverse thinking to combine the tri-band impedance matching network with the power amplifier to mismatch the intermediate frequency as the isolation band. And the intermediate frequency is 3.0 GHz. Besides, the design process of dual-band power amplifier is given, and an example is given. Through the actual test results of the amplifier, it can be seen that the additional power efficiency of the amplifier at the frequencies of 2.6GHz and 3.4GHz is about 60%, the output power is more than 40dBm, and the gain is above 10dB. In the test results, it can be seen that the stopband of the power amplifier is 2.95-3.05GHz, the minimum gain and the minimum drain efficiency output power of the stopband are −1dB and 2%, which has a good stopband suppression effect. Journal: Journal of Electromagnetic Waves and Applications Pages: 1601-1610 Issue: 12 Volume: 35 Year: 2021 Month: 08 X-DOI: 10.1080/09205071.2021.1909502 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1909502 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:12:p:1601-1610 Template-Type: ReDIF-Article 1.0 Author-Name: Sachin Seth Author-X-Name-First: Sachin Author-X-Name-Last: Seth Author-Name: Apala Banerjee Author-X-Name-First: Apala Author-X-Name-Last: Banerjee Author-Name: Nilesh K. Tiwari Author-X-Name-First: Nilesh K. Author-X-Name-Last: Tiwari Author-Name: M. Jaleel Akhtar Author-X-Name-First: M. Author-X-Name-Last: Jaleel Akhtar Title: Frequency controlled intelligent standalone RF sensor system for dispersive material testing Abstract: An artificial neural network (ANN) based frequency controlled automated RF sensor system for the characterization of dispersive liquids is presented. The frequency of the designed structure is electronically controlled by varying the applied reverse-biased voltage to the complementary split ring resonator (CSRR) attached varactor diode. A hybrid modelling approach has mainly been devised to account for the effects of biasing circuitry and the parasitic elements. The designed RF sensor can provide a relatively higher tuning bandwidth (800 MHz) for applied DC biasing voltage of 0–25 V. The proposed sensor system employs an artificially intelligent feed-forward neural network architecture, which is trained by the Levenberg–Marquardt training algorithm for the complex permittivity estimation in the designated frequency band with reasonable accuracy. It employs the Bayesian Regularization for better input–output correlation and system performance. The ANN based characterization algorithm is integrated with a graphical user interface (GUI) and implemented using MATLAB. Journal: Journal of Electromagnetic Waves and Applications Pages: 1619-1636 Issue: 12 Volume: 35 Year: 2021 Month: 08 X-DOI: 10.1080/09205071.2021.1914194 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1914194 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:12:p:1619-1636 Template-Type: ReDIF-Article 1.0 Author-Name: Fei Long Author-X-Name-First: Fei Author-X-Name-Last: Long Author-Name: Shixing Yu Author-X-Name-First: Shixing Author-X-Name-Last: Yu Author-Name: Na Kou Author-X-Name-First: Na Author-X-Name-Last: Kou Author-Name: Xucheng Li Author-X-Name-First: Xucheng Author-X-Name-Last: Li Author-Name: Zhao Ding Author-X-Name-First: Zhao Author-X-Name-Last: Ding Author-Name: Zhengping Zhang Author-X-Name-First: Zhengping Author-X-Name-Last: Zhang Title: High-efficiency asymmetric transmission of linear polarized waves based on tri-layered metamaterial structure Abstract: In this work, a broadband polarization converter in transmission mode based on tri-layered metamaterial structure is proposed to realize asymmetric transmission and linear polarization conversion simultaneously. The proposed design model consists of a hexapolar split ring structure and two orthogonal sub-wavelength gratings embedded in two dielectric substrates. The appropriate parameters of the unit cell are optimized and selected. Sequentially, a prototype is fabricated and measured in order to confirm performance of the proposed design structure. The simulation and measurement results consistently demonstrate that the conversion polarization transmission coefficient is greater than 0.9 within the frequency region of 4.516.7 GHz, which is equivalent to 115% of the relative bandwidth. Based on the Fabry–Perot-like cavity theory, the working mechanisms of this structure have been discussed in detail. Thus, the proposed design structure is expected high potential applications in irreversible electromagnetic devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 1564-1574 Issue: 12 Volume: 35 Year: 2021 Month: 08 X-DOI: 10.1080/09205071.2021.1908175 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1908175 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:12:p:1564-1574 Template-Type: ReDIF-Article 1.0 Author-Name: Hong Peng Author-X-Name-First: Hong Author-X-Name-Last: Peng Author-Name: Peng Lei Author-X-Name-First: Peng Author-X-Name-Last: Lei Author-Name: Hong Yang Author-X-Name-First: Hong Author-X-Name-Last: Yang Author-Name: Shiwei Zhao Author-X-Name-First: Shiwei Author-X-Name-Last: Zhao Author-Name: Xiaolun Ding Author-X-Name-First: Xiaolun Author-X-Name-Last: Ding Title: Π-type reconfigurable coupler based on a complementary tunable method Abstract: A complementary tunable method is proposed based on the Hybrid coupler. The odd-even mode analysis shows that the method can achieve continuously tunable power division ratio by changing two $ 50/\sqrt 2 \,\Omega $ 50/2Ω transmission lines in the circuit, and it can achieve larger tunable range by improving the complementary tunable method based on the cascaded Hybrid coupler. Using the improved method, a novel π-type reconfigurable coupler, which works at 2.45 GHz, is designed by replacing $ 50/\sqrt 2 \,\Omega $ 50/2Ω transmission lines with π-type circuit. The power division ratio of the fabricated reconfigurable coupler is changed in the range of −20.5–21.3 dB, with the bias voltage being 0∼6 V; meanwhile, the isolation and return loss are above 20 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 1611-1618 Issue: 12 Volume: 35 Year: 2021 Month: 08 X-DOI: 10.1080/09205071.2021.1911687 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1911687 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:12:p:1611-1618 Template-Type: ReDIF-Article 1.0 Author-Name: Jeong-Wook Kim Author-X-Name-First: Jeong-Wook Author-X-Name-Last: Kim Author-Name: Sol Kim Author-X-Name-First: Sol Author-X-Name-Last: Kim Author-Name: Hyunyoung Cho Author-X-Name-First: Hyunyoung Author-X-Name-Last: Cho Author-Name: Won-Young Song Author-X-Name-First: Won-Young Author-X-Name-Last: Song Author-Name: Jong-Won Yu Author-X-Name-First: Jong-Won Author-X-Name-Last: Yu Title: Fast ISAR motion compensation using improved stage-by-stage approaching algorithm Abstract: This paper proposes a fast inverse synthetic aperture radar (ISAR) motion compensation (MOCOM) method. The various motion compensation methods using minimum entropy algorithm such as stage-by-stage approaching (SSA) algorithm were reported recently. However, the computational efficiency and the clearance of the ISAR image were hard to achieve simultaneously. In particular, as the number of the local minima in the entropy curve increases, the processing time takes longer to find the global minimum. In this paper, we propose a new MOCOM algorithm based on an improved SSA algorithm to reduce the processing time. The proposed algorithm uses the envelope value as the fitness function instead of the entropy value, so the number of the local minima in the entropy curve is reduced. Therefore, the entropy curve becomes simple and the required number of the phase error samples is reduced. In the simulation, the processing time is improved by 88.8% than the conventional SSA algorithm. Also, in the experiment, the processing time is improved by 87.9% ∼ 89.2%. Journal: Journal of Electromagnetic Waves and Applications Pages: 1587-1600 Issue: 12 Volume: 35 Year: 2021 Month: 08 X-DOI: 10.1080/09205071.2021.1908917 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1908917 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:12:p:1587-1600 Template-Type: ReDIF-Article 1.0 Author-Name: Jayanta Bhattacharya Author-X-Name-First: Jayanta Author-X-Name-Last: Bhattacharya Author-Name: Sudipta Maity Author-X-Name-First: Sudipta Author-X-Name-Last: Maity Title: Investigating metallic rectangular waveguide using conformal mapping technique Abstract: The present paper deals with an approach to investigate the rectangular waveguide (RWG) using the conformal mapping technique, where the rectangular shape is converted to a sectoral one for the theoretical investigation. The wave equation is solved in the transformed domain to obtain the eigenfunction and the eigenvalue. The cut-off frequency and the internal field patterns for different $ TE $ TE and $ TM $ TM modes of the rectangular waveguide are investigated. The $ f - {k_z}({ = \beta } ) $ f−kz(=β) diagrams for different modes of RWG are plotted using the conformal mapping technique. The wave impedance of the RWG for different $ TE $ TE and $ TM $ TM modes are also investigated. Our theoretical results are compared with the conventional technique of RWG, as found in the open literature. It is found that the results obtained using our theory are in excellent agreement with published data. Journal: Journal of Electromagnetic Waves and Applications Pages: 1553-1563 Issue: 12 Volume: 35 Year: 2021 Month: 08 X-DOI: 10.1080/09205071.2021.1905561 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1905561 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:12:p:1553-1563 Template-Type: ReDIF-Article 1.0 Author-Name: M. Z. Yaqoob Author-X-Name-First: M. Z. Author-X-Name-Last: Yaqoob Author-Name: A. Ghaffar Author-X-Name-First: A. Author-X-Name-Last: Ghaffar Author-Name: M. Y. Naz Author-X-Name-First: M. Y. Author-X-Name-Last: Naz Author-Name: M. A. Hanif Author-X-Name-First: M. A. Author-X-Name-Last: Hanif Title: Graphene-loaded left-handed media for tunable electromagnetic surface waves Abstract: Theoretical investigation has been carried out on the tunable electromagnetic surface waves propagating along the Graphene loaded semi-infinite left-handed media (LHM) interface. The analytical modeling of the graphene has been done in the frame work of Kubo's formulation. The split ring resonators (SRRs) model and Kramers-Kronig relations-based causality principle have been used to simulate the GHz-LHMs and THz-LHMs respectively. To realize the graphene loaded LHM interface, the impedance boundary conditions (IBCs) have been employed. The dispersion curves, effective mode index, propagation length, penetration depth, phase velocity and fields profiles of surface waves supported by graphene loaded GHz-LHM and THz-LHM have been computed numerically. It has been concluded that the graphene parameters can be used to tune the characteristics of surface waves in GHz and THz range. The proposed study may have potential applications in designing the near field imaging platforms, communication devices and tunable surface wave guides. Journal: Journal of Electromagnetic Waves and Applications Pages: 1754-1769 Issue: 13 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1915885 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1915885 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:13:p:1754-1769 Template-Type: ReDIF-Article 1.0 Author-Name: Valeriy A. Khlusov Author-X-Name-First: Valeriy A. Author-X-Name-Last: Khlusov Author-Name: Peter V. Vorob'ov Author-X-Name-First: Peter V. Author-X-Name-Last: Vorob'ov Title: Monostatic radar sensing of partially nonreciprocal mediums backscatter Abstract: This paper presents the results of theoretical and experimental studies of electromagnetic waves backscattering by partially non-reciprocal media. It is proposed to implement a controlled reflector that allows to simulate the polarization properties of an arbitrary partially non-reciprocal medium. Journal: Journal of Electromagnetic Waves and Applications Pages: 1687-1698 Issue: 13 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1892533 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1892533 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:13:p:1687-1698 Template-Type: ReDIF-Article 1.0 Author-Name: Giacomo Muntoni Author-X-Name-First: Giacomo Author-X-Name-Last: Muntoni Author-Name: Giovanni Andrea Casula Author-X-Name-First: Giovanni Andrea Author-X-Name-Last: Casula Author-Name: Giorgio Montisci Author-X-Name-First: Giorgio Author-X-Name-Last: Montisci Author-Name: Tonino Pisanu Author-X-Name-First: Tonino Author-X-Name-Last: Pisanu Author-Name: Hendrik Rogier Author-X-Name-First: Hendrik Author-X-Name-Last: Rogier Author-Name: Andrea Michel Author-X-Name-First: Andrea Author-X-Name-Last: Michel Title: An eighth-mode SIW antenna for Low-Power Wide-Area Network applications Abstract: A wearable textile antenna based on the fundamental mode of an eighth-mode substrate-integrated waveguide cavity is presented for Low-Power Wide-Area Network (LPWAN) applications. The antenna operates in the UHF frequency band, at 867 MHz, and exhibits compact size, minimal manufacturing complexity and very low production cost. High isolation from the human body is observed, and a planar size reduction by more than 50% is achieved compared to similar SIW antennas in the literature. The proposed wearable antenna has been designed using CST Microwave Studio, then manufactured and tested, showing very good agreement with predicted performance. Journal: Journal of Electromagnetic Waves and Applications Pages: 1815-1829 Issue: 13 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1918264 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1918264 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:13:p:1815-1829 Template-Type: ReDIF-Article 1.0 Author-Name: Z. Dehghani Author-X-Name-First: Z. Author-X-Name-Last: Dehghani Author-Name: N. Parhizgar Author-X-Name-First: N. Author-X-Name-Last: Parhizgar Author-Name: H. Azad Author-X-Name-First: H. Author-X-Name-Last: Azad Title: Optimizing the performance of beamforming methods with high-resolution accuracy in a four-element array Abstract: As we know, the basis of some beamforming methods is the initial estimation of the input angle, so before applying these techniques, it is necessary to determine the angle of entry of signals into the array. As a result, estimating the input angle of the received waves is very important. In this paper, using the data of a four-element array as well as the data obtained from the electromagnetic simulation software of wired antennas, the performance of MUSIC, ROOT-MUSIC and ESPRIT algorithms is evaluated in real arrays and compared with the performance of this algorithms are discussed in the ideal array. The results show a decrease in the performance of these algorithms in real arrays compared to ideal arrays. This problem is due to the mutual coupling effect between the array elements in actual conditions, so it is necessary to compensate for the mutual coupling effect in practice. Journal: Journal of Electromagnetic Waves and Applications Pages: 1719-1741 Issue: 13 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1915883 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1915883 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:13:p:1719-1741 Template-Type: ReDIF-Article 1.0 Author-Name: Manotosh Biswas Author-X-Name-First: Manotosh Author-X-Name-Last: Biswas Author-Name: Mihir Dam Author-X-Name-First: Mihir Author-X-Name-Last: Dam Title: Investigation of equilateral triangular patch antenna covered with several dielectric layers: theoretical and experimental study Abstract: In this article an analytical model is proposed to compute the resonant frequency, quality factor, bandwidth, gain and input impedance of a co-axial probe-fed equilateral triangular patch antenna, covered with several dielectric layers. This model is very simple and fast and directly applied to the CAD programs. The computed values, employing the present model, are compared with simulation and new experimental results for various sets of relative permittivity and thickness of different multilayered structures. The present model shows excellent agreement with simulation and experimental result for a wide variation of thickness and permittivity of multi-dielectric structure. We have also measured the radiation patterns of triangular patch antenna with different multilayered structure. Journal: Journal of Electromagnetic Waves and Applications Pages: 1770-1801 Issue: 13 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1917003 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1917003 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:13:p:1770-1801 Template-Type: ReDIF-Article 1.0 Author-Name: Yogesh M. Jain Author-X-Name-First: Yogesh M. Author-X-Name-Last: Jain Author-Name: Shrey Thakker Author-X-Name-First: Shrey Author-X-Name-Last: Thakker Author-Name: P. K. Sharma Author-X-Name-First: P. K. Author-X-Name-Last: Sharma Author-Name: Harish V. Dixit Author-X-Name-First: Harish V. Author-X-Name-Last: Dixit Title: Design of a 3.7 GHz TE10 – TE30 mode converter using stepped impedance transformer for CW applications Abstract: This paper presents the design and simulation of a novel TE10 to TE30 mode converter operating at 3.7 GHz and is subjected to high RF power of 500 kW in Continuous Wave (CW) regime. The design incorporates a stepped impedance transformer as opposed to the conventional capacitive button to improve the return loss and power handling capacity of the converter. A rigorous RF, breakdown and multiphysics analysis including thermal, fluid dynamics and stress physics is performed on the mode converter to ascertain its viability and usefulness as a power dividing network in the Passive Active Multijunction launcher for Lower Hybrid Current Drive systems of tokamaks. The proposed mode converter exhibits a return loss of ∼50 dB, mode conversion efficiency of ∼97% and a peak E-field of 685 kV/m is obtained as compared to that of 4.2 MV/m obtained in the conventional mode converter. Thus, the power handling capacity of the proposed mode converter design is found to be 97.3% higher than the conventional mode converter. Journal: Journal of Electromagnetic Waves and Applications Pages: 1699-1707 Issue: 13 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1915187 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1915187 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:13:p:1699-1707 Template-Type: ReDIF-Article 1.0 Author-Name: Qiuzhan Zhou Author-X-Name-First: Qiuzhan Author-X-Name-Last: Zhou Author-Name: Xinyi Yao Author-X-Name-First: Xinyi Author-X-Name-Last: Yao Author-Name: Jikang Hu Author-X-Name-First: Jikang Author-X-Name-Last: Hu Title: Study on the propagation characteristic of electromagnetic wave based on WUSN Abstract: Wireless underground sensor network (WUSN) is widely used in agriculture, frontier defense, and other fields with great research value. This paper takes the propagation characteristics of the electromagnetic waves that propagate in WUSN as research target, and systematically tests the effect of influence factors on the communication quality of electromagnetic waves. The influence factors are chosen on the basis of the propagation theory of electromagnetic waves. Specifically, the influence factors include the burial depth of sensor sub-node, the horizontal distance between nodes, the communication frequency, and the thickness of snow. Moreover, the experiments are carried out in normal and snow-covered soil. The propagation characteristic of electromagnetic waves is measured by received signal strength (RSS) and symbol error rate (SER). Finally, the selection of communication frequency in different application scenarios is concluded. The conclusions have a great significance for guiding the arrangement of WUSN nodes in different scenarios. Journal: Journal of Electromagnetic Waves and Applications Pages: 1708-1718 Issue: 13 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1915882 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1915882 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:13:p:1708-1718 Template-Type: ReDIF-Article 1.0 Author-Name: S. Prasad Author-X-Name-First: S. Author-X-Name-Last: Prasad Author-Name: M. Meenakshi Author-X-Name-First: M. Author-X-Name-Last: Meenakshi Author-Name: N. Adhithiya Author-X-Name-First: N. Author-X-Name-Last: Adhithiya Author-Name: P. H. Rao Author-X-Name-First: P. H. Author-X-Name-Last: Rao Author-Name: Radha Krishna Ganti Author-X-Name-First: Radha Author-X-Name-Last: Krishna Ganti Author-Name: Saswata Bhaumik Author-X-Name-First: Saswata Author-X-Name-Last: Bhaumik Title: mmWave multibeam phased array antenna for 5G applications Abstract: A fully integrated 28 GHz, 5G mmWave microstrip phased array antenna on a multilayer substrate is presented. The proposed $ 8\times 8 $ 8×8 array provides independently steerable, simultaneous multiple beams in any arbitrary azimuth, elevation angles with equal or unequal peak gains. A computation method is proposed to calculate the weights required to generate multiple beams. Multiple beams (up to six) over various arbitrary angles are generated using the proposed method and the results are presented. The inherent amplitude and phase variations due to the hardware impairments are independently captured through simulation and measurements, and their impact on the performance of the phased array is analyzed. Measured results are compared with simulations for single, dual, and multiple beams over arbitrary angles. The phased array performance is measured and presented over $ {\pm }35^\circ $ ±35∘ and $ {\pm }25^\circ $ ±25∘ scan angles in azimuth and elevation planes respectively over 400 MHz bandwidth for both single and dual beam deployment. The proposed multibeam computation method is validated with measurements at 28 GHz for a dual beam case, ( $ \theta =25^\circ $ θ=25∘, $ \phi =0^\circ $ ϕ=0∘) and ( $ \theta =25^\circ $ θ=25∘, $ \phi =180^\circ $ ϕ=180∘) in azimuth plane for equal and unequal power beams with a side lobe level of better than 17 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 1802-1814 Issue: 13 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1917004 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1917004 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:13:p:1802-1814 Template-Type: ReDIF-Article 1.0 Author-Name: Zheng Liu Author-X-Name-First: Zheng Author-X-Name-Last: Liu Author-Name: Heng Liu Author-X-Name-First: Heng Author-X-Name-Last: Liu Author-Name: Daiwei Huang Author-X-Name-First: Daiwei Author-X-Name-Last: Huang Author-Name: Zhengwei Du Author-X-Name-First: Zhengwei Author-X-Name-Last: Du Title: Wideband antenna pair and its applications for 5G metal frame mobile phones Abstract: A wideband antenna pair used for 5G mobile phones is proposed in this paper. Both elements of the antenna pair consisting of an open slot and a coupled feeding line can cover the band of 3.3–6 GHz, and the isolation is larger than 10 dB. The ground clearance and the total size are 1.5 mm and 30 mm × 1.5 mm  × 7 mm, respectively. Using the antenna pair, four- and eight-element multiple-input–multiple-output (MIMO) antennas are constructed. The simulated results show that the proposed antenna pair can be used to construct MIMO antennas for 5G metal frame mobile phones. As an example, the four-element MIMO antenna is manufactured and tested. The measured results show that the four elements can cover the band of 3.3–6 GHz, and the n77, n78, n79, and 5 GHz WLAN bands are covered. At the working bands, the measured efficiencies and isolations are bigger than 46% and 11.4 dB, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 1742-1753 Issue: 13 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1915884 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1915884 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:13:p:1742-1753 Template-Type: ReDIF-Article 1.0 Author-Name: Zhiying Chen Author-X-Name-First: Zhiying Author-X-Name-Last: Chen Author-Name: Xingguang Chen Author-X-Name-First: Xingguang Author-X-Name-Last: Chen Author-Name: Feng Lin Author-X-Name-First: Feng Author-X-Name-Last: Lin Author-Name: Zan Gong Author-X-Name-First: Zan Author-X-Name-Last: Gong Title: Far-field characterization of wave oblique incidence on body channel for implant communication by using an analytical model Abstract: Characterization of human body channel is a necessity to pave way for the practical implementation of implant communication. Considering there are few investigations on the characterization of incident wave propagating at an arbitrary angle to human tissues, this paper applies an analytical model of wave oblique incidence onto multilayered planar lossy tissues to evaluate the far-field EMFs and PLs of body channel. With this model, EMFs and PLs of both TM and TE wave oblique incidence at different angles and frequencies in out-to-in and in-to-out propagations are calculated. A FEM model and a measurement on porcine tissues are also carried out. Comparing with simulation and experiment, the analytical results of PLs have the maximum differences of 0.03 and 1.0 dB, respectively, in out-to-in propagation and of 0.09 and 1.7 dB, respectively, in in-to-out propagation. Therefore, the analytical model is accurate and indicates the mechanism of EM wave propagation in body channel theoretically. Journal: Journal of Electromagnetic Waves and Applications Pages: 1922-1938 Issue: 14 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1925973 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1925973 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:14:p:1922-1938 Template-Type: ReDIF-Article 1.0 Author-Name: Deepthee Madenoor Ramapriya Author-X-Name-First: Deepthee Author-X-Name-Last: Madenoor Ramapriya Author-Name: Tamal Barman Author-X-Name-First: Tamal Author-X-Name-Last: Barman Author-Name: Mayur Appaiah Author-X-Name-First: Mayur Author-X-Name-Last: Appaiah Author-Name: Dyuti Roy Author-X-Name-First: Dyuti Author-X-Name-Last: Roy Title: A review of the Wigner distribution function approach to analyse electromagnetic field Abstract: The paper contributes by developing computational and reviewing theoretical methods to propagate electromagnetic fields in free space, while taking account of the fact that the sources are typically noisy and statistically characterized. The main focus is to develop propagators for correlation functions, which characterize the average properties of the wave field when compared at two nearby points. The methods used will involve Green function techniques, numerical approaches to wave propagation. The theoretical model involves analysing wave propagation in phase space by manipulating the relationship between the field–field correlation function and the Wigner distribution function in a purely statistical manner. Journal: Journal of Electromagnetic Waves and Applications Pages: 1939-1957 Issue: 14 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1924293 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1924293 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:14:p:1939-1957 Template-Type: ReDIF-Article 1.0 Author-Name: Jia Liu Author-X-Name-First: Jia Author-X-Name-Last: Liu Author-Name: Min Su Author-X-Name-First: Min Author-X-Name-Last: Su Author-Name: Qunyu Xu Author-X-Name-First: Qunyu Author-X-Name-Last: Xu Author-Name: Ning Fang Author-X-Name-First: Ning Author-X-Name-Last: Fang Author-Name: Bao Fa Wang Author-X-Name-First: Bao Fa Author-X-Name-Last: Wang Title: Multi-scale feature vector reconstruction for aircraft classification using high range resolution radar signatures Abstract: High-Resolution Range Profile (HRRP) is effective in various Radar Automatic Target Recognition problems. Multi-scale techniques have been verified in aircraft target HRRP feature enrichment to achieve aircraft recognition performance optimization. The involvement of multiple training-classification procedures in existing multi-scale methods results in tremendous resource consumption which challenges their real-time classification performance and application significance. This paper introduces a novel method that enables multi-scale HRRP features to be manipulated under a single scale for efficiency enhancement. Numerical analysis indicates that multi-scale intensity variations for particular HRRP scatterers could be modeled as Gaussian noises. Linear Discriminant Analysis and Singular Value Decomposition techniques are applied on reconstructed feature vectors for better separability and noise tolerance capability. Experimental results from dynamic aircraft recognition experiments verify the expected efficiency enhancement of the proposed method while maintaining comparable classification accuracy and better noise tolerance performance. Journal: Journal of Electromagnetic Waves and Applications Pages: 1843-1862 Issue: 14 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1923068 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1923068 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:14:p:1843-1862 Template-Type: ReDIF-Article 1.0 Author-Name: Abdullah Genc Author-X-Name-First: Abdullah Author-X-Name-Last: Genc Author-Name: I. Bahadir Basyigit Author-X-Name-First: I. Bahadir Author-X-Name-Last: Basyigit Author-Name: Habib Dogan Author-X-Name-First: Habib Author-X-Name-Last: Dogan Author-Name: Bektas Colak Author-X-Name-First: Bektas Author-X-Name-Last: Colak Title: Measuring and modelling the complex-permittivity of hemp plant (Cannabis Sativa) at X band for microwave remote sensing Abstract: It is vital to determine the dielectric characterization of hemp plant (Cannabis Sativa) for microwave remote sensing to increase its accuracy and to improve algorithms for satellite data interpretation. For that, this study provides the measurement results of complex permittivity of hemp stems and leaves in terms of various moisture contents (MC) in 8–12.4 GHz in a laboratory with a temperature of 25°C and a relative humidity of 59%. With the measurement data, the dielectric properties are modelled as a second-order polynomial function based on a curve-fitting method depending on the frequency and MC. For hemp stems and leaves with various MC, while the real part of the relative complex permittivity ( $ \varepsilon' $ ε′) ranges between 2.1–7.2 and 1.5–6.1, the imaginary part of that ( $ \varepsilon'' $ ε″) varies in 0.3–4.5 and 0.2–4.2, respectively. The measured and modelled results are compatible with each other. Journal: Journal of Electromagnetic Waves and Applications Pages: 1909-1921 Issue: 14 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1924294 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1924294 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:14:p:1909-1921 Template-Type: ReDIF-Article 1.0 Author-Name: Parul Dawar Author-X-Name-First: Parul Author-X-Name-Last: Dawar Author-Name: Mahmoud A. Abdalla Author-X-Name-First: Mahmoud A. Author-X-Name-Last: Abdalla Title: Near-zero-refractive-index metasurface antenna with bandwidth, directivity and front-to-back radiation ratio enhancement Abstract: In this paper, a novel metasurface-based Fabry–Perot Cavity antenna is presented. The antenna is wideband, directive and has a high front-to-back ratio. The idea of the antenna is based on loading a microstrip narrow band patch antenna resonating at 4.6 GHz by a metasurface superstrate. The metasurface superstrate consists of an aperiodic array of holes in contrast to the periodic nature of unit cell previously explored in the literature. The metasurface is designed as a near-zero-refractive-index material (NZRIM). By controlling the phase reflection properties of the structure, improved radiation pattern, improved front-to-back lobe ratio (7–25 dB), improved directivity (by 3 dB) and antenna bandwidth (five times) are obtained compared to a conventional microstrip antenna. The enhancement in bandwidth and directivity simultaneously using just a single layer of metasurface superstrate demonstrated for the first time, to best to authors’ knowledge, are obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 1863-1881 Issue: 14 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1923069 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1923069 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:14:p:1863-1881 Template-Type: ReDIF-Article 1.0 Author-Name: Hanshan Li Author-X-Name-First: Hanshan Author-X-Name-Last: Li Author-Name: Xiaoqian Zhang Author-X-Name-First: Xiaoqian Author-X-Name-Last: Zhang Author-Name: Junchai Gao Author-X-Name-First: Junchai Author-X-Name-Last: Gao Title: Laser reflection echo signal detection and calculation under multi-attitude intersection Abstract: To improve the detection capability of laser fuze, this paper researches the laser echo signal detection method and echo power calculation method on laser fuze. From the multi-attitude intersection relation of projectile and target, we analyze the laser echo characteristics of target, set up the modeling of laser echo power by using the finite element meshing method. Taking into account the parameters of yaw angle and pitch angle and roll angle, we derive the target reflection laser echo power calculation function by combining the non-Lambertian and bidirectional reflection function of target's surface, establish the target detection probability calculation model. According to the established laser echo signal and echo power calculation function, we calculate the laser echo power and detection probability under the multi-attitude intersection conditions and different detection distances. Through simulation tests, the test result accords with the theoretical model. Journal: Journal of Electromagnetic Waves and Applications Pages: 1894-1908 Issue: 14 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1924292 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1924292 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:14:p:1894-1908 Template-Type: ReDIF-Article 1.0 Author-Name: R. Adeline Mellita Author-X-Name-First: R. Author-X-Name-Last: Adeline Mellita Author-Name: S. S. Karthikeyan Author-X-Name-First: S. S. Author-X-Name-Last: Karthikeyan Author-Name: P. Damodharan Author-X-Name-First: P. Author-X-Name-Last: Damodharan Author-Name: D. S. Chandu Author-X-Name-First: D. S. Author-X-Name-Last: Chandu Title: A miniaturized quad-band frequency selective surface for C-band applications Abstract: In this paper, a low-profile quad-band frequency selective surface (FSS), designed as a sub-reflector for satellite communication is presented. This single layered FSS employs non-concentric open loops with controlled field coupling to provide four closely spaced transmission zeroes within the C-band. The proposed design approach occupies lesser metallized area which gives an additional benefit of frequency tuning while retaining the miniaturized cell dimension. The four band-stop center frequencies are 4.6, 5.5, 6.3 and 7.3 GHz with an average bandwidth of 240 MHz. The unit cell has a miniaturized dimension of 0.138 $ \lambda _{0}\times $ λ0×0.138 $ \lambda _{0}\times $ λ0×0.012 $ \lambda _{0} $ λ0, where $ \lambda _{0} $ λ0 stands for free space wavelength at the lowest resonating frequency. The FSS provides angularly stable frequency response up to $ 45^{\circ } $ 45∘ for TE as well as TM polarization. Additionally, the FSS can be mechanically tuned to allow either TE or TM polarized wave. This study also reports the outcomes based on parametric variations and verifies the frequency behaviour of the structure using a circuit model. The simulated results are validated by testing a design prototype of the proposed FSS. Good concordance is observed between the simulated and measured results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1882-1893 Issue: 14 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1923576 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1923576 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:14:p:1882-1893 Template-Type: ReDIF-Article 1.0 Author-Name: Santanu Karmakar Author-X-Name-First: Santanu Author-X-Name-Last: Karmakar Author-Name: Jagadish C. Mudiganti Author-X-Name-First: Jagadish C. Author-X-Name-Last: Mudiganti Title: Design of the interaction cavity for a 110-GHz, 1.5-MW Gyrotron Abstract: In this paper, the design of an interaction cavity for a very high-power W-band gyrotron is proposed for the generation of megawatt range of power. The proposed gyrotron is designed to generate 1.5 MW of pulsed power at 110 GHz. The operating mode is TE22,6. The beam voltage and beam current are 95 kV and 40 A, respectively. The beam velocity pitch factor is 1.4. For this structure, a unique kind of cavity profile is proposed which consists of a straight section, followed by a down-taper section, followed by a main interaction section (straight section), and followed by an up-taper section consisting of two raised cosine profiles. The simulation of the interaction cavity is done using the Code Gyro-K for different lengths of cavity mid-sections. The output power of 1.53 MW is estimated from the simulation. The diffractive quality factor and Ohmic loss are also estimated. Journal: Journal of Electromagnetic Waves and Applications Pages: 1831-1842 Issue: 14 Volume: 35 Year: 2021 Month: 09 X-DOI: 10.1080/09205071.2021.1918265 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1918265 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:14:p:1831-1842 Template-Type: ReDIF-Article 1.0 Author-Name: Tanmoy Sarkar Author-X-Name-First: Tanmoy Author-X-Name-Last: Sarkar Author-Name: Abhijyoti Ghosh Author-X-Name-First: Abhijyoti Author-X-Name-Last: Ghosh Author-Name: Subhradeep Chakraborty Author-X-Name-First: Subhradeep Author-X-Name-Last: Chakraborty Author-Name: L. L. K. Singh Author-X-Name-First: L. L. K. Author-X-Name-Last: Singh Author-Name: Sudipta Chattopadhyay Author-X-Name-First: Sudipta Author-X-Name-Last: Chattopadhyay Title: A new insightful exploration into a low profile ultra-wide-band (UWB) microstrip antenna for DS-UWB applications Abstract: Designing a simple and planar antenna for high speed short distance ultra-wideband (UWB) communication has become a buzzword over the last few years. There are two very different categories of UWB technologies of vital relevance, i.e. (i) carrier-free direct sequence UWB (DS-UWB), and (ii) the Multi-Band orthogonal frequency division multiplexing UWB (OFDM UWB) technology. In, Multi-Band OFDM UWB technology, multi narrowband UWB antennas with frequency notches are required. However, in DS-UWB technology, the frequency spectrum of very short duration transmitted pulses occupies wide bandwidth, and hence to transmit it, the antenna should be fully matched over the entire bandwidth without the presence of any frequency notch. In this paper, a novel, small and completely planar air gap and defected ground slot integrated rectangular microstrip antenna with dual shorting posts have been thoroughly investigated to yield UWB, i.e. (109%) bandwidth without the presence of any frequency notch. Journal: Journal of Electromagnetic Waves and Applications Pages: 2001-2019 Issue: 15 Volume: 35 Year: 2021 Month: 10 X-DOI: 10.1080/09205071.2021.1927855 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1927855 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:15:p:2001-2019 Template-Type: ReDIF-Article 1.0 Author-Name: M. Manohar Author-X-Name-First: M. Author-X-Name-Last: Manohar Author-Name: A. K. Chaudhary Author-X-Name-First: A. K. Author-X-Name-Last: Chaudhary Title: Wideband circularly polarized triangular monopole antenna for high-speed internet access Abstract: In this report, a miniaturized low profile circularly polarized (CP) monopole antenna with broad 3 dB axial ratio (AR) bandwidth is investigated. The proposed antenna comprises an equilateral triangular monopole radiator, an inverted L-shaped element (ILSE) protruded from the finite ground plane to perturb the current distribution on the finite ground plane and an inverted L-shaped strip (ILSS). The CP radiation characteristics can be achieved by protruding an ILSE from the finite ground plane and connecting ILSS with the triangular patch. The proposed CP antenna has a $ -10 $ −10 dB impedance bandwidth along with the 3 dB AR bandwidth of 127.3% in the frequency band of 2−9 GHz. The antenna occupies the overall footprint of $ 20\times 25\times 0.8\,{\rm mm}^{3} $ 20×25×0.8mm3 and is ideally propitious for broadband wireless communication systems which permit users to access high-speed internet. Furthermore, the proposed antenna has stable bidirectional radiation properties with a measured peak gain of 6.3 dBi. Journal: Journal of Electromagnetic Waves and Applications Pages: 2102-2113 Issue: 15 Volume: 35 Year: 2021 Month: 10 X-DOI: 10.1080/09205071.2021.1934568 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1934568 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:15:p:2102-2113 Template-Type: ReDIF-Article 1.0 Author-Name: Guohua Lin Author-X-Name-First: Guohua Author-X-Name-Last: Lin Author-Name: Xiaoqi Yin Author-X-Name-First: Xiaoqi Author-X-Name-Last: Yin Author-Name: Siwei Ren Author-X-Name-First: Siwei Author-X-Name-Last: Ren Author-Name: Zhengbin Wang Author-X-Name-First: Zhengbin Author-X-Name-Last: Wang Author-Name: Yongjian Zhi Author-X-Name-First: Yongjian Author-X-Name-Last: Zhi Author-Name: Tong He Author-X-Name-First: Tong Author-X-Name-Last: He Title: Compact and broadband directional coupler for high power applications Abstract: A compact, flat coupling, and broadband directional coupler are presented for high-power applications in the frequency band of 100 ∼ 1000 MHz. The coupler is mainly composed of two compact semi-flexible coaxial cables with the length of the λ0/4 (λ0 is the free-space wavelength at the frequency of 850 MHz), four chip ceramic capacitors, and two air wound inductors that can tune the coupling coefficient. The phase inverter of the coupler is well designed and experimentally validated. The directional coupler exhibits high performance in the whole operation frequency band with low insertion loss (less than 0.3 dB), high directivity (more than 18 dB), and high power (up to 300 W). The amplitude imbalance of the coupling coefficient is less than 0.3 dB. The measured results exhibit good consistency with the theoretical analysis. And the proposed design method can be readily extended to other low-cost, high-power, and broadband directional couplers. Journal: Journal of Electromagnetic Waves and Applications Pages: 1980-1986 Issue: 15 Volume: 35 Year: 2021 Month: 10 X-DOI: 10.1080/09205071.2021.1926339 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1926339 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:15:p:1980-1986 Template-Type: ReDIF-Article 1.0 Author-Name: Mohammad Amin Chaychi zadeh Author-X-Name-First: Mohammad Amin Author-X-Name-Last: Chaychi zadeh Author-Name: Nader Komjani Author-X-Name-First: Nader Author-X-Name-Last: Komjani Title: Improved performance of an axially-modulated conformal leaky-wave holographic antenna through using variable modulation index Abstract: In this paper, a novel method to decrease the sidelobe level (SLL) of conformal leaky-wave antennas (CLWAs) which are synthesized based on the holographic techniques is proposed. For this purpose, the holographic relation is modified by using the modulation index as a function of the spatial component corresponding to the propagation direction of the reference wave. In order to create a fascinating impedance matching between the launcher and the radiative metasurface, an initial phase is considered in the holographic formula. The designed one-dimensional (1D) sinusoidally modulated conformal antenna indicated a broadside fan beam at 18 GHz. At this frequency, about 3 dB SLL reduction was observed in the E-plane compared the traditinal holographic antenna. The measurement results indicated that the realized gain of the novel antenna at the design frequency was about 14.6dBi, and the SLL and the radiation efficiency of the antenna were −10.6 dB and 95%, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 2020-2033 Issue: 15 Volume: 35 Year: 2021 Month: 10 X-DOI: 10.1080/09205071.2021.1927856 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1927856 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:15:p:2020-2033 Template-Type: ReDIF-Article 1.0 Author-Name: Narinder Sharma Author-X-Name-First: Narinder Author-X-Name-Last: Sharma Author-Name: Sumeet Singh Bhatia Author-X-Name-First: Sumeet Singh Author-X-Name-Last: Bhatia Author-Name: Vipul Sharma Author-X-Name-First: Vipul Author-X-Name-Last: Sharma Title: Peano–Gosper, Koch and Minkowski fractal curves-based novel hybrid antenna using modified partial ground plane for multi-standard wireless applications Abstract: This paper presents the unique structure of a hybrid antenna with a blend of Peano–Gosper, Koch and Minkowski curves using a modified partial ground plane for multi-standard wireless applications. Initially, the Minkowski and Koch curves are amalgamated by using a versatile mathematical tool called Iterative Function System (IFS), and furthermore, their resultant structure is superimposed on each segment of Peano–Gosper curve to obtain the novel geometry of hybrid fractal antenna named Gosper–Koch–Minkowski Hybrid Fractal Antenna (GKMHFA). The partial ground plane with 50 Ω transmission line fed is used to analyse the performance of designed structure and found that it exhibits five different frequency bands above 9 GHz in the frequency range 1–20 GHz. Consequently, to attain the frequency bands below 9 GHz with enhanced bandwidth and reflection coefficient, the partial ground plane has been modified. The proposed antenna with the modified ground plane reveals seven distinct frequency points 1.5, 3.4, 8.6, 12.2, 14.1, 15.3 and 18.9 GHz with a maximum bandwidth 5.0 GHz along with improved reflection coefficient i.e. −45.65 dB at 1.5 GHz. The proposed antenna also reports positive gain and stable radiation patterns in the operational frequency bands, which make it a proficient candidate for the multi-standard wireless applications such as GPS, terrestrial communication, PCS, UMTS, advance wireless services, Bluetooth, WLAN, Wi-Fi, Wi-MAX, military satellite communication, television broadcasting, broadcasting satellite, FSS, Ku-band and K-band. Journal: Journal of Electromagnetic Waves and Applications Pages: 1959-1979 Issue: 15 Volume: 35 Year: 2021 Month: 10 X-DOI: 10.1080/09205071.2021.1925974 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1925974 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:15:p:1959-1979 Template-Type: ReDIF-Article 1.0 Author-Name: Ali Pesarakloo Author-X-Name-First: Ali Author-X-Name-Last: Pesarakloo Author-Name: Mohammad Khalaj-Amirhosseini Author-X-Name-First: Mohammad Author-X-Name-Last: Khalaj-Amirhosseini Title: Wide-angle monostatic RCS enhancement using symmetrical periodic structures Abstract: In this paper, first the basic principles of monostatic RCS enhancement (RCS ENH) for a structure are established. Then it is shown that for a periodic structure with periodicity larger than half wavelength, according to Fluquet’s theory, the larger the periodicity, the greater the number of incidence angles for which energy is reflected in the same direction, that is, monostatic RCS ENH. Then for a symmetrical patch unit cell, the optimum dimensions are obtained. Finally several symmetrical patch unit cells with different periodicities are arranged symmetrically with respect to the center of structure to achieve monostatic RCS ENH in a wide angle. Journal: Journal of Electromagnetic Waves and Applications Pages: 1987-2000 Issue: 15 Volume: 35 Year: 2021 Month: 10 X-DOI: 10.1080/09205071.2021.1927201 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1927201 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:15:p:1987-2000 Template-Type: ReDIF-Article 1.0 Author-Name: Maryam Rasool Author-X-Name-First: Maryam Author-X-Name-Last: Rasool Author-Name: Imran Rashid Author-X-Name-First: Imran Author-X-Name-Last: Rashid Author-Name: Abdul Rauf Author-X-Name-First: Abdul Author-X-Name-Last: Rauf Author-Name: Adil Masood Author-X-Name-First: Adil Author-X-Name-Last: Masood Author-Name: Farooq Ahmed Bhatti Author-X-Name-First: Farooq Ahmed Author-X-Name-Last: Bhatti Author-Name: Bilal Ijaz Author-X-Name-First: Bilal Author-X-Name-Last: Ijaz Title: A multi-slotted 2-element quadband MIMO antenna for 4G and 5G applications Abstract: This paper presents design of a multi-slotted quadband 2-element MIMO antenna suitable for 4G and 5G applications. The design is realized on an 18.5 × 56 mm2 (0.154 $ {\lambda _o} $ λo × 0.467 $ {\lambda _o} $ λo, where $ {\lambda _o} $ λo is the wavelength of the lowest resonant frequency of 2.5 GHz) FR4 epoxy substrate having a thickness of 1.6 mm and a relative permittivity of 4.4. The simulated and measured results agree well with each other. A simple de-coupler structure has been incorporated on the bottom side to reduce the mutual coupling at operating frequency bands (2.5, 3.7, 4.3, and 5.5 GHz). Furthermore, it was observed that the measured envelope correlation coefficient of the designed MIMO antenna is considerably lower than 0.05. Also, the design exhibits measured gains of 3.49, 2.97, 2.93, and 2.54 dBi at 2.5, 3.7, 4.3, and 5.5 GHz, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 2062-2077 Issue: 15 Volume: 35 Year: 2021 Month: 10 X-DOI: 10.1080/09205071.2021.1934565 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1934565 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:15:p:2062-2077 Template-Type: ReDIF-Article 1.0 Author-Name: Yiran Da Author-X-Name-First: Yiran Author-X-Name-Last: Da Author-Name: Xiaoming Chen Author-X-Name-First: Xiaoming Author-X-Name-Last: Chen Author-Name: Mengting Li Author-X-Name-First: Mengting Author-X-Name-Last: Li Author-Name: Zhenyuan Zhang Author-X-Name-First: Zhenyuan Author-X-Name-Last: Zhang Author-Name: Azremi Abdullah Al-Hadi Author-X-Name-First: Azremi Abdullah Author-X-Name-Last: Al-Hadi Author-Name: Anxue Zhang Author-X-Name-First: Anxue Author-X-Name-Last: Zhang Author-Name: Ahmed A. Kishk Author-X-Name-First: Ahmed A. Author-X-Name-Last: Kishk Title: Enhanced cross-polarization isolation of loop-dipole antenna array backed by dielectric cavities for 5G base stations Abstract: Various decoupling methods were proposed and investigated for multiple-input multiple-output (MIMO) Base Station (BS) systems. These methods can effectively decouple the dual-polarized co-polar signal but fail to decouple the cross-polarized signal, similarly limiting the BS's overall decoupling performance. In this paper, different antenna arrays are designed to illustrate the coupling mechanism of cross-polarized BS antennas, and a comprehensive study of the relationship between antenna configurations and mutual couplings is conducted. It is shown that compact size antenna elements enlarge the edge-to-edge separation, and the loop-shaped dipole elements reduce the cross-polarization couplings. Finally, the array-antenna decoupling surface (ADS) method is applied in a 2×2 array composed of the designed antennas. Thanks to the improved antenna unit, the decoupling task is eased, and a better decoupling performance is achieved compared with the original ADS work. Journal: Journal of Electromagnetic Waves and Applications Pages: 2034-2050 Issue: 15 Volume: 35 Year: 2021 Month: 10 X-DOI: 10.1080/09205071.2021.1929507 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1929507 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:15:p:2034-2050 Template-Type: ReDIF-Article 1.0 Author-Name: Milad Nosrati Author-X-Name-First: Milad Author-X-Name-Last: Nosrati Author-Name: Pejman Rezaei Author-X-Name-First: Pejman Author-X-Name-Last: Rezaei Author-Name: Mohammad Danaie Author-X-Name-First: Mohammad Author-X-Name-Last: Danaie Author-Name: Shahram Parvizi Author-X-Name-First: Shahram Author-X-Name-Last: Parvizi Title: Wideband transmitarray antenna using Electric ring resonator shaped slot element Abstract: This paper proposes a low-profile, low-cost, and wideband quad-layer element for designing transmitarray antenna (TA). Changing the dimensions of the element shifts its passband. Sometimes, this shift is so large that the passband of the element exits the desired operating band of the TA. In other words, areas of the passband with low transmission magnitudes match the desired operating band. In this case, elements with low transmission magnitudes have no beneficial effect on the total gain of the array, and the gain drops, thus shrinking the bandwidth. The bandwidth of the proposed element is so wide that passbands corresponding to different dimensions of the elements overlap in a large area around the central frequency. To display the effect of this feature, a 14×14-element TA is designed and manufactured using the proposed element. The measurement results indicate a 1-dB bandwidth of 18.4% and 54% aperture efficiency. Journal: Journal of Electromagnetic Waves and Applications Pages: 2092-2101 Issue: 15 Volume: 35 Year: 2021 Month: 10 X-DOI: 10.1080/09205071.2021.1934567 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1934567 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:15:p:2092-2101 Template-Type: ReDIF-Article 1.0 Author-Name: Dharmendra Singh Author-X-Name-First: Dharmendra Author-X-Name-Last: Singh Author-Name: Aqeel Ahmed Khan Author-X-Name-First: Aqeel Ahmed Author-X-Name-Last: Khan Author-Name: Syed Aftab Naqvi Author-X-Name-First: Syed Aftab Author-X-Name-Last: Naqvi Author-Name: M. Saeed Khan Author-X-Name-First: M. Author-X-Name-Last: Saeed Khan Author-Name: Antonio-D. Capobianco Author-X-Name-First: Antonio-D. Author-X-Name-Last: Capobianco Author-Name: Stefano Boscolo Author-X-Name-First: Stefano Author-X-Name-Last: Boscolo Author-Name: Michele Midrio Author-X-Name-First: Michele Author-X-Name-Last: Midrio Author-Name: Raed M. Shubair Author-X-Name-First: Raed M. Author-X-Name-Last: Shubair Title: Inverted-c ground MIMO antenna for compact UWB applications Abstract: A miniaturized four-port polarization diversity ultra-wide band multiple input multiple output (MIMO) antenna is presented in this article. Different structures are combined and excited with the tapered transmission line to obtain a reduced symmetric layout with the orthogonal arrangement in compact size. An inverted-c-shape partial ground plane is used to decouple the antenna elements placed in close proximity which reduced the overall size and improved the matched impedance of the MIMO antenna. Further, impedance bandwidth is improved by etching the slots in the ground plane. The overall dimension of the proposed compact MIMO antenna is 40 × 40 × 1.524 mm3. The measured characteristics of a fabricated prototype on the FR4 laminate well matched with the simulated results. The antenna exhibits a quasi-omnidirectional radiation pattern on the H-plane throughout the operational bandwidth, with isolation greater than 16 dB, low envelope correlation, and gain variation. this antenna can efficiently be usedfor diversity applications and portable devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 2078-2091 Issue: 15 Volume: 35 Year: 2021 Month: 10 X-DOI: 10.1080/09205071.2021.1934566 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1934566 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:15:p:2078-2091 Template-Type: ReDIF-Article 1.0 Author-Name: N. Zerounian Author-X-Name-First: N. Author-X-Name-Last: Zerounian Author-Name: W. Aouimeur Author-X-Name-First: W. Author-X-Name-Last: Aouimeur Author-Name: A.-S. Grimault-Jacquin Author-X-Name-First: A.-S. Author-X-Name-Last: Grimault-Jacquin Author-Name: G. Ducournau Author-X-Name-First: G. Author-X-Name-Last: Ducournau Author-Name: C. Gaquière Author-X-Name-First: C. Author-X-Name-Last: Gaquière Author-Name: F. Aniel Author-X-Name-First: F. Author-X-Name-Last: Aniel Title: Coplanar waveguides on BCB measured up to 760 GHz Abstract: The integrated THz pattern over any MMIC appears to be a good opportunity to enclose calibration kit suitable for accurate measurements. An original technology based on polymer has been developed. Sub-millimeter single-mode conductor-backed coplanar waveguides using benzocyclobutene polymer and interconnecting via between ground planes are processed and measured up to 760 GHz. The experimental performances show good agreement with analytical and numerical modeling. A two-tier Thru-Reflect-Line correction and a square root of Thru de-embedding are applied to extract the attenuation factor of about 3 dB/mm at 600 GHz, the relative phase velocity to light of about 0.716 and the characteristic impedance around 50 Ω. The fundamental propagating mode remains unique in this wide frequency range, enabling this technological to be integrated over existing circuit for THz applications. The loss performance of the coplanar waveguide ranges in the state-of-the-art opening the road for fully integrated THz circuits. Journal: Journal of Electromagnetic Waves and Applications Pages: 2051-2061 Issue: 15 Volume: 35 Year: 2021 Month: 10 X-DOI: 10.1080/09205071.2021.1930588 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1930588 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:15:p:2051-2061 Template-Type: ReDIF-Article 1.0 Author-Name: Juscelino Junior de Oliveira Author-X-Name-First: Juscelino Junior Author-X-Name-Last: de Oliveira Author-Name: Lucas Douglas Ribeiro Author-X-Name-First: Lucas Douglas Author-X-Name-Last: Ribeiro Author-Name: Elson José da Silva Author-X-Name-First: Elson José Author-X-Name-Last: da Silva Author-Name: Rose Mary de Souza Batalha Author-X-Name-First: Rose Mary Author-X-Name-Last: de Souza Batalha Title: Design of a free space metamaterial lens based on LC parameters at S-band Abstract: A metamaterial lens was designed based on a two-dimensional host transmission line network loaded with inductors and capacitors. The planar negative refractive index (NRI) periodic structure, consisting of a unit cell array with a concave side, works as a curved lens matched to free space operating at S-Band. An equivalent unit cell dispersion relation was developed to determine the transmission characteristics at the operating frequency range. The challenge in the metamaterial lens design is to increase the focal distance. In the simulated system, a high energy level throughout a focal region was observed in the whole frequency range. An equivalent bulky material is used as a resource to reduce computational effort. Journal: Journal of Electromagnetic Waves and Applications Pages: 2210-2223 Issue: 16 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1934904 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1934904 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:16:p:2210-2223 Template-Type: ReDIF-Article 1.0 Author-Name: Huayan Jin Author-X-Name-First: Huayan Author-X-Name-Last: Jin Author-Name: Chi-Yang Chiou Author-X-Name-First: Chi-Yang Author-X-Name-Last: Chiou Author-Name: An-Chien Li Author-X-Name-First: An-Chien Author-X-Name-Last: Li Author-Name: Chung-Yi Li Author-X-Name-First: Chung-Yi Author-X-Name-Last: Li Author-Name: Kuo-Sheng Chin Author-X-Name-First: Kuo-Sheng Author-X-Name-Last: Chin Title: Compact T-complementary split-ring resonator antenna and antenna array Abstract: A compact T-complementary split-ring resonator (CSRR) antenna was developed. Different from traditional designs, the proposed CSRR functioned not only as a loading structure but also as a radiator. The operation of the T-CSRR antenna was similar to that of a slot antenna with a gain of 3.1 dBi. Because of the loading effect of the CSRR, the size of the radiator of the proposed antenna was only 0.14λ0 × 0.26λ0. The circuit sizes of the proposed T-CSRR antenna were 50% and 74% smaller than those of the traditional half-wavelength slot and T-shaped monopole antennas, respectively. For further gain enhancement, the performance of two feasible array arrangements, namely collinear and parallel arrays with 1 × 4 T-CSRR elements, were compared, which revealed that the parallel 1 × 4 T-CSRR antenna array can achieve a gain of 9 dBi at 2.45 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 2193-2209 Issue: 16 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1934903 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1934903 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:16:p:2193-2209 Template-Type: ReDIF-Article 1.0 Author-Name: Jiang Li Author-X-Name-First: Jiang Author-X-Name-Last: Li Author-Name: Zhu Wang Author-X-Name-First: Zhu Author-X-Name-Last: Wang Author-Name: Yue Ma Author-X-Name-First: Yue Author-X-Name-Last: Ma Author-Name: Xuehong Ran Author-X-Name-First: Xuehong Author-X-Name-Last: Ran Author-Name: Honggang Hao Author-X-Name-First: Honggang Author-X-Name-Last: Hao Title: Design of high-resolution near-field focusing metasurface lens Abstract: A high-resolution near-field focusing metasurface lens (MSL) was proposed to meet the high-resolution and miniaturization requirements of focusing devices in the Ka-band passive millimeter wave (PMMW) imaging system. Based on coaxial ring structure with polarization insensitivity, the design of a single refraction surface phase gradient MSL capable of focusing on plane waves is completed. Furthermore, the near-field focusing is realized by the method of phase superposition. The overall size of the lens s is 80 × 80 mm2, composed of 25 × 25 unit with the thickness of only 0.24λ. The feed source used a tapered slot antenna based on substrate integrated waveguide. The simulation results indicate a good spatial resolution of the presented lens, which can focus the electromagnetic wave radiated from the feed antenna at 70 mm with the focal spot size of 9 mm. The lens can effectively reduce the system volume and achieve high resolution imaging when utilized in PMMW imaging system. Journal: Journal of Electromagnetic Waves and Applications Pages: 2115-2124 Issue: 16 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1934569 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1934569 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:16:p:2115-2124 Template-Type: ReDIF-Article 1.0 Author-Name: Aleksey S. Gvozdarev Author-X-Name-First: Aleksey S. Author-X-Name-Last: Gvozdarev Title: Average quality description of energy detection for generalised multipath shadowed κ – μ fading channels Abstract: The research addresses the problem of analytical description of energy detection procedure being one of the most favourable mechanism of white-space detection for cognitive radio and Internet-of-Things as well as unknown signal detection in radars and Unmanned Ground/Aerial Vehicle applications. A novel closed-form analytic solutions for average quality metrics (average receiver operating characteristic and area under the AROC curve) are derived for a generic shadowed fading $ \kappa -\mu $ κ−μ channel model. Numerical simulations verify the computational effectiveness of the derived expressions compared to straightforward numerical integration and analytical treatment demonstrated their consistency with the several specific simplified cases widely used in engineering practice. The results enable one to estimate signal detection quality on the stage of wireless communications' system design. Journal: Journal of Electromagnetic Waves and Applications Pages: 2163-2175 Issue: 16 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1934901 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1934901 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:16:p:2163-2175 Template-Type: ReDIF-Article 1.0 Author-Name: S. V. Ranganayakulu Author-X-Name-First: S. V. Author-X-Name-Last: Ranganayakulu Author-Name: K. V. Subrahmanyam Author-X-Name-First: K. V. Author-X-Name-Last: Subrahmanyam Author-Name: A. Niranjan Author-X-Name-First: A. Author-X-Name-Last: Niranjan Title: A novel algorithm for convective cell identification and tracking based on Optical Character Recognition Neural Network Abstract: Identifying the core of the convective cloud is paramount important to the identification of the Mesoscale Convective System (MCS) and its evolution is of great significance in the weather and climate system. To study the initiation and development of convective core systems, an automatic tracking algorithm named “Convective cell Identification and TRAcking (CITRA)” has been developed to identify and track the convective cells in MCSs using Doppler Weather Radar reflectivity images based Optical Character Recognition using Long Shortterm Memory Neural Network. Further, CITRA algorithm calculates the convective cell physical properties such as centroid, convective core size and area, duration, maximum extent, distance and direction from the Radar centre. CITRA algorithm tested on 1255 convective cells identification and tracked 90 distinct convective system families along with physical properties through their evolution during the monsoon periods of 2017–2019. The details of CITRA algorithm is described in the present paper. Journal: Journal of Electromagnetic Waves and Applications Pages: 2239-2255 Issue: 16 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1941299 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1941299 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:16:p:2239-2255 Template-Type: ReDIF-Article 1.0 Author-Name: Selcuk Helhel Author-X-Name-First: Selcuk Author-X-Name-Last: Helhel Author-Name: Alpaslan Bozkurt Karaman Author-X-Name-First: Alpaslan Bozkurt Author-X-Name-Last: Karaman Author-Name: Atalay Kocakusak Author-X-Name-First: Atalay Author-X-Name-Last: Kocakusak Title: Heatsinks as quasi-antennas and frog forming: frequency and feeding point effect Abstract: High-speed switching capabilities of modern ICs cause generating more heat, and it must be ejected via metallic heat-sinks behaving as an antenna at certain frequencies. Having different radiation patterns(RP) at different frequencies may cause a malfunction on nearby electronics placed on the other part of PCB. In this study, 50W equivalent heat-sink is investigated at 2-8 GHz in terms of feeding point. RP measurements and simulation results at four different feeding points are discussed, and it is observed that point of feeding is the pre-dominant factor of RP. As expected, the feeding of the heat-sinks from the center is to be preferred for lower frequencies, but it causes critical emission/interference problems at higher frequencies. As the frequency increases, it metamorphoses like a frog forming. While it behaves as an omnidirectional antenna having $ (\sim 2\,\textrm{dB}) $ (∼2dB) gain at 2GHz, RP turns to one that includes 6 beams with 30-degree beam-widths and $ (\sim 5\,\textrm{dB}) $ (∼5dB) gain. Journal: Journal of Electromagnetic Waves and Applications Pages: 2153-2162 Issue: 16 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1934572 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1934572 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:16:p:2153-2162 Template-Type: ReDIF-Article 1.0 Author-Name: Jamel Nebhen Author-X-Name-First: Jamel Author-X-Name-Last: Nebhen Author-Name: Blaise Ravelo Author-X-Name-First: Blaise Author-X-Name-Last: Ravelo Title: Bandpass NGD analysis of symmetric lumped Y-tree via tensorial analysis of networks formalism Abstract: This paper develops an original theory of bandpass (BP) negative group delay (NGD) function from three-port symmetric circuit. The BP NGD analysis is applied first time to three-port topology. The present study develops originally a BP NGD investigation of three-port circuit constituted by R, L and C lumped components. The equivalent S-matrix modelling is elaborated with the uncommon circuit theory. To validate the theory, a lumped circuit proof of concept is designed and simulated. A group delay value of about −0.3 ns is observed at the NGD centre frequency of about 76 MHz over 214 MHz bandwidth. For the further understanding on the BP NGD behaviour, a parametric study with the variations of the resistor, inductor and capacitor components of the Y-tree is performed. The results of the present study guarantee a potential microwave communication application of BP NGD function notably for systems operating with ISM and IEEE 802.11 standards. Journal: Journal of Electromagnetic Waves and Applications Pages: 2125-2140 Issue: 16 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1934570 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1934570 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:16:p:2125-2140 Template-Type: ReDIF-Article 1.0 Author-Name: Zhen-Hua Zhao Author-X-Name-First: Zhen-Hua Author-X-Name-Last: Zhao Author-Name: Hai-Feng Zhang Author-X-Name-First: Hai-Feng Author-X-Name-Last: Zhang Title: A wide-band circularly polarized antenna array using a sequential phase feed structure applied to 5G-band Abstract: In this article, a 2×2 broadband circularly polarized antenna array using the sequential rotation (SR) technique in the feed network is presented. This antenna covers the 5G-band of 3.5–3.6 GHz and 4.8–4.9 GHz. So, it can be used for 5G-band communication [1]. The performance of the antenna is obtained by simulation and experiment, as follows: the bandwidth of S11 parameter below -10 dB is 3.7 GHz (3.3–7 GHz), and AR bandwidth (AR < 3 dB) is 2.4 GHz (3.5–5.5 GHz and 5.8-6.2 GHz ), the maximum gain is about 10.2 dBi, and the gain is greater than 0 dBi in the range of 3.6–6.5 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 2141-2152 Issue: 16 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1934571 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1934571 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:16:p:2141-2152 Template-Type: ReDIF-Article 1.0 Author-Name: Arpan Shah Author-X-Name-First: Arpan Author-X-Name-Last: Shah Author-Name: Piyush Patel Author-X-Name-First: Piyush Author-X-Name-Last: Patel Title: E-textile slot antenna with spurious mode suppression and low SAR for medical wearable applications Abstract: In this paper, electronic textile (E-textile) antenna design, with spurious mode suppression and low specific absorption rate (SAR), at a nearest distance of 1 mm from on-body phantom is investigated. The textile antenna is designed using a denim substrate material with conductive patch as a radiating element. The slots are introduced on the patch for spurious mode suppression so that external radio frequency components can be integrated with textile antenna without hampering the efficiency of the body area network system. The measured bandwidth of the proposed antenna is 100 MHz (2.39–2.49 GHz) in the 2.45 GHz ISM frequency band with broadside radiation pattern. The radiation pattern at spurious mode is suppressed by 5 dB without any change in the resonance frequency of fundamental mode. Besides, considering human safety for wearable devices, the SAR values average over 1 g of tissue are 0.208, 0.106 and 0.087 W/Kg at a distance of 1, 3 and 5 mm from on-body phantom, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 2224-2238 Issue: 16 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1934905 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1934905 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:16:p:2224-2238 Template-Type: ReDIF-Article 1.0 Author-Name: Reza Zaker Author-X-Name-First: Reza Author-X-Name-Last: Zaker Author-Name: Shadi Hosseinkhani Author-X-Name-First: Shadi Author-X-Name-Last: Hosseinkhani Title: Decoupling and matching enhancement of compact two-element array antenna merging with Jerusalem-like coupled parasitic structure Abstract: An array antenna of two high-coupled patches with an edge-to-edge distance of only $ 0.02{\lambda _0} $ 0.02λ0 at 3.45 GHz merged with a Jerusalem-like parasitic structure (JPS) is reported. This JPS is compactly sandwiched between two patches and consists of two strips, horizontal (HS) and vertical (VS). HS perturbs the current distributions and so presents two mechanisms for improving the impedance matching and exciting the new half-mode of quasi TM1/2,1 in comparison with TM01. Additionally, a broadside pattern is provided with a 10 dB increment in polarization purity and a gain over 5.5 dB. VS with two symmetric vias decreases the mutual coupling extremely and isolation over 49 dB is obtained. Moreover, the theory of the excitation modes, the performance and the parametric studies are presented. Two array antennas are fabricated with and without JPS and their results are compared which prove a 15% increase in total MIMO efficiency and a significant reduction in ECC. Journal: Journal of Electromagnetic Waves and Applications Pages: 2176-2192 Issue: 16 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1934902 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1934902 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:16:p:2176-2192 Template-Type: ReDIF-Article 1.0 Author-Name: M. Mohaghegh Author-X-Name-First: M. Author-X-Name-Last: Mohaghegh Author-Name: B. Abbasi Arand Author-X-Name-First: B. Abbasi Author-X-Name-Last: Arand Title: Multi-layered parallel plate waveguide with electrically and magnetically biased graphene sheets Abstract: The performance of a multi-layered parallel plate waveguide, supported by graphene plates, is evaluated here. The graphene layers were biased with both magnetic and electric fields. The graphene plates weremodelled as an anisotropic surface derived from the Kubo formula. Maxwell's equations were solved for these waveguides; and it is shown when both magnetic and electric biases were applied to the graphene, hybrid modes propagated inside the waveguides. The intensity of each TM and TE mode could be adjusted with an applied external field bias. This study of wave confinement has shown that, by varying the bias, full control can be exerted over the wave's propagation within a waveguide; whereby, increasing the bias causes added phase changes over the propagation length, while increasing the waveguide's attenuation. It must be emphasized that the presented procedure is also applicable to other guiding structures that have boundary with isotropic or anisotropic conductivities. Journal: Journal of Electromagnetic Waves and Applications Pages: 2335-2348 Issue: 17 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1947391 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1947391 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:17:p:2335-2348 Template-Type: ReDIF-Article 1.0 Author-Name: Jose O. Vargas Author-X-Name-First: Jose O. Author-X-Name-Last: Vargas Author-Name: André Costa Batista Author-X-Name-First: André Costa Author-X-Name-Last: Batista Author-Name: Lucas S. Batista Author-X-Name-First: Lucas S. Author-X-Name-Last: Batista Author-Name: Ricardo Adriano Author-X-Name-First: Ricardo Author-X-Name-Last: Adriano Title: On the computational complexity of the conjugate-gradient method for solving inverse scattering problems Abstract: This paper presents an efficient implementation of the inversion algorithm based on the conjugate-gradient method (CGM) for solving inverse scattering problems. The original CGM provides good image reconstruction and robustness to noise-corrupted data. This method requires the solution of the forward scattering problem and the Fréchet derivative operator of the cost function at each iteration step. However, these procedures can make the computational cost prohibitive, even for moderately sized problems. To avoid the computational burden, a two-step conjugate gradient fast Fourier transform (CG-FFT) procedure is proposed. Such an approach reduces the computational cost and storage requirements of the CGM implementation. The efficient CGM is found to share a computational complexity similar to the distorted-Born iterative method (DBIM). Thus the convergence speed and accuracy of the CGM is compared with the DBIM. Numerical tests using both synthetic and experimental data show effectiveness for solving 2D inverse scattering problems. Journal: Journal of Electromagnetic Waves and Applications Pages: 2323-2334 Issue: 17 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1946862 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1946862 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:17:p:2323-2334 Template-Type: ReDIF-Article 1.0 Author-Name: Oleg Rybin Author-X-Name-First: Oleg Author-X-Name-Last: Rybin Author-Name: Sergey Shulga Author-X-Name-First: Sergey Author-X-Name-Last: Shulga Title: Analytical model for miniaturized patch antenna on metaferrite-like substrate Abstract: In this study, a 2-D mathematical model of a high-directive microwave antenna with a miniaturized volume profile is developed analytically. The antenna is a rectangular patch antenna on a metaferrite substrate. The substrate is a parallelepiped-shaped dielectric matrix with periodically embedded thin cylindrical ferromagnetic inclusions of a circular cross section. It is assumed that the inclusions are fully or partially magnetized by an external DC bias magnetic field. It has been shown that the use of such a metamaterial substrate, instead of a dielectric one with the same values of permittivity and permeability, leads to a miniaturization of the volume profile of the antenna and an increase in its efficiency and power gain. The commercial electromagnetic software is used in the study to validate the proposed antenna model. Journal: Journal of Electromagnetic Waves and Applications Pages: 2257-2268 Issue: 17 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1942234 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1942234 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:17:p:2257-2268 Template-Type: ReDIF-Article 1.0 Author-Name: Rahul Vashisth Author-X-Name-First: Rahul Author-X-Name-Last: Vashisth Author-Name: Deepak K. Ghodgaonkar Author-X-Name-First: Deepak K. Author-X-Name-Last: Ghodgaonkar Author-Name: Sanjeev Gupta Author-X-Name-First: Sanjeev Author-X-Name-Last: Gupta Title: Broadband microwave absorber using pixelated FSS embedded in CISR sheets in frequency range of 3.95 to 8.2 GHz Abstract: In this paper, pixelated Frequency Selective Surface (FSS) layer embedded in two carbonyl iron-filled silicon rubber (CISR) sheets are used for design of broadband microwave absorber in frequency range of 3.95 to 8.2 GHz. Top and bottom layers of CISR sheets are prepared with 24% and 33% of Carbonyl Iron (CI) powder by volume, respectively. Reflectivity of microwave absorber, complex permittivity and complex permeability of CISR sheets are evaluated using two Rectangular Dielectric Waveguide (RDWG) measurement systems in 3.95 to 5.85 GHz frequency band (WR-187) and 5.85 to 8.2 GHz frequency band (WR-137). An algorithm was developed using Geometry-Refinement Method (GRM) and Genetic Algorithm (GA) optimization technique to design pixelated FSS layer. Measured as well as simulated reflectivity of composite microwave absorber is better than −10 dB at normal incidence in the frequency range of 3.95–8.2 GHz. For oblique incidence from 0 $ ^\circ $ ∘ to 40 $ ^\circ $ ∘, simulated reflectivity of TE and TM polarizations carried out for all angles of incidence. Journal: Journal of Electromagnetic Waves and Applications Pages: 2349-2367 Issue: 17 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1947899 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1947899 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:17:p:2349-2367 Template-Type: ReDIF-Article 1.0 Author-Name: Shou-Xi Xu Author-X-Name-First: Shou-Xi Author-X-Name-Last: Xu Author-Name: Zhi-Hui Geng Author-X-Name-First: Zhi-Hui Author-X-Name-Last: Geng Author-Name: Wei Gu Author-X-Name-First: Wei Author-X-Name-Last: Gu Author-Name: Jie Yang Author-X-Name-First: Jie Author-X-Name-Last: Yang Author-Name: Jian Zhang Author-X-Name-First: Jian Author-X-Name-Last: Zhang Author-Name: Rui Zhang Author-X-Name-First: Rui Author-X-Name-Last: Zhang Title: Design and simulation of a W-band gyrotron traveling wave amplifier Abstract: The design of a W-band gyrotron traveling wave tube amplifier is presented. The device with a lossy ceramic interaction circuit operates in the fundamental harmonic TE01 circular electric mode. The 70-kV, 6-A electron beam is produced by a double anode magnetron injection gun with an average perpendicular-to-parallel velocity ratio of 1.2 and a parallel velocity spread of less than 3%. The beam-wave interaction is investigated by using a particle-in-cell code. The simulations predict that the amplifier can produce an output peak power of over 100 kW, 28% efficiency, 42 dB gain, and a 3 GHz bandwidth, respectively under the assumption of beam velocity spread 3%. Journal: Journal of Electromagnetic Waves and Applications Pages: 2384-2395 Issue: 17 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1950577 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1950577 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:17:p:2384-2395 Template-Type: ReDIF-Article 1.0 Author-Name: Igor Kudinov Author-X-Name-First: Igor Author-X-Name-Last: Kudinov Author-Name: Vasiliy Kudinov Author-X-Name-First: Vasiliy Author-X-Name-Last: Kudinov Author-Name: Anton Eremin Author-X-Name-First: Anton Author-X-Name-Last: Eremin Author-Name: Konstantin Trubitsyn Author-X-Name-First: Konstantin Author-X-Name-Last: Trubitsyn Title: A mathematical model for electromagnetic oscillation propagation that accounts for single and dual-phase lag Abstract: Telegrapher’s equations that account for the speed and acceleration of a current and voltage were derived using a modified Ohm’s law formula that includes relaxation components. Examining the exact analytical solutions to these equations allowed us to conclude that abrupt changes in the target functions observed in solutions to classic telegrapher’s equations were eliminated, which indicates the elimination of the infinite propagation speed of electric field potentials inherent in the classic Ohm’s law formula. Analysis of the analytical solutions showed the impossibility of instant current (voltage) adoption at the edges of the conductor at the initial time instant, as the process of establishing these edges requires a definite initial time interval. This serves as evidence that it is physically impossible to instantly set a boundary condition in an actual electric conductivity process. Journal: Journal of Electromagnetic Waves and Applications Pages: 2304-2322 Issue: 17 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1945497 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1945497 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:17:p:2304-2322 Template-Type: ReDIF-Article 1.0 Author-Name: H. Helali Author-X-Name-First: H. Author-X-Name-Last: Helali Author-Name: S. Smirani Author-X-Name-First: S. Author-X-Name-Last: Smirani Author-Name: M. Aidi Author-X-Name-First: M. Author-X-Name-Last: Aidi Author-Name: T. Aguili Author-X-Name-First: T. Author-X-Name-Last: Aguili Title: Electromagnetic modeling of reconfigurable antenna array for 5G communications Abstract: The integration of extra wireless services in the limited size of mobile devices is a very challenging task. In this context, the antenna array presents the best choice to meet these requirements. This research demonstrates a reconfigurable antenna array system proposed for future 5G applications. The characteristics of the proposed structure are examined while using electromagnetic modeling. The mathematical formulation reposes on combining the moment method and generalized equivalent circuit’s methods (MoM-GEC), and the deduced electromagnetic equations allow the computation of the input impedance $ {Z_{in}} $ Zin, the reflection parameter $ {S_{11}} $ S11 and the current and electric field distributions. Software simulations prove good agreement with MoM-GEC results. The obtained results offer the possibility to generate various modes governed by a decision tree. Thus, these modes are related to different resonant frequencies suitable for 5G mobile communications with a large bandwidth reaching 560 MHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 2368-2383 Issue: 17 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1950576 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1950576 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:17:p:2368-2383 Template-Type: ReDIF-Article 1.0 Author-Name: Abbas Karimi Nobandegani Author-X-Name-First: Abbas Author-X-Name-Last: Karimi Nobandegani Author-Name: S. Esmail Hosseini Author-X-Name-First: S. Esmail Author-X-Name-Last: Hosseini Title: Ku-band 8-way Wilkinson power divider based on ridge gap waveguide technology Abstract: The novel ridge-gap waveguide (RGW) technology which has recently been introduced has many advantages in micro/mm-wave frequencies such as low loss, broad bandwidth, low sensitivity to manufacturing errors and easy integration with active components, etc. In this paper, a Ku-band 8-way Wilkinson power divider (WPD) is proposed and simulated based on the RGW technology for the first time, to the best of our knowledge. An RGW-toWR62 transition is also designed and simulated. The proposed 8-way RGW-based WPD with WR62 transitions shows low-loss equal-power division in phase with good matching at all ports and isolation between output ports in the Ku band. The proposed RGW-based WPD can be extended to an arbitrary $ {2^N} $ 2N-way corporate power divider/combiner which can find many applications such as in array antenna feed networks, solid-state power amplifiers (SSPAs), etc. Journal: Journal of Electromagnetic Waves and Applications Pages: 2283-2303 Issue: 17 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1943003 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1943003 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:17:p:2283-2303 Template-Type: ReDIF-Article 1.0 Author-Name: Vineet Singh Author-X-Name-First: Vineet Author-X-Name-Last: Singh Author-Name: Somak Bhattacharyya Author-X-Name-First: Somak Author-X-Name-Last: Bhattacharyya Author-Name: Pradip Kumar Jain Author-X-Name-First: Pradip Kumar Author-X-Name-Last: Jain Title: Deep neural network-based target separation from mixed micro-Doppler signature of multiple moving targets Abstract: Under radar observation, every moving target contains a unique micro-Doppler (m-D) signature due to its structural component movement, which has been considered as one of the target class characteristics in their identification. It becomes challenging to identify the type of target and its motion parameter analysis for the simultaneous presence of multiple moving targets in the radar observation channel. This article aims to separate the desired target’s micro-Doppler (m-D) signature from the responses of multiple moving targets captured in a single channel radar with the help of a machine learning-based signal processing approach. A regressive deep neural network is designed to produce the probabilistic time-frequency mask, which separates the desired target time-frequency signature from the mixed m-D responses of more targets from different classes. The proposed method provides a high correlation of separated movement signature in comparison to the clean condition micro-Doppler signatures. Journal: Journal of Electromagnetic Waves and Applications Pages: 2269-2282 Issue: 17 Volume: 35 Year: 2021 Month: 11 X-DOI: 10.1080/09205071.2021.1943002 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1943002 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:17:p:2269-2282 Template-Type: ReDIF-Article 1.0 Author-Name: Cheng-Zhang Li Author-X-Name-First: Cheng-Zhang Author-X-Name-Last: Li Author-Name: Hai-Ming Li Author-X-Name-First: Hai-Ming Author-X-Name-Last: Li Title: Thinned linear array using joint optimization of IWDO/FFT algorithm Abstract: A sparse array synthesis method based on improved wind-driven optimization algorithm (IWDO) and fast Fourier transform (FFT) for the purpose of sidelobe suppression was introduced. First, the uniform linear array was sparse by the FFT algorithm. Then the amplitude excitation weighting of array elements was optimized by IWDO algorithm based on probability factor chaotic map. During the optimization process, the minimum peak sidelobe level was used as the fitness function. By comparing with the simulation results of classic Chebyshev weighting method, the method proposed in this paper has better performance. Journal: Journal of Electromagnetic Waves and Applications Pages: 2480-2491 Issue: 18 Volume: 35 Year: 2021 Month: 12 X-DOI: 10.1080/09205071.2021.1952902 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1952902 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:18:p:2480-2491 Template-Type: ReDIF-Article 1.0 Author-Name: Ashutosh Singh Author-X-Name-First: Ashutosh Author-X-Name-Last: Singh Author-Name: P. K. Jain Author-X-Name-First: P. K. Author-X-Name-Last: Jain Title: RF behavior of a 35 GHz conventional cavity gyrotron using multimode analysis and PIC simulation Abstract: In this paper, the RF behavior of a 35 GHz, TE04 mode cylindrical cavity gyrotron is investigated using the nonlinear multimode theory and PIC code “CST Particle Studio”. A code is developed to realize the beam-wave interaction mechanism using time-dependent multimode theory. The cold cavity behavior is observed for the cavity operation in the designed TE04 mode and 35 GHz frequency. The magnetic field profile is kept uniform along the length of the interaction structure. The output power is estimated for the designed mode as well as all nearby competing modes using the multimode analysis and PIC simulation. This yields the output power more than 200 kW with 33% efficiency in the designed TE04 mode, whereas the smaller output power in the nearby competing modes. Power sustainability is also observed for the stable operation of the device. The effects of beam velocity spread and detuning of magnetic field on its performance are also observed. Journal: Journal of Electromagnetic Waves and Applications Pages: 2428-2446 Issue: 18 Volume: 35 Year: 2021 Month: 12 X-DOI: 10.1080/09205071.2021.1952655 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1952655 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:18:p:2428-2446 Template-Type: ReDIF-Article 1.0 Author-Name: A. Khodja Author-X-Name-First: A. Author-X-Name-Last: Khodja Author-Name: M. C. E. Yagoub Author-X-Name-First: M. C. E. Author-X-Name-Last: Yagoub Author-Name: R. Touhami Author-X-Name-First: R. Author-X-Name-Last: Touhami Author-Name: H. Baudrand Author-X-Name-First: H. Author-X-Name-Last: Baudrand Title: Advanced recursive modal integral technique for accurate hybrid mode characterization of symmetrical/asymmetrical multilayered uniaxial anisotropic planar structures Abstract: This paper introduces, for the first time, an extended modal integral technique for reliable characterization of multilayered symmetrical/asymmetrical planar structures built on arbitrary number of uniaxial electric/magnetic anisotropic layers. Based on a simple but efficient recursive algorithm devoted to composite substrates, the proposed hybrid mode analysis involves the Galerkin’s procedure combined with the formalism concept of mathematical operators to more conveniently formulate the boundary conditions. By properly selecting adequate trial functions, the technique was demonstrated through a close agreement between the obtained results and published data. Journal: Journal of Electromagnetic Waves and Applications Pages: 2397-2427 Issue: 18 Volume: 35 Year: 2021 Month: 12 X-DOI: 10.1080/09205071.2021.1951362 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1951362 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:18:p:2397-2427 Template-Type: ReDIF-Article 1.0 Author-Name: Vikesh S. Bhadouria Author-X-Name-First: Vikesh S. Author-X-Name-Last: Bhadouria Author-Name: Zubair Akhter Author-X-Name-First: Zubair Author-X-Name-Last: Akhter Author-Name: M. Jaleel Akhtar Author-X-Name-First: M. Jaleel Author-X-Name-Last: Akhtar Author-Name: P. Munshi Author-X-Name-First: P. Author-X-Name-Last: Munshi Title: Automated microwave monitoring of hidden objects for strategic and security applications Abstract: An automated microwave technique for the monitoring of hidden objects for strategic applications has been presented. The proposed approach is quite novel as it implements and integrates the time-domain method in free-space with the indigenously developed automated scanning setup to obtain the dielectric profile of hidden objects in standard sand or behind the concrete structure. The existing imaging methods for concealed media cannot reveal detailed information of objects with restrictions to access the other side of the test media. The overall approach is implemented by measuring the S-parameters of the test region containing the hidden objects in the wide frequency range of 2-10 GHz using the horn-lens antenna and the network analyzer. The S-parameters are transformed into the equivalent time-domain using the standard IFFT algorithm to retrieve the test region's 2D microwave image and the approximate size of concealed objects, which helps in situations such as through-the-wall imaging, and landmine detection. Journal: Journal of Electromagnetic Waves and Applications Pages: 2492-2509 Issue: 18 Volume: 35 Year: 2021 Month: 12 X-DOI: 10.1080/09205071.2021.1953404 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1953404 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:18:p:2492-2509 Template-Type: ReDIF-Article 1.0 Author-Name: Yanliang Duan Author-X-Name-First: Yanliang Author-X-Name-Last: Duan Author-Name: Shunlan Zhang Author-X-Name-First: Shunlan Author-X-Name-Last: Zhang Author-Name: Weiping Cao Author-X-Name-First: Weiping Author-X-Name-Last: Cao Title: Covariance matrix reconstruction with iterative mismatch approximation for robust adaptive beamforming Abstract: The covariance matrix reconstruction based robust adaptive beamforming (RAB) methods overcome the performance degradation due to the imprecise knowledge of the steering vector and the covariance matrix. However, high complexity limits the application of them. In this paper, we proposed a new RAB method based on interference plus noise covariance (INC) matrix reconstruction and desired signal steering vector estimation. In this method, nominal interference steering vectors are estimated by the Capon spatial spectrum, as well as noise power. Subsequently, the iterative mismatch approximation algorithm based on maximizing the beamformer output power is proposed to estimate all the incident signal steering vectors and powers, and the INC matrix is reconstructed. Finally, the beamformer is determined by the estimated INC matrix and desired signal steering vector. Simulation results indicate that the proposed method obtains better performance than other existed methods at both the high signal to noise ratio (SNR) and the complexity. Journal: Journal of Electromagnetic Waves and Applications Pages: 2468-2479 Issue: 18 Volume: 35 Year: 2021 Month: 12 X-DOI: 10.1080/09205071.2021.1952901 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1952901 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:18:p:2468-2479 Template-Type: ReDIF-Article 1.0 Author-Name: Mathieu François Author-X-Name-First: Mathieu Author-X-Name-Last: François Author-Name: Sangil Han Author-X-Name-First: Sangil Author-X-Name-Last: Han Author-Name: Frédéric Segonds Author-X-Name-First: Frédéric Author-X-Name-Last: Segonds Author-Name: Corinne Dupuy Author-X-Name-First: Corinne Author-X-Name-Last: Dupuy Author-Name: Mickaël Rivette Author-X-Name-First: Mickaël Author-X-Name-Last: Rivette Author-Name: Simon Turpault Author-X-Name-First: Simon Author-X-Name-Last: Turpault Author-Name: Mehdi Mimouna Author-X-Name-First: Mehdi Author-X-Name-Last: Mimouna Author-Name: Ferdinando Salvatore Author-X-Name-First: Ferdinando Author-X-Name-Last: Salvatore Author-Name: Joël Rech Author-X-Name-First: Joël Author-X-Name-Last: Rech Author-Name: Patrice Peyre Author-X-Name-First: Patrice Author-X-Name-Last: Peyre Title: Electromagnetic performance of Ti6Al4V and AlSi7Mg0.6 waveguides with laser beam melting (LBM) produced and abrasive flow machining (AFM) finished internal surfaces Abstract: Metal additive manufacturing processes, such as laser beam melting (LBM), can play a key role in developing antenna-feed chains because monolithic and multifunctional parts can be manufactured with high geometric freedom in the design phase. Using LBM technology, lighter and more compact antennas can be produced and manufacturing costs can be reduced. However, the surface roughness of internal surfaces in waveguides produced by LBM is much higher (about 10 μm Ra) than that produced by conventional manufacturing technologies. Consequently, such high surface roughness of the internal surface can affect electrical current propagation through the waveguide and corresponding transmitted power. In this paper, abrasive flow machining (AFM) was used to reduce the surface roughness of the internal surfaces of four different waveguides used at both K and Q bands. A significant reduction in the transmission loss at both K and Q bands was observed as their internal surface roughness decreased from about 10 μm to 1 μm Ra. This was assumed to be due to an increase of the internal surface electrical conductivity with the decrease of roughness in waveguides channels. Journal: Journal of Electromagnetic Waves and Applications Pages: 2510-2526 Issue: 18 Volume: 35 Year: 2021 Month: 12 X-DOI: 10.1080/09205071.2021.1954554 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1954554 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:18:p:2510-2526 Template-Type: ReDIF-Article 1.0 Author-Name: Bin Yang Author-X-Name-First: Bin Author-X-Name-Last: Yang Author-Name: Wenxing Li Author-X-Name-First: Wenxing Author-X-Name-Last: Li Author-Name: Yuanyuan Li Author-X-Name-First: Yuanyuan Author-X-Name-Last: Li Author-Name: Chongyi Yue Author-X-Name-First: Chongyi Author-X-Name-Last: Yue Title: Novel robust adaptive beamforming against unknown mutual coupling Abstract: Mutual coupling effects among the array elements can degrade the performance of the beamformer seriously. In this paper, we propose a novel robust adaptive beamforming method, which is robust against unknown mutual coupling. The main idea is to reconstruct the interference-plus-noise covariance matrix (IPNCM) with the estimated eigenvector and eigenvalue corresponding to the interference. The eigenvector lies in the intersection of two special subspaces. The first subspace is the signal-plus-interference (SPI) subspace got from the sample covariance matrix (SCM). The second subspace, which is interference subspace, can be obtained by integrating the conduction matrix in each interference angular sector. According to the correlation between the estimated eigenvector and SPI subspace, the eigenvalues corresponding to each interference are determined. Therefore, the IPNCM is reconstructed. The desired signal steering vector (SV) is estimated by a similar method. Simulation results show that the proposed beamformer outperforms other methods in the presence of unknown mutual coupling. Journal: Journal of Electromagnetic Waves and Applications Pages: 2447-2467 Issue: 18 Volume: 35 Year: 2021 Month: 12 X-DOI: 10.1080/09205071.2021.1952656 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1952656 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:18:p:2447-2467 Template-Type: ReDIF-Article 1.0 Author-Name: Rivo Randriatsiferana Author-X-Name-First: Rivo Author-X-Name-Last: Randriatsiferana Author-Name: Lucius Ramifidisoa Author-X-Name-First: Lucius Author-X-Name-Last: Ramifidisoa Author-Name: Sébastien Lalléchère Author-X-Name-First: Sébastien Author-X-Name-Last: Lalléchère Author-Name: Zhifei Xu Author-X-Name-First: Zhifei Author-X-Name-Last: Xu Author-Name: Blaise Ravelo Author-X-Name-First: Blaise Author-X-Name-Last: Ravelo Title: TAN modelling of HH-shape microstrip interconnect tree Abstract: This paper develops an unfamiliar modelling of printed circuit board (PCB) interconnect behaving as HH-tree. The developed model is based on the tensorial analysis of networks (TAN) formalism. The HH-tree is implemented with the equivalent LC-network based on Hammerstad-Jensen modelling. The unfamiliar TAN methodology is described by starting from the equivalent graph topology. The HH-tree TAN model is established from the branch and mesh spaces implementation of voltage, current and impedance tensorial objects. Then, the HH-tree PCB problem is reformulated with the tensorial electrical system metric. The solution of the metric problem is validated with commercial tool simulation from DC up to 2.5 GHz with a microstrip circuit proof-of-concept. As expected, computed and simulated results are in good agreement. Journal: Journal of Electromagnetic Waves and Applications Pages: 139-149 Issue: 2 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1828183 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1828183 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:2:p:139-149 Template-Type: ReDIF-Article 1.0 Author-Name: M. Umair Author-X-Name-First: M. Author-X-Name-Last: Umair Author-Name: A. Ghaffar Author-X-Name-First: A. Author-X-Name-Last: Ghaffar Author-Name: Majeed A. S. Alkanhal Author-X-Name-First: Majeed A. S. Author-X-Name-Last: Alkanhal Author-Name: M.Y. Naz Author-X-Name-First: M.Y. Author-X-Name-Last: Naz Author-Name: Ali H. Alqahtani Author-X-Name-First: Ali H. Author-X-Name-Last: Alqahtani Author-Name: Y. Khan Author-X-Name-First: Y. Author-X-Name-Last: Khan Title: Dispersion characteristics of hybrid surface waves at chiral-plasma interface Abstract: The theoretical analysis of hybrid surface wave propagation at chiral-plasma planar interface is presented in this manuscript. The dispersion relation is obtained for the proposed structure by applying boundary conditions at the chiral-plasma interface. The characteristic of hybrid surface wave can be tuned by changing the plasma frequency, plasma collisional frequency, and chirality parameter. It is shown that phase constant $\textrm{ Re}(\beta ) $ Re(β), attenuation or propagation loss and propagation length are dependent on plasma and chiral parameters. The effect of plasma frequency, plasma collisional frequency, and chirality parameter on the normalized phase constant $\textrm{ Re}(\beta ) $ Re(β), attenuation constant, and propagation length are presented computationally. Moreover, to verify the surface wave's condition normalized filed distribution is also presented. The present work may have potential applications in chiral and plasma-sensing based waveguide and enantiomeric sensing devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 150-162 Issue: 2 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1828184 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1828184 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:2:p:150-162 Template-Type: ReDIF-Article 1.0 Author-Name: Bingfang Xie Author-X-Name-First: Bingfang Author-X-Name-Last: Xie Author-Name: Cong Wang Author-X-Name-First: Cong Author-X-Name-Last: Wang Author-Name: Alok Kumar Author-X-Name-First: Alok Author-X-Name-Last: Kumar Author-Name: Qun Wu Author-X-Name-First: Qun Author-X-Name-Last: Wu Author-Name: Meng Zhao Author-X-Name-First: Meng Author-X-Name-Last: Zhao Title: Ultra-compact wideband dual-mode Wilkinson power divider based on thin film integrated passive device fabrication technology Abstract: This paper presents an ultra-wideband and highly miniaturized dual-mode Wilkinson power divider fabricated using thin film integrated passive device (TFIPD) technology for GSM band (0.9 GHz). The four quarter-wavelength lines of conventional two-section Wilkinson power divider are replaced with π-type transformer. In addition, a RC filter is introduced at the input port to minimize the return loss. The presented power divider prototype is micro-fabricated on a gallium arsenide (GaAs) substrate through TFIPD technology to reduce overall structure size and minimize overall parasitic losses. The fabricated power divider exhibits compact size at central frequency of 0.9 GHz with an ultra-wideband working bandwidth. To the best of authors’ knowledge, the designed power divider is approximately 8 times smaller than the previously reported power dividers. Journal: Journal of Electromagnetic Waves and Applications Pages: 163-175 Issue: 2 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1828185 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1828185 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:2:p:163-175 Template-Type: ReDIF-Article 1.0 Author-Name: Chengxin Zhang Author-X-Name-First: Chengxin Author-X-Name-Last: Zhang Author-Name: Wenjie Fu Author-X-Name-First: Wenjie Author-X-Name-Last: Fu Author-Name: Yang Yan Author-X-Name-First: Yang Author-X-Name-Last: Yan Title: Study on a gyrotron quasi-optical mode converter for terahertz imaging Abstract: In this paper, a quasi-optical mode converter for terahertz imaging is presented. This design  is based on a 0.22 THz TE03 gyrotron oscillator. It includes a Vlasov launcher, an elliptical reflector and a parabolic reflector, which is used to convert TE03 cylindrical waveguide mode to a Gaussian-like beam. The quasi-optical system is analyzed in terms of geometric optics theory and the vector diffraction theory. Numerical optimization code is programmed by MATLAB software for analyzing the quasi-optical system. Simulation results show that the power transmission efficiency of the operating cavity mode to a fundamental Gaussian distribution is 82.14%, the output Gaussian beam can be propagated over 0.8 m without divergence and the scalar Gaussian mode content is 98.2%. A cold test experiment platform is built up to verify the design based on numerical calculation. In experiment, the scalar Gaussian mode content of 97.0% is measured which shows good agreement with numerical calculation. Journal: Journal of Electromagnetic Waves and Applications Pages: 176-184 Issue: 2 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1828186 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1828186 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:2:p:176-184 Template-Type: ReDIF-Article 1.0 Author-Name: Saurabh Singh Author-X-Name-First: Saurabh Author-X-Name-Last: Singh Author-Name: Sudhanshu Verma Author-X-Name-First: Sudhanshu Author-X-Name-Last: Verma Title: Compact wearable dual wideband circularly polarized L-strip fed slotted textile antenna with parasitic elements for ISM band applications Abstract: This paper presents an L-strip fed compact wearable dual wide band circularly polarized textile antenna (DWCPTA) with a pair of parasitic elements and dual wide band operations at frequencies 2.45 and 5.80 GHz for industrial, scientific and medical (ISM) band applications. The antenna is printed on top of denim (jeans) substrate having dielectric constant 1.7 and thickness of 1.43 mm with wide slot ground plane on back side. The proposed DWCPTA of size 40 × 40 × 1.43 mm3 achieves -10 dB simulation impedance bandwidth of 89.16% (2.3 – 6.0 GHz) and 3-dB axial ratio bandwidth (ARBW) of 47.55% (2.34 – 3.80 GHz) and 12.60% (5.20 – 5.90 GHz) and essentially, low specific absorption rate (SAR) values of 0.8 and 0.95 W/Kg over 10 g of human tissues for wide band operations at frequencies 2.45 and 5.80 GHz respectively. The proposed DWCPTA is designed, fabricated and tested, which shows good agreement between measured and simulated ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 185-197 Issue: 2 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1828187 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1828187 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:2:p:185-197 Template-Type: ReDIF-Article 1.0 Author-Name: M. Khorramizadeh Author-X-Name-First: M. Author-X-Name-Last: Khorramizadeh Author-Name: S. Mohammad-Ali-Nezhad Author-X-Name-First: S. Author-X-Name-Last: Mohammad-Ali-Nezhad Title: Low-RCS feature for UWB antenna with band-notch characteristics Abstract: This paper presents a new technique to reduce radar cross-section (RCS) of dual-band antennas. In order to show that the proposed method can be applied in various types of monopole antennas, two different patch antennas are designed one of which is fabricated. The primary model of the fabricated antenna without modification is composed of a circular radiator with two pairs of T-shaped strips. To reduce the RCS of the antenna, a half of its radiator that is not connected to the feed line is removed with its substrate. A perfect electric conductor (PEC) wall is designed and located in front of the remained half patch to generate an image of it. The results indicate that the proposed structure offers an omni-directional radiation pattern over a wide frequency range and a very wide impedance bandwidth with a WLAN band rejection as well as an in-band and out-of-band RCS reduction. Journal: Journal of Electromagnetic Waves and Applications Pages: 198-207 Issue: 2 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1828188 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1828188 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:2:p:198-207 Template-Type: ReDIF-Article 1.0 Author-Name: Eugene Smolkin Author-X-Name-First: Eugene Author-X-Name-Last: Smolkin Author-Name: Yury Smirnov Author-X-Name-First: Yury Author-X-Name-Last: Smirnov Author-Name: Maxim Snegur Author-X-Name-First: Maxim Author-X-Name-Last: Snegur Title: Surface TE-polarized waves in an inhomogeneous dielectric layer Abstract: The problem of normal waves in an inhomogeneous dielectric layer is reduced to a boundary value problem for the longitudinal components of the electromagnetic field in Sobolev spaces. Nonhomogeneous filling and entering of spectral parameter in transmission conditions lead to the necessity of special definition of solution to the problem. We formulate the definition of solution using variational relation. The variational problem is reduced to the study of an operator function. We investigate properties of the operators of the operator function needed for the analysis of its spectral properties. We prove theorem of discrete spectrum and theorem of localization of eigenvalues of the operator function on complex plane. Journal: Journal of Electromagnetic Waves and Applications Pages: 208-219 Issue: 2 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1828189 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1828189 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:2:p:208-219 Template-Type: ReDIF-Article 1.0 Author-Name: Fábio J. F. Gonçalves Author-X-Name-First: Fábio J. F. Author-X-Name-Last: Gonçalves Author-Name: Renato C. Mesquita Author-X-Name-First: Renato C. Author-X-Name-Last: Mesquita Author-Name: Elson J. Silva Author-X-Name-First: Elson J. Author-X-Name-Last: Silva Title: Hybrid nonsingular mappings in the multi-objective design of a transverse-magnetic reduced cloak Abstract: This paper describes the integrated use of two design strategies for controlling the permittivity and permeability of a transformation electromagnetics two-dimensional cloak. This hybrid process permits more freedom in the choice of the constitutive properties, which could simplify the implementation with metamaterials. Because simplicity of materials and scattering performance are inherently conflicting characteristics, a multi-objective genetic algorithm is applied to optimize them. According to the presented results for a transverse-magnetic layered cloak, it is possible to have a good performance in terms of scattering even with an approximated reduced set of parameters with unitary axial permeability. Journal: Journal of Electromagnetic Waves and Applications Pages: 220-232 Issue: 2 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1829092 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1829092 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:2:p:220-232 Template-Type: ReDIF-Article 1.0 Author-Name: Ranjeet Kumar Author-X-Name-First: Ranjeet Author-X-Name-Last: Kumar Author-Name: Rashmi Sinha Author-X-Name-First: Rashmi Author-X-Name-Last: Sinha Author-Name: Arvind Choubey Author-X-Name-First: Arvind Author-X-Name-Last: Choubey Author-Name: Santosh Kumar Mahto Author-X-Name-First: Santosh Kumar Author-X-Name-Last: Mahto Title: An ultrawide band monopole antenna using hexagonal-square shaped fractal geometry Abstract: Fractal geometry antennas are much sought after in present scenario of wireless communication due to ever increasing demand for high gain, wide bandwidth, low cost, compact size and easily deployable antennas. An ultrawide band monopole antenna using compact hexagonal-square shaped fractal geometry is proposed here, which nearly fulfils the above demands. The fractal geometry is introduced by iteration of square slots in the hexagonal radiating patch etched on a circular chunk. The proposed antenna achieves percentage bandwidth of 146% approximately ranging from $2.1 $2.1 to $13.5 $13.5 GHz with return loss of $-25 $−25 dB and voltage standing wave ratio (VSWR) less than 2. It achieves maximum peak gain of 7.2 dBi at 11.7 GHz and an average gain of 3.9 dBi in the entire operating range of frequency, efficiency of 87.57% and good radiation pattern. A prototype of simulated antenna is developed and the tested results are validated using equivalent circuit model as well. The results are in conformity with each other. Therefore, the proposed design can be used for UWB applications such as Bluetooth ( $2.4 $2.4 GHz), LTE ( $2.3 $2.3  GHz), WLAN ( $2.4-2.48 $2.4−2.48  GHz), 5G, WiMAX ( $2.5-2.69/3.4-3.69/5.25-5.85 $2.5−2.69/3.4−3.69/5.25−5.85  GHz), military communication in C-band, satellite communication in X-band and S-band. Journal: Journal of Electromagnetic Waves and Applications Pages: 233-244 Issue: 2 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1829094 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1829094 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:2:p:233-244 Template-Type: ReDIF-Article 1.0 Author-Name: Shiping Tang Author-X-Name-First: Shiping Author-X-Name-Last: Tang Author-Name: Junfa Mao Author-X-Name-First: Junfa Author-X-Name-Last: Mao Title: A quantification control method of electromagnetic environmental effects for complex systems Abstract: Modern aircraft, ship, and other systems have different consequences when faced with the own and external radio frequency, lightning and other electromagnetic environments (EME) radiation, that is called electromagnetic environmental effects (E3). In this paper, a new method of system-level E3 quantitative control is proposed. A two factor E3 impact degree model composed of susceptible receptor importance and consequence severity is established. The selection and calculation method of relevant parameters is given. The application process of this method is illustrated with examples of high intensity radiated fields (HIRF), lightning, electromagnetic interference (EMI) and radiation hazard elements for aircraft. It is proved that this method can quantitatively, clearly and accurately express the impact degree of E3, balance the conflict of multi-index and multi-objective design, and achieve the engineering optimization when solving the whole system, whole element and whole process E3 control problems. Journal: Journal of Electromagnetic Waves and Applications Pages: 245-261 Issue: 2 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1832149 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1832149 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:2:p:245-261 Template-Type: ReDIF-Article 1.0 Author-Name: Sahar Saleh Author-X-Name-First: Sahar Author-X-Name-Last: Saleh Author-Name: Widad Ismail Author-X-Name-First: Widad Author-X-Name-Last: Ismail Author-Name: Intan Sorfina Zainal Abidin Author-X-Name-First: Intan Sorfina Author-X-Name-Last: Zainal Abidin Author-Name: Mohd Haizal Jamaluddin Author-X-Name-First: Mohd Haizal Author-X-Name-Last: Jamaluddin Author-Name: Samir A. Al-Gailani Author-X-Name-First: Samir A. Author-X-Name-Last: Al-Gailani Author-Name: Asem S. Alzoubi Author-X-Name-First: Asem S. Author-X-Name-Last: Alzoubi Author-Name: Mohammed H. Bataineh Author-X-Name-First: Mohammed H. Author-X-Name-Last: Bataineh Title: Compact UWB 1:2:1 unequal-split 3-way bagley power divider using non-uniform transmission lines Abstract: In this paper, compact Ultra-Wide Band (UWB) 1:2:1 unequal split modified Bagley Power Divider (BPD) using Non-Uniform Transmission Lines (NTLs) theory is designed and tested. Based on this theory, 42.44% and 31.1% size reductions are obtained in the lower and upper λ/4 Uniform Transmission Lines (UTLs) in the first and second sections of the proposed divider. To evaluate the effect of the divider’s compactness on its performance, it is compared with UWB 1:2:1 unequal split BPD using Tapered Transmission Lines (TTLs). Both dividers show good results where the measured return loss is appeared to be S11 < −10.6 dB and < −13.4 dB for NTL and TTL BPDs, respectively. However, the insertion losses S12 = S14 and S13 are around −6 ± 1.5 dB and – 3 ± 1.3 dB, respectively for both dividers. In this study, simulations are carried out using High-Frequency Structure Simulator (HFSS) software. The evaluation of the proposed divider is obtained from the simulation and hardware measurements results. Journal: Journal of Electromagnetic Waves and Applications Pages: 262-276 Issue: 2 Volume: 35 Year: 2021 Month: 1 X-DOI: 10.1080/09205071.2020.1832586 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1832586 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:2:p:262-276 Template-Type: ReDIF-Article 1.0 Author-Name: Puspendu Bikash Saha Author-X-Name-First: Puspendu Bikash Author-X-Name-Last: Saha Author-Name: Dibyendu Ghoshal Author-X-Name-First: Dibyendu Author-X-Name-Last: Ghoshal Author-Name: Rajib Kumar Dash Author-X-Name-First: Rajib Kumar Author-X-Name-Last: Dash Title: A miniaturized frequency reconfigurable antenna with half-mode CRLH-embedded metamaterial arm Abstract: Metamaterial properties of a novel half-mode CRLH unit cell are investigated and hence a compact dual-wideband antenna is designed using an array of four unit cells. The negative refraction of the metamaterial cell is utilized to miniature the antenna. A via-free open stub, in combination with an interdigital capacitor, makes the half-mode CRLH unit cell. The proposed antenna operates at both C-band (6.2–6.8 GHz) and X-band (8.5–9.2 GHz). The dual-wideband antenna is enabled with frequency reconfigurability by incorporating RF PIN diode in its ground plane in the next design step. The ON–OFF conditions of the PIN diode electrically switch the antenna into dual-band and single-band modes, respectively. In OFF state of the diode, the antenna behaves as a monopole and operates in single-band mode resonating at C-band (5.9–6.5 GHz) only. The measured results of the fabricated sample are in good agreement with the simulated ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 277-290 Issue: 3 Volume: 35 Year: 2021 Month: 02 X-DOI: 10.1080/09205071.2020.1832587 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1832587 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:3:p:277-290 Template-Type: ReDIF-Article 1.0 Author-Name: Soumojit Shee Author-X-Name-First: Soumojit Author-X-Name-Last: Shee Author-Name: Smrity Dwivedi Author-X-Name-First: Smrity Author-X-Name-Last: Dwivedi Title: Design and simulation study of double side-cavity gridless reltron with dual extraction sections Abstract: Reltron is a high power microwave (HPM) oscillator with many attractive features. Here, we report a computer-aided design and simulation-based study of a double side-cavity (DSC) gridless reltron, which is an advancement of the conventional reltron. Commercially available software package CST Microwave Studio (MWS) has been used for the device simulation. The modulation section has been designed and studied by obtaining the S-parameters. From the electromagnetic (EM) field patterns and the frequencies of normal modes, we identify an extra mode in a DSC reltron, in addition to the three normal modes of a conventional reltron – (0, $\pi /2 $π/2, and π). Furthermore, the whole device has been modeled and simulated using particle in cell (PIC) solver to study the device performance under different post acceleration (PA) potentials. The use of the dual extraction section results in a peak efficiency of 38.6%. Journal: Journal of Electromagnetic Waves and Applications Pages: 291-304 Issue: 3 Volume: 35 Year: 2021 Month: 02 X-DOI: 10.1080/09205071.2020.1835562 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1835562 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:3:p:291-304 Template-Type: ReDIF-Article 1.0 Author-Name: Shiva Hayati Raad Author-X-Name-First: Shiva Hayati Author-X-Name-Last: Raad Author-Name: Zahra Atlasbaf Author-X-Name-First: Zahra Author-X-Name-Last: Atlasbaf Title: Broadband optical absorption using graphene-wrapped cross-hair/nano-rod combination Abstract: In this paper, an assembly of substrate mediated graphene-coated cylindrical nano-rods is proposed as an efficient broadband absorber. Initially, a square lattice of isolated graphene-based particles is considered and a single-band perfect optical absorber is obtained. Then, the possibility of absorption spectrum modulation using the lattice periodicity is illustrated. Moreover, it is exhibited that the performance is stable concerning any polarization state and incident angle up to around 60°. The absorption mechanism relies on the excitation of localized surface plasmon resonances (LSPRs) of various orders on the different sections of the unit cell. Later, the particles are connected through optimized bridges to enhance the operating bandwidth. The bridges also offer the opportunity for the real-time tunability of the absorption spectrum by the electrostatic scheme. The attained absorption band regarding the efficiency of 90% is extended to a 15.43 THz span (18.57–34 THz) using a geometrically simple structure. Journal: Journal of Electromagnetic Waves and Applications Pages: 305-314 Issue: 3 Volume: 35 Year: 2021 Month: 02 X-DOI: 10.1080/09205071.2020.1835563 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1835563 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:3:p:305-314 Template-Type: ReDIF-Article 1.0 Author-Name: J. Yousaf Author-X-Name-First: J. Author-X-Name-Last: Yousaf Author-Name: M. Ghazal Author-X-Name-First: M. Author-X-Name-Last: Ghazal Author-Name: H. Lee Author-X-Name-First: H. Author-X-Name-Last: Lee Author-Name: M. Faisal Author-X-Name-First: M. Author-X-Name-Last: Faisal Author-Name: J. G. Yang Author-X-Name-First: J. G. Author-X-Name-Last: Yang Author-Name: W. Nah Author-X-Name-First: W. Author-X-Name-Last: Nah Title: Efficient assessment of well-stirred operation of reverberation chamber using coupling transfer gain functions Abstract: This study presents a new efficient alternative procedure for the assessment of the well-stirred (ws) condition of a mode-stirred reverberation chamber (RC) using newly developed coupling transfer gain functions. Coupling transfer voltage and current gain functions of the RC environment are developed from the ABCD parameters of the measured two-port S parameters in an RC. The proposed procedure involves the determination of the frequency corresponding to the well-stirred operation ( $ f_{{\rm wso}} $ fwso) of RC through the assessment of RC EM-field distribution and checking of theindependent samples requirements for a particular stirred environment. The estimated $ f_{{\rm wso}} $ fwso of the RC using proposed method provides a faster way for the determination of the over-modded condition of RC when the placement of the two-antennas in imperative in RC.  The minimization of antenna loading facotr results in more accurate esitmation of fwso  using proposed procedure than only transfer characteristics. Journal: Journal of Electromagnetic Waves and Applications Pages: 315-335 Issue: 3 Volume: 35 Year: 2021 Month: 02 X-DOI: 10.1080/09205071.2020.1837682 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1837682 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:3:p:315-335 Template-Type: ReDIF-Article 1.0 Author-Name: Hong Yang Author-X-Name-First: Hong Author-X-Name-Last: Yang Author-Name: Li He Author-X-Name-First: Li Author-X-Name-Last: He Author-Name: Hongsheng Zhang Author-X-Name-First: Hongsheng Author-X-Name-Last: Zhang Title: Asymmetric frequency reconfigurable compact antenna using CRLH-TL structure Abstract: An asymmetric coplanar waveguide fed frequency reconfigurable antenna based on composite right/left-handed transmission line is presented in this paper. The antenna is a composite right/left-handed transmission line composed of the meander line and a PIN diode. By controlling the switch of the PIN diode the antenna can change the frequency. Simulation and experimental results show that the −10 dB impedance bandwidth can change from 3.25–5.63 GHz to 2.73–2.96 GHz and 5.0–5.4 GHz. The antenna has good omnidirectional radiation in the working frequency band. The antenna can be widely used in WLAN and WiMAX. Journal: Journal of Electromagnetic Waves and Applications Pages: 336-347 Issue: 3 Volume: 35 Year: 2021 Month: 02 X-DOI: 10.1080/09205071.2020.1838956 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1838956 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:3:p:336-347 Template-Type: ReDIF-Article 1.0 Author-Name: Rajorshi Bandyopadhyay Author-X-Name-First: Rajorshi Author-X-Name-Last: Bandyopadhyay Author-Name: Saikat Majumder Author-X-Name-First: Saikat Author-X-Name-Last: Majumder Author-Name: Rajib Chakraborty Author-X-Name-First: Rajib Author-X-Name-Last: Chakraborty Title: Silicon waveguide as virtual photonic bandgap structure array for realizing compact optical filters Abstract: An engineered silicon rib waveguide on Silicon-On-Insulator platform which can act as virtual photonic bandgap structure is proposed. Selective periodic etching of materials from a rib waveguide is done to create a periodic rib-ridge structure. Each of the rib-ridge sections will therefore have different effective refractive indices and will act as virtual multilayered periodic structure or one-dimensional photonic bandgap structure. Their spatial positions and widths can be controlled to realize different type of photonic filters for integrated photonics applications. Realization of narrowband, multi-band and band-pass filter are shown here. These types of waveguide based monomaterial optical filters avoid the challenges generally faced while fabricating multilayer structures of different heterogeneous materials having different refractive indices. Moreover, as the device is waveguide based, its size is very small and will be useful for compact integrated photonics. Journal: Journal of Electromagnetic Waves and Applications Pages: 348-356 Issue: 3 Volume: 35 Year: 2021 Month: 02 X-DOI: 10.1080/09205071.2020.1839568 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1839568 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:3:p:348-356 Template-Type: ReDIF-Article 1.0 Author-Name: Shiquan Wang Author-X-Name-First: Shiquan Author-X-Name-Last: Wang Author-Name: Kang Li Author-X-Name-First: Kang Author-X-Name-Last: Li Author-Name: Fanmin Kong Author-X-Name-First: Fanmin Author-X-Name-Last: Kong Author-Name: Liuge Du Author-X-Name-First: Liuge Author-X-Name-Last: Du Title: A miniaturized triple-band planar antenna combing single-cell metamaterial structure and defected ground plane for WLAN/WiMAX applications Abstract: In this paper, a novel miniaturized triple-band planar monopole antenna combing single-cell metamaterial structure and defected ground plane is proposed. The miniaturization and triple-band characteristic of the antenna are achieved by loading the designed multiresonant metamaterial unit cell. Furthermore, a compact annular defected ground structure is proposed and used to improve the bandwidth of the antenna effectively. The presented metamaterial inspired triple-band antenna has a compact size and a simple structure. To verify the performances of the antenna, a prototype is manufactured and measured. The experimental results indicate that the presented antenna has enough operating bandwidth of the 2.38–2.48, 3.37–3.79, and 4.36–6.06 GHz to cover all the desired WLAN and WiMAX operations. And the tested results also demonstrate that this antenna has good omnidirectional radiation patterns and reliable gains in three required bands. Thus, the presented antenna has broad prospects in many wireless communication applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 357-370 Issue: 3 Volume: 35 Year: 2021 Month: 02 X-DOI: 10.1080/09205071.2020.1839569 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1839569 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:3:p:357-370 Template-Type: ReDIF-Article 1.0 Author-Name: Aria Hosseini Tabatabaee Author-X-Name-First: Aria Author-X-Name-Last: Hosseini Tabatabaee Author-Name: Farzin Shama Author-X-Name-First: Farzin Author-X-Name-Last: Shama Author-Name: Mohammad Amir Sattari Author-X-Name-First: Mohammad Amir Author-X-Name-Last: Sattari Author-Name: Saeed Veysifard Author-X-Name-First: Saeed Author-X-Name-Last: Veysifard Title: A miniaturized Wilkinson power divider with 12th harmonics suppression Abstract: In this study, a miniaturized Wilkinson Power Divider (WPD) has been designed. Central frequency of the passband for designed power divider (PD) is 1.55 GHz. Using the oval and rectangular- shaped resonators instead of each quarter-wavelength transmission lines of conventional Wilkinson power divider (CWPD) will result in reducing the size of proposed PD by 55%. Presented PD has many advantages, such as low insertion loss (3.015 dB), high return loss (24 dB), high isolation rate between output ports (27 dB), and suppressing the high-frequency harmonics (eliminating the 2nd to 12th unwanted harmonics). Finally presented PD was fabricated and measured on The RT-5880 with ϵr = 2.2 and TanD = 0.0009 with a thickness of 0.787 mm as the substrate. The measured results have good agreement with the simulation one. Due to the appropriate specifications and the small size of the designed divider, this divider can be nominated to use in many communication applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 371-388 Issue: 3 Volume: 35 Year: 2021 Month: 02 X-DOI: 10.1080/09205071.2020.1839570 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1839570 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:3:p:371-388 Template-Type: ReDIF-Article 1.0 Author-Name: Seyed Jalil Hosseini Author-X-Name-First: Seyed Jalil Author-X-Name-Last: Hosseini Author-Name: Masoud Dahmardeh Author-X-Name-First: Masoud Author-X-Name-Last: Dahmardeh Author-Name: Mohsen Yousefian Author-X-Name-First: Mohsen Author-X-Name-Last: Yousefian Title: A high power TEM to TE10 mode converter with 70% bandwidth Abstract: In the paper, the design and simulation of the TEM-TE10 wideband and high-power mode converter (MC) are investigated. The working frequency of the MC is in the frequency range of 4.3–8.8 GHz (68.7% bandwidth). Due to increasing the waveguide cross-section, the probability of the electrical breakdown dramatically reduces. Electrical breakdown may occur at very high-power outputs of the electromagnetic sources. The power-handling capacity of the MC is 2.34 GW, at the centre frequency. Journal: Journal of Electromagnetic Waves and Applications Pages: 389-399 Issue: 3 Volume: 35 Year: 2021 Month: 02 X-DOI: 10.1080/09205071.2020.1842255 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1842255 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:3:p:389-399 Template-Type: ReDIF-Article 1.0 Author-Name: Andrian Andaya Lestari Author-X-Name-First: Andrian Andaya Author-X-Name-Last: Lestari Author-Name: Leo P. Ligthart Author-X-Name-First: Leo P. Author-X-Name-Last: Ligthart Title: FMCW radar antenna using a half parabolic reflector with microstrip-patch-array offset feed and tuning strip Abstract: In this paper, we propose a reflector antenna with a microstrip-patch-array offset feed. The proposed antenna offers several advantages in design flexibility, especially to determine the horizontal and vertical beam patterns by the modular feed and the reflector curvature design, respectively. Moreover, it provides an internal tuning mechanism in the form of a tuning strip which is relatively simple to apply. The paper describes the steps in a parametric study carried out to minimize the antenna dimensions. The resulting optimized design is found to be around 50% smaller in dimension than the initial design of the proposed antenna. A demonstrator for experimental analysis, consisting of a transmit and a receive antenna, has been constructed, and the isolation between the antennas is found to be better than 70 dB. The antenna demonstrator has been integrated with an FMCW radar transceiver and satisfactorily tested to operate as a coastal surveillance radar. Journal: Journal of Electromagnetic Waves and Applications Pages: 400-415 Issue: 3 Volume: 35 Year: 2021 Month: 02 X-DOI: 10.1080/09205071.2020.1844597 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1844597 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:3:p:400-415 Template-Type: ReDIF-Article 1.0 Author-Name: Ashish Kumar Singh Author-X-Name-First: Ashish Kumar Author-X-Name-Last: Singh Author-Name: Kyung-Bin Bae Author-X-Name-First: Kyung-Bin Author-X-Name-Last: Bae Author-Name: Seong-Ook Park Author-X-Name-First: Seong-Ook Author-X-Name-Last: Park Title: NLFM pulse radar for drone detection using predistortion technique Abstract: The development of radar technology for the detection of small drones is getting attention of researchers. In this work, the detection of drones using Ku-band radar system has been discussed. We have utilized the advantage of nonlinear frequency modulation (NLFM) waveform for the suppression of range sidelobes. The performance and sensitivity of a radar system can be related with the linearity of system response. Here, we have made an effort to minimize non-linearity in the radar system response by using digital predistortion method. In this method, amplitude weighting coefficients have been calculated based on the received data. We have used FPGA-based transceiver for intermediate frequency (IF) signal generation and data acquisition, along with Ku-band up-down converters. The radar system was first calibrated for desired frequency band using amplitude predistortion method. In this article, experiment results for the detection of single drone and two drones using NLFM pulse signal are presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 416-429 Issue: 3 Volume: 35 Year: 2021 Month: 02 X-DOI: 10.1080/09205071.2020.1844598 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1844598 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:3:p:416-429 Template-Type: ReDIF-Article 1.0 Author-Name: Jiufu Ruan Author-X-Name-First: Jiufu Author-X-Name-Last: Ruan Author-Name: Feng Lan Author-X-Name-First: Feng Author-X-Name-Last: Lan Author-Name: Liang Wang Author-X-Name-First: Liang Author-X-Name-Last: Wang Author-Name: Shengwei Ji Author-X-Name-First: Shengwei Author-X-Name-Last: Ji Title: Ultra-wideband THz metamaterial filter with steep cut-off Abstract: An ultra-wideband metamaterial (MM) filter with steep cut-off is proposed at terahertz (THz) region. The filter is based on the flexible hybrid structure of copper (Cu)–polyimide (PI)–polymethacrylamide (PMI) multilayer, which reduces the mutual coupling in multilayer MMs. Simulation results prove that the central frequency of the filter is 125 GHz, while the square ratio reaches 0.92 and the relative bandwidth is up to 65%. In addition, it has excellent flat-top characteristics, and the stopband absorption exceeds 95%. Due to the strict symmetry of the structure, the filter shows polarization insensitivity. The transmission mechanism of THz wave is investigated by surface current distribution and the role of each layer in filtering is explored. This work may provide a further step in the development of broadband MM filters with high square ratio, which have potential applications in THz communications and sensors. Journal: Journal of Electromagnetic Waves and Applications Pages: 431-440 Issue: 4 Volume: 35 Year: 2021 Month: 03 X-DOI: 10.1080/09205071.2020.1842256 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1842256 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:4:p:431-440 Template-Type: ReDIF-Article 1.0 Author-Name: Pingjuan Zhang Author-X-Name-First: Pingjuan Author-X-Name-Last: Zhang Author-Name: Minquan Li Author-X-Name-First: Minquan Author-X-Name-Last: Li Author-Name: Huayong Zhang Author-X-Name-First: Huayong Author-X-Name-Last: Zhang Title: Scattering by a uniaxially anisotropic chiral object under electromagnetic beam illumination Abstract: We propose a semi-analytical scheme for investigating the electromagnetic beam scattering by a uniaxially anisotropic chiral object. The scattered and internal fields are expanded in terms of appropriate spherical vector wave functions, and the method of moments procedure is employed for determining the unknown expansion coefficients. Normalized differential scattering cross sections are evaluated for a uniaxially anisotropic chiral spheroid and circular cylinder of finite length, respectively illuminated by a Gaussian beam, Hermite-Gaussian beam and zero-order Bessel beam. The scattering properties are analyzed briefly. Journal: Journal of Electromagnetic Waves and Applications Pages: 441-453 Issue: 4 Volume: 35 Year: 2021 Month: 03 X-DOI: 10.1080/09205071.2020.1844599 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1844599 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:4:p:441-453 Template-Type: ReDIF-Article 1.0 Author-Name: Fernando J. S. Magalhaes Author-X-Name-First: Fernando J. S. Author-X-Name-Last: Magalhaes Author-Name: Diogo B. Oliveira Author-X-Name-First: Diogo B. Author-X-Name-Last: Oliveira Title: Design of low-cost microstrip patch antennas with robust optimization Abstract: This paper presents a robust optimization method to design patch antennas that consider uncertainties from the substrate electromagnetic properties and the manufacturing equipment. The robust optimization method is proposed to design an antenna that uses FR-4 as a substrate, addressing the uncertainties originated from the lack of standardization of this material properties and errors in the manufacturing process of the antenna. By addressing these uncertainties, robust design can result in a low-cost antenna with good performance that is less sensitive to deviations in the defined project variables. The optimization scheme used in this paper is based on NSGA-II, and the robustness of its solutions is quantified with the standard deviation of samples from the performance parameters in the uncertainty set from the design parameters. Two prototypes of patch antennas, one with linear and the other with circular polarization are designed, built, and measured. Journal: Journal of Electromagnetic Waves and Applications Pages: 454-465 Issue: 4 Volume: 35 Year: 2021 Month: 03 X-DOI: 10.1080/09205071.2020.1844600 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1844600 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:4:p:454-465 Template-Type: ReDIF-Article 1.0 Author-Name: Seunghwan Yoon Author-X-Name-First: Seunghwan Author-X-Name-Last: Yoon Author-Name: Alfred Grau Besoli Author-X-Name-First: Alfred Grau Author-X-Name-Last: Besoli Author-Name: Franco De Flaviis Author-X-Name-First: Franco Author-X-Name-Last: De Flaviis Author-Name: Nicolaos G. Alexopoulos Author-X-Name-First: Nicolaos G. Author-X-Name-Last: Alexopoulos Title: Poly-spiral shapes and applications: the Celtic-Archimedean spiral antenna Abstract: Poly-spirals are composed of contiguously interconnected spiral elements and are ubiquitous in the monuments of various cultures since prehistoric times. In adopting poly-spiral geometries for antenna applications, we may in general choose these contiguously connected spirals to be identical or dissimilar, such as by selecting them to be of circular, eccentric, or polygonal shape. We focus on a special class of poly-spirals with circular elements, namely the Celtic-Archimedean spiral. We subsequently compare its radiation properties with those of a regular circular Archimedean of the same size and number of turns. The Celtic-Archimedean spiral could be used as a pattern and polarization diversity reconfigurable antenna due to its feeding mechanism. We compute the diversity gain provided by the Celtic-Archimedean spiral when used in a WLAN network operating at 2.4 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 466-484 Issue: 4 Volume: 35 Year: 2021 Month: 03 X-DOI: 10.1080/09205071.2020.1845821 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1845821 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:4:p:466-484 Template-Type: ReDIF-Article 1.0 Author-Name: Yury Shestopalov Author-X-Name-First: Yury Author-X-Name-Last: Shestopalov Title: Cloaking: analytical theory for benchmark structures Abstract: Proceeding from the scattered field expansion in cylindrical harmonics, we define partial invisibility or partial cloaking as suppression of finitely many lowest-order field harmonics. We show that for benchmark structures (a dielectric rod and a perfectly conducting cylinder of circular cross section covered by a concentric dielectric layer), such multiple suppression can be achieved. For this purpose, we prove the solvability and explicitly determine the solution of the corresponding equation system which provide vanishing of the lowest-order field expansion coefficients and the resulting simultaneous suppression of up to five lowest-order scattered harmonics. We investigate the character and qualitative properties of partial invisibility and partial cloaking by analyzing the scattered field patterns. Journal: Journal of Electromagnetic Waves and Applications Pages: 485-510 Issue: 4 Volume: 35 Year: 2021 Month: 03 X-DOI: 10.1080/09205071.2020.1846629 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1846629 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:4:p:485-510 Template-Type: ReDIF-Article 1.0 Author-Name: Nada El-Maradny Author-X-Name-First: Nada Author-X-Name-Last: El-Maradny Author-Name: Heba Shaban Author-X-Name-First: Heba Author-X-Name-Last: Shaban Author-Name: Mohamad Abou El-Nasr Author-X-Name-First: Mohamad Abou Author-X-Name-Last: El-Nasr Title: Comprehensive performance evaluation of on-body communications in MBANs for different node positions in static and dynamic channel conditions Abstract: Federal Communications Commission (FCC) has released the regulation for medical body area network (MBAN) in 2012 as a BAN specialized for medical applications. MBAN is a narrowband BAN allocated on the 2360-2400 MHz frequency band. It is very promising, as it has the advantages of BAN modules like low power and high accuracy, which are essential parameters for medical applications. This paper provides a comprehensive study of the on-body MBAN operating in the 2360-2390 MHz band. In particular, it introduces link budget signaling parameters required for reliable transmission of biological signals for the MBAN channels, and investigates the bit-error-rate (BER) and maximum allowable data throughput performances assuming different node positions and body activities. Numerical results show that a single arm receiver is ideal for medical applications that do not require movement. Moreover, the relative movement between the transmitter and receiver nodes highly affects the performance of the link. Journal: Journal of Electromagnetic Waves and Applications Pages: 511-528 Issue: 4 Volume: 35 Year: 2021 Month: 03 X-DOI: 10.1080/09205071.2020.1847693 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1847693 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:4:p:511-528 Template-Type: ReDIF-Article 1.0 Author-Name: Pritam Kumar Singh Author-X-Name-First: Pritam Kumar Author-X-Name-Last: Singh Author-Name: S. K. Chualya Author-X-Name-First: S. K. Author-X-Name-Last: Chualya Author-Name: V. K. Singh Author-X-Name-First: V. K. Author-X-Name-Last: Singh Title: Development of microwave radar based periphery surveillance system in a selected mining area Abstract: This paper deals with a periphery surveillance system, which has been developed and deployed by CSIR-Central Institute of Mining and Fuel Research, Dhanbad, India as an aid for keeping constant vigilance on a selected area even in adverse weather conditions like foggy weather, rainy weather, dusty environment, etc. The developed system consists of a frequency modulated continuous wave radar with 400 m range, a pan-tilt-camera, a wireless sensor network, a fast dedicated graphics processing unit, and a display unit. It is capable of controlling illegal mining, theft of minerals, and ensuring safety and security of the mine to a great extent. When an intrusion is detected, the system automatically gives audio-visual warning at the intrusion site where the radar is installed as well as in the control room. The system has the facility to record the intrusion data and video footage with timestamp events in the form of log. Journal: Journal of Electromagnetic Waves and Applications Pages: 529-548 Issue: 4 Volume: 35 Year: 2021 Month: 03 X-DOI: 10.1080/09205071.2020.1847694 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1847694 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:4:p:529-548 Template-Type: ReDIF-Article 1.0 Author-Name: Abdel-Baset M. A. Ibrahim Author-X-Name-First: Abdel-Baset M. A. Author-X-Name-Last: Ibrahim Author-Name: R. Julius Author-X-Name-First: R. Author-X-Name-Last: Julius Author-Name: P. K. Choudhury Author-X-Name-First: P. K. Author-X-Name-Last: Choudhury Title: Progress in quantum electronics research: a bibliometric analysis Abstract: The race towards quantum superiority has stimulated efforts on quantum electronics research. This article aims at providing a comprehensive overview of the global research trends and performance in the field, from a bibliometric perspective, using the Scopus database. A total of 10,115 journal articles from the earliest year of publications were retrieved and analysed. Results show that quantum electronics research has gained considerable development since 2008. These reports were mainly contributed by researchers from the United States, China, Germany, the United Kingdom, and Japan. Nevertheless, the publication track faced a striking reduction in the most recent years. Based on the analysis, the most explored topics in quantum electronics were quantum transport, quantum dots, and quantum electrodynamics. The review throws a glimpse of the current trends of quantum electronics research. Journal: Journal of Electromagnetic Waves and Applications Pages: 549-565 Issue: 4 Volume: 35 Year: 2021 Month: 3 X-DOI: 10.1080/09205071.2020.1821298 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1821298 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:4:p:549-565 Template-Type: ReDIF-Article 1.0 Author-Name: Claudio Paoloni Author-X-Name-First: Claudio Author-X-Name-Last: Paoloni Author-Name: Diana Gamzina Author-X-Name-First: Diana Author-X-Name-Last: Gamzina Author-Name: Rosa Letizia Author-X-Name-First: Rosa Author-X-Name-Last: Letizia Author-Name: Yuan Zheng Author-X-Name-First: Yuan Author-X-Name-Last: Zheng Author-Name: Neville C. Luhmann Author-X-Name-First: Neville C. Author-X-Name-Last: Luhmann Title: Millimeter wave traveling wave tubes for the 21st Century Abstract: Traveling wave tubes are rapidly evolving to provide unprecedented power level in comparison to solid state devices in the millimeter waves region of the spectrum (80–300 GHz) thus enabling a wide range of applications.Wireless communications, imaging, plasma diagnostics, healthcare and many others will gain substantial features if high power at millimeter waves would be available from compact sources.The development of fabrication technologies is proving crucial for introducing new topologies and structures for millimeter wave vacuum electronic devices, compatible with the dimensions dictated by the short wavelength that poses substantial manufacturing challenges due to tight tolerances.This review paper will provide an overview of the principles, evolution and state of the art of one of the most widely utilized vacuum electronic device, the traveling wave tube (TWT). The wide band, high gain features of TWTs make those devices the most promising solutions for high power at millimeter waves and THz frequencies. Journal: Journal of Electromagnetic Waves and Applications Pages: 567-603 Issue: 5 Volume: 35 Year: 2021 Month: 03 X-DOI: 10.1080/09205071.2020.1848643 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1848643 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:5:p:567-603 Template-Type: ReDIF-Article 1.0 Author-Name: Prakash Kumar Panda Author-X-Name-First: Prakash Kumar Author-X-Name-Last: Panda Author-Name: Debalina Ghosh Author-X-Name-First: Debalina Author-X-Name-Last: Ghosh Title: High-gain dual-band antenna with AMC surface for satellite communications Abstract: A dual-band planar dipole antenna, incorporated with a zigzag-shaped dual-band artificial magnetic conductor with gain enhancement, is proposed here. By using 5×9 AMC surface as substrate to the dipole antenna, the bidirectional radiation pattern of the dipole antenna is transformed to unidirectional radiation pattern. The separation distance between the dipole antenna and the AMC surface is λ/6 at 5.5 GHz. The proposed antenna has been fabricated and measured to verify the simulation results. The experimental results ensure good impedance matching (S11 < −10 dB) over two frequency bands (i.e. 5.1–6.2 GHz and 6.75–7.24 GHz). The composite antenna also provides a maximum gain of 8.94 dB at 5.5 GHz with a gain variation of only 0.5 dB over the two operating frequency bands. In addition, the cross-polarization level is less than −15 dB for both E and H planes. Journal: Journal of Electromagnetic Waves and Applications Pages: 604-619 Issue: 5 Volume: 35 Year: 2021 Month: 03 X-DOI: 10.1080/09205071.2020.1848641 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1848641 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:5:p:604-619 Template-Type: ReDIF-Article 1.0 Author-Name: Young-Dam Kim Author-X-Name-First: Young-Dam Author-X-Name-Last: Kim Author-Name: Taehwan Joo Author-X-Name-First: Taehwan Author-X-Name-Last: Joo Author-Name: Chan-Ho Hwang Author-X-Name-First: Chan-Ho Author-X-Name-Last: Hwang Author-Name: Kichul Kim Author-X-Name-First: Kichul Author-X-Name-Last: Kim Author-Name: Jae-Soo Jung Author-X-Name-First: Jae-Soo Author-X-Name-Last: Jung Title: Antenna isolation method using sub-array structure with soft-surface for Tx/Rx separated FDD hybrid beamforming system Abstract: The FDD method is normally used for the stability of the Tx and the Rx links in a fast-varying channel. It is required to physically separate the Tx and Rx arrays for independent Tx and Rx beam control. In this system, it is important to reduce the Tx self-interference (SI) that causes the problem of active element saturation and ADC dynamic range in the Rx beamformer. To suppress Tx SI, we proposed two simple techniques. The first is the general soft-surface which attenuates the surface current flow from the Tx tile array to the Rx array. The second is the sub-array structure of the Rx hybrid beamforming system. Based on the Cauchy–Schwartz inequality, the electrical sum by the sub-array acts as a destructive interference of the complex SI signals, and it can be shown as an additional isolation effect. The proposed idea was validated through measurement. Journal: Journal of Electromagnetic Waves and Applications Pages: 620-633 Issue: 5 Volume: 35 Year: 2021 Month: 03 X-DOI: 10.1080/09205071.2020.1848642 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1848642 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:5:p:620-633 Template-Type: ReDIF-Article 1.0 Author-Name: Sofiane Ben Mbarek Author-X-Name-First: Sofiane Author-X-Name-Last: Ben Mbarek Author-Name: Fethi Choubani Author-X-Name-First: Fethi Author-X-Name-Last: Choubani Title: FDTD modeling and experiments of microfabricated coplanar waveguide probes for electromagnetic compatibility applications Abstract: We present the design, fabrication and experiment of a miniature nonresonant probe based on a coplanar waveguide dedicated to near-field imaging for electromagnetic compatibility applications. Our modeling approach, based on the Finite Difference Time Domain and Finite Element Method, proves that this probe is sensitive to the longitudinal component of the electric field. In addition to its compatibility with integrated circuits, this probe is suitable for wide frequency band applications since it is produced from a micro-metric coplanar line which has no cut-off frequency. We achieved prototypes using the clean room techniques. Using this probe on a precision X-Y scanning table, two-dimensional images of micro-strip line and electric dipole antenna have been successfully constructed. Simulations and measurements results on a microstrip line have shown that the probe is mainly sensitive to the normal electric field. The estimated sensitivity is 30 μV/(V/m). Journal: Journal of Electromagnetic Waves and Applications Pages: 634-646 Issue: 5 Volume: 35 Year: 2021 Month: 03 X-DOI: 10.1080/09205071.2020.1851776 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1851776 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:5:p:634-646 Template-Type: ReDIF-Article 1.0 Author-Name: Mária Švecová Author-X-Name-First: Mária Author-X-Name-Last: Švecová Author-Name: Dušan Kocur Author-X-Name-First: Dušan Author-X-Name-Last: Kocur Title: Localization of a person moving with an unknown character of motion Abstract: In the last decade, it has been shown that short-range ultra-wideband (UWB) sensors can provide promising solutions to the issue of people localization in many interesting applications. The applicability of particular localization methods utilizing this wireless technology depends on the form of the motion of the monitored person. Therefore, great effort was initially taken to localize people who always carry out the same type of movement, i.e. to localize either moving or only static persons. In real life, people do not move always by the same form of the motion, but the character of their movement is normally time-variable. Moreover, a person-monitoring system has usually no a priori information about the movement status of the person to be monitored. The issue of localization of persons moving both by an unknown and changing character of motion has not been satisfactorily addressed. Motivated by these findings, we will introduce a new concept of UWB sensor signal processing focused on localization of a person moving with an unknown and time-variable character of motion. This concept is based on the decomposition of possible motion activities of persons into a finite set of basic forms of movement defining the so-called types of persons, while a specific signal processing procedure is proposed. The corresponding form of a person's movement is first identified and then the person is detected and localized. The performance properties of this concept will be illustrated by its application for through-the-wall localization of a person moving with short and long stops. Journal: Journal of Electromagnetic Waves and Applications Pages: 647-671 Issue: 5 Volume: 35 Year: 2021 Month: 03 X-DOI: 10.1080/09205071.2020.1851777 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1851777 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:5:p:647-671 Template-Type: ReDIF-Article 1.0 Author-Name: Alok Mishra Author-X-Name-First: Alok Author-X-Name-Last: Mishra Author-Name: A. Bera Author-X-Name-First: A. Author-X-Name-Last: Bera Author-Name: M. V. Kartikeyan Author-X-Name-First: M. V. Author-X-Name-Last: Kartikeyan Title: Investigation of electron optical gun and beam collector for 42 GHz, 200 kW second harmonic gyrotron Abstract: This paper presents a design investigation of the Electron Optical Gun (EOG) for a 42 GHz, 200 kW second harmonic gyrotron operating in the TE0, 3 mode. The initial design of MIG is done using established design equations and then optimized through numerical simulations. The different software, such as 2D-Numerical codes EGUN, TRAK and 3D-CST Particle Studio, are used to optimize the design and found good agreement in results obtained from these codes. The sensitivity analysis has also been carried out for the sake of complete design. Furthermore in brief, a design has been done for the un-depressed and Single-Stage Depressed Collector (SDC). In addition, the uneven or uniform beam distribution on collector wall is presented with result comparison of both the collectors. The optimized beam voltage and single-stage depressed collector voltage are 65 kV, 30 kV respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 672-689 Issue: 5 Volume: 35 Year: 2021 Month: 03 X-DOI: 10.1080/09205071.2020.1854870 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1854870 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:5:p:672-689 Template-Type: ReDIF-Article 1.0 Author-Name: Zailei Luo Author-X-Name-First: Zailei Author-X-Name-Last: Luo Author-Name: Feng Liu Author-X-Name-First: Feng Author-X-Name-Last: Liu Author-Name: Zhibin Zou Author-X-Name-First: Zhibin Author-X-Name-Last: Zou Author-Name: Shaojun Guo Author-X-Name-First: Shaojun Author-X-Name-Last: Guo Author-Name: Tongsheng Shen Author-X-Name-First: Tongsheng Author-X-Name-Last: Shen Title: Optimum design of both linear and planar sparse arrays with sidelobe level reduction using salp swarm algorithm Abstract: Sparse arrays play an important role in the widely used acoustic and electromagnetic applications such as sonar, radar, and satellite. In this paper, a recently proposed swarm intelligence algorithm, salp swarm algorithm (SSA), is introduced for design of both linear and planar sparse antenna arrays with optimum sidelobe level (SLL). The design of sparse antenna arrays can be regarded as a nonlinear optimization problem, which the main optimization goal is finding optimum excitations and positions for antenna elements to achieve antenna array beam pattern with desired SLL. The SSA is a new kind of swarm intelligence algorithm which inspired by the swarming behavior of salps. Compared to other evolutionary algorithms, the SSA requires few algorithm-specified tuning parameters, which makes it simple and easy to use for engineering. Illustrative examples of both linear and planar arrays are given to verify the validity of the SSA for SLL reduction of sparse arrays. Journal: Journal of Electromagnetic Waves and Applications Pages: 690-704 Issue: 5 Volume: 35 Year: 2021 Month: 03 X-DOI: 10.1080/09205071.2020.1855259 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1855259 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:5:p:690-704 Template-Type: ReDIF-Article 1.0 Author-Name: D. Poljak Author-X-Name-First: D. Author-X-Name-Last: Poljak Author-Name: V. Doric Author-X-Name-First: V. Author-X-Name-Last: Doric Author-Name: M. Birkic Author-X-Name-First: M. Author-X-Name-Last: Birkic Title: Analysis of curved thin wires radiating over a layered medium and some engineering applications Abstract: The paper deals with modelling of radiation from arbitrarily shaped thin wires above a multilayer and related engineering applications. The formulation is based on the set of corresponding Pocklington integro-differential equations (IDEs) for curved wires. The influence of lower layered half-space is taken into account by means of simplified reflection coefficient stemming from modified image theory (MIT). The set of coupled IDEs is handled via Galerkin Bubnov variant of indirect boundary element method (GB-IBEM) for curvilinear elements. The related field radiated from a wire configuration is obtained from corresponding integral expressions including integration of the currents along a given wire configuration. Some illustrative computational examples for certain wire configurations pertaining to dipole antennas, power communication systems (PLC) and instrumental landing systems (ILS) are given in the paper. Journal: Journal of Electromagnetic Waves and Applications Pages: 705-738 Issue: 6 Volume: 35 Year: 2021 Month: 04 X-DOI: 10.1080/09205071.2020.1858974 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1858974 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:6:p:705-738 Template-Type: ReDIF-Article 1.0 Author-Name: Zhen-Hua Zhao Author-X-Name-First: Zhen-Hua Author-X-Name-Last: Zhao Author-Name: Hai-Feng Zhang Author-X-Name-First: Hai-Feng Author-X-Name-Last: Zhang Author-Name: Cai-Xing Hu Author-X-Name-First: Cai-Xing Author-X-Name-Last: Hu Author-Name: Xing-Liang Tian Author-X-Name-First: Xing-Liang Author-X-Name-Last: Tian Title: A theoretical proposal for a plasma density sensor based on the dielectric substrate antenna with high dielectric constant Abstract: With the rapid development of industrial production and aerospace, how to measure the plasma density has also developed rapidly. So a radio-frequency plasma transducer based on a three-layer dielectric substrate antenna with a high dielectric constant is introduced. The top and bottom layers are dielectric plates, which protect the internal antenna structure and improve the equivalent permittivity of the antenna. The middle layer is the structure layer of the designed antenna. And the antenna size is 3.8 × 2 × 1.8 mm3. When the plasma frequency changes from 0.3 GHz to 7 GHz, the corresponding dielectric substrate antenna resonant frequency (RF) changes from 4.076 to 5.213 GHz. The minimum unit is 0.1 GHz, and all the measurement accuracy is more than 90%. The method based on the effective dielectric constant of plasma will change under different plasma frequencies, so the RF of the antenna is different. In this paper, the radio-frequency plasma transducer is studied theoretically and analyzed numerically. Journal: Journal of Electromagnetic Waves and Applications Pages: 739-753 Issue: 6 Volume: 35 Year: 2021 Month: 04 X-DOI: 10.1080/09205071.2020.1860833 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1860833 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:6:p:739-753 Template-Type: ReDIF-Article 1.0 Author-Name: Hong-Jie He Author-X-Name-First: Hong-Jie Author-X-Name-Last: He Author-Name: Ya Zhang Author-X-Name-First: Ya Author-X-Name-Last: Zhang Title: An effective method for electromagnetic scattering from a coated object partially buried in a dielectric rough surface Abstract: An effective method combined with finite element method (FEM) and boundary integral method (BIM) is presented in this paper to study the composite electromagnetic scattering from a 2-D coated object partially buried in a 1-D dielectric rough surface. The field within the coated object is modelled by FEM, while the coupling field between the object and rough surface is considered by BIM. The fields inside and outside the object are coupled together via boundary conditions on the boundary of the object. Since the boundary of the object is divided by the rough surface into two parts with different electromagnetic properties, the boundary conditions on the object are more complicated. A detailed derivation of the FEM-BIM formula for the composite model is given in this paper. Our numerical code is validated by the method of moments (MoM), and several numerical simulations are conducted to discuss the scattering characteristics. Journal: Journal of Electromagnetic Waves and Applications Pages: 754-765 Issue: 6 Volume: 35 Year: 2021 Month: 04 X-DOI: 10.1080/09205071.2020.1860834 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1860834 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:6:p:754-765 Template-Type: ReDIF-Article 1.0 Author-Name: Evgenii Starodubtsev Author-X-Name-First: Evgenii Author-X-Name-Last: Starodubtsev Title: Transmission of layered nanoresonators including epsilon-near-zero metamaterials: interference-enabled opportunities to realize ultrathin polarization converters Abstract: Polarization conversion of electromagnetic waves transmitted through multilayer nanoresonators, including a main homogeneous layer made of a transparent uniaxial dielectric sandwiched between epsilon-near-zero and metallic spacer layers, has been analytically modeled. The numerical analysis, based on exact solutions of electromagnetic boundary problems, confirms opportunities to use such multilayers as utracompact polarization converters (in particular, zero-order quarter and half waveplates) of a new type. The proposed systems are characterized by much wider ranges of parameters and significantly reduced (nanometric) thicknesses in comparison with the conventional waveplates. The operation regimes, resulting from the features of amplification of proper wave phase differences under multibeam interference conditions, are considered. The concept can be realized for both metamaterial-dielectric-metamaterial and metal-dielectric-metal structures and used for the development of ultrathin, large area, and simple in fabrication polarization devices for photonic applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 766-783 Issue: 6 Volume: 35 Year: 2021 Month: 04 X-DOI: 10.1080/09205071.2020.1860835 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1860835 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:6:p:766-783 Template-Type: ReDIF-Article 1.0 Author-Name: Zi Meng Li Author-X-Name-First: Zi Meng Author-X-Name-Last: Li Author-Name: Victor A. Sledkov Author-X-Name-First: Victor A. Author-X-Name-Last: Sledkov Author-Name: Viacheslav V. Zemlyakov Author-X-Name-First: Viacheslav V. Author-X-Name-Last: Zemlyakov Title: Multi-conductor coaxial cavity resonators for miniaturization of UHF bandpass filters Abstract: In this paper, we present the compact bandpass cavity filters for UHF range. We investigate the properties of coaxial resonators with various numbers of tubular posts from one to four. We show that the resonant frequency can be four times smaller for the four-post resonator in comparison with the single post resonator with the same cavity dimensions. We synthesized and manufactured fifth-order bandpass cavity filter on four-post coaxial resonators for the 690–806 MHz frequency range with 20-dB return loss. The filter dimensions were 30 mm × 44 mm × 127 mm. We also synthesized and manufactured the fifth-order bandpass cavity filter on four-post coaxial resonators with inductive and capacitive cross-coupling between first and fifth resonators to provide transmission zeros in amplitude–frequency characteristic in lower- and upper-frequency band, respectively. Comparison with the standard double-post coaxial cavity filters demonstrates more than 30% volume reduction with similar transmission characteristics. Journal: Journal of Electromagnetic Waves and Applications Pages: 784-800 Issue: 6 Volume: 35 Year: 2021 Month: 04 X-DOI: 10.1080/09205071.2020.1860836 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1860836 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:6:p:784-800 Template-Type: ReDIF-Article 1.0 Author-Name: Dongmeng Li Author-X-Name-First: Dongmeng Author-X-Name-Last: Li Author-Name: Yinrui Li Author-X-Name-First: Yinrui Author-X-Name-Last: Li Author-Name: Xian Wang Author-X-Name-First: Xian Author-X-Name-Last: Wang Author-Name: Jiaji Yang Author-X-Name-First: Jiaji Author-X-Name-Last: Yang Author-Name: Fu Chen Author-X-Name-First: Fu Author-X-Name-Last: Chen Author-Name: Hui Luo Author-X-Name-First: Hui Author-X-Name-Last: Luo Author-Name: Yan Nie Author-X-Name-First: Yan Author-X-Name-Last: Nie Author-Name: Rongzhou Gong Author-X-Name-First: Rongzhou Author-X-Name-Last: Gong Title: Dual-band resonance induced broadband low-frequency radar absorber based on electric ring resonator embedded magnetic absorbing materials Abstract: Magnetic absorbing material (MAM) embedded with electric ring resonator (ERR) is demonstrated to broaden the absorbing bandwidth in low-frequency range. We obtained the relation between input impedance and absorption bandwidth under specific reflection threshold to verify the influence of the embedded ERRs on impedance matching characteristic. Numerical simulations were carried out and the results are in agreement with theoretical analysis. We investigated the absorption mechanism through analyzing the distributions of electric and magnetic fields. The incidence angle sensitivity under different polarization modes is also discussed. It is demonstrated that the MAM with embedded-ERR increased the bandwidth under −10 dB from 1.73–3.17 to 1.48–3.87 GHz and 1.47–4.07 GHz for the TE-incidence and TM-incidence, which is 1.66 and 1.81 times wider than that of MAM, respectively. The proposed structure could broaden the absorption bandwidth in low-frequency range by means of introducing dual-band resonance in a single-layer medium. Journal: Journal of Electromagnetic Waves and Applications Pages: 801-812 Issue: 6 Volume: 35 Year: 2021 Month: 04 X-DOI: 10.1080/09205071.2020.1861553 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1861553 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:6:p:801-812 Template-Type: ReDIF-Article 1.0 Author-Name: Hyunyoung Cho Author-X-Name-First: Hyunyoung Author-X-Name-Last: Cho Author-Name: Seongju Lim Author-X-Name-First: Seongju Author-X-Name-Last: Lim Author-Name: Hye-Won Jo Author-X-Name-First: Hye-Won Author-X-Name-Last: Jo Author-Name: Soo-Chang Chae Author-X-Name-First: Soo-Chang Author-X-Name-Last: Chae Author-Name: Jong-Won Yu Author-X-Name-First: Jong-Won Author-X-Name-Last: Yu Title: Microstrip-line type bruce array antenna with wide fan beam and high gain Abstract: In this letter, a microstrip-line type Bruce array antenna with a wide fan beam and high gain is proposed. The unit composed of the radiating edge and non-radiating edge is repeatedly arranged symmetry to the feeding part. The repeated radiating edge operates as an array of magnetic current sources, which radiates the wide beam pattern in the E-plane and achieves high gain in the H-plane. The far-field radiation pattern and the input impedance according to the number of units was shown. The proposed array antenna has a wide half-power beamwidth (HPBW), simulated result $ 150.4^\circ $ 150.4∘ in the E-plane, and has a high peak gain, simulated 10.5 dB. The proposed array antenna with five units was fabricated and measured. The measured HPBW and peak gain were $ 104.2^\circ $ 104.2∘ and 10.97 dB, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 813-821 Issue: 6 Volume: 35 Year: 2021 Month: 04 X-DOI: 10.1080/09205071.2020.1861990 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1861990 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:6:p:813-821 Template-Type: ReDIF-Article 1.0 Author-Name: Mohamed Bayjja Author-X-Name-First: Mohamed Author-X-Name-Last: Bayjja Author-Name: Gamil Alsharahi Author-X-Name-First: Gamil Author-X-Name-Last: Alsharahi Author-Name: Lahcen Amhaimar Author-X-Name-First: Lahcen Author-X-Name-Last: Amhaimar Author-Name: Naima Amar Touhami Author-X-Name-First: Naima Author-X-Name-Last: Amar Touhami Author-Name: Mohamed Aghoutane Author-X-Name-First: Mohamed Author-X-Name-Last: Aghoutane Title: Applying biorthogonal and orthogonal wavelets basis functions to the method of moments for modeling the helix antenna Abstract: An efficient moment-method algorithm for analyzing helix antenna is presented. This algorithm is developed based on solving the helix integral equations using two categories of continuous wavelets-like basis functions, Biorthogonal and Orthogonal wavelets. In the first part, the current in the helix antenna is obtained using the method of moments with the triangle basis and pulse testing functions. Secondly, the orthogonal (Daubechies and Symlets) and the biorthogonal (spline generated biorthogonal) wavelets are used and compared in solving the helix integral equation. The grounds of comparison between the two categories are accurate in characterizing the induced current, matrix sparsity, relative error and computation time. The advantages and limitations of solving integral equations with each of the two wavelet categories are discussed. The numerical example is provided to demonstrate the validity and applicability of our proposed algorithm which can be easily implemented to produce a desired accuracy. Journal: Journal of Electromagnetic Waves and Applications Pages: 822-832 Issue: 6 Volume: 35 Year: 2021 Month: 04 X-DOI: 10.1080/09205071.2020.1856006 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1856006 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:6:p:822-832 Template-Type: ReDIF-Article 1.0 Author-Name: Najib AL-Fadhali Author-X-Name-First: Najib Author-X-Name-Last: AL-Fadhali Author-Name: Huda A. Majid Author-X-Name-First: Huda A. Author-X-Name-Last: Majid Author-Name: Rosli Omar Author-X-Name-First: Rosli Author-X-Name-Last: Omar Author-Name: Jumadi Abdul Sukor Author-X-Name-First: Jumadi Author-X-Name-Last: Abdul Sukor Author-Name: Mohamad K. A. Rahim Author-X-Name-First: Mohamad K. A. Author-X-Name-Last: Rahim Author-Name: Zuhairiah Zainal Abidin Author-X-Name-First: Zuhairiah Author-X-Name-Last: Zainal Abidin Author-Name: Mohammed Al-Bukhaiti Author-X-Name-First: Mohammed Author-X-Name-Last: Al-Bukhaiti Author-Name: Abdul Malik Momin Author-X-Name-First: Abdul Malik Author-X-Name-Last: Momin Author-Name: Najmaddin Abo Mosali Author-X-Name-First: Najmaddin Author-X-Name-Last: Abo Mosali Title: Review on frequency reconfigurable antenna using substrate-integrated waveguide for cognitive radio application Abstract: Cognitive radio (CR) exploits the spectrum efficiently and minimizes the interference between different devices. Meanwhile, multiband frequency-reconfigurable antennas (FRA) are desirable for CR where it is beneficial to dynamically reconfigure a single antenna to be transmitted and/or received on multiple frequency bands. As stated by the literature review, there is a dearth of work into multiband FRA that is directly applied in CR applications with substrate-integrated waveguide (SIW) technology. Frequency-reconfigurable SIW (FRSIW) is seen as promising for the development of microwave and millimeter waveband antennas. This study’s key objective is for the technical operational advances of SIW antennas to be summarized and compared. The design structure of FRSIW elements using different techniques is discussed in detail. The findings supported the effectiveness of FRSIW for managing radio spectrum to work in most efficient way. Journal: Journal of Electromagnetic Waves and Applications Pages: 958-990 Issue: 7 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1865207 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1865207 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:7:p:958-990 Template-Type: ReDIF-Article 1.0 Author-Name: Anupma Gupta Author-X-Name-First: Anupma Author-X-Name-Last: Gupta Author-Name: Vipan Kumar Author-X-Name-First: Vipan Author-X-Name-Last: Kumar Title: DGS-based wideband MIMO antenna for on–off body communication with port isolation enhancement operating at 2.45 GHz industrial scientific and medical band Abstract: A wide band, dual radiator Multiple input multiple output (MIMO) antenna resonating at 2.4 GHz Industrial Scientific and Medical (ISM) band is designed and analysed for the body-centric wireless communication. Defected ground structure (DGS) is used to reduce the antenna size and to achieve wide bandwidth. Moreover, a decoupling slot is also etched in the ground plane to improve the port isolation. Proposed 2 × 1 array MIMO structure has occupied the volume of 90 × 40 × 0.8 mm3. Rectangular and cylindrical shaped multi-layered tissue models are used for simulation and pork tissue is used for the measurement of antenna performance. Broad 10-dB bandwidth of 1250/900 MHz, port isolation of 21/20 dB, gain of 5.53/5.07 dBi with, SAR value of 0.628/0.627 W/kg is achieved for the flat/deformed state of antenna. Results show that the proposed DGS-based antenna is reliable to operate on different tissue environment for body area network. Journal: Journal of Electromagnetic Waves and Applications Pages: 888-901 Issue: 7 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1865209 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1865209 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:7:p:888-901 Template-Type: ReDIF-Article 1.0 Author-Name: C. P. do N. Silva Author-X-Name-First: C. P. do N. Author-X-Name-Last: Silva Author-Name: J. A. I. Araujo Author-X-Name-First: J. A. I. Author-X-Name-Last: Araujo Author-Name: M. S. Coutinho Author-X-Name-First: M. S. Author-X-Name-Last: Coutinho Author-Name: M. R. T. de Oliveira Author-X-Name-First: M. R. T. Author-X-Name-Last: de Oliveira Author-Name: I. Llamas-Garro Author-X-Name-First: I. Author-X-Name-Last: Llamas-Garro Author-Name: M. T. de Melo Author-X-Name-First: M. T. Author-X-Name-Last: de Melo Title: Multi-band microwave sensor based on Hilbert’s fractal for dielectric solid material characterization Abstract: A planar sensor designed using the fourth Hilbert fractal curve iteration for solid material characterization at multiple frequencies is reported in this paper. The fractal curve is self-similar with space-filling properties. The Hilbert fractal geometry is used to form a compact resonator, with a multiband frequency response where miniaturization is achieved since a large transmission line length is effectively confined in a limited area. The sensor provides five resonances in the frequency range from 0 to 5 GHz. The resonant frequencies are 0.56, 1.68, 2.72, 3.69 and 4.72 GHz, all used to measure the real permittivity of known samples with a sensitivity of 7, 20, 27, 43 and 50 MHz/permittivity, respectively. The sensor is used to measure dielectric samples with 20 × 20 mm2 areas with several thicknesses. Simulations and measurements demonstrate that the Hilbert fractal geometry can be used to design a multiband planar sensor for solid dielectric material characterization. Journal: Journal of Electromagnetic Waves and Applications Pages: 848-860 Issue: 7 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1861992 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1861992 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:7:p:848-860 Template-Type: ReDIF-Article 1.0 Author-Name: U. Mahaveer Author-X-Name-First: U. Author-X-Name-Last: Mahaveer Author-Name: K. T. Chandrasekaran Author-X-Name-First: K. T. Author-X-Name-Last: Chandrasekaran Author-Name: M. P. Mohan Author-X-Name-First: M. P. Author-X-Name-Last: Mohan Author-Name: A. Alphones Author-X-Name-First: A. Author-X-Name-Last: Alphones Author-Name: M. Y. Siyal Author-X-Name-First: M. Y. Author-X-Name-Last: Siyal Author-Name: M. F. Karim Author-X-Name-First: M. F. Author-X-Name-Last: Karim Title: A tri-band Frequency-Selective Surface Abstract: A novel low-profile tri-band bandpass frequency-selective surface (FSS) is proposed in this paper. The structure is designed by the two-dimensional repetition of a unit cell consisting of four apertures. Each aperture is a combination of T-shaped, U-shaped and a rectangular-shaped aperture aligned horizontally or vertically. The performance of the designed FSS structure is independent of the angle of incidence of the incident wave due to the orientation of the apertures in the unit cell. The designed FSS structure operates at the desired frequency bands close to 8-14 GHz. The insertion loss is close to 3.26, 2.68 and 1.12 dB at the respective frequencies of 8.1, 9.8 and 11 GHz. The advantage of this design is that it exhibits tri-band characteristics for various angles of incidence of the incident wave even though it is a low-profile single layer structure. The total dimensions of the unit cell are approximately 0.55 λ0 × 0.55 λ0 at 8 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 861-873 Issue: 7 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1865206 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1865206 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:7:p:861-873 Template-Type: ReDIF-Article 1.0 Author-Name: Lakshmi C. R. Author-X-Name-First: Lakshmi Author-X-Name-Last: C. R. Author-Name: D. Kannadassan Author-X-Name-First: D. Author-X-Name-Last: Kannadassan Title: Coupled microstrip slot resonators for bandstop filters: theory and design Abstract: Bandstop filters with single and dual stop-bands were implemented using coupled mode microstrip slot resonators (MSRs) for the first time. With compact and ease of fabrication, the MSRs provide excellent filter response as desired. It is found that the MSRs can offer narrow bandwidth of less than 20% fractional bandwidth and large isolation of more than 40 dB. The designs of MSRs and filters are systematically demonstrated with the method of coupled mode resonator theory. MSRs may be potential alternative for complicated and arbitrary design of BSFs to achieve desired frequency response. Journal: Journal of Electromagnetic Waves and Applications Pages: 833-847 Issue: 7 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1861991 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1861991 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:7:p:833-847 Template-Type: ReDIF-Article 1.0 Author-Name: Abdullah G. Al-Sehemi Author-X-Name-First: Abdullah G. Author-X-Name-Last: Al-Sehemi Author-Name: Ahmed A. Al-Ghamdi Author-X-Name-First: Ahmed A. Author-X-Name-Last: Al-Ghamdi Author-Name: Nikolay T. Dishovsky Author-X-Name-First: Nikolay T. Author-X-Name-Last: Dishovsky Author-Name: Nikolay T. Atanasov Author-X-Name-First: Nikolay T. Author-X-Name-Last: Atanasov Author-Name: Gabriela L. Atanasova Author-X-Name-First: Gabriela L. Author-X-Name-Last: Atanasova Title: Design of a flexible waterproof antenna for Internet of Things applications Abstract: We propose a new broadband flexible waterproof antenna suitable for Internet of Things applications. The antenna is comprised of three components: radiating elements fed by a 50-Ω coplanar waveguide transmission line and two layers from an elastomer composite (used as a substrate and top encapsulation) which completely covers the antenna's radiating elements to provide water and dust resistance. An antenna prototype is fabricated and tested. Experimental and numerical results show that the proposed antenna has broad bandwidth (|S11| ≤ −10 dB) over the frequency range of 0.83–2.52 GHz, high radiation efficiency of about 92% and good radiation patterns. The antenna was also immersed into water for 10 s, 10, 30 and 60 min, respectively and reflection coefficient magnitudes were measured, to verify its waterproof capability. The durability and flexibility tests were performed on the antenna prototype. Results show that there is no significant degradation in the antenna performance. Journal: Journal of Electromagnetic Waves and Applications Pages: 874-887 Issue: 7 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1865208 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1865208 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:7:p:874-887 Template-Type: ReDIF-Article 1.0 Author-Name: D. Tharani Author-X-Name-First: D. Author-X-Name-Last: Tharani Author-Name: R. K. Barik Author-X-Name-First: R. K. Author-X-Name-Last: Barik Author-Name: Q. S. Cheng Author-X-Name-First: Q. S. Author-X-Name-Last: Cheng Author-Name: K. Selvajyothi Author-X-Name-First: K. Author-X-Name-Last: Selvajyothi Author-Name: S. S. Karthikeyan Author-X-Name-First: S. S. Author-X-Name-Last: Karthikeyan Title: Compact dual-band SIW filters loaded with double ring D-shaped resonators for sub-6 GHz applications Abstract: In this paper, a compact substrate integrated waveguide (SIW) based dual-band filter which utilizes the dual resonance provided by asymmetric double-ring D-shaped resonators that are incorporated on the upper metallic layer of SIW is communicated. The two passbands are generated well below the cut-off frequency of the SIW due to evanescent mode propagation. Such propagation is responsible for the substantial miniaturization of the filter as well. Two types of two-pole dual-band filters are designed that exhibit low insertion loss, wide out-of-band-rejection, compact size, easy fabrication and integration with other microwave components. To validate the proposed idea, three filter prototypes working around 2.66 and 3.54 GHz are designed, fabricated for demonstration and experimentally tested. Parametric analysis is performed to verify the dependence of filter parameters on the proposed filter prototype. Expected agreements are achieved between the experimental and simulated results. The proposed filter finds applications in the upcoming 5G sub-6 GHz communication. Journal: Journal of Electromagnetic Waves and Applications Pages: 923-936 Issue: 7 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1865211 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1865211 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:7:p:923-936 Template-Type: ReDIF-Article 1.0 Author-Name: Yanfei Gong Author-X-Name-First: Yanfei Author-X-Name-Last: Gong Author-Name: Xingtong Chen Author-X-Name-First: Xingtong Author-X-Name-Last: Chen Title: An efficient time-domain method for the electromagnetic transient response of multiconductor transmission lines excited by an electromagnetic field Abstract: An efficient time-domain method based on the waveform relaxation with transverse partitioning (WR-TP) techniques and the delay extraction passive compact circuit (DEPACT) macromodel is presented for evaluating the electromagnetic (EM) transient response of multiconductor transmission lines (MTLs) excited by an external EM field. Firstly, the equivalent distributed sources due to the tangential components of the electric field are introduced into the MTLs equations. Then, the TLs are divided into a cascaded of DEPACT subnetworks, where the telegrapher’s equations of lossless TLs are decoupled by applying the WR-TP techniques. And the relaxation sources over the lossy TLs are updated by using the waveform scaling algorithm, which can completely avoid performing the numerical convolution. Finally, the equivalent circuit is established and the transient responses induced on the lines can be obtained by using the circuit simulation software PSCAD. Journal: Journal of Electromagnetic Waves and Applications Pages: 937-957 Issue: 7 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1865841 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1865841 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:7:p:937-957 Template-Type: ReDIF-Article 1.0 Author-Name: Santanu Karmakar Author-X-Name-First: Santanu Author-X-Name-Last: Karmakar Author-Name: Jagadish C. Mudiganti Author-X-Name-First: Jagadish C. Author-X-Name-Last: Mudiganti Title: Design of the interaction cavity extending to the nonlinear taper for a 10 kw, W-band gyrotron Abstract: In this paper, the design of an interaction structure for a 10-kW, W-band gyrotron is presented. The beam voltage and beam current are chosen as 30 kV and 1 A, respectively. The mode of interaction was chosen as TE6,2. A parametric design code and a gyro large-signal analysis (LSA) code were developed. The computational steps are discussed in brief. The LSA was done using the in-house developed code and the Gyro-K code. The results of these two codes were found to be in good agreement. The design of the nonlinear taper (NLT) was also carried out. Based on Ohmic loss, the power dissipated in the cavity was estimated. A novel cooling arrangement was proposed with two concentric cylindrical jackets around the cavity. The computational fluid dynamics (CFD) analysis was done using the software FloEFD. Steady-state analysis for the CW mode of operation and the transient analysis for the pulsed mode of operation were carried out for various flow-rates of the coolant. Journal: Journal of Electromagnetic Waves and Applications Pages: 902-922 Issue: 7 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1865210 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1865210 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:7:p:902-922 Template-Type: ReDIF-Article 1.0 Author-Name: Deepika Singh Author-X-Name-First: Deepika Author-X-Name-Last: Singh Author-Name: Rana Pratap Yadav Author-X-Name-First: Rana Pratap Author-X-Name-Last: Yadav Title: A frequency selective surface with 3-D unit cells Abstract: This paper conceptualizes the development of a frequency selective surface (FSS) with 3-D unit cells. The FSS unit cells individually present a three-dimensional structure, whereas collectively these are more like planar FSS. The unit cell substrate has been printed using 3-D printing technique and metallized using copper paint. The 3-D printing offers a degree of freedom to fabricate substrate material in three dimensions. Various designs of unit cell have been studied by fabricating a dual-band FSS which highlights the significance of the dimensional change of the 3-D unit cell over FSS performance. The designed FSS has been fabricated and tested using VNA where test results are found as per desire. The main objective of the paper is to develop a comprehensive method for rapid prototyping of FSS in applications in the area of radar, satellite and navigation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1059-1071 Issue: 8 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1868355 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1868355 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:8:p:1059-1071 Template-Type: ReDIF-Article 1.0 Author-Name: Sajjad Tijeri-Mofrad Author-X-Name-First: Sajjad Author-X-Name-Last: Tijeri-Mofrad Author-Name: Sajad Mohammad-Ali-nezhad Author-X-Name-First: Sajad Author-X-Name-Last: Mohammad-Ali-nezhad Author-Name: Amir Hossein Zarif Author-X-Name-First: Amir Hossein Author-X-Name-Last: Zarif Title: Low bandwidth chipless RFID tag using complementary split ring resonator Abstract: A small structure for chipless RFID tag is proposed; it is inspired by a C-shaped structure and based on HCSRR. This structure has curved strips, which are obtained by fine cutting the substrate from the symmetry of the C-shaped structure as base structure, and then missing part of the path is compensated by creating the PMC boundary condition in the cut-off point according to the image theory. Hence, the resonant frequencies of the proposed structure remain the same as those of the base structure. The substrate is Rog4003 with ϵr=3.55 and dimensions of 30×15×0.8 mm3, the ratio of area to lambda for the first resonant in 2.4 GHz is 0.073, and the average distance between two resonances is 300 MHz Half the structure without adding any other element reduces the production cost by 50%. Moreover, the structure can be printed on flexible substrates due to its simple design and non-complexity. Journal: Journal of Electromagnetic Waves and Applications Pages: 991-1007 Issue: 8 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1865842 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1865842 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:8:p:991-1007 Template-Type: ReDIF-Article 1.0 Author-Name: Megha M. Kartha Author-X-Name-First: Megha M. Author-X-Name-Last: Kartha Author-Name: Jayakumar. M Author-X-Name-First: Jayakumar. Author-X-Name-Last: M Title: Performance analysis of circularly polarized dual annular ring patch antenna for MIMO satellite application Abstract: In this paper, a dual annular ring patch antenna with high isolation for Multiple Input Multiple Output (MIMO) Satellite application at 4 GHz is presented. The mutual coupling reduction and circular polarization are achieved by some perturbations in annular ring patch and microstrip stubs between antennas. These perturbations will excite two modes which is orthogonal ie. equal amplitude and phase shift to make it circularly polarized. The antenna design is fabricated on a substrate with permittivity 4.4 and 1.6 mm thickness. The simulated results are studied and analyzed for the proposed antenna. The isolation of better than 30 dB, axial ratio lower than 3 dB and gain of about 3.4 dB are obtained. The performance characteristics are simulated, measured and analyzed with different antenna parameters. The validated antenna shows that the simulated and measured results are in good agreement with each other. Journal: Journal of Electromagnetic Waves and Applications Pages: 1099-1112 Issue: 8 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1871080 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1871080 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:8:p:1099-1112 Template-Type: ReDIF-Article 1.0 Author-Name: Adnan Jamil Author-X-Name-First: Adnan Author-X-Name-Last: Jamil Author-Name: Thomas Sikina Author-X-Name-First: Thomas Author-X-Name-Last: Sikina Title: A review of the RF Characteristics of a Cascade Network of an LNA with an attenuator Abstract: In this endeavor, a cascade system of an attenuator in series with a Low Noise Amplifier (LNA) will be studied. A discussion on past related works followed by a study of different Attenuator-LNA arrangements not analyzed collectively in those previous works will be presented. This is important for addressing the lowering of system noise figure (NF), which is critical for applications such as GPSs and Radars. The effects of the attenuator on the overall NF will be looked at. The attenuator can also act as a protection for the spectrum analyzer from Device Under Test (DUT) which in this case is an LNA. Journal: Journal of Electromagnetic Waves and Applications Pages: 1113-1123 Issue: 8 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1866682 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1866682 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:8:p:1113-1123 Template-Type: ReDIF-Article 1.0 Author-Name: Chengzhu Du Author-X-Name-First: Chengzhu Author-X-Name-Last: Du Author-Name: Gaoya Jin Author-X-Name-First: Gaoya Author-X-Name-Last: Jin Title: A compact CPW-fed band-notched UWB-MIMO flexible antenna for WBAN application Abstract: A compact coplanar waveguide (CPW)-fed band-notched ultra-wideband (UWB) multiple-input multiple-output (MIMO) flexible antenna on liquid crystal polymer (LCP) substrate is designed. It is composed of two orthogonal elements, tampered feeder and asymmetric ground plate. To improve the port isolation (S21), an inverted F-shaped branch is added. The measurement results demonstrate that the antenna has achieved impedance bandwidths (S11 < −10 dB) of 890 MHz (2.4–11.3 GHz) except one rejected band of 3.1–4.3 GHz, and the port isolation is higher than 23 dB. The influence of human body and bending have also been experimented. The results show that the designed antenna has satisfactory bandwidth, high isolation, sound gain in working bands, the characteristics of flexibility and low specific absorption ratio (SAR) values, which indicate the excellent application in the WBAN systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 1046-1058 Issue: 8 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1868354 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1868354 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:8:p:1046-1058 Template-Type: ReDIF-Article 1.0 Author-Name: Avishek Das Author-X-Name-First: Avishek Author-X-Name-Last: Das Author-Name: Durbadal Mandal Author-X-Name-First: Durbadal Author-X-Name-Last: Mandal Author-Name: Rajib Kar Author-X-Name-First: Rajib Author-X-Name-Last: Kar Title: An optimal time modulated compact circular antenna array design using a stochastic optimization technique Abstract: This paper presents a time modulated far-field radiation pattern synthesis of a compact circular antenna array (CAA) by employing a stochastic optimization technique known as grey wolf optimization (GWO). The compactness of the antenna array is achieved by reducing the inter-element distances between the elements of the array which leads to the miniaturization of the antenna array size. On the other hand, an optimal far-field radiation characteristic is achieved by suppressing the side lobe level (SLL) as well as by narrowing the first null beamwidth (FNBW). A lower SLL value is necessary to avoid the interference with the system working in the same frequency, whereas, a narrow FNBW helps the antenna array to attain a high directivity. The performance of a time modulated antenna array (TMAA) depends on the rise on–off time, pulse shape as well as on the switching time duration of each element of the array which radiates at different harmonic frequencies. In this paper, the generation of radiation pattern at the fundamental/central frequency and its first two harmonic frequencies are considered for the design issue. Journal: Journal of Electromagnetic Waves and Applications Pages: 1025-1045 Issue: 8 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1868353 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1868353 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:8:p:1025-1045 Template-Type: ReDIF-Article 1.0 Author-Name: Run Wang Author-X-Name-First: Run Author-X-Name-Last: Wang Author-Name: Binfeng Yang Author-X-Name-First: Binfeng Author-X-Name-Last: Yang Author-Name: Zhen Zhao Author-X-Name-First: Zhen Author-X-Name-Last: Zhao Author-Name: Hua Guan Author-X-Name-First: Hua Author-X-Name-Last: Guan Title: Research on MGT target location method based on rotating combined magnetic beacon Abstract: Based on the MGT positioning method, the performance of combined magnetic beacon is studied. The unit size of beacon is designed as D = 2 cm and L = 8 cm, the performance of different structure magnetic beacons combined have been studied and compared in detail, results show that the magnetic field intensity of cross structure is about 30000nT higher than the orthogonal structure which have generated sine waves. According to the TLS to filter the signal based on the regular tetrahedral gradient tensor measurement array. In the laboratory environment (Bearth=46157nT) to validate the model in this paper, the experimental results show that the array of two identical cross-combined permanent magnets will increase the magnetic induction value at the same distance by 1.7 times and the max-average positioning error on the 6 experimental paths is 1.52m. The implications of these findings particularly regarding the array rotation combined magnetic beacon may be useful for the high-precision magnetic position systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 1072-1087 Issue: 8 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1870050 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1870050 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:8:p:1072-1087 Template-Type: ReDIF-Article 1.0 Author-Name: Saeed Ur Rahman Author-X-Name-First: Saeed Author-X-Name-Last: Ur Rahman Author-Name: Habib Ullah Author-X-Name-First: Habib Author-X-Name-Last: Ullah Author-Name: Qunsheng Cao Author-X-Name-First: Qunsheng Author-X-Name-Last: Cao Author-Name: Muhammad Kabir Khan Author-X-Name-First: Muhammad Author-X-Name-Last: Kabir Khan Author-Name: Naveed Ullah Author-X-Name-First: Naveed Author-X-Name-Last: Ullah Title: Comments on “A set square design metamaterial absorber for X band applications” Abstract: In a recently published paper, Chetan Barde et al. [Barde C, Choubey A, Sinha R. A set square design metamaterial absorber for X-band applications. J Electromagn Waves Appl. 2019:1–14.] have proposed a wideband metamaterial absorber and have attempted to elaborate reflection theory for the absorptivity. They have claimed a wideband absorption rate due to ignorance of cross-polarization component of the reflected wave. They have erroneously interpreted a linear reflective polarization converter as a wideband absorber. Journal: Journal of Electromagnetic Waves and Applications Pages: 1020-1024 Issue: 8 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1868352 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1868352 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:8:p:1020-1024 Template-Type: ReDIF-Article 1.0 Author-Name: Mingook Jung Author-X-Name-First: Mingook Author-X-Name-Last: Jung Author-Name: Namjoon Heo Author-X-Name-First: Namjoon Author-X-Name-Last: Heo Author-Name: Jinwoo Park Author-X-Name-First: Jinwoo Author-X-Name-Last: Park Author-Name: Jeonghoon Yoo Author-X-Name-First: Jeonghoon Author-X-Name-Last: Yoo Title: Multi-directional cloaking structure design using topology optimization Abstract: Cloaking structure designs have been widely performed in a form of metamaterial development. However, physics-based design approach makes it difficult to define complex material profiles. This study proposes an alternative design method for multi-directional cloak design via topology optimization method using a dielectric material. The phase field design method, which uses the reaction-diffusion equations combined with the double well potentials as the update scheme for design variables, is employed for systematic derivation of a topological configuration of the cloaking structure. In addition, the concept of symmetric design sensitivity mapping is introduced for multi-directional cloaking effect. Design results of four-, six- and eight-directional cloak are presented, and experimental verification was performed for six-directional cloak using the fabricated structure through 3D printing technology. Journal: Journal of Electromagnetic Waves and Applications Pages: 1008-1019 Issue: 8 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1866683 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1866683 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:8:p:1008-1019 Template-Type: ReDIF-Article 1.0 Author-Name: Jiufu Ruan Author-X-Name-First: Jiufu Author-X-Name-Last: Ruan Author-Name: Shengwei Ji Author-X-Name-First: Shengwei Author-X-Name-Last: Ji Author-Name: Zhi Tao Author-X-Name-First: Zhi Author-X-Name-Last: Tao Author-Name: Feng Lan Author-X-Name-First: Feng Author-X-Name-Last: Lan Title: Ultra-wideband metamaterial absorber doped GaAs in the infrared region Abstract: An improved ultra-wideband metamaterial absorber (MA) with high absorptivity in the infrared region is proposed. It features a mixture of copper and GaAs at the top layer, which can greatly raise the bandwidth and absorption rate due to the coupling effect between copper and GaAs. The spectrum with absorption rate of 90% in the infrared region from 98 to 152 THz can be obtained. The input-impedance matching theory, as well as surface current distributions and power loss density have been investigated to analyze the absorption mechanism of the perfect absorption performance. In addition, the MA is insensitive to polarization and incident angle. This work may provide a further step in the development of ultra-broadband devices, such as filters, sensors and energy harvesting and stealth devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 1088-1098 Issue: 8 Volume: 35 Year: 2021 Month: 05 X-DOI: 10.1080/09205071.2020.1870163 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1870163 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:8:p:1088-1098 Template-Type: ReDIF-Article 1.0 Author-Name: E. A. Andrade-González Author-X-Name-First: E. A. Author-X-Name-Last: Andrade-González Author-Name: J. A. Tirado-Méndez Author-X-Name-First: J. A. Author-X-Name-Last: Tirado-Méndez Author-Name: H. Jardón-Aguilar Author-X-Name-First: H. Author-X-Name-Last: Jardón-Aguilar Author-Name: M. Reyes-Ayala Author-X-Name-First: M. Author-X-Name-Last: Reyes-Ayala Author-Name: A. Rangel-Merino Author-X-Name-First: A. Author-X-Name-Last: Rangel-Merino Author-Name: Michael Pascoe-Chalke Author-X-Name-First: Michael Author-X-Name-Last: Pascoe-Chalke Title: UWB four ports MIMO antenna based on inscribed Fibonacci circles Abstract: In this paper, a novel ultrawideband (UWB) four ports multiple-input multiple-output (MIMO) antenna was developed. The MIMO antenna is based on four wideband circular monopoles with inscribed Fibonacci circles in order to reduce the size and stabilize the impedance over a wider bandwidth. The array shows a frequency bandwidth from 3.6 GHz to 13.8 GHz, obtaining inter-port coupling below −15 dB over the entire bandwidth. Convergent TARC curves over the entire bandwidth exhibit values less than −25 dB and high stability against phase changes in the incoming signals to the different radiators. Finally, the UWB MIMO antenna proposed generates a quasi-omnidirectional radiation pattern with orthogonal properties among radiators, demonstrated by a very small Envelope Correlation Coefficient (ECC) value, averaging 0.005. Journal: Journal of Electromagnetic Waves and Applications Pages: 1202-1220 Issue: 9 Volume: 35 Year: 2021 Month: 06 X-DOI: 10.1080/09205071.2021.1873196 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1873196 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:9:p:1202-1220 Template-Type: ReDIF-Article 1.0 Author-Name: Vadher Pratik Author-X-Name-First: Vadher Author-X-Name-Last: Pratik Author-Name: Mahesh Singh Bisht Author-X-Name-First: Mahesh Author-X-Name-Last: Singh Bisht Author-Name: Kumar Vaibhav Srivastava Author-X-Name-First: Kumar Author-X-Name-Last: Vaibhav Srivastava Title: Improving performance of mantle cloak for electrically large PEC cylinders by reducing higher-order scattering coefficients Abstract: Based on the scattering cancellation technique, an approach is proposed to improve the mantle cloak’s performance for electrically large cylinders. The procedure is based on the observation that the number of dominant scattering coefficients and corresponding magnitudes for a cylinder decreases when oriented obliquely to the incident wave. Thus, it is quite advantageous to design a mantle cloak under the oblique incidence than the normal incidence. The proposed method starts with determining the optimum angle of incidence at which if the object is oriented with respect to the incident wave, the maximum scattering reduction can be obtained with a mantle cloak explicitly designed for that orientation. The procedure is applied to cylinders of radii $ 0.25\lambda _0 $ 0.25λ0 and $ 0.85\lambda _0 $ 0.85λ0, where $ \lambda _0 $ λ0 is the design wavelength. The proposed approach’s advantages are highlighted by comparing it with the previously published literature. Additionally, the mantle cloak is realized using a periodic grid of metallic patches, and simulations in Ansys HFSS are performed to verify the design. Journal: Journal of Electromagnetic Waves and Applications Pages: 1176-1191 Issue: 9 Volume: 35 Year: 2021 Month: 06 X-DOI: 10.1080/09205071.2021.1872042 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1872042 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:9:p:1176-1191 Template-Type: ReDIF-Article 1.0 Author-Name: Daniel Hernandez Author-X-Name-First: Daniel Author-X-Name-Last: Hernandez Author-Name: Yeji Han Author-X-Name-First: Yeji Author-X-Name-Last: Han Author-Name: Seong Son Author-X-Name-First: Seong Author-X-Name-Last: Son Author-Name: Kyoung-Nam Kim Author-X-Name-First: Kyoung-Nam Author-X-Name-Last: Kim Title: Design of microstrip transmission line array for magnetic resonance imaging at 300 MHz for spinal cord examination Abstract: In this simulation study, we describe a microstrip transmission line (MTL) array coil, designed to provide a uniform |B1| field along the spinal cord in 7 T MRI. The coil structure was designed by segmenting the spinal cord into four sections according to its shape. The geometry and properties of the MTL coils were optimized individually to obtain a uniform |B1| field distributed according to the shape of the spinal cord in each section. On combining the individually-optimized MTL coils, we present a microstrip array design that produces a highly uniform |B1| field for the whole spinal cord. Furthermore, with this design, the |B1­| field contour lines followed the shape of the spinal cord. A comparison with a standard 8-channel loop array coil shows that our design produces a more uniform |B1­| field in the target imaging area, demonstrating its potential for spinal cord imaging. Journal: Journal of Electromagnetic Waves and Applications Pages: 1125-1139 Issue: 9 Volume: 35 Year: 2021 Month: 06 X-DOI: 10.1080/09205071.2021.1871779 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1871779 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:9:p:1125-1139 Template-Type: ReDIF-Article 1.0 Author-Name: Varun Chaudhary Author-X-Name-First: Varun Author-X-Name-Last: Chaudhary Author-Name: Ravi Panwar Author-X-Name-First: Ravi Author-X-Name-Last: Panwar Title: ECM Enabled Whale optimization assisted facile design of dual-band conformal FSS for WLAN shielding applications Abstract: A new modified Equivalent Circuit Model (M-ECM) enabled Whale Optimization (WO) assisted electromagnetic (EM) approach is presented for an efficient design of a double square loop frequency selective surface (DSL-FSS) based conformal shielding structure. A simple single-layer DSL-FSS is designed, fabricated, and measured to suppress both wireless local area network (WLAN) bands without affecting the rest of the considered spectrum using ECM enabled WO. The analytical and measured results have been found in quite good congruence with each other. The measured transmission coefficient at 2.4 and 5.0 GHz shows suppression of 35 and 38 dB, respectively. Further, the angular stability, polarization insensitivity, and physical interpretation of the DSL-FSS shielding structure are investigated. Finally, the conformal behavior of the structure has been investigated for different bending radius and good agreement between simulated and measured results shows the effectiveness of the aforementioned technique for planar and conformal WLAN shielding applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1261-1272 Issue: 9 Volume: 35 Year: 2021 Month: 06 X-DOI: 10.1080/09205071.2021.1884995 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1884995 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:9:p:1261-1272 Template-Type: ReDIF-Article 1.0 Author-Name: Honglin Zhang Author-X-Name-First: Honglin Author-X-Name-Last: Zhang Author-Name: Wei Wang Author-X-Name-First: Wei Author-X-Name-Last: Wang Author-Name: Linjian Liang Author-X-Name-First: Linjian Author-X-Name-Last: Liang Author-Name: Zuocheng Yang Author-X-Name-First: Zuocheng Author-X-Name-Last: Yang Author-Name: Dong Chen Author-X-Name-First: Dong Author-X-Name-Last: Chen Author-Name: Chunlan Zhao Author-X-Name-First: Chunlan Author-X-Name-Last: Zhao Title: A novel printed monopole antenna with folded-line SIR loading Abstract: A novel printed monopole antenna with simple, low-profile and convenient design is presented in this paper. The antenna composes of a printed monopole antenna and a folded-line stepped impedance resonator (SIR) loaded on the bottom of the substrate. The resonant frequency is decreased by the coupling between the folded-line SIR as the near-field resonant parasitic (NFRP) element and radiation patch of the monopole antenna. The stronger the coupling, the lower the frequency. At the same time, the introduction of the NFRP element does not require an additional circuit for impedance matching, a novel the printed monopole antenna can be achieved. After analyzing the principle of the proposed antenna, a sample antenna has been manufactured and measured to prove the estimated performance of the proposed antenna. The measured results of the proposed antenna are consistent with the simulation, which shows that the design method in this paper is accurate and effective. Journal: Journal of Electromagnetic Waves and Applications Pages: 1192-1201 Issue: 9 Volume: 35 Year: 2021 Month: 06 X-DOI: 10.1080/09205071.2021.1872422 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1872422 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:9:p:1192-1201 Template-Type: ReDIF-Article 1.0 Author-Name: Seyed Hamed Kazemi Author-X-Name-First: Seyed Hamed Author-X-Name-Last: Kazemi Author-Name: Mohsen Hayati Author-X-Name-First: Mohsen Author-X-Name-Last: Hayati Title: Compact and very sharp roll-off low-pass filter using folded flag resonator Abstract: In this paper, a microstrip low-pass filter (LPF) using folded-flag-shaped resonators is designed and presented. Its base resonator length is 12.4 mm, and the proposed low-pass filter has a sharpness of 0.08 GHz. The filter cut-off frequency is 1.44 GHz, and the return loss is reduced to a level of −17 dB, indicating a flat pass-band. Also, the suppressing cell is used to weaken the disturbing harmonics by a stepped impedance structure and two high-impedance stubs with an L-shaped structure, which results in a bandwidth of 17.78 GHz. The circuit area of the LPF is 20.9 × 7.5 mm2, which it has created a suitable normalized circuit size (NCS) rate due to the −3 dB cut-off frequency. The figure of merit (FOM) of the proposed filter is 114450, and it indicates that the microstrip LPF responses are optimal as compared to previous works. Journal: Journal of Electromagnetic Waves and Applications Pages: 1161-1175 Issue: 9 Volume: 35 Year: 2021 Month: 06 X-DOI: 10.1080/09205071.2021.1871865 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1871865 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:9:p:1161-1175 Template-Type: ReDIF-Article 1.0 Author-Name: Tripta Kumari Author-X-Name-First: Tripta Author-X-Name-Last: Kumari Author-Name: Gourab Das Author-X-Name-First: Gourab Author-X-Name-Last: Das Author-Name: Ravi Kumar Gangwar Author-X-Name-First: Ravi Kumar Author-X-Name-Last: Gangwar Title: Spatially decoupled 8-port box shaped MIMO DRA with quad-directional pattern diversity Abstract: In this study, a spatially separated eight-port box shaped multiple-input-multiple-output (MIMO) cylindrical dielectric resonator antenna (cDRA) is presented which supports quad-directional pattern diversity characteristics. Initially, a cDRA is radiated with the assistance of two different excitation mechanisms to generate decoupled orthogonal modes. This dual-port primary structure is combined with a similar primary structure in a box-shaped manner to yield an eight-port MIMO antenna system. The antenna elements (Dielectric Resonators) are located in such a way that each antenna element can able to excite in diverse directions to achieve spatially separated radiated beams. Two different isolation improvement mechanisms are applied within the structure (i) excitation of decoupled orthogonal modes; (ii) spatially decoupled radiation pattern. With these dual techniques, the presented MIMO antenna can able to deliver better than 20 dB of isolation between the antenna elements without using any extra decoupling structure. Journal: Journal of Electromagnetic Waves and Applications Pages: 1221-1234 Issue: 9 Volume: 35 Year: 2021 Month: 06 X-DOI: 10.1080/09205071.2021.1874544 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1874544 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:9:p:1221-1234 Template-Type: ReDIF-Article 1.0 Author-Name: Junsik Park Author-X-Name-First: Junsik Author-X-Name-Last: Park Author-Name: Wooryong Lee Author-X-Name-First: Wooryong Author-X-Name-Last: Lee Author-Name: Namsu Kim Author-X-Name-First: Namsu Author-X-Name-Last: Kim Author-Name: Bonggyu Kang Author-X-Name-First: Bonggyu Author-X-Name-Last: Kang Author-Name: Chunghyun Ryu Author-X-Name-First: Chunghyun Author-X-Name-Last: Ryu Author-Name: Jongsung Lee Author-X-Name-First: Jongsung Author-X-Name-Last: Lee Author-Name: Cheolgu Jo Author-X-Name-First: Cheolgu Author-X-Name-Last: Jo Author-Name: Jingook Kim Author-X-Name-First: Jingook Author-X-Name-Last: Kim Title: Field source extraction of an ESD generator and its application to system-level ESD analysis in a solid-state storage system Abstract: System-level electrostatic discharge (ESD) noise due to electromagnetic fields radiating from an ESD generator were measured and analyzed in a solid-state drive (SSD) storage system. The field sources of an ESD generator were efficiently modeled from the measured tangential magnetic fields in front of a ESD generator. The extracted field sources were incorporated into a full-wave solver, and the fields inside the disk-array enclosure (DAE) were simulated and validated by comparing to measured fields. The field source models of the ESD generator were then also utilized to predict transient ESD-induced noise voltages in a simplified SSD. Finally, the coupling mechanism and the effects of the DAE geometry were investigated. Journal: Journal of Electromagnetic Waves and Applications Pages: 1247-1260 Issue: 9 Volume: 35 Year: 2021 Month: 06 X-DOI: 10.1080/09205071.2021.1884135 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1884135 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:9:p:1247-1260 Template-Type: ReDIF-Article 1.0 Author-Name: M. Benavides Author-X-Name-First: M. Author-X-Name-Last: Benavides Author-Name: D. Miralles Author-X-Name-First: D. Author-X-Name-Last: Miralles Author-Name: A. Andújar Author-X-Name-First: A. Author-X-Name-Last: Andújar Author-Name: J. Anguera Author-X-Name-First: J. Author-X-Name-Last: Anguera Title: Effects on human body and conductive body over a near field communication antenna Abstract: The paper presents an NFC antenna based on a rectangular spiral examining the effect of the geometry and the addition of a ferrite sheet. Several prototypes are fabricated and tested where the influence of a human wrist and a conducting body close to the antenna are studied. Journal: Journal of Electromagnetic Waves and Applications Pages: 1235-1246 Issue: 9 Volume: 35 Year: 2021 Month: 06 X-DOI: 10.1080/09205071.2021.1875889 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1875889 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:9:p:1235-1246 Template-Type: ReDIF-Article 1.0 Author-Name: Auns Khaled Author-X-Name-First: Auns Author-X-Name-Last: Khaled Author-Name: Dorsaf Omri Author-X-Name-First: Dorsaf Author-X-Name-Last: Omri Author-Name: Taoufik Aguili Author-X-Name-First: Taoufik Author-X-Name-Last: Aguili Title: A novel space hybrid meshing technique combined with Laguerre polynomial to solve TD-EFIE Abstract: In this paper, we have developed a system of Time Domain Electric Field Integral Equation (TD-EFIE) for the resolution of a scattering electromagnetic problem by various shapes illuminated by an incident transient wave. The solvability of the TD-EFIE system is based on the Time Domain Method of Moments (TD-MoM) using Galerkin's method in space and time domains. In time domain, a linear combination of Laguerre functions is used as temporal basis functions. In order to approximate the unknown space variation of the transient current, we develop a novel space hybrid basis functions derived from the Rao-Wilton-Glisson function. The elaborated hybrid mesh technique using hexagonal and triangular mesh is applied for various analyzed structures: regular grid for planar structures and irregular grid for curved structures. The validity, the efficiency and the precision of developed meshing techniques are presented and discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1140-1160 Issue: 9 Volume: 35 Year: 2021 Month: 06 X-DOI: 10.1080/09205071.2021.1871780 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1871780 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:35:y:2021:i:9:p:1140-1160 Template-Type: ReDIF-Article 1.0 Author-Name: Guokai Zhao Author-X-Name-First: Guokai Author-X-Name-Last: Zhao Author-Name: Bin You Author-X-Name-First: Bin Author-X-Name-Last: You Author-Name: Xuan Wen Author-X-Name-First: Xuan Author-X-Name-Last: Wen Author-Name: GuoQing Luo Author-X-Name-First: GuoQing Author-X-Name-Last: Luo Title: A reconfigurable dual-band bandpass filter using memristive switches Abstract: In this paper, a reconfigurable dual-band bandpass filter, using memristive switches, is proposed. The applied memristor is non-volatile and has low-power consumption, which could be potentially used as an RF switch. The dual-band bandpass filter is based on the dual-mode resonator with a memristor. The odd-mode and even-mode method is utilized to analyse the proposed reconfigurable filter. By loading a memristor to the optimum position of the resonator, the proposed dual-band bandpass filter’s responses can be switched. The memristor is equivalent to a low-impedance resistor in ON state and a high-impedance capacitor in OFF state. The frequency responses of the proposed reconfigurable dual-band bandpass filter can be tuned by transforming the state of two memristors. The alternative test method is used in this paper, and measured results are consistent with simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 115-130 Issue: 1 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1958381 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1958381 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:1:p:115-130 Template-Type: ReDIF-Article 1.0 Author-Name: Xiao Wang Author-X-Name-First: Xiao Author-X-Name-Last: Wang Author-Name: Jun-Ge Liang Author-X-Name-First: Jun-Ge Author-X-Name-Last: Liang Author-Name: He Jing Author-X-Name-First: He Author-X-Name-Last: Jing Author-Name: Jia-Kang Wu Author-X-Name-First: Jia-Kang Author-X-Name-Last: Wu Author-Name: Nam-Young Kim Author-X-Name-First: Nam-Young Author-X-Name-Last: Kim Author-Name: Xiao-Feng Gu Author-X-Name-First: Xiao-Feng Author-X-Name-Last: Gu Title: BPFs with oct-resonance and -transmission-zero realized by coupling optimization on open-loop resonator Abstract: This paper presents a series of novel designs for dual-band bandpass filters (BPFs) with excellent in-band and out-band filtering performances. By imbedding the spiral-line resonator into the coupling open-loop structures and adjusting the symmetrical structure, the second-order quad-mode BPFs are designed and then the fourth-order oct-mode dual-band BPFs. The final two designs possess eight resonant modes in the passband and also four/eight transmission zeros in the stopband, achieving a high transition-band selectivity with the roll-off rate over 1000 dB/GHz, broad out-band rejection from 1.5 GHz to 5.3 GHz (lower than 30 dB), and strong isolation between dual bands with the suppression level of 30 dB, operating at 3.2/3.4 GHz and 3.2/3.5 GHz respectively. Measured results agree well with simulations and prove the validity of the asymmetry feeders for multi-transmission-zero characteristics. Journal: Journal of Electromagnetic Waves and Applications Pages: 83-100 Issue: 1 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1957026 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1957026 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:1:p:83-100 Template-Type: ReDIF-Article 1.0 Author-Name: Li He Author-X-Name-First: Li Author-X-Name-Last: He Author-Name: Shenghong Yi Author-X-Name-First: Shenghong Author-X-Name-Last: Yi Author-Name: Hong Yang Author-X-Name-First: Hong Author-X-Name-Last: Yang Title: High-efficiency compact SRR–CSRR–SIW antenna based on CRLH-TL Abstract: A high-efficiency compact split-ring resonator (SRR)–complimentary split-ring resonator (CSRR)–substrate integrated waveguide (SIW) rectangular resonator antenna based on a composite right/left-handed transmission line is presented in this paper. A four-element rectangular CSRR structure is etched on the front of the antenna, and a four-element rectangular SRR structure is loaded on the back of the metal to correspond with each other, thus forming a composite right/left-handed transmission line structure. By meandering technique, a rectangular CSRR is etched on the front of the metal surface to reduce the frequency and realize the miniaturization of the antenna. Combined with SIW rectangular resonator, the high-efficiency compact antenna is finally realized. Simulation and experimental results show that the −10 dB impedance bandwidth of the SRR–CSRR–SIW rectangular resonator antenna is 5.26∼5.29 GHz (1.14%) and 9.07∼9.15 GHz (0.88%). The resonance frequency is 5.26 and 9.11 GHz. The gains are 5.33 and 5.25 dBi. The antenna can be widely used in WLAN and WiMAX. Journal: Journal of Electromagnetic Waves and Applications Pages: 69-82 Issue: 1 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1957025 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1957025 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:1:p:69-82 Template-Type: ReDIF-Article 1.0 Author-Name: Ruijun Wang Author-X-Name-First: Ruijun Author-X-Name-Last: Wang Author-Name: Bin Deng Author-X-Name-First: Bin Author-X-Name-Last: Deng Author-Name: Hongqiang Wang Author-X-Name-First: Hongqiang Author-X-Name-Last: Wang Author-Name: Feng Zhou Author-X-Name-First: Feng Author-X-Name-Last: Zhou Title: Scattering cross section of rough metallic spheres at terahertz frequencies Abstract: At terahertz frequencies, the detailed fine structures on target’s surface can be compared with the wavelength, and the dispersive dielectric property of metals becomes obvious. Then, it is naturally thought that scattering characteristics of metallic spheres will exhibit a special phenomenon when compared with the situation in microwave band or infrared. Thus, a novel method of scattering modeling and calculation is proposed based on a full-wave approach for rough spheres at terahertz frequencies. The influence of the surface roughness and dielectric parameters of metal spheres on the scattering characteristics is evaluated by the proposed calculation method. With the further analyzing, it is clarified that the backscattering characteristics of metallic sphere can be depicted by Rayleigh region, resonant region, optical region, rough attenuation region, scattering enhancement region and ultraviolet transparent region with the increase of frequencies. Both the frequency dispersion and the rough surface decide the scattering characteristics of the metallic sphere, and also determine the frequency positions and amplitude levels of the rough attenuation region and scattering enhancement region. Journal: Journal of Electromagnetic Waves and Applications Pages: 1-17 Issue: 1 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1955751 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1955751 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:1:p:1-17 Template-Type: ReDIF-Article 1.0 Author-Name: S. Di Meo Author-X-Name-First: S. Author-X-Name-Last: Di Meo Author-Name: J. Bonello Author-X-Name-First: J. Author-X-Name-Last: Bonello Author-Name: I. Farhat Author-X-Name-First: I. Author-X-Name-Last: Farhat Author-Name: L. Farrugia Author-X-Name-First: L. Author-X-Name-Last: Farrugia Author-Name: M. Pasian Author-X-Name-First: M. Author-X-Name-Last: Pasian Author-Name: M. T. Camilleri Podesta Author-X-Name-First: M. T. Author-X-Name-Last: Camilleri Podesta Author-Name: S. Suleiman Author-X-Name-First: S. Author-X-Name-Last: Suleiman Author-Name: J. Calleja-Agius Author-X-Name-First: J. Author-X-Name-Last: Calleja-Agius Author-Name: C. V. Sammut Author-X-Name-First: C. V. Author-X-Name-Last: Sammut Title: The variability of dielectric permittivity of biological tissues with water content Abstract: Several experimental campaigns aimed at the dielectric characterization of healthy and malignant tissues, have been proposed over many years. However, disagreements among the results posed a number of questions on accurate knowledge of dielectric properties of biological tissues up to date. The reason for these disagreements are several. We aim to partially address these issues by firstly establishing a rigorous procedure for the measurement of ex-vivo animal and human-derived tissue samples. Then, we investigate the correlation between the dielectric data variability and sample hydration. Measurements were obtained from 0.5 to 50 GHz from liver and kidney cortex of porcine, ovine and bovine animals and one human cadaver. The correlation between the standard deviation of the measurements for each sample and its exact water content is investigated. This enabled the thorough analysis of both the intra- and inter-organ variability together with the intra- and inter-animal variability. Results show that the sample hydration level has a direct influence on the intra- and inter-organ variability, both for homogeneous animal and human tissues. Journal: Journal of Electromagnetic Waves and Applications Pages: 48-68 Issue: 1 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1956375 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1956375 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:1:p:48-68 Template-Type: ReDIF-Article 1.0 Author-Name: Zhijun Tang Author-X-Name-First: Zhijun Author-X-Name-Last: Tang Author-Name: Jie Zhan Author-X-Name-First: Jie Author-X-Name-Last: Zhan Author-Name: Bin Zhong Author-X-Name-First: Bin Author-X-Name-Last: Zhong Author-Name: Long Chen Author-X-Name-First: Long Author-X-Name-Last: Chen Author-Name: Guocai Zuo Author-X-Name-First: Guocai Author-X-Name-Last: Zuo Title: An ultra-wideband frequency selective surface with high stability for electromagnetic stealth Abstract: Aiming at the problems of low-frequency coverage, angle and polarization instability of ultra-wideband (UWB) frequency selective surface (FSS) in practical application, this paper introduces the additional circular parasitic patches and two-stage rectangular bent grids to enhance coupling, miniaturize geometry size, broaden bandwidth and suppress the drift of resonance frequencies based on the construction of a FSS unit cell by using a basic circular patch and a Jerusalem cross grid. The simulated and measured results show that the bandwidth of the FSS is 13.47 GHz, and its fractional bandwidth is 140.53%, which fully covers the UWB band (3.1–10.6 GHz). The UWB FSS has the flat transmission passband, and high transmission characteristics, and maintains stable performance at large incident angles and different polarization modes. The size of the UWB FSS unit cell is 0.25 λc × 0.25 λc × 0.12 λc. Therefore, the UWB FSS can be applied to electromagnetic stealth and the related fields of UWB communications. Journal: Journal of Electromagnetic Waves and Applications Pages: 141-153 Issue: 1 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1958703 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1958703 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:1:p:141-153 Template-Type: ReDIF-Article 1.0 Author-Name: Dudekula Shaikshavali Author-X-Name-First: Dudekula Author-X-Name-Last: Shaikshavali Author-Name: D. Kannadassan Author-X-Name-First: D. Author-X-Name-Last: Kannadassan Title: Influence of surface trap states on RF/microwave performance of lateral AlGaN/GaN Schottky barrier diode Abstract: In this paper, we have presented the influence of surface traps/states on RF and microwave performance of fully recessed Schottky anode AlGaN/GaN lateral Schottky barrier diode (L-SBD) using numerical modeling and simulation. During the etching/treatment of AlGaN or GaN surface, the surface traps are induced, whose physical modeling is proposed here. Through this study, the physical insights on the influence of surface states, near the 2DEG, on the DC and RF/microwave performance of the L-SBDs are presented. It was observed that induced donor states due to etching for recessed anode significantly affect the Schottky barrier and modify the tunneling behavior of anode/GaN interface. This influences the DC and RF/microwave characteristics of L-SBDs, which enhances the cut-off frequency of >140 GHz and high detector sensitivity of $ \beta _{V} $ βV >1000 mV/mW. Journal: Journal of Electromagnetic Waves and Applications Pages: 29-47 Issue: 1 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1956374 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1956374 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:1:p:29-47 Template-Type: ReDIF-Article 1.0 Author-Name: Shahreyar Sahraeian Author-X-Name-First: Shahreyar Author-X-Name-Last: Sahraeian Author-Name: Roozbeh Negahdari Author-X-Name-First: Roozbeh Author-X-Name-Last: Negahdari Author-Name: Farzin Emami Author-X-Name-First: Farzin Author-X-Name-Last: Emami Title: Design of a tunable nano sensor based on terahertz graphene-based absorbers Abstract: In this paper, tunable and efficient absorbers are proposed based on graphene–metal nano structures. The designed structures are consisted of multi layers of graphene (ring- and plate-shaped) and gold (5*5 cells) on the background of silica. By introducing different ring-shaped graphene layers (one, two or three), the near unity absorption coefficient can be achieved. The effects of different parameters like the distance, radius and chemical potential (h1, Rin1, EfR1, h2, Rin2, EfR2, h3, Rin3, EfR3) on the absorption spectrum (wavelength and value) are also considered. The best resonant peak (near unity) is obtained for the structure with three ring-shaped graphene layers. The final proposed structure (with three rings) can be utilized as an effective sensor for detecting materials with different refractive indices (from 1. to 1.5) with sensitivity of 100 (nm/RIU). The designed structure can be applied as a strong absorber or sensitive sensor in nano-optical systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 131-140 Issue: 1 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1958382 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1958382 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:1:p:131-140 Template-Type: ReDIF-Article 1.0 Author-Name: JingJing Yang Author-X-Name-First: JingJing Author-X-Name-Last: Yang Author-Name: Qianyin Xiang Author-X-Name-First: Qianyin Author-X-Name-Last: Xiang Author-Name: Xiaoguo Huang Author-X-Name-First: Xiaoguo Author-X-Name-Last: Huang Author-Name: Dinghong Jia Author-X-Name-First: Dinghong Author-X-Name-Last: Jia Author-Name: Quanyuan Feng Author-X-Name-First: Quanyuan Author-X-Name-Last: Feng Title: Tunable bandpass filters with constant absolute bandwidth cascaded trisection topology Abstract: A novel cascade trisection (CT) coupling structure, based on half-wavelength resonators, is proposed for designing constant absolute bandwidth (CABW) tunable bandpass filters. The tunable resonators have both electric and magnetic dominant coupling regions with predefined coupling coefficients. The third-order and fifth-order tunable bandpass filters (BPFs), which can realize CABW and a high side cross-coupling transmission zero (Tz), are designed based on the proposed CT structure. Measurement results show that the central frequency tuning of the third-order filter is from 1.47 to 1.83 GHz with −3dB bandwidth of 108.75 ± 2.05 MHz, and the high side 3 to 25 dB attenuation slope is 327.32–623.57 dB/GHz. The tuning range of the fifth-order filter is from 1.45 to 1.92 GHz with −3dB bandwidth of 101.9 ± 1.3 MHz, and high side 3 to 30 dB attenuation slope is 442.75–843.59 dB/GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 18-28 Issue: 1 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1955752 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1955752 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:1:p:18-28 Template-Type: ReDIF-Article 1.0 Author-Name: Liang-Pei Wu Author-X-Name-First: Liang-Pei Author-X-Name-Last: Wu Author-Name: Quan-Hai Fang Author-X-Name-First: Quan-Hai Author-X-Name-Last: Fang Author-Name: Wei-Kang Pan Author-X-Name-First: Wei-Kang Author-X-Name-Last: Pan Author-Name: Min-Hua Li Author-X-Name-First: Min-Hua Author-X-Name-Last: Li Author-Name: Jian-Feng Dong Author-X-Name-First: Jian-Feng Author-X-Name-Last: Dong Title: Realizing of cross-polarization conversion for linearly polarized waves in multiband by orthotropic metasurface Abstract: A multiband reflective linear-polarization (LP) converter based on an anisotropic metasurface is proposed. The unit cell of the metasurface is composed of a hollow oval sheet and a rectangle patch. Simulation results show that the converter can convert LP wave to its orthogonal state and the polarization conversion ratio (PCR) is above 90% in four frequency bands (4.60–12.27 GHz, 13.79–13.90 GHz, 14.61–14.69 GHz, 15.44–15.52 GHz). Interestingly, the relative bandwidth of first band reaches up to 90.9%, which is even broader than most single-band polarization conversion metasurfaces. Furthermore, we analyze the physical mechanism of polarization conversion of the metasurface, and simplify the derived formulas to make approximate calculations for co- and cross-polarization coefficients. The proposed formulas have better applicability than the equations in previous work. The laboratory sample is fabricated, and we have experimentally characterized our idea in microwave region. This design can advance applications in microwave sensors and mm-wave systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 101-114 Issue: 1 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1958380 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1958380 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:1:p:101-114 Template-Type: ReDIF-Article 1.0 Author-Name: Abhishek Kumar Author-X-Name-First: Abhishek Author-X-Name-Last: Kumar Author-Name: Vishal Kesari Author-X-Name-First: Vishal Author-X-Name-Last: Kesari Title: Meta-surface-assisted ultra-wideband dielectric window Abstract: A novel meta-surface-assisted dielectric window with periodically arranged square cross-sectional pillars with a cylindrical tip is presented to demonstrate a wider bandwidth than that without a cylindrical tip. The window bandwidth of 20.11 GHz (54.07%) at allowable return loss of 20 dB is obtained for the operating TE0,1 mode in the Ka-Q band. The bandwidth of the proposed window is improved with 17.1 GHz and 45.92% in comparison with that of the plane disk window. The window bandwidth is wider by 910 MHz and 1.18% than that for square cross-sectional pillars without a cylindrical tip. Journal: Journal of Electromagnetic Waves and Applications Pages: 237-245 Issue: 2 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1961613 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1961613 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:2:p:237-245 Template-Type: ReDIF-Article 1.0 Author-Name: Seong-Ju Lim Author-X-Name-First: Seong-Ju Author-X-Name-Last: Lim Author-Name: Jeong-Wook Kim Author-X-Name-First: Jeong-Wook Author-X-Name-Last: Kim Author-Name: Sol Kim Author-X-Name-First: Sol Author-X-Name-Last: Kim Author-Name: Hyunyoung Cho Author-X-Name-First: Hyunyoung Author-X-Name-Last: Cho Author-Name: Jong-Won Yu Author-X-Name-First: Jong-Won Author-X-Name-Last: Yu Author-Name: Woo-Kyung Lee Author-X-Name-First: Woo-Kyung Author-X-Name-Last: Lee Title: A low-sidelobe and wideband dual linearly polarized array antenna for UAV SAR application in X-band Abstract: In this letter, a $ 4\times 6 $ 4×6 microstrip patch array antenna with a low sidelobe level (SLL) for dual linearly polarized synthetic aperture radar (SAR) is proposed. The low SLL in wide-band is obtained by implementing the Chevyshev taper distribution. An optimal approach to design an unequal-power symmetric microstrip divider for dual-polarization is employed in the same layer with high isolation between the polarizations. The proposed antenna consists of squared patches excited by aperture coupled slots. With the analysis of resolution, swath, and noise equivalent sigma zero (NESZ) of the SAR system, we selected the antenna parameters such as bandwidth, beamwidth, gain, and SLL. The proposed antenna has a more than 10 % bandwidth and peak gains of 18.2 dBi and 18.3 dBi in V and H-polarization, respectively. The measured SLL in both polarizations are under −21.1 dB in the E-plane and −17.0 dB in the H-plane at the 10 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 168-179 Issue: 2 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1959418 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1959418 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:2:p:168-179 Template-Type: ReDIF-Article 1.0 Author-Name: Ali Abdulkhaleq Alwahib Author-X-Name-First: Ali Abdulkhaleq Author-X-Name-Last: Alwahib Author-Name: Shatha mezher hasan Author-X-Name-First: Shatha mezher Author-X-Name-Last: hasan Author-Name: Kadhim A. Hubeatir Author-X-Name-First: Kadhim A. Author-X-Name-Last: Hubeatir Title: A surface plasmon temperature sensor based on E7 liquid crystal using angle interrogation method Abstract: A prism-based surface plasmon resonance (SPR) sensor supported water/gas-based liquid crystal (LC) E7 is presented. A gold layer was internally attached to the chamber filled with LC. The results demonstrated that LC's resonance angle increases with the increasing temperature, and the variation can be detected by the absorption and angle shift of the plasmonic dip. The modeling results presented that the refractive index increases with increasing temperature at the variation from 15°C to 85°C. The temperature sensitivity was started at 0.06 degrees/°C at 15°C and reached the maximum value from 35 to 50 degrees/°C. The liquid crystal type E7 experimental results were compared with simulation results from 15°C to 85°C of MLC-9200-000, MLC9200-100, MLC-6608, TL-216, and E44. The water/LC-based SPR shows angle shift and absorption shift compared to gas/LC-based SPR. The SPR curve's sharpness was enhanced, but low angle shift and no absorption shift were recognized. Journal: Journal of Electromagnetic Waves and Applications Pages: 213-227 Issue: 2 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1960901 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1960901 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:2:p:213-227 Template-Type: ReDIF-Article 1.0 Author-Name: Jian Sun Author-X-Name-First: Jian Author-X-Name-Last: Sun Author-Name: Yanfei Gong Author-X-Name-First: Yanfei Author-X-Name-Last: Gong Author-Name: Luhang Jiang Author-X-Name-First: Luhang Author-X-Name-Last: Jiang Title: An improved model for the analysis of the shielding performance of an apertured enclosure based on EMT theory and BLT equation Abstract: An improved model based on the electromagnetic topology (EMT) theory and Baum-Liu-Tesche (BLT) equation is presented to evaluate the shielding performance of an apertured enclosure. First, the total aperture impedance of arbitrarily positioned apertures can be easily obtained through the coupling factor. Then, the expression of the electric field components at any monitor point inside the enclosure is derived according to the relation between voltage response and field distribution, hence, the shielding effectiveness (SE) and resonances can be analyzed conveniently. Finally, the improved model is validated by the CST, showing high efficiency and accuracy for the prediction of the SE and resonant modes of an enclosure. The improved model is suitable for handling slots that have a large length-width ratio, irregularly arranged aperture arrays, multiple apertures with different shapes and dimensions, and cascaded triple enclosures with off-centered apertures, showing the wide application range of this model. Journal: Journal of Electromagnetic Waves and Applications Pages: 246-260 Issue: 2 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1961614 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1961614 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:2:p:246-260 Template-Type: ReDIF-Article 1.0 Author-Name: Shreyas Charola Author-X-Name-First: Shreyas Author-X-Name-Last: Charola Author-Name: Shobhit K. Patel Author-X-Name-First: Shobhit K. Author-X-Name-Last: Patel Author-Name: Juveriya Parmar Author-X-Name-First: Juveriya Author-X-Name-Last: Parmar Author-Name: Rajendrasinh Jadeja Author-X-Name-First: Rajendrasinh Author-X-Name-Last: Jadeja Title: Multiband Jerusalem cross-shaped angle insensitive metasurface absorber for X-band application Abstract: In this paper, a multiband symmetrical Jerusalem cross-shaped metasurface absorber is designed, fabricated, and measured. The upper layer consists of Jerusalem cross metasurface placed over FR-4 substrate to achieve perfect absorption. The unit cell of the proposed absorber is symmetrical and periodic in the horizontal and vertical axis. The Jerusalem cross absorber gives good impedance response at five different frequencies in the X-band region. The proposed absorber gives absorptivity of 97.3%, 97%, 96.1%, 98.8%, and 97.4% at 8.82 GHz, 9 GHz, 9.25 GHz, 9.43 GHz, and 10.1 GHz. In transverse electric and magnetic field response, the absorptivity is angle insensitive up to 600. The change in absorption spectra for the proposed absorber with a change in different physical parameters, electric field distribution is presented. The measured results of the fabricated absorber are similar to the numerically investigated results. The proposed absorber can be applicable in X-band satellite and radar applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 180-192 Issue: 2 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1960643 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1960643 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:2:p:180-192 Template-Type: ReDIF-Article 1.0 Author-Name: Tao Wang Author-X-Name-First: Tao Author-X-Name-Last: Wang Author-Name: Meng-Di Ding Author-X-Name-First: Meng-Di Author-X-Name-Last: Ding Author-Name: He-He He Author-X-Name-First: He-He Author-X-Name-Last: He Author-Name: Jian-Bo Mao Author-X-Name-First: Jian-Bo Author-X-Name-Last: Mao Author-Name: Jiu-Fu Ruan Author-X-Name-First: Jiu-Fu Author-X-Name-Last: Ruan Title: Ultra-wideband polarization- and angle-insensitive metamaterial absorber based on multilayer resistive ink Abstract: An ultra-wideband metamaterial absorber (MA) consisting of three layers of resistive ink separated by two layers of polymethacrylimide is proposed. The results of full-wave simulation show that the absorptivity is high up to 95% with a bandwidth ratio of 1:9.73 over the wide frequency range from 4.20 to 40.87 GHz, covering the whole C, X, Ku, K, and Ka bands. Moreover, the MA is insensitive to polarization and exhibits wide-angle stability, which is investigated by the full-wave simulation results as well as the analysis of multi-reflection interference theory. The fabricated prototype with a single unit cell of 0.081 g is tested using free-space measurement in an anechoic chamber, and the measured results are in good agreement with the simulation results, which prove the robustness of the design and indicates a practical application prospect of the proposed ultra-wideband MA with lightweight, simple, and compact structure. Journal: Journal of Electromagnetic Waves and Applications Pages: 272-284 Issue: 2 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1965038 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1965038 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:2:p:272-284 Template-Type: ReDIF-Article 1.0 Author-Name: Jeong-Wook Kim Author-X-Name-First: Jeong-Wook Author-X-Name-Last: Kim Author-Name: Sol Kim Author-X-Name-First: Sol Author-X-Name-Last: Kim Author-Name: Hyunyoung Cho Author-X-Name-First: Hyunyoung Author-X-Name-Last: Cho Author-Name: ByungKuon Ahn Author-X-Name-First: ByungKuon Author-X-Name-Last: Ahn Author-Name: Jin-Woo Kim Author-X-Name-First: Jin-Woo Author-X-Name-Last: Kim Author-Name: Jong-Won Yu Author-X-Name-First: Jong-Won Author-X-Name-Last: Yu Title: Wide-angle scanning phased-array system using arc-shorted half elliptic elements Abstract: Vehicles to everything (V2X) communication includes a variety of types, so wide-angle scanning is integral. For wide-angle scanning, the half power beam width (HPBW) of a single antenna must be wide. Moreover, the gain, low cross-polarization level, and impedance bandwidth are essential factors in high communication performance. In this paper, a wide-angle scanning phased-array system using an arc-shorted half-elliptic patch antenna at 5.8 GHz is presented. The design of both a single antenna and the entire phased-array system are covered, and to verify the design method, the proposed single antenna and phased array system were fabricated. The proposed antenna had 162 $ ^{\circ } $ ∘ HPBW in the E-plane and 8.63 dBi of peak gain. Its fractional bandwidth was 5%, and the level of cross-polarization was −16.8 dBi. Furthermore, the measured 3 dB scanning angle of the phased-array system was from $ -90^{\circ } $ −90∘ to 90 $ ^{\circ } $ ∘. The proposed system has wide-angle scanning. Journal: Journal of Electromagnetic Waves and Applications Pages: 261-271 Issue: 2 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1962739 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1962739 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:2:p:261-271 Template-Type: ReDIF-Article 1.0 Author-Name: Maharana Pratap Singh Author-X-Name-First: Maharana Pratap Author-X-Name-Last: Singh Author-Name: Rahul Kumar Jaiswal Author-X-Name-First: Rahul Kumar Author-X-Name-Last: Jaiswal Author-Name: Kumar Vaibhav Srivastava Author-X-Name-First: Kumar Vaibhav Author-X-Name-Last: Srivastava Author-Name: Saptarshi Ghosh Author-X-Name-First: Saptarshi Author-X-Name-Last: Ghosh Title: A miniaturized triple-band circularly polarized antenna using meander geometry Abstract: In this paper, a compact triple-band printed monopole antenna with circular polarization (CP) has been presented for C-band wireless applications. To achieve the triple-band CP response, the top layer of antenna geometry consists of a meander structure and two orthogonal stubs, whereas a ground plane consists of a vertical slot. The 10-dB impedance bandwidth of the proposed antenna is 450, 560, and 830 MHz at center frequencies of 4.1, 5.8, and 6.7 GHz, respectively. The 3-dB axial ratio (AR) bandwidth’s attained around center frequencies is 4.29%, 4.03%, and 3.52%, respectively. Additionally, the proposed design exhibits a miniaturized performance with an overall size of 0.35 × 0.39 × 0.017 λ, where λ represents free space wavelength at smallest CP frequency. Furthermore, the structure has a simple topology, broadside radiation, and sufficient moderate gain. The proposed antenna has been fabricated and its measured responses are in good agreement with the simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 228-236 Issue: 2 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1961612 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1961612 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:2:p:228-236 Template-Type: ReDIF-Article 1.0 Author-Name: Alberto Hernández-Escobar Author-X-Name-First: Alberto Author-X-Name-Last: Hernández-Escobar Author-Name: Elena Abdo-Sánchez Author-X-Name-First: Elena Author-X-Name-Last: Abdo-Sánchez Author-Name: Carlos Camacho-Peñalosa Author-X-Name-First: Carlos Author-X-Name-Last: Camacho-Peñalosa Title: Leaky-wave antenna with continuous backward-to-forward frequency scanning using strip-fed cavity-backed slots Abstract: A leaky-wave antenna made of cavity-backed-slot radiating elements with open-stopband suppression is presented. The cavity-backed slots are seriesly fed by a strip. The bandwidth of the unit cell of the array is enhanced by a recently-proposed technique that uses a matching stub. The open-stopband effect is mitigated by misaligning the stub with respect to the slot. An array is designed and fabricated. The array is built using an aluminum set of cavities filled with 3D printed material to support the substrate where the feed and slots are etched. The measurement of the prototype shows the overall good performance of the array. The array is able to scan its beam from $ -70^\circ $ −70∘ to 50 $ ^\circ $ ∘ in the 2.8–4.4 GHz frequency range, keeping good matching even at the broadside frequency. The gain is stable over the band. Journal: Journal of Electromagnetic Waves and Applications Pages: 155-167 Issue: 2 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1958706 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1958706 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:2:p:155-167 Template-Type: ReDIF-Article 1.0 Author-Name: Asutosh Mohanty Author-X-Name-First: Asutosh Author-X-Name-Last: Mohanty Author-Name: Sudhakar Sahu Author-X-Name-First: Sudhakar Author-X-Name-Last: Sahu Title: A compact uni-planar printed slot UWB antenna with reconfigurable functionality Abstract: In this article, a compact uni-planar printed slot antenna with SAS geometry is proposed, facilitating UWB multi-bands, band-rejectionality, LP and CP using reconfigurable technique, with 2 x SMD diodes. For SMD1-ON, SMD2-ON, states antenna operates in SAS mode from 2.4–10.6 GHz and for SMD1-OFF, SMD2-OFF states antenna operates in slot mode, resulted in band-rejection from 2.7–4.3 GHz. For aforementioned states $ \pm 45^{\circ } $ ±45∘ LP patterns are observed. At [(SMD1-OFF, SMD2-ON) and (SMD1-ON, SMD2-OFF)] states, the antenna asserts CP with minimum 3-dB axial ratio at 6.05 GHz and 9.31 GHz, respectively, where the polarization sense is electronically reversed asserting dual-sense CP . Additionally, it shows band-rejection from 2.5–5 GHz for (SMD1-OFF, SMD2-ON) state and 3.6–4.8 GHz for (SMD1-ON, SMD2-OFF) state. A prototype antenna of size $ 0.208_{2.4\,{\rm GHz}} \times 0.208_{2.4\,{\rm GHz}} \times 0.012_{2.4\,{\rm GHz}} $ 0.2082.4GHz×0.2082.4GHz×0.0122.4GHz is fabricated and measured to be potentially used in cognitive radio systems and UWB applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 193-212 Issue: 2 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1960644 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1960644 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:2:p:193-212 Template-Type: ReDIF-Article 1.0 Author-Name: Qilei Zhou Author-X-Name-First: Qilei Author-X-Name-Last: Zhou Author-Name: Guang Fu Author-X-Name-First: Guang Author-X-Name-Last: Fu Author-Name: Chao Sun Author-X-Name-First: Chao Author-X-Name-Last: Sun Title: High-gain low-profile circularly polarized patch antenna for universal RFID reader application Abstract: It is known that for a microstrip antenna, if the height of the antenna is strictly limited, then the bandwidth is narrow. A way to solve this problem is to combine two modes. However, for almost all the two-mode resonant patch antennas reported, the height of the antenna conflicts with the frequency ratio of the two modes. The smaller the frequency ratio is, the higher the antenna. In this paper, a detailed mode analysis is performed, and a comprehensive mode shift design method is established. A dual resonant patch antenna with any frequency ratio can be designed. Guided by this method, a low-profile wideband patch antenna with a size of only 0.6λ0 × 0.6λ0 × 0.05λ0 for the universal RFID reader (840-960 MHz) is designed. The simulated and measured results show that a low-profile is achieved for universal RFID reader antennas. Journal: Journal of Electromagnetic Waves and Applications Pages: 285-306 Issue: 2 Volume: 36 Year: 2022 Month: 01 X-DOI: 10.1080/09205071.2021.1965499 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1965499 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:2:p:285-306 Template-Type: ReDIF-Article 1.0 Author-Name: D. da M. Colares Author-X-Name-First: D. da M. Author-X-Name-Last: Colares Author-Name: R. F. Abreu Author-X-Name-First: R. F. Author-X-Name-Last: Abreu Author-Name: F. R. Silva Author-X-Name-First: F. R. Author-X-Name-Last: Silva Author-Name: T. O. Abreu Author-X-Name-First: T. O. Author-X-Name-Last: Abreu Author-Name: F. A. C. Nobrega Author-X-Name-First: F. A. C. Author-X-Name-Last: Nobrega Author-Name: D. B. Freitas Author-X-Name-First: D. B. Author-X-Name-Last: Freitas Author-Name: J. P. C. do Nascimento Author-X-Name-First: J. P. C. Author-X-Name-Last: do Nascimento Author-Name: F. G. S. Oliveira Author-X-Name-First: F. G. S. Author-X-Name-Last: Oliveira Author-Name: I. F. Vasconcelos Author-X-Name-First: I. F. Author-X-Name-Last: Vasconcelos Author-Name: A. Ghosh Author-X-Name-First: A. Author-X-Name-Last: Ghosh Author-Name: S. J. T. Vasconcelos Author-X-Name-First: S. J. T. Author-X-Name-Last: Vasconcelos Author-Name: J. C. Sales Author-X-Name-First: J. C. Author-X-Name-Last: Sales Author-Name: R. S. Silva Author-X-Name-First: R. S. Author-X-Name-Last: Silva Author-Name: A. S. B. Sombra Author-X-Name-First: A. S. B. Author-X-Name-Last: Sombra Title: Improving the microwave dielectric properties of BiCu3Ti3FeO12 with the addition of Bi2O3 Abstract: In this work, the influence of the addition of Bi2O3 on the dielectric properties in the microwave range of BiCu3Ti3FeO12 (BCTFO) ceramic matrix and its potential application as a dielectric resonator antenna are analysed. X-ray diffraction shows that a reaction between BCTFO and Bi2O3 occurs that results in the formation of new crystalline phases. The morphology of the samples is studied by field-emission scanning electron microscopy and demonstrates a dependence of the grain size on the Bi2O3 content. From the Mössbauer spectroscopic analysis, it is found that the Fe3+ ions replace the Ti4+ in the crystalline structure. The addition of Bi2O3 also reduces the dielectric permittivity (ϵr), dielectric loss (tan δ) and the coefficient of the resonance frequency (τf) values. Finally, numerical simulations are carried out in order to obtain the antenna parameters and they demonstrate that BCTFO could be a potential candidate for devices operating in the S-band. Journal: Journal of Electromagnetic Waves and Applications Pages: 321-331 Issue: 3 Volume: 36 Year: 2022 Month: 02 X-DOI: 10.1080/09205071.2021.1968958 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1968958 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:3:p:321-331 Template-Type: ReDIF-Article 1.0 Author-Name: Fei Huang Author-X-Name-First: Fei Author-X-Name-Last: Huang Author-Name: Yufa Sun Author-X-Name-First: Yufa Author-X-Name-Last: Sun Title: Characteristic basis function method based on mixed discretization for analyzing scattering from electrically large inhomogeneous objects Abstract: The characteristic basis function method (CBFM) based on the mixed discretization (MD) is firstly proposed to analyze the electromagnetic scattering from electrically large inhomogeneous objects. The discontinuous Galerkin volume integral equation (DGVIE) method which employs nonconformal discretization permits to independently discretize the various component regions of the inhomogeneous object depending on its local shape or dielectric permittivity. Moreover, by the means of the CBFM, the low-level basis functions employed in the DGVIE method are converted into high-level basis functions, dramatically reducing the number of basis functions for modeling. In addition, the conformal discretization which is superior in dealing with homogenous regions is mixed with the nonconformal discretization to further cut down the number of the basis functions. Numerical results show that the CBFM based on mixed discretization (MD-CBFM) generates much less unknowns in contrast to several conventional methods. Several composite inhomogeneous examples are given to demonstrate the accuracy and efficiency of the proposed method. Journal: Journal of Electromagnetic Waves and Applications Pages: 441-455 Issue: 3 Volume: 36 Year: 2022 Month: 02 X-DOI: 10.1080/09205071.2021.1971116 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1971116 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:3:p:441-455 Template-Type: ReDIF-Article 1.0 Author-Name: Honggang Hao Author-X-Name-First: Honggang Author-X-Name-Last: Hao Author-Name: Yihao Tang Author-X-Name-First: Yihao Author-X-Name-Last: Tang Author-Name: Sen Zheng Author-X-Name-First: Sen Author-X-Name-Last: Zheng Author-Name: Xuehong Ran Author-X-Name-First: Xuehong Author-X-Name-Last: Ran Title: Design of metasurface beam splitter based on polarization characteristics of incident wave Abstract: A transmissive metasurface polarization beam splitter (MPBS) with three-layer dielectric substrate was designed to meet the application requirements of polarization beam splitting devices. The microstructure unit cell was composed of an elliptical patch and a square resonant ring, and the phase and amplitude responses to the x- and y-polarized incident waves were independent. Here 16 transmissive unit cells designed with a 90° phase difference and more than 0.8 transmission coefficient could be used to realize different functions by pre-designing distribution of “00”, “01”, “10”, “11” encoding particles in x- and y-direction. We experimentally demonstrated a 2-bit encoding MPBS that separated x- and y-polarization incident waves into two different directions at 15 GHz respectively using specially designed encoding unit cells. The work may alleviate the shortage of advanced multifunctional devices and provide important application prospect in imaging, MIMO system, etc. Journal: Journal of Electromagnetic Waves and Applications Pages: 307-320 Issue: 3 Volume: 36 Year: 2022 Month: 02 X-DOI: 10.1080/09205071.2021.1965500 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1965500 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:3:p:307-320 Template-Type: ReDIF-Article 1.0 Author-Name: Panlin Shu Author-X-Name-First: Panlin Author-X-Name-Last: Shu Author-Name: Ao Liao Author-X-Name-First: Ao Author-X-Name-Last: Liao Author-Name: An Zhang Author-X-Name-First: An Author-X-Name-Last: Zhang Author-Name: Yang Luo Author-X-Name-First: Yang Author-X-Name-Last: Luo Author-Name: Binhan Tang Author-X-Name-First: Binhan Author-X-Name-Last: Tang Author-Name: Chunfu Wang Author-X-Name-First: Chunfu Author-X-Name-Last: Wang Author-Name: Yanrui Li Author-X-Name-First: Yanrui Author-X-Name-Last: Li Title: High selective wideband bandpass filter with mixed-coupled resonators Abstract: Novel electric and magnetic mixed-coupled resonators and a general design method for high selective wideband bandpass filters are presented in this paper. Transmission zeros are introduced in the filters for high selectivity, and the location of the transmission zeros can be adjusted without passband characters changing. To verify the design method, an eighth-order mixed-coupled filter is designed, fabricated and measured; the measured results show higher rejection compared with the conventional interdigital filters. Good agreements are obtained between simulated and measured results. Journal: Journal of Electromagnetic Waves and Applications Pages: 356-365 Issue: 3 Volume: 36 Year: 2022 Month: 02 X-DOI: 10.1080/09205071.2021.1969689 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1969689 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:3:p:356-365 Template-Type: ReDIF-Article 1.0 Author-Name: Daasari Surender Author-X-Name-First: Daasari Author-X-Name-Last: Surender Author-Name: Md. Ahsan Halimi Author-X-Name-First: Md. Ahsan Author-X-Name-Last: Halimi Author-Name: Taimoor Khan Author-X-Name-First: Taimoor Author-X-Name-Last: Khan Author-Name: Fazal A. Talukdar Author-X-Name-First: Fazal A. Author-X-Name-Last: Talukdar Author-Name: Shiban K. Koul Author-X-Name-First: Shiban K. Author-X-Name-Last: Koul Author-Name: Yahia M.M. Antar Author-X-Name-First: Yahia M.M. Author-X-Name-Last: Antar Title: 2.45 GHz Wi-Fi band operated circularly polarized rectenna for RF energy harvesting in smart city applications Abstract: This article proposes a single band circularly polarized (CP) rectenna operate at a 2.45 GHz Wi-Fi band, using a hexagonal shape of a microstrip radiator and a voltage doubler rectifier for smart city applications. A partial ground plane embedded with isosceles triangular slot and notch helps in obtaining the desired resonance characteristics with improved antenna performance and reasonable miniaturization. Two crossed-slots, introduced into the radiating patch, yield CP characteristics. Also, the proposed antenna shows an omnidirectional radiational behavior that helps in harvesting RF energy from all of its surroundings. A voltage doubler configuration using the SMS7630-005 LF diode is chosen for designing a rectifier circuit to achieve a maximum conversion efficiency of 65.1% and an output voltage of 1.65 V at an input power of 0 dBm for the load resistance value of 4.1 kΩ which is very much suitable for powering low power sensing devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 407-423 Issue: 3 Volume: 36 Year: 2022 Month: 02 X-DOI: 10.1080/09205071.2021.1970030 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1970030 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:3:p:407-423 Template-Type: ReDIF-Article 1.0 Author-Name: A. Habibi Daronkola Author-X-Name-First: A. Author-X-Name-Last: Habibi Daronkola Author-Name: F. Tavakkol Hamedani Author-X-Name-First: F. Author-X-Name-Last: Tavakkol Hamedani Author-Name: P. Rezaei Author-X-Name-First: P. Author-X-Name-Last: Rezaei Author-Name: N. Montaseri Author-X-Name-First: N. Author-X-Name-Last: Montaseri Title: Mutual coupling reduction using plane spiral orbital angular momentum electromagnetic wave Abstract: Circular phased array antennas with a quasi-omnidirectional pattern to generate transverse orbital angular momentum (OAM) waves with modes $ \textrm{l = 0 } $ l = 0  and $ - 1 $ −1 are designed at the frequency of 4 GHz. Proposed antennas consist of eight substrates integrated waveguide (SIW) H-plane horn elements and microstrip corporate feeding networks. Experimental results show that the mutual coupling between array antennas can be reduced by employing transverse OAM waves with different modes. Journal: Journal of Electromagnetic Waves and Applications Pages: 346-355 Issue: 3 Volume: 36 Year: 2022 Month: 02 X-DOI: 10.1080/09205071.2021.1969688 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1969688 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:3:p:346-355 Template-Type: ReDIF-Article 1.0 Author-Name: Sivakumar Ellusamy Author-X-Name-First: Sivakumar Author-X-Name-Last: Ellusamy Author-Name: Ramachandran Balasubramanian Author-X-Name-First: Ramachandran Author-X-Name-Last: Balasubramanian Title: Sub-6 GHz quad-band frequency tunable MIMO antenna for 5G applications Abstract: This paper describes a slot-based, reconfigurable multiple-input multiple-output (MIMO) quad-band antenna for sub-6 GHz 5G applications. The structure contains a simple arrangement of closely spaced stub-loaded monopole radiating elements and a partial ground plane, realized on FR-4 epoxy substrate with a board dimension of 50 mm × 25 mm × 1 mm. The design has a C-shaped slot and PIN diodes for frequency reconfigurability. The ground plane includes two stubs embedded in it to improve port isolation. The antenna works in four frequency bands: 3.22–5.82, 3.3–4.4, 3.7–5.1, and 4.68–5.64 GHz with port isolation below −20 dB. Scattering parameters, envelope correlation coefficient (ECC), diversity gain (DG), total radiation efficiency, mean effective gain (MEG), and multiplexing efficiency are all determined to validate the fabricated MIMO antenna. The calculated values confirm that the developed antenna is quite promising for sub-6 GHz 5G MIMO systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 424-440 Issue: 3 Volume: 36 Year: 2022 Month: 02 X-DOI: 10.1080/09205071.2021.1970031 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1970031 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:3:p:424-440 Template-Type: ReDIF-Article 1.0 Author-Name: Yaqeen Sabah Mezaal Author-X-Name-First: Yaqeen Sabah Author-X-Name-Last: Mezaal Title: New printed slot antennas with etched SIR components in the ground plane Abstract: In this study, two new printed slot antennas have been simulated and fabricated using a single layer of FR4 substrate for modern wireless applications. The first printed slot antenna with etched stair-step topology in the ground plane is proposed to achieve the single-band operation. This topology is based on two components of asymmetrical step-impedance resonator (SIR) and one component of symmetrical SIR. The first designed printed slot antenna satisfies the requirements of WLAN applications at 5.75 GHz. The second printed slot antenna is a developed version of the first one with one inserted component of symmetrical SIR and one asymmetrical SIR component to be operated as a multiband antenna applicable for WiMAX, WLAN, and X-band downlink satellite systems at 3.5, 5.75, and 7.75 GHz, respectively. The proposed antennas have small sizes, and competitive electrical specifications than many reported SIR and non-SIR antennas in the literature. Journal: Journal of Electromagnetic Waves and Applications Pages: 388-406 Issue: 3 Volume: 36 Year: 2022 Month: 02 X-DOI: 10.1080/09205071.2021.1970029 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1970029 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:3:p:388-406 Template-Type: ReDIF-Article 1.0 Author-Name: Le-Cuong Nguyen Author-X-Name-First: Le-Cuong Author-X-Name-Last: Nguyen Author-Name: Trong-Hieu Le Author-X-Name-First: Trong-Hieu Author-X-Name-Last: Le Author-Name: Manh-Cuong Ho Author-X-Name-First: Manh-Cuong Author-X-Name-Last: Ho Author-Name: Xiao-Wei Zhu Author-X-Name-First: Xiao-Wei Author-X-Name-Last: Zhu Title: Design of broadband RF transceiver front-end using highly selective diplexer and high Q-factor hybrid resonator bandpass filters Abstract: In this paper, a development of low cost, miniature, highly integration broadband RF transceiver front-end using the high selectivity hybrid resonator RF bandpass filters, and diplexer integrated with shielding case is presented. The proposed RF transceiver frontend operates at the 2.7 GHz for transmitting and 2.4 GHz for receiving, supporting a channel bandwidth of 100 MHz with frequency division duplexing mode. The designed low loss, high selectivity hybrid resonator bandpass filters are utilized to channel selection and reject the interference signal. The high isolation diplexer is employed to separate the Tx and Rx signals and reject the interferences from other systems to the RF receiver as well as filter out the harmonics generated by the RF transmitter. The measured performance of the proposed RF transceiver front-end module is superior to the requirements as well as can support high spectrum efficiency and high data rate communications with low error vector magnitude. Journal: Journal of Electromagnetic Waves and Applications Pages: 366-377 Issue: 3 Volume: 36 Year: 2022 Month: 02 X-DOI: 10.1080/09205071.2021.1970027 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1970027 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:3:p:366-377 Template-Type: ReDIF-Article 1.0 Author-Name: Shiwen Lei Author-X-Name-First: Shiwen Author-X-Name-Last: Lei Author-Name: Haoquan Hu Author-X-Name-First: Haoquan Author-X-Name-Last: Hu Author-Name: Bo Chen Author-X-Name-First: Bo Author-X-Name-Last: Chen Author-Name: Jing Tian Author-X-Name-First: Jing Author-X-Name-Last: Tian Author-Name: Ziyuan He Author-X-Name-First: Ziyuan Author-X-Name-Last: He Author-Name: Pu Tang Author-X-Name-First: Pu Author-X-Name-Last: Tang Author-Name: Xiangdong Qiu Author-X-Name-First: Xiangdong Author-X-Name-Last: Qiu Title: Mainlobe beamwidth maximization for wide-beam array antenna with desired minimum power gain constraint Abstract: In this paper, the problem of maximizing the beamwidth with array antenna giving the desired minimum power gain in the wide-beam mainlobe is addressed. Termed this problem as Mainlobe BeamWidth Maximization (MBWM). This paper, by optimizing the gain pattern instead of optimizing the beam pattern, first sets up the mathematical model for the MBWM problem. It comes out that the MBWM problem is non-convex, hence cannot be solved effectively in polynomial time. To simplify the solving processes, the MBWM problem, thereafter, is converted into a series of power gain pattern synthesis (PGPS) problems. The bisection strategy together with the processing procedures for the PGPS problem are utilized to design an iterative algorithm to solve the MBWM problem. Numerical simulations compared with the existing methods which optimize the beam pattern are carried out. Journal: Journal of Electromagnetic Waves and Applications Pages: 332-345 Issue: 3 Volume: 36 Year: 2022 Month: 02 X-DOI: 10.1080/09205071.2021.1969687 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1969687 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:3:p:332-345 Template-Type: ReDIF-Article 1.0 Author-Name: Gaoya Dong Author-X-Name-First: Gaoya Author-X-Name-Last: Dong Author-Name: Xiaolong Yang Author-X-Name-First: Xiaolong Author-X-Name-Last: Yang Title: General design equations for arbitrary odd-way filtering Bagley polygon power divider with notch band Abstract: The general design equations are derived for arbitrary odd-way Bagley polygon power divider (BPPD) with filtering response and notch band. Firstly, conditions are derived to achieve a perfect input port impedance matching at centre frequency. Then, the formulas of introduced transmission zeros (TZs) are obtained for high-frequency selectivity, wide upper stopband and notch band. Based on the deduced equations, wideband BPPD (WBPPD), filtering BPPD (FBPPD) and FBPPD integrating notch band (FBPPD-N) with arbitrary odd-way power splitting are designed. Finally, a FBPPD-N with a wide passband bandwidth is fabricated and measured to verify the presented ideal. The experimental results indicate that the proposed FBPPD-N has compact size, high-frequency selectivity, wide upper stopband and required notch band. Consequently, the presented general design equations can provide effective guidance for the design of arbitrary odd-way power splitting FBPPD-N. Journal: Journal of Electromagnetic Waves and Applications Pages: 378-387 Issue: 3 Volume: 36 Year: 2022 Month: 02 X-DOI: 10.1080/09205071.2021.1970028 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1970028 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:3:p:378-387 Template-Type: ReDIF-Article 1.0 Author-Name: Yanfei Gong Author-X-Name-First: Yanfei Author-X-Name-Last: Gong Author-Name: Xingtong Chen Author-X-Name-First: Xingtong Author-X-Name-Last: Chen Title: An analytical model for predicting the shielding effectiveness and resonances of a lossy enclosure with apertures Abstract: In this paper, an improved analytical model is presented to predict the shielding effectiveness (SE) and resonances of an apertured enclosure composed of the material of finite conductivity. In the model, the modified parameters of the rectangular waveguide are introduced to deal with the lossy enclosure with apertures, which can consider the effects of wall loss on the SE. Firstly, according to the circuit theory and electromagnetic topology (EMT) theory, the lossy enclosure is modeled as the circuit model and signal flow graph, respectively. Then, the electric field components at the monitor point can be obtained; hence, the SE can be predicted accurately. Finally, the presented model is utilized to analyze the effects of various parameters and conditions on the SE. The validity of the presented model is verified by the CST through several cases, showing that the lossy enclosure is feasible to damp all the resonant modes. Journal: Journal of Electromagnetic Waves and Applications Pages: 488-504 Issue: 4 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1972844 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1972844 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:4:p:488-504 Template-Type: ReDIF-Article 1.0 Author-Name: Chan-Ho Hwang Author-X-Name-First: Chan-Ho Author-X-Name-Last: Hwang Author-Name: Tae-Hwan Joo Author-X-Name-First: Tae-Hwan Author-X-Name-Last: Joo Author-Name: Ju-Man Park Author-X-Name-First: Ju-Man Author-X-Name-Last: Park Author-Name: Kichul Kim Author-X-Name-First: Kichul Author-X-Name-Last: Kim Author-Name: Jae-Soo Jung Author-X-Name-First: Jae-Soo Author-X-Name-Last: Jung Title: Fast digital multi-beam search method for active phased array antenna system with full azimuth beam steering Abstract: This paper proposes a multi-beam search method based on an active phased array antenna system using digital beamforming. It includes initial beamforming, valid beam selection, and beam angle estimation using phase comparison mono pulses for multi-channel signals. To verify DoA estimation error, simulation and measurement are performed using the proposed antenna system. As a result, we confirm the performance of estimating each channel's angle and the beam directional error within 0.5°. Journal: Journal of Electromagnetic Waves and Applications Pages: 579-596 Issue: 4 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1977184 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1977184 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:4:p:579-596 Template-Type: ReDIF-Article 1.0 Author-Name: Jiu-Fu Ruan Author-X-Name-First: Jiu-Fu Author-X-Name-Last: Ruan Author-Name: Feng Lan Author-X-Name-First: Feng Author-X-Name-Last: Lan Author-Name: Rui-Zhi Zou Author-X-Name-First: Rui-Zhi Author-X-Name-Last: Zou Author-Name: Zi-Fan Meng Author-X-Name-First: Zi-Fan Author-X-Name-Last: Meng Author-Name: Yao-Hui Hu Author-X-Name-First: Yao-Hui Author-X-Name-Last: Hu Title: Broadband water-based metamaterial absorber for millimeter-wave, high-power applications Abstract: An all-dielectric metamaterial absorber based on water resonator encapsulated in resin container is proposed. The absorber can afford the maximum absorption up to 98% at 190 GHz, as well as the wide absorption frequency range from 115 GHz to 300 GHz and a nearly 90% relative absorption bandwidth. The role of water resonator sealed in the resin shell in improving absorption capability is demonstrated by the comparison result that the proposed absorber is superior to pure water or pure resin absorber with the same dimension and interpreted by a further study on the fields and power loss density distributions. Moreover, the proposed absorber can remain excellent absorption performance even for the oblique incidence with large angles. Besides the outstanding absorption performance, the proposed absorber has the advantage of low cost endowed by the use of water, which makes it promising for EM compatibility in the millimetre-wave and high-power cases. Journal: Journal of Electromagnetic Waves and Applications Pages: 557-567 Issue: 4 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1975316 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1975316 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:4:p:557-567 Template-Type: ReDIF-Article 1.0 Author-Name: Khan Md. Zobayer Hassan Author-X-Name-First: Khan Md. Zobayer Author-X-Name-Last: Hassan Author-Name: Nantakan Wongkasem Author-X-Name-First: Nantakan Author-X-Name-Last: Wongkasem Title: Development of microwave metamaterial-inspired sensors with multiple-band reactivity for mercury contamination detection Abstract: Alternative contactless metamaterial-inspired microwave sensors, composed of a multi-band omnidirectional bowtie antenna and metamaterials, are developed to detect and identify mercury, one of the most widespread toxic heavy metals, in the C-band and S-band, using reflection coefficients. A multi-negative refractive index band metamaterial is specifically designed as a sensing enhancer, where the multi bands can effectively trigger the electromagnetic properties, as well as enhance the differentiation between the mercury samples. The geometry of the metamaterial and its arrangement and orientation are optimized to reach the system highest sensitivity. The proposed sensors were tested on mercury traces of various volumes and weights. Our study has shown that the electromagnetic responses of the mercury in the microwave range are nonlinear, yet predictable. Six distinguishable resonances generated while testing the samples specify the capability of identifying the mercury amount, which can effectively trace mercury contamination in water and seawater. Journal: Journal of Electromagnetic Waves and Applications Pages: 520-541 Issue: 4 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1973914 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1973914 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:4:p:520-541 Template-Type: ReDIF-Article 1.0 Author-Name: Ghida Al Achkar Author-X-Name-First: Ghida Author-X-Name-Last: Al Achkar Author-Name: Lionel Pichon Author-X-Name-First: Lionel Author-X-Name-Last: Pichon Author-Name: Laurent Daniel Author-X-Name-First: Laurent Author-X-Name-Last: Daniel Title: Homogenization of woven composites for shielding applications: the case of oblique incidence Abstract: When reinforced with conductive fibers, woven composites can exhibit interesting shielding properties. This paper focuses on their response for obliquely incident plane waves in the high-frequency range (500 MHz to 40 GHz). A two-step homogenization technique is carried out. First, the composite response (shielding effectiveness and reflection coefficient) is computed using a 3D finite element simulation, then the effective properties are estimated by implementing an optimization process to solve the inverse problem. Results show that composites effective properties are independent of the angle of incidence and wave configuration. This suggests that oblique incidence scenarios can be studied by homogenizing the material based on the case of normal incidence. Journal: Journal of Electromagnetic Waves and Applications Pages: 568-578 Issue: 4 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1975574 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1975574 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:4:p:568-578 Template-Type: ReDIF-Article 1.0 Author-Name: Wei Shen Author-X-Name-First: Wei Author-X-Name-Last: Shen Author-Name: Xian-Bao Ling Author-X-Name-First: Xian-Bao Author-X-Name-Last: Ling Author-Name: Wen-Jing Zou Author-X-Name-First: Wen-Jing Author-X-Name-Last: Zou Author-Name: Shuo Huang Author-X-Name-First: Shuo Author-X-Name-Last: Huang Author-Name: Kai Chen Author-X-Name-First: Kai Author-X-Name-Last: Chen Title: A tri-section substrate integrated waveguide filtering power divider with a wide stopband Abstract: In this article, a substrate integrated waveguide (SIW) power divider with tri-section filtering topology is proposed. Two TE101-mode SIW cavities and one TE102-mode SIW cavity are placed in the upper and lower substrate layers, respectively. Two vertically stacked SIW cavities are excited simultaneously by one section of SIW. The TE102-mode SIW cavity is introduced to achieve 180°- phase conversion. And then, two controllable transmission zeros and a wide stopband can be obtained. Finally, a tri-section SIW filtering power divider sample is fabricated using the printed circuit board (PCB) technology; and good agreements are achieved in the measured and simulated S-parameters. Journal: Journal of Electromagnetic Waves and Applications Pages: 479-487 Issue: 4 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1972843 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1972843 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:4:p:479-487 Template-Type: ReDIF-Article 1.0 Author-Name: Eugene Smolkin Author-X-Name-First: Eugene Author-X-Name-Last: Smolkin Author-Name: Yury Smirnov Author-X-Name-First: Yury Author-X-Name-Last: Smirnov Author-Name: Yury Shestopalov Author-X-Name-First: Yury Author-X-Name-Last: Shestopalov Title: Surface waves in an open circular waveguide filled with inhomogeneous chiral media Abstract: Propagation of surface waves in a radially inhomogeneous chiral waveguide is considered. The setting is reduced to a boundary eigenvalue problem for the longitudinal components of the electromagnetic field in Sobolev spaces. To find the solution, variational formulation is used. The variational problem is reduced to the analysis of an operator-valued function. Discreteness of the spectrum is proved and distribution of the characteristic numbers of the operator-valued function on the complex plane is determined. The results of numerical modeling of the spectrum of propagating surface waves in an open chiral waveguide are presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 505-519 Issue: 4 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1973913 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1973913 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:4:p:505-519 Template-Type: ReDIF-Article 1.0 Author-Name: Shihao Gao Author-X-Name-First: Shihao Author-X-Name-Last: Gao Author-Name: Qunjing Wang Author-X-Name-First: Qunjing Author-X-Name-Last: Wang Author-Name: Guoli Li Author-X-Name-First: Guoli Author-X-Name-Last: Li Author-Name: Zheng Li Author-X-Name-First: Zheng Author-X-Name-Last: Li Title: Optimal design of wireless power transmission system suitable for multi-degree-of-freedom motion devices Abstract: Traditional flat wireless power transmission is charging in a “one-to-one” manner. When the rotation angle of the receiving and transmitting coils is offset, their mutual inductance M and coupling coefficient will decrease. Multi-freedom motor is used in bionics, it is necessary to supply power to the visual acquisition device inside the rotor when rotating, and it is more convenient to use wireless charging instead of wired charging. A receiving structure suitable for moving devices is proposed, which can effectively improve the power transmission efficiency (PTE) when the angle is shifted. In the wireless power transmission, the mutual inductance M and coupling coefficient of the transmitting coil and the single-coil structure, the three-coil structure and its single coil in the rotation are calculated. The advantages and disadvantages of each structure are analyzed. Finally, experiments verify the accuracy and validity of the theory. Journal: Journal of Electromagnetic Waves and Applications Pages: 457-478 Issue: 4 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1972842 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1972842 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:4:p:457-478 Template-Type: ReDIF-Article 1.0 Author-Name: Rahul Kumar Jaiswal Author-X-Name-First: Rahul Kumar Author-X-Name-Last: Jaiswal Author-Name: Kahani Kumari Author-X-Name-First: Kahani Author-X-Name-Last: Kumari Author-Name: Anuj Kumar Ojha Author-X-Name-First: Anuj Kumar Author-X-Name-Last: Ojha Author-Name: Kumar Vaibhav Srivastava Author-X-Name-First: Kumar Vaibhav Author-X-Name-Last: Srivastava Title: Five-port MIMO antenna for n79-5G band with improved isolation by diversity and decoupling techniques Abstract: A compact five-port multi-input multi-output (MIMO) antenna for n79 (4.4–5 GHz) 5G band exhibiting pattern and polarization diversity with good isolation is proposed in this paper. This MIMO antenna system comprises of four linearly polarized (LP) endfire monopole antenna elements and one broadside L-shaped slot circularly polarized (CP) antenna element, which provides both pattern and polarization diversity. A T-shaped slot as a decoupling structure is further used to improve the interport isolation by 4 dB. The return loss bandwidth for all antenna elements is in the desired frequency range, and antenna elements provide isolation better than 23 dB. The pattern and polarization diversity provide a low envelope correlation coefficient and good isolation between any two-port of the MIMO antenna. For experimental verification, the proposed 5-port MIMO antenna system is fabricated and measured, which provides decent agreement with the simulated performance. Journal: Journal of Electromagnetic Waves and Applications Pages: 542-556 Issue: 4 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1975315 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1975315 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:4:p:542-556 Template-Type: ReDIF-Article 1.0 Author-Name: Teddy Purnamirza Author-X-Name-First: Teddy Author-X-Name-Last: Purnamirza Author-Name: M. Bagoes Poerwanto Author-X-Name-First: M. Bagoes Author-X-Name-Last: Poerwanto Author-Name: Dodi Purwanto Author-X-Name-First: Dodi Author-X-Name-Last: Purwanto Author-Name: Muhammad I. Ibrahim Author-X-Name-First: Muhammad I. Author-X-Name-Last: Ibrahim Author-Name: Depriwana Rahmi Author-X-Name-First: Depriwana Author-X-Name-Last: Rahmi Title: The technique to design multibeam Radial Line Slot Array (RLSA) antennas Abstract: The Technique, to design multibeam Radial Line Slot Array (RLSA) antennas optimally, was proposed in this study, using high beam squint values to produce more slots. This is necessary to maintain gain, which dropped due to the beam splitting. A gap was also incorporated between the slots group to overcome a coupling between adjacent beams which can lessen gains. RLSA models for 42 dual and 42 triple-beams were simulated after which a prototype for each was measured to verify the simulation. The results showed the possibility of obtaining multibeam antennas with similar symmetrical beams in terms of beamwidth, gain, and direction. The gains obtained were 13.5 dBi for the dual-beam and 10.5 dBi for the triple-beam, indicating a difference of 3 and 4.77 dB, respectively, with the single-beam antennas, thereby, making them suitable for the theory of beam splitting. The antennas also have sufficient bandwidth and a good reflection coefficient. Journal: Journal of Electromagnetic Waves and Applications Pages: 626-636 Issue: 5 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1978332 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1978332 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:5:p:626-636 Template-Type: ReDIF-Article 1.0 Author-Name: Bao-qin Lin Author-X-Name-First: Bao-qin Author-X-Name-Last: Lin Author-Name: Wenzhun Huang Author-X-Name-First: Wenzhun Author-X-Name-Last: Huang Author-Name: Yongsheng Yang Author-X-Name-First: Yongsheng Author-X-Name-Last: Yang Author-Name: Jianxin Guo Author-X-Name-First: Jianxin Author-X-Name-Last: Guo Author-Name: Lintao Lv Author-X-Name-First: Lintao Author-X-Name-Last: Lv Author-Name: Jintao Zhang Author-X-Name-First: Jintao Author-X-Name-Last: Zhang Title: An ultra-wideband polarization conversion metasurface for RCS reduction Abstract: In this paper, a polarization conversion metasurface is proposed, which can realized ultra-wideband circular polarization (CP) maintaining reflection in the frequency range 7.3–28.7 GHz; in addition, when its unit cell structure is rotated by an angle ψ, almost ±2ψ Pancharatnam-Berry (PB) phase will be generated in its co-polarized reflection coefficient under CP incidence. Thus, base on the polarization conversion metasurface, an ultra-wideband PB 2-dit coding metasurface is further proposed for Radar Cross Section (RCS) reduction. The simulation and experiment results show that the coding metasurface can achieve more than 10 dB RCS reduction in the ultra-wide frequency band 7.2–28.6 GHz under normal incidence with arbitrary polarizations; in addition, when the incident angle is increased to 45°, the ultra-wideband RCS reduction can still be realized, which shows that the coding metasurface has good stealth performance in X, Ku and K bands, and it is very practical for most airborne radar, fire control radar and imaging radar working in these bands. Journal: Journal of Electromagnetic Waves and Applications Pages: 597-606 Issue: 5 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1977185 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1977185 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:5:p:597-606 Template-Type: ReDIF-Article 1.0 Author-Name: M. Vafaei Author-X-Name-First: M. Author-X-Name-Last: Vafaei Author-Name: M. Nejati Author-X-Name-First: M. Author-X-Name-Last: Nejati Author-Name: A. Abdoli-Arani Author-X-Name-First: A. Author-X-Name-Last: Abdoli-Arani Author-Name: A. R. Niknam Author-X-Name-First: A. R. Author-X-Name-Last: Niknam Title: Dispersion properties and beam excitation of symmetric slow waves in helix traveling wave tubes in the presence of plasma Abstract: The propagation of the hybrid slow waves in the new helix traveling wave tube, including a dielectric rod, gas plasma layer, and helix sheath is examined. It is assumed that the plasma is strongly magnetized. The dispersion relation of symmetric hybrid slow waves in this waveguide is obtained. It is shown that the frequency increases by increasing the axial wavenumber and the group velocity of slow waves reduces with increasing the dielectric constant. Moreover, by injecting the electron beam in the vacuum area in the waveguide, the symmetric hybrid slow waves are excited and the influence of various parameters on the growth rate of these waves is examined. Furthermore, therequired parameters such as plasma frequency, dielectric constant, and other geometric parameters for waveguide fabrication are expressed. According to this configuration, the allowed region for the operation of this waveguide and its growth rate and other results are obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 637-654 Issue: 5 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1978333 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1978333 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:5:p:637-654 Template-Type: ReDIF-Article 1.0 Author-Name: Andrey D. Andreev Author-X-Name-First: Andrey D. Author-X-Name-Last: Andreev Author-Name: Liangjie Bi Author-X-Name-First: Liangjie Author-X-Name-Last: Bi Author-Name: Edl Schamiloglu Author-X-Name-First: Edl Author-X-Name-Last: Schamiloglu Title: Dispersion diagrams of linear slow-wave structures. Identification of electromagnetic waves, all electromagnetic waves: forward-traveling, backward-traveling and standing electromagnetic waves Abstract: The analytically calculated dispersion diagram of an overmoded 9-period V-band slow-wave structure (SWS) designed to operate in a high-order transverse-magnetic TM03 waveguide mode of a backward-traveling electromagnetic wave [Ye et al., Phys. Plasmas, 22, 063104 (2015)] is re-examined using the two-dimensional (2D) Poisson SuperFish code allowing to precisely calculate spatial patterns of electric field vectors, wavenumbers and characteristic frequencies of all azimuthally-symmetric TM0nl cavity modes that exist in a closed SWS, where n and l are the radial and axial indices of TM0nl cavity modes, respectively [Main et al., IEEE Trans. Plasma Sci., Vol. 22, No. 5, Oct. 1994, p. 566]. It is shown that the analytically calculated higher-order TM0n waveguide modes of the open SWS are actually not pure TM0n modes, but fascinating combinations of selected portions of the modes with selected portions of all possible lower-order TM0(n-j) waveguide modes, where j=1 … (n-1). An analytically calculated TM03 waveguide mode, therefore, turns out to be in fact a combination of three different TM0n waveguide modes sequentially identified by numerically calculated TM0nl cavity modes: (i) TM03l mode with l=0 … 4, (ii) TM01l mode with l=13 … 11, and (iii) TM02l mode with l=8 … 9. Journal: Journal of Electromagnetic Waves and Applications Pages: 655-668 Issue: 5 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1978872 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1978872 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:5:p:655-668 Template-Type: ReDIF-Article 1.0 Author-Name: Wael Zeinelabedeen Author-X-Name-First: Wael Author-X-Name-Last: Zeinelabedeen Author-Name: Rasime Uyguroglu Author-X-Name-First: Rasime Author-X-Name-Last: Uyguroglu Title: A study on health care monitoring of femoral shaft fracture healing by using implanted antenna for wireless in-to-out body channel communication Abstract: This work proposes a health care monitoring method of femoral fractured bone healing as a novel application, based on the oblique incidence case and transmission of electromagnetic waves. The difference between the transmitted average power densities of normal and fractured bone cases is used to monitor the bone healing status. The study demonstrates the in-to-out body channel characteristics regarding the electromagnetic wave propagation and angle of incidence on a multi-layered human tissue in the range of frequencies from 100 MHz to 10 GHz. The monitoring method is presented by the analysis of electromagnetic wave propagation through a multilayer model and simulated by the CST Microwave studio. Fully insulated planar and meander half-wave dipole antennas are designed and used to simulate both types of bone fracture healing. Results show good monitoring of common types of fractures. Verification is carried out by experimental measurements on non-living animal tissues. Journal: Journal of Electromagnetic Waves and Applications Pages: 722-742 Issue: 5 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1983473 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1983473 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:5:p:722-742 Template-Type: ReDIF-Article 1.0 Author-Name: Peiyu Wu Author-X-Name-First: Peiyu Author-X-Name-Last: Wu Author-Name: Yongjun Xie Author-X-Name-First: Yongjun Author-X-Name-Last: Xie Author-Name: Haolin Jiang Author-X-Name-First: Haolin Author-X-Name-Last: Jiang Author-Name: Toshiaki Natsuki Author-X-Name-First: Toshiaki Author-X-Name-Last: Natsuki Title: Bandpass Crank–Nicolson form with approximation and absorption for nonreciprocal ferrite material Abstract: Due to the unique nonreciprocal characteristic, ferrite exhibits anisotropic behaviour in electric performance. Owing to such special phenomenon, it is difficult to efficiently analyse and simulate the ferrite material. Here, an alternative scheme is proposed for the bandpass ferrite finite-difference time-domain simulation. This algorithm is carried out which is based on approximate Crank–Nicolson procedure and incorporated with the complex method and higher-order formulation. The ferrite material can be calculated by the modified auxiliary differential equation approach according to the bandpass sampling theorem. The introduction of numerical example validates the effectiveness. As shown in the results, the proposed scheme can take advantage of these methods which can be demonstrated from the aspect of accuracy, efficiency and absorption. In addition, the proposed scheme can solve the time increment problem caused by the solution of tri-diagonal matrices during the simulation of implicit algorithms. Journal: Journal of Electromagnetic Waves and Applications Pages: 706-721 Issue: 5 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1980914 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1980914 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:5:p:706-721 Template-Type: ReDIF-Article 1.0 Author-Name: Payel Mondal Author-X-Name-First: Payel Author-X-Name-Last: Mondal Author-Name: Debapratim Dhara Author-X-Name-First: Debapratim Author-X-Name-Last: Dhara Author-Name: A. R. Harish Author-X-Name-First: A. R. Author-X-Name-Last: Harish Title: Enhancement of isolation between two closely spaced patch antennas using inter-digital capacitor and short-circuited stub-based band pass decoupling network Abstract: A novel decoupling network consisting of inter-digital capacitors and a short-circuited stub to improve the isolation of two closely spaced (edge-to-edge separation is 0.013λ0, where λ0 is the resonating frequency) patch antennas is investigated. Before and after the implementation of the proposed decoupling network (DN), the effect on the isolation is explored and the final decoupled structure shows a high isolation of 40 dB at 4.83 GHz. As the proposed structure can provide a good input impedance match after connecting the decoupling network in the system, there is no requirement of additional matching circuitry. Journal: Journal of Electromagnetic Waves and Applications Pages: 669-681 Issue: 5 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1980116 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1980116 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:5:p:669-681 Template-Type: ReDIF-Article 1.0 Author-Name: Stepan Piltyay Author-X-Name-First: Stepan Author-X-Name-Last: Piltyay Author-Name: Andrew Bulashenko Author-X-Name-First: Andrew Author-X-Name-Last: Bulashenko Author-Name: Vadym Shuliak Author-X-Name-First: Vadym Author-X-Name-Last: Shuliak Title: Development and optimization of microwave guide polarizers using equivalent network method Abstract: In this article, we have developed a new mathematical model of a microwave square guide polarization converter with diaphragms. The applied model was created using the microwave theory of equivalent networks. The novelty of the developed theoretical model consists in its possibility to take into account the thickness of the diaphragms. This feature is achieved by using more accurate but complicated T- and Π-shaped equivalent networks. Theoretical analysis and optimization of a guide polarizer were performed using the scattering and transmission matrices of the diaphragms in a square guide. The parametric optimization of a guide polarizer was performed by means of the developed equivalent networks and using finite elements method in the frequency domain. The optimal sizes and electromagnetic characteristics of the polarizer, which were obtained by both methods, are in good agreement. The main advantage of the suggested mathematical model consists in the calculation time reduction. Developed compact waveguide polarizer can be used in modern satellite and radar antenna systems with circular polarization of applied electromagnetic waves. Journal: Journal of Electromagnetic Waves and Applications Pages: 682-705 Issue: 5 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1980913 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1980913 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:5:p:682-705 Template-Type: ReDIF-Article 1.0 Author-Name: Kalyan Sundar Kola Author-X-Name-First: Kalyan Author-X-Name-Last: Sundar Kola Author-Name: R. Kousalya Author-X-Name-First: R. Author-X-Name-Last: Kousalya Author-Name: BNS Mahalakshmi Author-X-Name-First: BNS Author-X-Name-Last: Mahalakshmi Author-Name: Anirban Chatterjee Author-X-Name-First: Anirban Author-X-Name-Last: Chatterjee Title: A high-gain and low cross-polarized wave-fractal shaped printed antenna for DBS application Abstract: This article presents the design of a printed antenna for Direct Broadcast Satellite (DBS) (12.2 – 12.7 GHz) services. The newly designed proposed structure, named as ‘wave-fractal’, is having a considerably high gain and can heavily suppress cross-polarization level along the entire HPBW region. The radiating area of one-quadrant of structure is derived by superimposing six numbers of ‘Golden-ratio’ based squares, and it poses 2D-quadrantal symmetry. In order to resonate the structure at desired frequency, two parallel slots and a circle based defective ground structure is imposed. Furthermore, to achieve a symmetric radiation pattern, a 2D-Octagonal symmetry has been implemented on the proposed structure. The fabricated prototype resonates at 12.49 GHz and gives a gain and x-pol. as 9.52 dBi and −35.36 dB, respectively. The measured impedance bandwidth is 502 MHz, which ensures 100% bandwidth coverage for the DBS band. The measured results make an excellent agreement with its simulated counterpart. Journal: Journal of Electromagnetic Waves and Applications Pages: 607-625 Issue: 5 Volume: 36 Year: 2022 Month: 03 X-DOI: 10.1080/09205071.2021.1978331 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1978331 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:5:p:607-625 Template-Type: ReDIF-Article 1.0 Author-Name: Hossein Davoudabadifarahani Author-X-Name-First: Hossein Author-X-Name-Last: Davoudabadifarahani Author-Name: Behbod Ghalamkari Author-X-Name-First: Behbod Author-X-Name-Last: Ghalamkari Title: Correction to “scattering of electromagnetic plane wave by a PEC strip in homogeneous isotropic chiral medium” Abstract: The aim of this paper is to correct errors of a published study [Afzaal M, Syed A, Imran A, et al. Scattering of electromagnetic plane wave by a PEC strip in homogeneous isotropic chiral medium. Journal of Electromagnetic Waves and Applications. 2014;28(8):999–1010]. The investigation is a prominent and attractive subject in the field of electromagnetic scattering that has studied the electromagnetic scattering from a PEC strip located in the chiral medium; but unfortunately, the errors cause that readers be confused and cannot understand the work. Also, the figures of the paper are incorrect because of the basic errors. The formulation of this investigation is validated by a previously published paper [Davoudabadifarahani H, Ghalamkari B. Analytical solution of electromagnetic scattering by PEMC strip embedded in the chiral medium. Engineering Analysis with Boundary Elements. 2020;113:1–8]. Journal: Journal of Electromagnetic Waves and Applications Pages: 743-747 Issue: 6 Volume: 36 Year: 2022 Month: 4 X-DOI: 10.1080/09205071.2020.1764872 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1764872 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:6:p:743-747 Template-Type: ReDIF-Article 1.0 Author-Name: Zion Menachem Author-X-Name-First: Zion Author-X-Name-Last: Menachem Title: Effective technique for analyzing rectangular helical and toroidal waveguides with a hollow rectangle bounded by dielectrical material and metal boundary Abstract: The main objective of this research is to present an effective technique to solve discontinuous cross section with dielectric material between the hollow rectangle and the metal of rectangular helical and toroidal waveguides. The second objective is to examine the influence of the curved waveguide with the proposed discontinuous cross section on the output field. The proposed technique is based on subtracting a waveguide with dielectric material located at the center of the cross section from a waveguide entirely filled with dielectric material and by using the image method. The method is based on Laplace and Fourier transforms and the inverse Laplace and Fourier transforms. The application can be practical in the laboratory by connecting the rectangular helical and toroidal waveguides to the analyzer spectrum in order to analyze the effect of the proposed curved waveguide with the proposed discontinuous cross section on the behavior of the output field. Journal: Journal of Electromagnetic Waves and Applications Pages: 804-829 Issue: 6 Volume: 36 Year: 2022 Month: 04 X-DOI: 10.1080/09205071.2021.1987336 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1987336 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:6:p:804-829 Template-Type: ReDIF-Article 1.0 Author-Name: Pratik Mevada Author-X-Name-First: Pratik Author-X-Name-Last: Mevada Author-Name: Sanjeev Gupta Author-X-Name-First: Sanjeev Author-X-Name-Last: Gupta Author-Name: Soumyabrata Chakrabarty Author-X-Name-First: Soumyabrata Author-X-Name-Last: Chakrabarty Author-Name: Milind Mahajan Author-X-Name-First: Milind Author-X-Name-Last: Mahajan Title: A novel approach for design of beam steerable aperiodic planar array antenna with reduced number of elements Abstract: This paper introduces the design of an aperiodic beam steerable planar array antenna using a novel strip-projection (SP) method, offering the reduced array elements with improved peak SLL with beam scan. The SP method generates the aperiodic lattice by projecting a section of the 3D body-centric tetragonal lattice onto the aperture and rotating it using Rodrigue's formula. The optimized lattice parameters are obtained using Jaya algorithm. The proposed SP method requires only three optimization parameters for any aperture dimensions and 21.9% less elements as compared to the rectangular lattice. For comparison, pinwheel-based aperiodic planar array antenna has been designed and analyzed. The peak SLL is maintained <−11.63 dB and <−12.70 dB for 0°-30° beam scan by proposed array and pinwheel-based array respectively. Both types of aperiodic lattice have been populated with S-band dielectric resonator antenna and simulated. Position standard deviation has also been introduced and computed to quantify the aperiodic distribution. Journal: Journal of Electromagnetic Waves and Applications Pages: 748-766 Issue: 6 Volume: 36 Year: 2022 Month: 04 X-DOI: 10.1080/09205071.2021.1983474 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1983474 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:6:p:748-766 Template-Type: ReDIF-Article 1.0 Author-Name: Andrew Bulashenko Author-X-Name-First: Andrew Author-X-Name-Last: Bulashenko Author-Name: Stepan Piltyay Author-X-Name-First: Stepan Author-X-Name-Last: Piltyay Author-Name: Ivan Dikhtyaruk Author-X-Name-First: Ivan Author-X-Name-Last: Dikhtyaruk Author-Name: Oleksandr Bulashenko Author-X-Name-First: Oleksandr Author-X-Name-Last: Bulashenko Title: FDTD and wave matrix simulation of adjustable DBS-band waveguide polarizer Abstract: This article presents the results of numerical simulation and optimization of electromagnetic characteristics of a new waveguide polarizer design containing a conducting diaphragm and pins. The theoretical model of a waveguide polarizer with one diaphragm and four pins is developed and applied for the optimization. The main electromagnetic characteristics of the polarizer were obtained based on the elements of general scattering matrix of the designed device. In order to check the performance of the developed mathematical model it was simulated in a software using the finite difference time domain (FDTD) technique. The proposed design of a waveguide polarizer has the ability of fine tuning of its characteristics by mechanical change of the heights of applied pins. Developed theoretical approach and obtained numerical results can be used to develop new tunable waveguide polarizers and filters with diaphragms and pins. Journal: Journal of Electromagnetic Waves and Applications Pages: 875-891 Issue: 6 Volume: 36 Year: 2022 Month: 04 X-DOI: 10.1080/09205071.2021.1995897 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1995897 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:6:p:875-891 Template-Type: ReDIF-Article 1.0 Author-Name: Yang Xie Author-X-Name-First: Yang Author-X-Name-Last: Xie Author-Name: Ningfeng Bai Author-X-Name-First: Ningfeng Author-X-Name-Last: Bai Author-Name: Wei Hong Author-X-Name-First: Wei Author-X-Name-Last: Hong Author-Name: Xiaohan Sun Author-X-Name-First: Xiaohan Author-X-Name-Last: Sun Title: Study of a hexagonal lattice defect photonic crystal waveguide slow wave structure for G-band traveling wave tube Abstract: A defect photonic crystal waveguide (DPCW) slow wave structure (SWS) for G-band traveling wave tube (TWT) is proposed. This DPCW SWS is arrayed in hexagonal lattice with the center defect cells. The TWT based on DPCW SWS operates at 16 kV beam voltage and 120 mA beam current with a 0.6 T focusing magnetic field. A saturated output power of 22.3W, corresponding to a gain of 36.5 dB, is achieved with an input power of 5 mW. The output power is over 10W in a 30 GHz bandwidth. Stable output signal can be achieved without attenuator or sever which shows that the proposed DPCW SWS can depress the oscillation and harmonic in nature. A DPCW SWS sample was fabricated by computer control (CNC) milling, and the measured results show great agreement with the simulation results. Journal: Journal of Electromagnetic Waves and Applications Pages: 843-855 Issue: 6 Volume: 36 Year: 2022 Month: 04 X-DOI: 10.1080/09205071.2021.1988870 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1988870 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:6:p:843-855 Template-Type: ReDIF-Article 1.0 Author-Name: Arshad Karimbu Vallappil Author-X-Name-First: Arshad Author-X-Name-Last: Karimbu Vallappil Author-Name: Mohamad Kamal A. Rahim Author-X-Name-First: Mohamad Kamal Author-X-Name-Last: A. Rahim Author-Name: Bilal A. Khawaja Author-X-Name-First: Bilal Author-X-Name-Last: A. Khawaja Author-Name: Muhammad Naeem Iqbal Author-X-Name-First: Muhammad Naeem Author-X-Name-Last: Iqbal Author-Name: Noor Asniza Murad Author-X-Name-First: Noor Asniza Author-X-Name-Last: Murad Author-Name: Mohamed Musthapa Gajibo Author-X-Name-First: Mohamed Musthapa Author-X-Name-Last: Gajibo Author-Name: Levy O. Nur Author-X-Name-First: Levy Author-X-Name-Last: O. Nur Author-Name: Bambang S. Nugroho Author-X-Name-First: Bambang Author-X-Name-Last: S. Nugroho Title: Complementary split-ring resonator and strip-gap based metamaterial fractal antenna with miniature size and enhanced bandwidth for 5G applications Abstract: This paper proposes two different types of metamaterial (MTM) antennas for fifth-generation (5G) mid-band frequency operation. The radiating patch of the proposed antenna is based on the combined Minkowski-Sierpinski carpet fractal structure. On the ground plane, two different types of MTM structures: Complementary split-ring resonator (CSRR), and Strip-gap are etched to enhance the overall bandwidth and gain of the antenna. The introduction of these structures on the ground plane also leads to antenna miniaturization. Both the proposed MTM structure based antennas resonate at 3.5GHz. The overall size of the two fabricated prototypes is 28×29.5 mm2 / 28×28.5 mm2, which shows the compactness of the proposed design by 43% / 42% as compared to the conventional microstrip patch antenna (MPA). The measured bandwidth/gain achieved by the proposed combined Minkowski-Sierpinski carpet fractal antenna (CMSFA) having CSRR MTM and strip-gap etched on the ground plane are 370 MHz / 2.42dBi and 440 MHz / 3.75dBi, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 787-803 Issue: 6 Volume: 36 Year: 2022 Month: 04 X-DOI: 10.1080/09205071.2021.1983878 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1983878 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:6:p:787-803 Template-Type: ReDIF-Article 1.0 Author-Name: Naveen Gupta Author-X-Name-First: Naveen Author-X-Name-Last: Gupta Author-Name: Sanjeev Kumar Author-X-Name-First: Sanjeev Author-X-Name-Last: Kumar Author-Name: S. B. Bhardwaj Author-X-Name-First: S. B. Author-X-Name-Last: Bhardwaj Title: Stimulated Raman scattering of self focused elliptical q-Gaussian laser beam in plasma with axial temperture ramp: effect of ponderomotive force Abstract: The phenomenon of stimulated Raman scattering (SRS) of elliptical q-Gaussian laser beams interacting nonlinearly with underdense plasmas has been investigated theoretically. Using variational theory semi analytical solutions of the coupled nonlinear wave equations for the three waves (pump, EPW and scattered) have been obtained under W.K.B approximation technique. The equations so obtained have been solved numerically to envision the effects of laser as well as plasma parameters on the dynamics of pump beam and further its effect on the power of scattered wave. It has been observed that power of the scattered wave is significantly affected by the self focusing effect of pump beam. Journal: Journal of Electromagnetic Waves and Applications Pages: 767-786 Issue: 6 Volume: 36 Year: 2022 Month: 04 X-DOI: 10.1080/09205071.2021.1983877 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1983877 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:6:p:767-786 Template-Type: ReDIF-Article 1.0 Author-Name: N. C. Pradhan Author-X-Name-First: N. C. Author-X-Name-Last: Pradhan Author-Name: S. S. Karthikeyan Author-X-Name-First: S. S. Author-X-Name-Last: Karthikeyan Author-Name: R. K. Barik Author-X-Name-First: R. K. Author-X-Name-Last: Barik Author-Name: Q. S. Cheng Author-X-Name-First: Q. S. Author-X-Name-Last: Cheng Title: A novel compact diplexer employing substrate integrated waveguide loaded by triangular slots for C-band application Abstract: This article presents a novel design of compact Substrate Integrated Waveguide (SIW) filters loaded with a triangular slot. First, the filtering response is obtained by loading a triangular slot on the top of the SIW cavities. Later, these SIW filter structures are cascaded to develop a SIW planar diplexer. To achieve lower and upper channels of the diplexer, two SIW cavity-backed filters loaded with triangular slots are excited with in-line feedings. To demonstrate the analysis, the proposed SIW diplexer has been simulated, fabricated, and tested. The measured S-parameters are in good agreement with the simulated results, showing the lower and upper passband insertion losses based at 6.2 GHz and 7.75 GHz are obtained as 0.87 dB and 0.75 dB including the losses from both the SMA connectors, respectively. The fractional bandwidth (FBW) is more than 5.1% at each passband with high isolation better than 22 dB. The fabricated prototype has a compact size of 0.88 ( $ \lambda _g^2 $ λg2). Journal: Journal of Electromagnetic Waves and Applications Pages: 830-842 Issue: 6 Volume: 36 Year: 2022 Month: 04 X-DOI: 10.1080/09205071.2021.1987991 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1987991 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:6:p:830-842 Template-Type: ReDIF-Article 1.0 Author-Name: Phan Van Hung Author-X-Name-First: Phan Van Author-X-Name-Last: Hung Author-Name: Nguyen Quoc Dinh Author-X-Name-First: Nguyen Quoc Author-X-Name-Last: Dinh Author-Name: Yoshihide Yamada Author-X-Name-First: Yoshihide Author-X-Name-Last: Yamada Title: Negative refractive index-shaped lens antenna with straight line condition for wide angle beam scanning Abstract: For a base station antenna in 5G mobile communications, lens antennas have been proposed for excellent multiple beam performances. In this paper, the negative refractive index (NRI) lens is selected for thinning the lens thickness. By applying lens shaping method, straight-line condition lens is designed. Multi beam radiation characteristics are compared with the conventional hyperbolic shape lens and Abbe's sine condition lens. In order to determine the feed positions for multi beam performances, the focal region ray tracing is performed. The best feed positions are obtained. For calculating multi beam radiation characteristics, ANSYS HFSS software is employed. Multi beam radiation patterns in the wide angle scanning up to 45° are obtained. The results show that the proposed straight-line condition lens achieves higher gain and lower sidelobe level compared to the other two structures. The usefulness of the proposed lens antenna is ensured. Journal: Journal of Electromagnetic Waves and Applications Pages: 856-874 Issue: 6 Volume: 36 Year: 2022 Month: 04 X-DOI: 10.1080/09205071.2021.1990801 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1990801 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:6:p:856-874 Template-Type: ReDIF-Article 1.0 Author-Name: Ubaid ur Rahman Qureshi Author-X-Name-First: Ubaid ur Rahman Author-X-Name-Last: Qureshi Author-Name: Moazam Maqsood Author-X-Name-First: Moazam Author-X-Name-Last: Maqsood Author-Name: Muhammad Amin Author-X-Name-First: Muhammad Author-X-Name-Last: Amin Author-Name: Abdur Rahman Maud Author-X-Name-First: Abdur Rahman Author-X-Name-Last: Maud Author-Name: Nosherwan Shoaib Author-X-Name-First: Nosherwan Author-X-Name-Last: Shoaib Title: A boomerang-shaped UWB antenna for spectrum sensing Abstract: A boomerang-shaped ultra wide band (UWB) planar antenna has been presented for spectrum sensing applications. The presented antenna has been built upon a narrow band isotropic antenna design. In order to achieve a wider bandwidth, an exponential profile (similar to log spiral) is used. Simulation results show that the antenna has an impedance bandwidth of 163% (1.3–12 GHz) for VSWR≤2 with good radiation properties. In order to quantify the antenna performance, antenna radiation pattern and efficiency have been compared with previously reported designs. It is shown that the proposed design is able to achieve nearly omnidirectional patterns in more than one planes while achieving a maximum radiation efficiency of 92%. The overall dimensions of the proposed design are $ 193.6\,{\rm mm} \times 196.5 $ 193.6mm×196.5 mm. The prototype of the proposed antenna is manufactured using FR4 substrate ( $ \varepsilon _\mathrm {r} = 4.4 $ εr=4.4, h = 1.6 mm). Journal: Journal of Electromagnetic Waves and Applications Pages: 977-993 Issue: 7 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.1996281 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1996281 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:7:p:977-993 Template-Type: ReDIF-Article 1.0 Author-Name: El Khamlichi Dahbi Author-X-Name-First: El Khamlichi Author-X-Name-Last: Dahbi Author-Name: Tajeddin Elhamadi Author-X-Name-First: Tajeddin Author-X-Name-Last: Elhamadi Author-Name: Naima Amar Touhami Author-X-Name-First: Naima Author-X-Name-Last: Amar Touhami Title: Optimization of the SIW cavity-backed slots antenna for X-band applications using the Particle Swarm Optimization algorithm Abstract: Substrate Integrated Waveguide (SIW) technology has recently drawn attention to its microwave benefits, such as integration into planar microwave circuits, low manufacturing cost and high-quality factor compared to other voluminous technologies. In this paper, a cavity-backed slot antenna structure has been designed and optimised by the Particle Swarm Optimization (PSO) algorithm and manufactured for X-band applications. Indeed, the starting cavity-backed slot antenna has three pairs of resonators placed on the lower wall of the cavity, and the PSO algorithm seeks the optimal antenna by automating HFSS using MATLAB script. Two antennas have been chosen from the last PSO generation. The selected antennas operate respectively on the bands [9.17 GHz. 10.63 GHz] and [9.09 GHz, 10.6 GHz] with a bandwidth of 15%, and can achieve a maximum gain of 8.8 dBi. The total size of the proposed design is $ 0.46{\lambda _0} \times 1.95{\lambda _0} $ 0.46λ0×1.95λ0. The gain, reflection coefficient and radiation partners are measured and compared to the EM simulation results and a very good agreement is obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 928-939 Issue: 7 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.1996278 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1996278 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:7:p:928-939 Template-Type: ReDIF-Article 1.0 Author-Name: Shuvodip Majumdar Author-X-Name-First: Shuvodip Author-X-Name-Last: Majumdar Author-Name: Amitabha Bhattacharya Author-X-Name-First: Amitabha Author-X-Name-Last: Bhattacharya Title: A heuristic method to calculate the field diffracted from a double-layered dielectric wedge Abstract: Double-layered dielectric wedges (e.g. forest or snow-covered hills, building corners with vertical gardens) are quite common obstacles that appear in radio-wave propagation channels. This article presents a heuristic method to obtain the field diffracted from a double-layered dielectric wedge. Though it uses a framework that appeared in an earlier publication, it improves upon the issue of complexity. The method proposed here reduces the requirement of solving nonlinear equations to half and makes the process substantially less time-consuming without compromising the accuracy. Hence this improvement makes the method more useful for real-time usage in emergency situations. Apart from this advantage on time consumption, this method also improves upon the memory consumption and limit of validity. Journal: Journal of Electromagnetic Waves and Applications Pages: 964-976 Issue: 7 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.1996280 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1996280 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:7:p:964-976 Template-Type: ReDIF-Article 1.0 Author-Name: Narinder Sharma Author-X-Name-First: Narinder Author-X-Name-Last: Sharma Author-Name: Sumeet Singh Bhatia Author-X-Name-First: Sumeet Singh Author-X-Name-Last: Bhatia Title: Design of antenna by amalgamating staircase and hexagonal ring-shaped structures with the modified ground plane for multi-standard wireless applications Abstract: In this article, an antenna has been designed by amalgamating staircase structure on hexagonal ring-shaped geometry using the modified ground plane for multi-standard wireless applications. The proposed antenna is compact in size with volumetric dimension of 24 × 30 × 1.6 mm3 and designed on a low-cost FR4 glass epoxy substrate. Initially, the partial ground plane is being used, and antenna reports an impedance bandwidth of 2.64, 0.96, 0.59 and 1.24 GHz at the respective frequency ranges. Furthermore, the ground plane of the proposed antenna is modified by introducing stubs and parasitic elements to improve the performance parameters such as bandwidth and reflection coefficient. The final geometry of antenna reveals the enhanced bandwidth of 3.04 GHz (1.55–4.59 GHz), 930 MHz (5.19–6.12 GHz) and 3.92 GHz (7.0–10.92 GHz). Also, the proposed antenna resonates at four frequency bands of 3.0, 5.7, 8.5 and 10.1 GHz with the corresponding reflection coefficient of −32.17, −38.37, −46.0 and −28.61 dB. Thus, the final optimized structure is also being fabricated for the authentication of simulated results. Both the results are compared and found in agreement with each other. The rest of the parameters such as gain, radiation efficiency and radiation patterns are analyzed and found satisfactory for the wireless operations. Due to the wider bandwidth and proper impedance matching in the desired frequency ranges, the proposed antenna can be considered as a proficient candidate for distinct wireless applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 893-911 Issue: 7 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.1995898 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1995898 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:7:p:893-911 Template-Type: ReDIF-Article 1.0 Author-Name: I.V. Donets Author-X-Name-First: I.V. Author-X-Name-Last: Donets Author-Name: A.M. Lerer Author-X-Name-First: A.M. Author-X-Name-Last: Lerer Author-Name: Zi Meng Li Author-X-Name-First: Zi Meng Author-X-Name-Last: Li Author-Name: V.A. Sledkov Author-X-Name-First: V.A. Author-X-Name-Last: Sledkov Author-Name: S.M. Tsvetkovskaya Author-X-Name-First: S.M. Author-X-Name-Last: Tsvetkovskaya Title: Electrodynamic analysis method of a photon crystal consisting of perfectly conducting hollow 3d cylinders Abstract: A strict, effective electrodynamic method for analysing three-dimensional periodic lattices made of hollow metal cylinders with walls of finite thickness has been developed. The software developed has high accuracy and short computing time. It is used to find the dependences of the delays of eigenwaves on dimensions of the lattices and cylinders (length, diameter, wall thickness) for different directions of propagation and polarization of the wave. Analysis of rectangular and hexagonal lattices is performed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1020-1042 Issue: 7 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.1999860 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1999860 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:7:p:1020-1042 Template-Type: ReDIF-Article 1.0 Author-Name: Meha Agrawal Author-X-Name-First: Meha Author-X-Name-Last: Agrawal Author-Name: Trivesh Kumar Author-X-Name-First: Trivesh Author-X-Name-Last: Kumar Title: SIW-based enhanced gain self-diplexing antenna using higher order modes Abstract: A self-diplexing antenna using slot-loaded cavity-backed Substrate Integrated Waveguide (CB-SIW) is presented with the enhanced gain. Higher-order modes (TE130 and TE310) in a square-shaped SIW cavity are utilized to emit linear and orthogonally polarized radiation with gain enhancement. Two concentric square ring slots are etched on the top conducting layer of the cavity to achieve broadside radiation. The asymmetric width of the outer square ring slot helps in achieving two different resonant frequencies at TE130 and TE310 modes. The proposed antenna is verified by observing a good match between the simulated and measured results. An excellent self-diplexing characteristic is achieved by getting isolation better than 28.0 dB between the two ports for a large tuning range. The proposed antenna radiates unidirectionally at two close frequencies 11.4 GHz and 12.2 GHz exhibiting gain of 9.8 dBi and 9.15dBi, respectively. In addition, the proposed design is single-layered, easy to fabricate as compared to traditional diplexing antennas. Journal: Journal of Electromagnetic Waves and Applications Pages: 912-927 Issue: 7 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.1995899 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1995899 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:7:p:912-927 Template-Type: ReDIF-Article 1.0 Author-Name: Shriman Narayana Author-X-Name-First: Shriman Author-X-Name-Last: Narayana Author-Name: Nagendra Kumar Author-X-Name-First: Nagendra Author-X-Name-Last: Kumar Author-Name: Yatendra Kumar Singh Author-X-Name-First: Yatendra Author-X-Name-Last: Kumar Singh Title: Constant absolute bandwidth third-order tunable bandpass filter with reconfigurable bandwidth using single λ/2 resonator Abstract: This paper presents a third-order bandpass filter with bandwidth tuning and constant bandwidth center frequency tuning. Based on the analysis of modal voltage waveforms of a varactor-terminated half-wavelength microstrip line, a varactor is loaded at the center to control even modes, four varactors are loaded between two symmetric specific positions to tune, only, odd modes and two varactors at the ends to tune both the even and odd modes. Using these varactors, the passband is formed by bringing the first even and second, third odd modes close to each other. To keep the bandwidth of the passband constant, these three modes are controlled separately. The S-matrix has been derived to analyze and the coupling matrix has been synthesized to design the filter for a specification. An example filter has been designed and fabricated whose band can be tuned from 1.0 to 1.45  GHz (36.73 $ \% $ %) with absolute bandwidth of 260 MHz and bandwidth is tunable from 130 to 490 MHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 940-963 Issue: 7 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.1996279 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1996279 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:7:p:940-963 Template-Type: ReDIF-Article 1.0 Author-Name: Thi Duyen Bui Author-X-Name-First: Thi Duyen Author-X-Name-Last: Bui Author-Name: Hong Son Vu Author-X-Name-First: Hong Son Author-X-Name-Last: Vu Author-Name: Quoc Cuong Nguyen Author-X-Name-First: Quoc Cuong Author-X-Name-Last: Nguyen Author-Name: Minh Thuy Le Author-X-Name-First: Minh Thuy Author-X-Name-Last: Le Title: Smart antenna with circular polarization for high accuracy indoor localization system Abstract: This article presents a new switched beam antenna (SBA) for indoor localization applications. The SBA consists of seven circularly polarized (CP) element antennas using a novel feeding network. The attractive characteristics of the proposed CP antenna are high gain, wide bandwidth (BW) with the BW of 36.2% at the reflection coefficient less than −10 dB (4.6–6.7 GHz), the 3 dB axial ratio (AR) BW of 22.4% (5.4–6.7 GHz), wide 3 dB AR beamwidth as about 60 degrees, and maximum gain of 9 dBi within the total bandwidth. Experimental results show good agreement with simulated ones in terms of radiation pattern, AR, and reflection coefficient. We proposed a low-cost and simple RF-based indoor localization system based on a single anchor node equipped with this SBA. The system is demonstrated through experimental validations in a 6 m × 6.5 m × 3.5 m office room with a mean localization error of 0.72 m. Journal: Journal of Electromagnetic Waves and Applications Pages: 994-1007 Issue: 7 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.1997650 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1997650 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:7:p:994-1007 Template-Type: ReDIF-Article 1.0 Author-Name: Rajan Agrahari Author-X-Name-First: Rajan Author-X-Name-Last: Agrahari Author-Name: Akhlesh Lakhtakia Author-X-Name-First: Akhlesh Author-X-Name-Last: Lakhtakia Author-Name: Pradip Kumar Jain Author-X-Name-First: Pradip Author-X-Name-Last: Kumar Jain Author-Name: Somak Bhattacharyya Author-X-Name-First: Somak Author-X-Name-Last: Bhattacharyya Title: Pixelated metasurfaces for linear-polarization conversion and absorption Abstract: Terahertz metasurfaces with pixelated meta-atoms were designed for linear-polarization conversion and absorption. The differences between the two functionalities emerged from the number and arrangement of metal-dielectric combos patching some but not necessarily every pixel of each meta-atom. A patching arrangement for a meta-atom with $ 3\times 3 $ 3×3 pixels yielded polarization conversion ratio (PCR) $ { \gt }0.9 $ >0.9 over the 10.20–16.08 THz band, whereas another yielded absorptance (A) $ { \gt }0.9 $ >0.9 over the 27.67–28.73 THz band. A third patching arrangement delivered both functionalities, albeit in different spectral regimes: high PCR and high A at 13.92 THz and 29.1 THz, respectively. The spatial profiles of the electric and magnetic fields in each meta-atom suffice to explain the display of these functionalities. The generality of the pixelated meta-atom approach was supported by a meta-atom with $ 4\times 4 $ 4×4 pixels. Journal: Journal of Electromagnetic Waves and Applications Pages: 1008-1019 Issue: 7 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.1998928 File-URL: http://hdl.handle.net/10.1080/09205071.2021.1998928 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:7:p:1008-1019 Template-Type: ReDIF-Article 1.0 Author-Name: Ying Luo Author-X-Name-First: Ying Author-X-Name-Last: Luo Author-Name: Qun Zhang Author-X-Name-First: Qun Author-X-Name-Last: Zhang Author-Name: Chengwei Qiu Author-X-Name-First: Chengwei Author-X-Name-Last: Qiu Author-Name: Tat Soon Yeo Author-X-Name-First: Tat Soon Author-X-Name-Last: Yeo Title: Micro-motion feature extraction of target in inverse synthetic aperture radar imaging with sparse aperture Abstract: Micro-motion features are very useful for target recognition in inverse synthetic aperture radar (ISAR). In this paper, we propose an effective algorithm for micro-motion feature extraction in ISAR imaging with sparse aperture. The micro-Doppler effect induced by rotational micro-motion in ISAR with sparse aperture is analysed first, and then an improved four-parameter Hough transform and an Orthogonal matching pursuit decomposition method are proposed to extract the micro-motion parameters, such as rotation rate and radius. Simulations are given to demonstrate the effectiveness of the proposed algorithm. Journal: Journal of Electromagnetic Waves and Applications Pages: 1841-1849 Issue: 14 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.825890 File-URL: http://hdl.handle.net/10.1080/09205071.2013.825890 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:14:p:1841-1849 Template-Type: ReDIF-Article 1.0 Author-Name: H.A. Shaban Author-X-Name-First: H.A. Author-X-Name-Last: Shaban Author-Name: M. Abou El-Nasr Author-X-Name-First: M. Author-X-Name-Last: Abou El-Nasr Title: Improved lower bounds on ranging accuracy of rectangular template-based UWB correlation radar for vital sign monitoring Abstract: This paper proposes and investigates low-power rectangular ultra wideband (UWB) correlation-based radars for vital sign monitoring with a target ranging accuracy of 0.08 mm. The lower bounds on the time-of-arrival estimation error are studied. In particular, we study and compare the improved Ziv-Zakai lower bound of rectangular template-based estimators to the corresponding optimal estimators via semi-analytic simulations in the UWB IEEE 802.15.6a CM #3 channel and a simulated channel model based on actual on-body measurements. We show that the investigated radar achieves the target ranging accuracy at a signal-to-noise-ratio (SNR) = 40 dB. Also, we study the effect of template pulse misalignment on the proposed estimators. We provide theoretical as well as numerical results based on semi-analytic simulations in the IEEE 802.15.6a UWB channels. A link budget is designed for the achievement of the target SNR with a link margin = 3 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 355-364 Issue: 3 Volume: 27 Year: 2013 Month: 2 X-DOI: 10.1080/09205071.2013.746631 File-URL: http://hdl.handle.net/10.1080/09205071.2013.746631 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:3:p:355-364 Template-Type: ReDIF-Article 1.0 Author-Name: J.A. Brandão Faria Author-X-Name-First: J.A. Author-X-Name-Last: Brandão Faria Title: Reformulation of magnetic transmission line theory using magnetic charges, magnetic currents, and magnetic voltages Abstract: Transmission line structures are commonly used to support guided wave propagation. To that end, ordinary transmission lines utilize two parallel electric wires of very high conductivity. Very recently, another option has emerged, the so-called magnetic transmission line (MGTL), which utilizes two parallel magnetic wires of very high permeability. The theory of magnetic transmission lines is not completely settled; adjustments are still needed, and its own vocabulary requires some tuning as well. In this paper, new grounds are established for MGTL theory, encompassing two-wire and multiwire systems. For that purpose, the new concepts of magnetic charge, magnetic current, and magnetic voltage are introduced and discussed. These conceptual tools are made use not only to describe field equations in the transverse plane, but also field-wave equations in the propagation direction. With these new tools, the duality between electric and magnetic transmission line analysis becomes self-evident. Journal: Journal of Electromagnetic Waves and Applications Pages: 2145-2154 Issue: 17 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.833860 File-URL: http://hdl.handle.net/10.1080/09205071.2013.833860 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:17:p:2145-2154 Template-Type: ReDIF-Article 1.0 Author-Name: W.-J. Liu Author-X-Name-First: W.-J. Author-X-Name-Last: Liu Author-Name: M. Lei Author-X-Name-First: M. Author-X-Name-Last: Lei Title: Analytic study on amplification of solitons in inhomogeneous optical fibers Abstract: An analytic study on soliton amplification in inhomogeneous optical fibers is presented in this paper. By use of the Hirota method, the bilinear forms for the nonlinear Schrödinger equation, which describes the soliton propagation in inhomogeneous optical fibers, are obtained. The analytic soliton solutions are derived with symbolic computation. According to the solution obtained, the solitons are amplified without the pedestals, and the technique permit high-quality amplification of solitons, which to our knowledge has not been reported before. The physical effects affecting soliton amplification are discussed. The gain of the amplifier, the soliton velocity and phase can be adjusted with two arbitrary parameters. The influences of group-velocity dispersion and Kerr nonlinearity on soliton amplification are studied. With the different values of group-velocity dispersion and Kerr nonlinearity, amplification of solitons in inhomogeneous optical fibers can be controlled. The results of this paper provide a simple and efficient approach to amplify solitons in the communication systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 884-889 Issue: 7 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.789413 File-URL: http://hdl.handle.net/10.1080/09205071.2013.789413 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:7:p:884-889 Template-Type: ReDIF-Article 1.0 Author-Name: Huiping Tian Author-X-Name-First: Huiping Author-X-Name-Last: Tian Author-Name: Lamei Zhao Author-X-Name-First: Lamei Author-X-Name-Last: Zhao Author-Name: Qun Luo Author-X-Name-First: Qun Author-X-Name-Last: Luo Author-Name: Jiatian Huang Author-X-Name-First: Jiatian Author-X-Name-Last: Huang Author-Name: Yuefeng Ji Author-X-Name-First: Yuefeng Author-X-Name-Last: Ji Title: Wideband quasi-isotropic H-shaped slot fractal UC-EBGs with alternately arranged symmetrical unit cells Abstract: The arrangement of the alternately symmetrical unit cells of an H-shaped slot fractal uniplanar electromagnetic bandgap structure (HSF-UC-EBGs) is investigated in this study. It is shown that different bandgap characteristics can be obtained when the unit cells are arranged in different ways. Two bandgaps of 1.30–2.52 and 2.85–3.76 GHz are obtained when 5 unit cells are arranged along x direction, while a bandgap of 2.30–4.78 GHz is obtained when 5 unit cells are arranged along y direction. Therefore, one can predict that when the symmetrical unit cells and the 90° rotated symmetrical unit cells are arranged alternately, the bandgap will extend to the sum of the three bandgaps mentioned previously. Based on the study described previously, we design an ultra-wideband quasi-isotropic HSF-UC-EBGs and the measured results show that its relative bandwidth reach up to at least 105.4% GHz at 3.32 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 962-968 Issue: 8 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.793621 File-URL: http://hdl.handle.net/10.1080/09205071.2013.793621 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:8:p:962-968 Template-Type: ReDIF-Article 1.0 Author-Name: C.-Y. Li Author-X-Name-First: C.-Y. Author-X-Name-Last: Li Author-Name: J.-X. Chen Author-X-Name-First: J.-X. Author-X-Name-Last: Chen Author-Name: H. Tang Author-X-Name-First: H. Author-X-Name-Last: Tang Author-Name: L.-H. Zhou Author-X-Name-First: L.-H. Author-X-Name-Last: Zhou Author-Name: J. Shi Author-X-Name-First: J. Author-X-Name-Last: Shi Author-Name: Z.-H. Bao Author-X-Name-First: Z.-H. Author-X-Name-Last: Bao Title: Tri-band bandpass filter with wide stop-band using stub-loaded triple-mode resonator Abstract: A novel microstrip tri-band bandpass filter (BPF) based on stub-loaded triple-mode resonator is proposed. The open- and short-circuited stubs are asymmetrically loaded to a uniform impedance open-loop resonator, constructing a triple-mode resonator. Benefiting from the proposed asymmetrical loading scheme, the designed tri-band BPF not only possesses the controllable bandwidths of the three passbands, but also shows very wide stopband. Finally, a tri-band microstrip BPF with good performance is designed at 1.5, 2.57, and 3.83 GHz. Three transmission zeros near the passbands are obtained to improve the selectivity of the tri-band BPF. Meanwhile, the other transmission zeros produced in the stopband enhance the harmonic suppression level. The rejection level from 4.3 to 13.7 GHz is better than 20 dB. The measured results are in good agreement with the simulated data. Journal: Journal of Electromagnetic Waves and Applications Pages: 439-447 Issue: 4 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.748638 File-URL: http://hdl.handle.net/10.1080/09205071.2013.748638 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:4:p:439-447 Template-Type: ReDIF-Article 1.0 Author-Name: H. Choe Author-X-Name-First: H. Author-X-Name-Last: Choe Author-Name: S. Lim Author-X-Name-First: S. Author-X-Name-Last: Lim Title: Diversity and directivity mode-switchable planar antenna by stacking and unfolding four antenna elements Abstract: A novel diversity and directivity mode-switchable planar antenna is presented. The antenna structure consists of four circular antenna elements. In the diversity mode, the four elements are unfolded on a plane for polarization diversity. Because of the orthogonal arrangement of the four elements, good diversity performance can be achieved. The antenna function is changed to directivity mode when the four elements are folded and stacked. Each element works as a reflector, a driver, and a director, as seen in the Yagi-Uda antenna principle, indicating that the antenna represents high directivity. A bent feed line and two methods of feeding are used to improve the directivity, for which a 4.5-dB greater peak gain is achieved than with the diversity mode. At 2.4 GHz, the antenna simulation results are consistent with the measurement results, and the performance is successfully proven. Journal: Journal of Electromagnetic Waves and Applications Pages: 978-988 Issue: 8 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.794717 File-URL: http://hdl.handle.net/10.1080/09205071.2013.794717 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:8:p:978-988 Template-Type: ReDIF-Article 1.0 Author-Name: Hai-Feng Zhang Author-X-Name-First: Hai-Feng Author-X-Name-Last: Zhang Author-Name: Shao-Bin Liu Author-X-Name-First: Shao-Bin Author-X-Name-Last: Liu Author-Name: Xiang-Kun Kong Author-X-Name-First: Xiang-Kun Author-X-Name-Last: Kong Title: Analysis of Voigt effects in dispersive properties for tunable three-dimensional face-centered-cubic magnetized plasma photonic crystals Abstract: The Voigt effects in dispersive properties of three-dimensional magnetized plasma photonic crystals (magnetized plasma spheres immersed in dielectric background), composed of homogeneous dielectric and magnetized plasma with face-centered-cubic lattices are theoretically investigated based on the plane wave expansion method, as incidence electromagnetic wave vector is perpendicular to the external magnetic field. The equations for calculating the band diagrams are theoretically deduced. The influences of dielectric constant of dielectric, plasma collision frequency, filling factor, plasma cyclotron frequency, and plasma frequency on the dispersive properties are studied in detail, respectively, and some corresponding physical explanations are also given. From the numerical results, it has been shown that the photonic band gap (PBG) can be manipulated by plasma frequency, filling factor, plasma cyclotron frequency, and the relative dielectric constant of dielectric, respectively. However, the plasma collision frequency has no effects on the location and relative bandwidth of the PBG. The locations of two flatbands regions cannot be tuned by any parameters except for plasma frequency and plasma cyclotron frequency. Journal: Journal of Electromagnetic Waves and Applications Pages: 1276-1292 Issue: 10 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.805436 File-URL: http://hdl.handle.net/10.1080/09205071.2013.805436 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:10:p:1276-1292 Template-Type: ReDIF-Article 1.0 Author-Name: Xiang-kun Kong Author-X-Name-First: Xiang-kun Author-X-Name-Last: Kong Author-Name: Shao-bin Liu Author-X-Name-First: Shao-bin Author-X-Name-Last: Liu Author-Name: Hai-feng Zhang Author-X-Name-First: Hai-feng Author-X-Name-Last: Zhang Author-Name: Bo-rui Bian Author-X-Name-First: Bo-rui Author-X-Name-Last: Bian Author-Name: Hui-chao Zhao Author-X-Name-First: Hui-chao Author-X-Name-Last: Zhao Author-Name: Huan Yang Author-X-Name-First: Huan Author-X-Name-Last: Yang Title: A broadband omnidirectional absorber based on a hetero-structure composed of a collision plasma and a ternary plasma Bragg mirror Abstract: A broadband omnidirectional absorber which is realized by heterostructures containing a collision plasma layer and a ternary plasma Bragg mirror is theoretically investigated. A collision plasma layer and an appropriate dielectric layer are put on the top of the ternary plasma photonic crystals to obtain a broadband omnidirectional absorption. It is shown to absorb roughly 70% of all available electromagnetic wave in a relative omnidirectional absorption band width 0.58 GHz with plasma width 3 mm in PCs. The band edges are impacted by the range of reflection band gap and the absorption range for transverse magnetic (TM) wave decreases at large incidence. Compared with some previous designs, our proposed structure has a relative flatter total absorption spectrum over a broad frequency range in microwave. This kind of hererostructures offer additional opportunities to design novel optoelectronic devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 945-952 Issue: 8 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.792753 File-URL: http://hdl.handle.net/10.1080/09205071.2013.792753 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:8:p:945-952 Template-Type: ReDIF-Article 1.0 Author-Name: Yang Ding Author-X-Name-First: Yang Author-X-Name-Last: Ding Author-Name: Yong-Chang Jiao Author-X-Name-First: Yong-Chang Author-X-Name-Last: Jiao Author-Name: Biao Li Author-X-Name-First: Biao Author-X-Name-Last: Li Author-Name: Peng Fei Author-X-Name-First: Peng Author-X-Name-Last: Fei Title: Band-notched printed log-periodic dipole antennas using loaded slots pair (LSP) resonators Abstract: Novel printed log-periodic dipole antennas (PLPDAs) with 3.5/5.5 GHz dual band-notched characteristics are investigated in this paper. The proposed antennas are comprised of a modified ground plane etched with rectangular slots, which are capable of tailoring the input impedance. Loaded slots pair (LSP) resonators are cut in the radiators to achieve band-notch mechanism. By etching several pairs of U-shaped LSPs on the radiation structure of the PLPDA, multiple notched bands are generated for blocking the interference from other narrow band wireless communication systems. Antennas with the notched-band of World Interoperability for Microwave Access/Wireless Local Area Network operating frequencies are designed and fabricated. The measured impedance bandwidth defined by voltage standing wave ratios <2 of 8.0 GHz (3.0–11 GHz), with the dual notched bands of 3.3–3.6 and 5.0–6.0 GHz, is obtained. Measured and simulated reflection coefficient curves are provided along with normalized beam patterns, gain and group delay values as a function of frequency. Journal: Journal of Electromagnetic Waves and Applications Pages: 1949-1958 Issue: 15 Volume: 27 Year: 2013 Month: 10 X-DOI: 10.1080/09205071.2013.829757 File-URL: http://hdl.handle.net/10.1080/09205071.2013.829757 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:15:p:1949-1958 Template-Type: ReDIF-Article 1.0 Author-Name: M. Abou El-Nasr Author-X-Name-First: M. Author-X-Name-Last: Abou El-Nasr Author-Name: P.K. Choudhury Author-X-Name-First: P.K. Author-X-Name-Last: Choudhury Title: Electromagnetics: driving the future Journal: Journal of Electromagnetic Waves and Applications Pages: 1587-1588 Issue: 13 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.827410 File-URL: http://hdl.handle.net/10.1080/09205071.2013.827410 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:13:p:1587-1588 Template-Type: ReDIF-Article 1.0 Author-Name: F. Liang Author-X-Name-First: F. Author-X-Name-Last: Liang Author-Name: G. Wang Author-X-Name-First: G. Author-X-Name-Last: Wang Author-Name: R. Wang Author-X-Name-First: R. Author-X-Name-Last: Wang Author-Name: D. Guo Author-X-Name-First: D. Author-X-Name-Last: Guo Author-Name: D. Zhao Author-X-Name-First: D. Author-X-Name-Last: Zhao Author-Name: B.-Z. Wang Author-X-Name-First: B.-Z. Author-X-Name-Last: Wang Title: A novel PLRC-WCS FDTD method for dispersive materials Abstract: One-directional weakly conditionally stable finite-difference time-domain (WCS-FDTD) method is extended to solve electromagnetic problems in linear dispersive media by virtue of piecewise linear recursive convolution (PLRC) technique. This proposed method provides similar accuracy to PLRC alternating direction implicit (ADI) FDTD approach, yet consumes less computational time and less memory. This proposed method is particularly suitable for solving problems in linear dispersive materials with fine features along two spatial directions. Journal: Journal of Electromagnetic Waves and Applications Pages: 464-472 Issue: 4 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.752317 File-URL: http://hdl.handle.net/10.1080/09205071.2013.752317 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:4:p:464-472 Template-Type: ReDIF-Article 1.0 Author-Name: M.J. Xu Author-X-Name-First: M.J. Author-X-Name-Last: Xu Author-Name: Z.Q. Xu Author-X-Name-First: Z.Q. Author-X-Name-Last: Xu Author-Name: K. Chen Author-X-Name-First: K. Author-X-Name-Last: Chen Author-Name: B. Fu Author-X-Name-First: B. Author-X-Name-Last: Fu Author-Name: J.X. Liao Author-X-Name-First: J.X. Author-X-Name-Last: Liao Title: Multilayer substrate integrated hexagonal cavity (SIHC) filter with mixed coupling (MC) Abstract: A novel multilayer substrate integrated hexagonal cavity filter with mixed coupling (MC) is proposed. Based on the substrate integrated waveguide techniques, the filter configuration is composed of hexagonal resonators which combine flexibility of rectangular cavities and performance of circular cavities. Meanwhile, by introducing MC into two adjacent resonators in the middle layer, the proposed filter has not only good selectivity due to the controllable transmission zeros, but also a compact size by profit from low-temperature co-fired ceramic technology. A fourth-order bandpass filter with three transmission zeros has been designed and fabricated. The measured results validate the feasibility of the proposed design, with its high selectivity demonstrated. Journal: Journal of Electromagnetic Waves and Applications Pages: 131-139 Issue: 2 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.740779 File-URL: http://hdl.handle.net/10.1080/09205071.2013.740779 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:2:p:131-139 Template-Type: ReDIF-Article 1.0 Author-Name: Y.S. Wu Author-X-Name-First: Y.S. Author-X-Name-Last: Wu Author-Name: X.Q. Lin Author-X-Name-First: X.Q. Author-X-Name-Last: Lin Author-Name: F. Cheng Author-X-Name-First: F. Author-X-Name-Last: Cheng Author-Name: J. Zhang Author-X-Name-First: J. Author-X-Name-Last: Zhang Author-Name: Y. Fan Author-X-Name-First: Y. Author-X-Name-Last: Fan Title: A compact tunable bandpass filter with high selectivity and low insertion loss using novel CRLH cell Abstract: This paper presents the realization of a tunable bandpass filter with high selectivity and low insertion loss using one tunable composite right/left-handed (CRLH) cell. The tunable CRLH cell is proposed with varactor diodes loaded both on series and shut circuits. Two shut circuits are designed to form the needed paralleled CR and LL, by which two transmission zeros beside the passband are obtained at the same time. Each varactor diode is shunted by a lumped capacitor for lower insertion loss. The filter is tuned by only one DC bias, which results in easily control and compact size. The measured results agree well with the simulated results, and a tunable range of the center frequency from 1.75 to 2.25 GHz is achieved in measurement with the insertion loss less than 2.5 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 1466-1472 Issue: 12 Volume: 27 Year: 2013 Month: 8 X-DOI: 10.1080/09205071.2013.812941 File-URL: http://hdl.handle.net/10.1080/09205071.2013.812941 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:12:p:1466-1472 Template-Type: ReDIF-Article 1.0 Author-Name: G. Sener Author-X-Name-First: G. Author-X-Name-Last: Sener Title: A new algorithm to locate the zero fields in antenna radiation pattern measurements Abstract: This article describes a new method to determine the directions of the zero fields in antenna radiation measurements. Zero-field detection is important when there are null constraints in antenna analysis or synthesis. To identify the directions of the zero fields, the general practice is to measure the propagating field in a number of small incremental angles in 2D space. For an antenna with narrow beam characteristics, even more sampling is necessary for accuracy. As a result, the time efficiency is decreased. In order to speed up the process, an optimization algorithm may be employed such that the measurements may converge to the zero-field locations faster. However, the difficulty is that many optimization algorithms require the use of derivatives of the pattern function. The algorithm proposed in this paper is derivative free and utilizes only the amplitude data, hence it is suitable and applicable to antenna measurements providing time efficiency. Journal: Journal of Electromagnetic Waves and Applications Pages: 1238-1245 Issue: 10 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.805169 File-URL: http://hdl.handle.net/10.1080/09205071.2013.805169 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:10:p:1238-1245 Template-Type: ReDIF-Article 1.0 Author-Name: Y.-L. Lu Author-X-Name-First: Y.-L. Author-X-Name-Last: Lu Author-Name: G.-L. Dai Author-X-Name-First: G.-L. Author-X-Name-Last: Dai Title: An investigation of novel capacitor-based coupling scheme and its applications to microstrip bandpass filters Abstract: In this paper, we present a novel capacitor-based coupling scheme for realizing both harmonic-suppressed and miniaturized microstrip bandpass filters. The proposed coupling scheme employs lumped-/distributed-capacitors to provide the desired coupling strength between the resonance elements instead of traditional parallel-coupled lines. Certain coupling regions are replaced by coupling points resulting in high freedom degree of the filter topologies. Thus, the filter structure can be effectively miniaturized by meandering microstrip lines. To investigate the properties of the novel coupling scheme, an analytical equation is derived for describing the coupling coefficient variation vs. the positions of coupling points and the values of coupled-capacitors. Theoretical analysis indicates that several zero-voltage points can be chosen to suppress the harmonics, and the coupling coefficient can be easily tuned in a wide range by adjusting the capacitance of the coupled-capacitor. For demonstration, two sample filters are designed and fabricated. Simulation and experimental results agree well, validating the proposed methodologies. Journal: Journal of Electromagnetic Waves and Applications Pages: 659-669 Issue: 5 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.761120 File-URL: http://hdl.handle.net/10.1080/09205071.2013.761120 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:5:p:659-669 Template-Type: ReDIF-Article 1.0 Author-Name: H.T. Wen Author-X-Name-First: H.T. Author-X-Name-Last: Wen Author-Name: L. Jin Author-X-Name-First: L. Author-X-Name-Last: Jin Title: A miniaturization of compact band-pass filter with radial stubs utilizing modified composite right/left-handed structure Abstract: A novel compact band-pass filter (BPF) with radial stubs (RS) utilizing modified composite-right/left-handed (CRLH) structure is proposed. A pair of microstrip RS is loaded as a combination of inductance and capacitance, which creates a transmission zero at the upper stop band. By introducing the magnetic coupling to the traditional interdigital coupled lines, two more transmission zeros are created. In addition, the fractional bandwidth is just more than 30% contrasted with super-wide BPF implemented by traditional CRLH transmission lines(CLRH-TL). Due to the good performance of out-of-band rejection and to guarantee the compactness in size, only one unit cell is adopted. The interdigital coupled lines are used to realize the strong coupling for the design which is shown to have the compact size of ( is the guided wavelength at the center frequency of 2.45 GHz). The insertion loss is no more than 1.7 dB in the pass band from 2.28 GHz to 2.62 GHz, and the spurious response up to is controlled effectively with more than 20 dB attenuation from 3.5 GHz up to 6.0 GHz, where is the pass band center frequency. Simulated and measured results are in good agreement with each other. Journal: Journal of Electromagnetic Waves and Applications Pages: 87-95 Issue: 1 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.739131 File-URL: http://hdl.handle.net/10.1080/09205071.2013.739131 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:1:p:87-95 Template-Type: ReDIF-Article 1.0 Author-Name: C. Wu Author-X-Name-First: C. Author-X-Name-Last: Wu Author-Name: F. Yang Author-X-Name-First: F. Author-X-Name-Last: Yang Author-Name: J. Ouyang Author-X-Name-First: J. Author-X-Name-Last: Ouyang Author-Name: P. Yang Author-X-Name-First: P. Author-X-Name-Last: Yang Author-Name: H. Zhou Author-X-Name-First: H. Author-X-Name-Last: Zhou Title: A novel quasi-analytic method for transient analysis of a reflector illuminated by a corrugated horn for IRA applications Abstract: A novel quasi-analytic method for transient analysis of a reflector antenna illuminated by a corrugated horn for impulse-radiating-antenna applications is presented in this paper. Based on time-domain Gaussian beam (TD-GB) approach, the proposed method is highly efficient, independent of reflector’s size and can avoid ray-caustic problem in the ray-tracing method. The time-domain field radiated by the corrugated horn is expanded in terms of TD-GBs by matching its far-field patterns in the frequency domain (FD). TD-GB approach is utilized to investigate impulse responses. Convolution theorem and superposition theorem are adopted to achieve transient responses. In addition, fast Fourier transform of transient responses are compared with direct FD results, and good agreement is achieved. Journal: Journal of Electromagnetic Waves and Applications Pages: 233-241 Issue: 2 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.743451 File-URL: http://hdl.handle.net/10.1080/09205071.2013.743451 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:2:p:233-241 Template-Type: ReDIF-Article 1.0 Author-Name: J. Zhong Author-X-Name-First: J. Author-X-Name-Last: Zhong Author-Name: F. Wang Author-X-Name-First: F. Author-X-Name-Last: Wang Author-Name: G. Wen Author-X-Name-First: G. Author-X-Name-Last: Wen Author-Name: Y. Huang Author-X-Name-First: Y. Author-X-Name-Last: Huang Author-Name: J. Li Author-X-Name-First: J. Author-X-Name-Last: Li Author-Name: W. Zhu Author-X-Name-First: W. Author-X-Name-Last: Zhu Author-Name: H. Sun Author-X-Name-First: H. Author-X-Name-Last: Sun Title: Tunable triple-band negative permeability metamaterial consisting of single-loop resonators and ferrite Abstract: We numerically propose a novel tunable metamaterial with triple bands of negative permeabilities. This metamaterial is composed of an array of single-loop resonators (SLRs) and ferrite slabs, where the SLRs provide two magnetic resonances while the ferrite slabs under an applied dc magnetic bias give rise to the third magnetic resonance. By adjusting the intensity of the dc magnetic bias, it is able to tune all the three magnetic resonances. The -negative features of these resonant bands are investigated by retrieving the constitutive parameters from simulated -parameters. The results in this paper open a new approach for designing tunable multiband metamaterials, which is sure to find extensive applications in fields such as tunable multiband notched ultra-wideband (UWB) antennas, tunable multiband perfect lens, and tunable multiband absorbers. Journal: Journal of Electromagnetic Waves and Applications Pages: 267-275 Issue: 3 Volume: 27 Year: 2013 Month: 2 X-DOI: 10.1080/09205071.2013.743958 File-URL: http://hdl.handle.net/10.1080/09205071.2013.743958 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:3:p:267-275 Template-Type: ReDIF-Article 1.0 Author-Name: J.-I. Baik Author-X-Name-First: J.-I. Author-X-Name-Last: Baik Author-Name: E.-H. Lee Author-X-Name-First: E.-H. Author-X-Name-Last: Lee Author-Name: H.-K. Song Author-X-Name-First: H.-K. Author-X-Name-Last: Song Title: Adaptive cooperative communications with multiple antennas Abstract: Although multiple-input multiple-output antenna transmission is advantageous on orthogonal frequency division multiple access system, it may not be possible that practical systems have more than two antennas because of its size and cost. Therefore, cooperative communication has been recently studied as a way to solve this problem in a wireless environment. However, if cooperative communication system selects relay in a bad channel environment between source and relay, the relay has a bad effect on the bit error ratio performance. Thus, selective relay technique is proposed in this paper. The proposed system can select the best relay which has the best SNR between source and relay among the candidates. The proposed system also easily finds the best relay with low complexity. Journal: Journal of Electromagnetic Waves and Applications Pages: 1632-1639 Issue: 13 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.821677 File-URL: http://hdl.handle.net/10.1080/09205071.2013.821677 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:13:p:1632-1639 Template-Type: ReDIF-Article 1.0 Author-Name: Won-Jae Shin Author-X-Name-First: Won-Jae Author-X-Name-Last: Shin Author-Name: Hyun Yang Author-X-Name-First: Hyun Author-X-Name-Last: Yang Author-Name: Young-Hwan You Author-X-Name-First: Young-Hwan Author-X-Name-Last: You Title: Performance of carrier frequency synchronization for OFDM-based mobile cellular systems over time selective fading channels Abstract: This paper evaluates the performance of a cell-specific reference signal (RS)-assisted residual carrier-frequency offset (CFO) detection scheme for a long-term evolution (LTE) downlink in a time-varying channel. Channel variations severely degrade the performance of OFDM by introducing both a complicated multiplicative distortion and an additive inter-carrier interference. Taking into consideration the effect of time-variant fading channels, an analytical closed-form expression of the mean square error (MSE) of the post-FFT CFO detection scheme is derived. The analytical expression is verified through simulations using the parameters of the LTE standard. Journal: Journal of Electromagnetic Waves and Applications Pages: 989-998 Issue: 8 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.795119 File-URL: http://hdl.handle.net/10.1080/09205071.2013.795119 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:8:p:989-998 Template-Type: ReDIF-Article 1.0 Author-Name: L.X. Zhou Author-X-Name-First: L.X. Author-X-Name-Last: Zhou Author-Name: W. Hu Author-X-Name-First: W. Author-X-Name-Last: Hu Author-Name: Y.Z. Yin Author-X-Name-First: Y.Z. Author-X-Name-Last: Yin Author-Name: X. Yang Author-X-Name-First: X. Author-X-Name-Last: Yang Title: Design of a wideband bandpass filter based on signal-interaction concepts Abstract: A novel wideband bandpass filter (BPF) based on signal-interaction concepts is presented in this paper. Two transmission paths with a wideband double-sided parallel-strip line 180° inverter and a 3λ/4 transmission line are employed to transmit signals from Port 1 to Port 2. By introducing two λ/4 shorted lines, the passband transmission performance of the BPF can be improved effectively. The experimental results demonstrate that the proposed BPF can achieve three transmission zeros and good harmonic suppression in the whole operating band ranging from 1.35 to 3.41 GHz, with 3-dB fractional bandwidth of 86%. Journal: Journal of Electromagnetic Waves and Applications Pages: 1197-1205 Issue: 10 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.803939 File-URL: http://hdl.handle.net/10.1080/09205071.2013.803939 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:10:p:1197-1205 Template-Type: ReDIF-Article 1.0 Author-Name: Olga Korostynska Author-X-Name-First: Olga Author-X-Name-Last: Korostynska Author-Name: Alex Mason Author-X-Name-First: Alex Author-X-Name-Last: Mason Author-Name: Ahmed I. Al-Shamma’a Author-X-Name-First: Ahmed I. Author-X-Name-Last: Al-Shamma’a Title: Flexible microwave sensors for real-time analysis of water contaminants Abstract: This paper reports on the development of novel microwave sensors for water contaminant analysis in real time. In particular, changes in the microwave part of the electromagnetic spectrum are used as an indicator of water quality. The sensing element was designed on a flexible substrate in order that it is less prone to failure due to mechanical damage, thus providing longevity. This also allows for a broad range of applications where a sensor, or sensors, could be placed in water reservoirs or water pipes. The sensing element consists of silver metal patterns which form interdigitated electrodes (IDE) in various configurations on polyimide flexible laminate substrates. The effect of IDE sensor configuration on the sensitivity of reflected signals represented by S11 parameters was studied. The developed system confirmed the viability of using microwaves for real-time water quality monitoring as the corresponding spectra for air, deionised water and tap water were unique with clearly observed shifts in the resonant frequencies of the sensors when placed in direct contact with various water samples. Journal: Journal of Electromagnetic Waves and Applications Pages: 2075-2089 Issue: 16 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.832393 File-URL: http://hdl.handle.net/10.1080/09205071.2013.832393 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:16:p:2075-2089 Template-Type: ReDIF-Article 1.0 Author-Name: Vasa Radonić Author-X-Name-First: Vasa Author-X-Name-Last: Radonić Author-Name: Riana H. Geschke Author-X-Name-First: Riana H. Author-X-Name-Last: Geschke Author-Name: Vesna Crnojević-Bengin Author-X-Name-First: Vesna Author-X-Name-Last: Crnojević-Bengin Title: Dual-band filters with independent passbands based on perturbed grounded patch resonators Abstract: In this paper, two novel dual-band filters with independent passbands are proposed, which operate according to the IEEE 802.11b/g/n standard. The filters are based on a rectangular grounded patch, modified by introducing an edge slot perturbation. In that way, separate control of the couplings at both operating frequencies of the filter is achieved, resulting in independent control of both the position and the bandwidths of two filters passbands. Journal: Journal of Electromagnetic Waves and Applications Pages: 2110-2122 Issue: 16 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.832397 File-URL: http://hdl.handle.net/10.1080/09205071.2013.832397 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:16:p:2110-2122 Template-Type: ReDIF-Article 1.0 Author-Name: Heeralal Gargama Author-X-Name-First: Heeralal Author-X-Name-Last: Gargama Author-Name: Sanjay Kumar Chaturvedi Author-X-Name-First: Sanjay Kumar Author-X-Name-Last: Chaturvedi Author-Name: Awalendra Kumar Thakur Author-X-Name-First: Awalendra Kumar Author-X-Name-Last: Thakur Title: Reliability-based design optimization of broadband microwave absorbers Abstract: This paper proposes a reliability-based design optimization approach to handle variability/uncertainties involved in the design variables/parameters of microwave absorber. The proposed approach uses hybrid genetic algorithm for optimization and Monte Carlo simulation with Latin hypercube sampling technique for probabilistic analysis to identify the optimal design of absorbing structure under probabilistic constraints. The proposed approach is illustrated with examples considering broadband absorbing coatings in the frequency range of 0.2–2, 2–8, and 0.5–8 GHz, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 1407-1418 Issue: 11 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.810124 File-URL: http://hdl.handle.net/10.1080/09205071.2013.810124 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:11:p:1407-1418 Template-Type: ReDIF-Article 1.0 Author-Name: J. Li Author-X-Name-First: J. Author-X-Name-Last: Li Author-Name: L.-X. Guo Author-X-Name-First: L.-X. Author-X-Name-Last: Guo Author-Name: Y.-C. Jiao Author-X-Name-First: Y.-C. Author-X-Name-Last: Jiao Author-Name: K. Li Author-X-Name-First: K. Author-X-Name-Last: Li Title: Wide-band scattering of 1-D dispersive soil surface by the ADE-FDTD algorithm Abstract: In this paper, a wide-band scattering of one-dimensional (1-D) soil surface with exponential spectrum is investigated by the finite-difference time-domain (FDTD) algorithm with pulsed wave excitation. Soil is regarded as isotropic and dispersive media, and it satisfies the two-pole Debye model. And the auxiliary differential equation (ADE) technique is incorporated into the FDTD scheme to deal with the dispersive soil. To ensure the validity of our present method, the wide-band scattering of dispersive soil surface by the ADE-FDTD method is computed and compared with the result by the conventional method of moments (MOM), which requires an individual calculation for every frequency point of interest. Finally, the scattering characteristic of dispersive soil surface is analyzed for different parameters in detail. Journal: Journal of Electromagnetic Waves and Applications Pages: 421-429 Issue: 4 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.748438 File-URL: http://hdl.handle.net/10.1080/09205071.2013.748438 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:4:p:421-429 Template-Type: ReDIF-Article 1.0 Author-Name: Xin Cao Author-X-Name-First: Xin Author-X-Name-Last: Cao Author-Name: Zongxi Tang Author-X-Name-First: Zongxi Author-X-Name-Last: Tang Author-Name: Fei Wang Author-X-Name-First: Fei Author-X-Name-Last: Wang Author-Name: Yunqiu Wu Author-X-Name-First: Yunqiu Author-X-Name-Last: Wu Author-Name: Wei Yao Author-X-Name-First: Wei Author-X-Name-Last: Yao Author-Name: Biao Zhang Author-X-Name-First: Biao Author-X-Name-Last: Zhang Author-Name: Yingcong Wang Author-X-Name-First: Yingcong Author-X-Name-Last: Wang Title: A novel tri-band band-pass filter using combined simplified CRLH and right-handed SIRs Abstract: In this study, a novel tri-band band-pass filter using combined simplified composite right-/left-handed (CRLH) and right-handed (RH) stepped impedance resonators (SIR) is presented. This filter utilizes the zeroth order resonance of the SIRs in the CRLH region and RH resonance in the RH region to produce three different passbands. The proposed filter is simulated and measured, and measurement results match well with simulation ones. Good properties of low in-band insertion loss, good out-band rejection, and compact size have been achieved and verified, and it can be easily applied in the microwave circuits and wireless communication systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 999-1007 Issue: 8 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.796863 File-URL: http://hdl.handle.net/10.1080/09205071.2013.796863 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:8:p:999-1007 Template-Type: ReDIF-Article 1.0 Author-Name: O.-S. Kwon Author-X-Name-First: O.-S. Author-X-Name-Last: Kwon Author-Name: Y.-S. Chung Author-X-Name-First: Y.-S. Author-X-Name-Last: Chung Author-Name: H.-G. Yang Author-X-Name-First: H.-G. Author-X-Name-Last: Yang Author-Name: C.-Y. Cheon Author-X-Name-First: C.-Y. Author-X-Name-Last: Cheon Author-Name: D.-S. Kim Author-X-Name-First: D.-S. Author-X-Name-Last: Kim Author-Name: H.-Y. Lee Author-X-Name-First: H.-Y. Author-X-Name-Last: Lee Author-Name: S.-H. Jang Author-X-Name-First: S.-H. Author-X-Name-Last: Jang Author-Name: S.-J. Kim Author-X-Name-First: S.-J. Author-X-Name-Last: Kim Title: A new circular subarray configuration using a modified genetic algorithm Abstract: In recent times, digital beamforming with an analog-to-digital converter for a phased-array radar has attracted wide interest due to its stability and accuracy. Generally, to obtain a high gain, a phased array radar requires many antenna elements, which results in high cost and computing load. To mitigate these problems, subarraying, which divides the entire array elements into a few disjoint groups, is a good solution. In this paper, we propose a new design methodology for disjoint subarray configuration based on a modified Genetic algorithm and a new grouping rule to preserve the number of desired subarrays. The validity of the proposed algorithm is demonstrated through simulation. Journal: Journal of Electromagnetic Waves and Applications Pages: 405-412 Issue: 4 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.747946 File-URL: http://hdl.handle.net/10.1080/09205071.2013.747946 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:4:p:405-412 Template-Type: ReDIF-Article 1.0 Author-Name: Huan Liu Author-X-Name-First: Huan Author-X-Name-Last: Liu Author-Name: Jianxiong Zhou Author-X-Name-First: Jianxiong Author-X-Name-Last: Zhou Author-Name: Qiang Fu Author-X-Name-First: Qiang Author-X-Name-Last: Fu Title: Focusing of translational variant bistatic forward-looking SAR with Chirp-Z transform Abstract: The forward-looking imaging problem of synthetic aperture radar can be resolved by adopting the bistatic configuration. This paper introduces a translational variant bistatic forward-looking SAR (BFSAR) configuration with a moving transmitter and a forward-looking receiver. Focusing bistatic SAR data in frequency domain requires two-dimensional (2D) point target spectrum. However, the existence of the double square root (DSR) term in the bistatic range makes it difficult to get the exact solution for the 2D spectrum. Approximate solutions such as the method of series reversion (MSR) have been derived to get the 2D spectrum, but the accumulative error to DSR of MSR is not the smallest one. To improve the accuracy of the 2D spectrum, the method of Legendre polynomial expansion is proposed to obtain the least square approximation of the bistatic range and get a more accurate 2D spectrum. Then, the Chirp-Z transform is chosen to focus the translational variant BFSAR data based on this spectrum, and the imaging quality is compared with the traditional MSR spectrum; the simulation results verify the 2D imaging ability of the proposed method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1455-1465 Issue: 12 Volume: 27 Year: 2013 Month: 8 X-DOI: 10.1080/09205071.2013.809508 File-URL: http://hdl.handle.net/10.1080/09205071.2013.809508 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:12:p:1455-1465 Template-Type: ReDIF-Article 1.0 Author-Name: Fei Liu Author-X-Name-First: Fei Author-X-Name-Last: Liu Author-Name: Jie Jin Author-X-Name-First: Jie Author-X-Name-Last: Jin Author-Name: Xing Zheng Author-X-Name-First: Xing Author-X-Name-Last: Zheng Title: Application of finite impulse response network concept in wavelength-tunable electro-optic filter Abstract: We present a model of wavelength-tunable electro-optic filter on x-cut, y-propagation Ti-diffused lithium niobate. The filter is composed of two polarization beam splitters and a polarization converter which is controlled by an N-stage cascade of alternating coupled-mode and phase-shifted electrodes. The concept of finite impulse response digital filtering is used to calculate the voltage matrices and in the z field, which control the mode coupling and phase shift respectively. By changing the input voltages, a wavelength-tunable bandpass filter or a non-periodic multi-wavelength selector can be obtained. For the bandpass filter, the rectangular degree of passband can be improved by increasing the number of cascading stages . If is equal to 24, the side mode suppression ratio (SMSR) could reach 25 dB. And the passband can be tuned by simply changing the voltage matrix . For the multi-wavelength selector, the design process can be fulfilled by the discrete Fourier transform method. The bandwidth of each selected wavelength increases but the number of selected wavelengths decreases when the number of cascading stages decreases. If is equal to 24, a bandwidth of 0.29 nm with a SMSR of 12 dB is achieved within a 8 nm range centered at 1550 nm. Journal: Journal of Electromagnetic Waves and Applications Pages: 2123-2134 Issue: 16 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.832638 File-URL: http://hdl.handle.net/10.1080/09205071.2013.832638 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:16:p:2123-2134 Template-Type: ReDIF-Article 1.0 Author-Name: Junping Geng Author-X-Name-First: Junping Author-X-Name-Last: Geng Author-Name: Richard W. Ziolkowski Author-X-Name-First: Richard W. Author-X-Name-Last: Ziolkowski Author-Name: Ronghong Jin Author-X-Name-First: Ronghong Author-X-Name-Last: Jin Author-Name: Xianling Liang Author-X-Name-First: Xianling Author-X-Name-Last: Liang Title: Active cylindrical coated nano-particle antennas: polarization-dependent scattering properties Abstract: The polarization-dependent properties of electromagnetic plane wave scattering from active cylindrical coated nano-particle (C-CNP) antennas are investigated in the visible frequency band. It is demonstrated with three independent orthogonal polarizations that the dipole mode is excited resonantly in each case, even though the resonant size of the particles, as seen by these normally incident plane waves, is different. Moreover, the scattering behaviors for various angles of incidence are studied. It is shown that the polarization state along the main axis of the cylinder dominates the scattering properties of these resonant, active C-CNP’s; and because of the natural symmetry, they mainly depend on the elevation angle α and not the azimuth angle β. Journal: Journal of Electromagnetic Waves and Applications Pages: 1392-1406 Issue: 11 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.809669 File-URL: http://hdl.handle.net/10.1080/09205071.2013.809669 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:11:p:1392-1406 Template-Type: ReDIF-Article 1.0 Author-Name: H.M. Liu Author-X-Name-First: H.M. Author-X-Name-Last: Liu Author-Name: Z.B. Wang Author-X-Name-First: Z.B. Author-X-Name-Last: Wang Author-Name: S.J. Fang Author-X-Name-First: S.J. Author-X-Name-Last: Fang Title: Trans-directional coupler with capacitor-shunted ground-defected coupled CPWs and inductor-loaded ACPWs for weak coupling applications Abstract: Trans-directional (TRD) couplers with capacitor-shunted ground-defected coupled coplanar waveguides (CPWs) and inductor-loaded asymmetric coplanar waveguides are proposed for weak coupling applications. To achieve weak coupling as well as perfect impedance match, unequal shunt capacitors and same series inductors are loaded on the coupled CPWs. In addition, a defected-ground structure is etched under the coupled CPWs for realizing high-impedance coupled lines with the printed circuit board technology. Two TRD couplers with coupling values of 10 and 20 dB are investigated theoretically and experimentally. The measured results show that the directivity of the proposed TRD coupler is better than that of conventional parallel-coupled microstrip-line coupler. Journal: Journal of Electromagnetic Waves and Applications Pages: 104-116 Issue: 1 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.739541 File-URL: http://hdl.handle.net/10.1080/09205071.2013.739541 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:1:p:104-116 Template-Type: ReDIF-Article 1.0 Author-Name: Z.R. Li Author-X-Name-First: Z.R. Author-X-Name-Last: Li Author-Name: L.Y. Chen Author-X-Name-First: L.Y. Author-X-Name-Last: Chen Author-Name: H. Zhang Author-X-Name-First: H. Author-X-Name-Last: Zhang Author-Name: Q.X. Guo Author-X-Name-First: Q.X. Author-X-Name-Last: Guo Author-Name: X.Q. Zhang Author-X-Name-First: X.Q. Author-X-Name-Last: Zhang Author-Name: X.F. Wu Author-X-Name-First: X.F. Author-X-Name-Last: Wu Author-Name: J.H. Wang Author-X-Name-First: J.H. Author-X-Name-Last: Wang Author-Name: Y. Yang Author-X-Name-First: Y. Author-X-Name-Last: Yang Title: Dual-polarized patch antenna with high isolation for DTV applications Abstract: In this paper, the design, simulation results, and measurements of a coaxial-fed dual-polarized patch antenna with high port isolation are presented. The proposed antenna consists of two cross center-fed patch dipole antennas against a reflector as ground plane, while the patch antenna contains two pairs of X-shaped slots along the diagonals and two pairs of T-shaped slots along the centerlines. The proposed antenna achieves a -10 dB with bandwidth of 470–730 MHz and demonstrates the dual polarization in both directions. Stable radiation patterns at slanted polarization have been obtained within the band. Measurements show two linear polarizations with an isolation of more than 33 dB over the operating frequency band. The proposed antenna can be used for Digital television applications (DTV). Journal: Journal of Electromagnetic Waves and Applications Pages: 1759-1766 Issue: 14 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.823359 File-URL: http://hdl.handle.net/10.1080/09205071.2013.823359 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:14:p:1759-1766 Template-Type: ReDIF-Article 1.0 Author-Name: Yan-liang Wu Author-X-Name-First: Yan-liang Author-X-Name-Last: Wu Author-Name: Xuan-ming Zhong Author-X-Name-First: Xuan-ming Author-X-Name-Last: Zhong Author-Name: Xiang-zheng Xiong Author-X-Name-First: Xiang-zheng Author-X-Name-Last: Xiong Author-Name: Cheng Liao Author-X-Name-First: Cheng Author-X-Name-Last: Liao Title: Design of dual-mode dual-band bandpass filters with controllable frequencies for multimode wireless communication applications Abstract: A flexible approach for designing dual-mode dual-band bandpass filters with controllable passband frequencies is presented. Two dual-mode dual-band bandpass filters are proposed for experimental verification. The first filter, whose two passbands are centered at 3.4 and 5.5 GHz with the corresponding fractional bandwidth of 19 and 13%, respectively, is suitable for the applications of worldwide interoperability for microwave access (WiMAX) and wireless local area network. The second filter, whose two passbands are centered at 4 and 7.4 GHz with the corresponding fractional bandwidth of 25 and 13%, respectively, is suitable for the downlink of C-band and X-band satellite communication systems. Both filters have been designed, fabricated, and measured. The measured results show good agreements with those of the simulation. Journal: Journal of Electromagnetic Waves and Applications Pages: 2176-2189 Issue: 17 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.835702 File-URL: http://hdl.handle.net/10.1080/09205071.2013.835702 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:17:p:2176-2189 Template-Type: ReDIF-Article 1.0 Author-Name: M.Z.M. Nor Author-X-Name-First: M.Z.M. Author-X-Name-Last: Nor Author-Name: S.K.A. Rahim Author-X-Name-First: S.K.A. Author-X-Name-Last: Rahim Author-Name: M.I. Sabran Author-X-Name-First: M.I. Author-X-Name-Last: Sabran Author-Name: F. Malek Author-X-Name-First: F. Author-X-Name-Last: Malek Title: Dual-band, parabolic, slotted ground plane-directive antenna for WLAN applications Abstract: Wireless local area network (WLAN) is one of the common terms used by researchers in the communications area that allows wireless, long-range communication. Antennas are used as a medium of transmission, and in recent WLAN applications, manufacturers have tended to use antennas which are small, have simple structures, are inexpensive, and can operate at several sets of frequencies. In this paper, a dual-band antenna with defected ground plane structure is introduced. With the proposed combination of slots in its radiating element and defected ground plane, the antenna can operate at two frequency bands 2.45 and 5.8 GHz and direct the main beam at 30° at these respective bands. Simulated results and measurements show good agreement in terms of return loss and radiation pattern. Journal: Journal of Electromagnetic Waves and Applications Pages: 205-214 Issue: 2 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.743448 File-URL: http://hdl.handle.net/10.1080/09205071.2013.743448 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:2:p:205-214 Template-Type: ReDIF-Article 1.0 Author-Name: M.A. Baqir Author-X-Name-First: M.A. Author-X-Name-Last: Baqir Author-Name: P.K. Choudhury Author-X-Name-First: P.K. Author-X-Name-Last: Choudhury Title: Propagation through uniaxial anisotropic chiral waveguide under DB-boundary conditions Abstract: The paper describes the propagation of electromagnetic waves through a cylindrical waveguide composed of uniaxial anisotropic chiral medium that is treated under the DB-boundary. The emphasis is given on the energy flux density in the guide considering varieties of chiral mediums and the waveguide dimensions. For this purpose, the eigenvalue equation is obtained using the appropriate boundary conditions, and the modal propagation constants of the guide are deduced. It has been investigated that the flux density mostly remains confined in the central regions of guide which, however, strongly depends on the type of waveguide medium as well as the dimensional measures. Both forward and backward wave propagations are observed in such guides – the feature essentially governed by the characteristics of the guiding medium. Journal: Journal of Electromagnetic Waves and Applications Pages: 783-793 Issue: 6 Volume: 27 Year: 2013 Month: 4 X-DOI: 10.1080/09205071.2013.786209 File-URL: http://hdl.handle.net/10.1080/09205071.2013.786209 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:6:p:783-793 Template-Type: ReDIF-Article 1.0 Author-Name: Truong Khang Nguyen Author-X-Name-First: Truong Khang Author-X-Name-Last: Nguyen Author-Name: Sangin Kim Author-X-Name-First: Sangin Author-X-Name-Last: Kim Author-Name: Ikmo Park Author-X-Name-First: Ikmo Author-X-Name-Last: Park Title: Impact of varying the DC bias stripline connection angle on terahertz coplanar stripline dipole antenna characteristics Abstract: We investigated the dependence of the input impedance and radiation characteristics on the connection angle between the DC bias stripline and the center dipole of a terahertz coplanar stripline dipole antenna in a semi-infinite substrate. Three connection angles, namely 0° (typical horizontal connection), 45° (diagonal connection), and 90° (vertical connection), were examined and an overall performance comparison was provided. The antenna with a sufficiently long bias stripline exhibited a traveling-wave behavior with stable impedance variation, regardless of the connection angle between the DC bias stripline and the center dipole. The antenna with diagonal and vertical bias connections performed much better than the typical H-shaped electrode with a horizontal bias connection in terms of radiation characteristics exhibiting flat gain and low frequency cut-off of the radiation efficiency. In addition, the antenna with a diagonal bias connection exhibited a better radiation pattern and more efficient use of a given substrate area than that with a vertical bias connection. The result indicates that in terms of the overall aspect of the terahertz stripline dipole antenna designs on a high-dielectric-constant substrate, the antenna with a diagonal bias connection is the best configuration. Journal: Journal of Electromagnetic Waves and Applications Pages: 1725-1734 Issue: 14 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.823125 File-URL: http://hdl.handle.net/10.1080/09205071.2013.823125 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:14:p:1725-1734 Template-Type: ReDIF-Article 1.0 Author-Name: X.-H. Yuan Author-X-Name-First: X.-H. Author-X-Name-Last: Yuan Author-Name: Q.-Y. Feng Author-X-Name-First: Q.-Y. Author-X-Name-Last: Feng Author-Name: L.-C. Zhou Author-X-Name-First: L.-C. Author-X-Name-Last: Zhou Title: RF power amplifiers behavioral modeling based on extended neural network with additional dynamic fuzzy weights Abstract: This paper presents an extended neural network (NN)-based behavioral model of RF power amplifiers (PAs) with memory effects. PA behavioral models are traditionally constructed based on the relationship between the input and output of PA, without regard to the physical mechanisms of distortions in PA however. To more accurately predict the dynamic nonlinear behavior of PA, the novel proposed NN-based behavioral model takes into account the characteristics of the amplitude modulation to amplitude modulation and amplitude modulation to phase modulation distortions that are incorporated into the behavioral model by means of additional dynamic fuzzy weights. In addition, the NN-based behavioral model employs orthonormal Hermite polynomial functions rather than commonly used sigmoid function, as nonlinear activation functions resulting in significant improvement in accuracy and convergence. Experimental results on a class-AB PA driven with the wideband Mobile Multimedia Broadcasting signals show a superior performance of the proposed extended NN-based model over the traditional NN-based ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 1694-1701 Issue: 13 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.823121 File-URL: http://hdl.handle.net/10.1080/09205071.2013.823121 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:13:p:1694-1701 Template-Type: ReDIF-Article 1.0 Author-Name: Y. Li Author-X-Name-First: Y. Author-X-Name-Last: Li Title: Wave propagation along a one-dimensional metal cut-wire array Abstract: The wave propagation mechanism in a 1D metal cut-wire array is investigated. It is shown that a surface wave can be supported along the interface between the cut-wire array and the air region in multiple frequency bands. The propagation constant, attenuation constant, and the field distribution of the surface wave are extracted from both numerical simulation and measurement and are compared between the 1D and the 2D cut-wire arrays. The effect of array geometrical parameters on the surface wave propagation is examined through parametric studies. Journal: Journal of Electromagnetic Waves and Applications Pages: 3-13 Issue: 1 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2012.737451 File-URL: http://hdl.handle.net/10.1080/09205071.2012.737451 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:1:p:3-13 Template-Type: ReDIF-Article 1.0 Author-Name: Chuan Wu Author-X-Name-First: Chuan Author-X-Name-Last: Wu Author-Name: Feng Yang Author-X-Name-First: Feng Author-X-Name-Last: Yang Author-Name: Jun Ouyang Author-X-Name-First: Jun Author-X-Name-Last: Ouyang Author-Name: Peng Yang Author-X-Name-First: Peng Author-X-Name-Last: Yang Author-Name: Haijing Zhou Author-X-Name-First: Haijing Author-X-Name-Last: Zhou Title: Calculation of physical optics integrals over electrically large NURBS surface illuminated by a Gaussian beam for reflector antenna applications Abstract: For reflector antenna applications, a method for calculation of physical optics (PO) integrals over electrically large nonuniform rational B-spline surfaces illuminated by a Gaussian Beam is presented in this paper. This method has efficient advantages and its computation cost does not increase with frequency. The highly oscillatory PO integral is calculated with delaminating quadrature method. The influence of critical points is taken into account by subdividing the integral intervals. Numerical examples are presented to validate this approach. Journal: Journal of Electromagnetic Waves and Applications Pages: 1496-1508 Issue: 12 Volume: 27 Year: 2013 Month: 8 X-DOI: 10.1080/09205071.2013.817955 File-URL: http://hdl.handle.net/10.1080/09205071.2013.817955 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:12:p:1496-1508 Template-Type: ReDIF-Article 1.0 Author-Name: S.W. Jeong Author-X-Name-First: S.W. Author-X-Name-Last: Jeong Author-Name: K.C. Hwang Author-X-Name-First: K.C. Author-X-Name-Last: Hwang Author-Name: J.-Y. Park Author-X-Name-First: J.-Y. Author-X-Name-Last: Park Author-Name: S.-J. Kim Author-X-Name-First: S.-J. Author-X-Name-Last: Kim Author-Name: D.-H. Kim Author-X-Name-First: D.-H. Author-X-Name-Last: Kim Title: Spidron fractal tapered slot antenna for dual-band radar applications Abstract: A dual-broadband Spidron fractal tapered slot antenna is proposed for radar applications in the S and X bands. Dual-Spidron fractal patches are symmetrically arranged adjacent to each other, and a slot is etched from the central section of the patch to form a feeding slot. A microstrip-to-slotline transition is used to excite the tapered aperture of the Spidron fractal patch. The proposed antenna is fabricated and tested, and has compact dimensions of 35.8 mm × 24 mm (0.358 λ0 × 0.24 λ0). The measured −10 dB reflection bandwidths for the lower and upper frequency bands are 39.42% (2.75–4.10 GHz) and 34.74% (7.85–11.15 GHz), respectively. The measurements also indicate that the proposed antenna exhibits two types of radiation patterns, namely, a near omni-directional pattern in the lower band and a directional pattern in the upper band. The measured peak gains range from 0.4 to 2.97 dBi in the lower band and from 1.42 to 5.52 dBi in the upper band. Journal: Journal of Electromagnetic Waves and Applications Pages: 1329-1337 Issue: 11 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.808597 File-URL: http://hdl.handle.net/10.1080/09205071.2013.808597 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:11:p:1329-1337 Template-Type: ReDIF-Article 1.0 Author-Name: Biying Lu Author-X-Name-First: Biying Author-X-Name-Last: Lu Author-Name: Xin Sun Author-X-Name-First: Xin Author-X-Name-Last: Sun Author-Name: Yang Zhao Author-X-Name-First: Yang Author-X-Name-Last: Zhao Author-Name: Zhimin Zhou Author-X-Name-First: Zhimin Author-X-Name-Last: Zhou Title: Phase coherence factor for mitigation of sidelobe artifacts in through-the-wall radar imaging Abstract: The phase coherence factor (PCF) is revised according to stepped frequency signal imaging radar, adding additional phase diversity in frequency domain. Then, it is applied to through-the-wall moving target indication processing for side and grating lobe artifacts mitigation. Experimental results show that PCF weighting approach can suppress both side and grating lobe artifacts effectively for through-the-wall images. Journal: Journal of Electromagnetic Waves and Applications Pages: 716-725 Issue: 6 Volume: 27 Year: 2013 Month: 4 X-DOI: 10.1080/09205071.2013.774111 File-URL: http://hdl.handle.net/10.1080/09205071.2013.774111 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:6:p:716-725 Template-Type: ReDIF-Article 1.0 Author-Name: H.F. Contopanagos Author-X-Name-First: H.F. Author-X-Name-Last: Contopanagos Author-Name: P. Broutas Author-X-Name-First: P. Author-X-Name-Last: Broutas Author-Name: A. Papió Toda Author-X-Name-First: A. Author-X-Name-Last: Papió Toda Author-Name: F. De Flaviis Author-X-Name-First: F. Author-X-Name-Last: De Flaviis Author-Name: S. Chatzandroulis Author-X-Name-First: S. Author-X-Name-Last: Chatzandroulis Title: A PCB-integrated multi-slotted PIFA for 2.5 GHz autonomous RFID or Bluetooth applications Abstract: We present a compact planar antenna integrated on printed circuit board (PCB) for power-harvesting RFID tags operating at 2.5 GHz or Bluetooth dongles. The antenna, printed on FR4, is a Planar Inverted-F Antenna (PIFA)-type design with a set of optimized slots and provides high radiation efficiency and appropriate bandwidth, while presenting a low profile and very small area. Unlike expensive ceramic antennas, the present implementation is integrated directly on the system’s PCB and provides an inexpensive approach of equal or better performance to expensive ceramic antennas. The small size is due to the optimized multiple slots and the scaling with the permittivity of the FR4. A special design separating the PIFA into two stacked dielectric layers by-passes the traditionally suppressed efficiencies, which was the main obstacle for integrating PIFAs on PCBs, and restores much higher efficiencies. Hence, it creates a practical implementation of a very small antenna completely integrated on the system’s PCB appropriate for 2.5 GHz power-harvester or Bluetooth tags. We validate the design with a prototype embedded within the PCB of an autonomous RFID tag by measuring its return loss, efficiency, and radiation patterns at the operation frequency band. Journal: Journal of Electromagnetic Waves and Applications Pages: 736-749 Issue: 6 Volume: 27 Year: 2013 Month: 4 X-DOI: 10.1080/09205071.2013.786205 File-URL: http://hdl.handle.net/10.1080/09205071.2013.786205 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:6:p:736-749 Template-Type: ReDIF-Article 1.0 Author-Name: Hsien-Chin Chiu Author-X-Name-First: Hsien-Chin Author-X-Name-Last: Chiu Author-Name: Po-Yu Ke Author-X-Name-First: Po-Yu Author-X-Name-Last: Ke Author-Name: Fan-Hsiu Huang Author-X-Name-First: Fan-Hsiu Author-X-Name-Last: Huang Title: A high output power V-band GaAs HEMT push–pull power amplifier using meandering baluns technology Abstract: A broadband, high saturation output power 0.15-μm gate length GaAs pseudomorphic high-electron mobility transistor push-pull V-band power amplifier has been demonstrated using meandering balun designs. Two meandering low-loss planar three-coupled-line baluns were used to form push–pull mechanism for both stages. The meandering baluns provide 180° differential outputs from the applied single-ended input at the V-band and the size was reduced for 23% compared to traditional design. The proposed push–pull amplifier achieved a peak small-signal gain of 16.8 dB at 58 GHz, a 3 dB bandwidth of 55–62 GHz, and a peak power added efficiency of 13.8%. Journal: Journal of Electromagnetic Waves and Applications Pages: 1869-1881 Issue: 15 Volume: 27 Year: 2013 Month: 10 X-DOI: 10.1080/09205071.2013.826149 File-URL: http://hdl.handle.net/10.1080/09205071.2013.826149 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:15:p:1869-1881 Template-Type: ReDIF-Article 1.0 Author-Name: S. Bhuyan Author-X-Name-First: S. Author-X-Name-Last: Bhuyan Author-Name: K. Sivanand Author-X-Name-First: K. Author-X-Name-Last: Sivanand Author-Name: S.K. Panda Author-X-Name-First: S.K. Author-X-Name-Last: Panda Title: Effect of design parameters on resonant wireless energy transfer system Abstract: The effect of various parameters on the resonance-based wireless energy transfer system has been investigated to obtain the design steps for efficient wireless energy transfer. Both theoretically and experimentally, it has been observed that every system has its own strongly coupled region that is an optimum frequency band for which maximum energy transfer occurs. The frequency band of the strongly coupled region changes with the coil size, structure, physical spacing, relative location, and material properties of the wire. Based on the theoretical results, experiments have been carried out to demonstrate the effectiveness and characteristics of the resonant wireless energy transfer method. It is found that the energy transfer efficiency reaches maximum at resonant frequency. The energy transfer efficiency is further enhanced by changing the configuration of coil and through low-resistance wire with high-quality factor. The analyses will give future guidelines for designing a compact efficient wireless energy transfer system to energize macro as well as micro devices used for various applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 288-298 Issue: 3 Volume: 27 Year: 2013 Month: 2 X-DOI: 10.1080/09205071.2013.744125 File-URL: http://hdl.handle.net/10.1080/09205071.2013.744125 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:3:p:288-298 Template-Type: ReDIF-Article 1.0 Author-Name: M.F. Manzano Author-X-Name-First: M.F. Author-X-Name-Last: Manzano Author-Name: J.F. Valenzuela-Valdes Author-X-Name-First: J.F. Author-X-Name-Last: Valenzuela-Valdes Author-Name: I.T. Castro Author-X-Name-First: I.T. Author-X-Name-Last: Castro Author-Name: L. Landesa Author-X-Name-First: L. Author-X-Name-Last: Landesa Title: Looking in complex angles for improving the accuracy of antenna array DoA estimation Abstract: The direction of arrival estimation (DoA) can be improved by extending the search of the angle to the complex space. In particular, the MUltiple SIgnal Classification algorithm for DoA estimation is clearly enhanced if the usual search of the angle is extended to the complex plane. Furthermore, this approach can be used even in really adverse conditions such as low SNR, small number of snapshots, or when the direction of arrivals is very close. Journal: Journal of Electromagnetic Waves and Applications Pages: 345-354 Issue: 3 Volume: 27 Year: 2013 Month: 2 X-DOI: 10.1080/09205071.2013.745805 File-URL: http://hdl.handle.net/10.1080/09205071.2013.745805 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:3:p:345-354 Template-Type: ReDIF-Article 1.0 Author-Name: J.-H. Tian Author-X-Name-First: J.-H. Author-X-Name-Last: Tian Author-Name: J.-P. Sun Author-X-Name-First: J.-P. Author-X-Name-Last: Sun Author-Name: S.-T. Lu Author-X-Name-First: S.-T. Author-X-Name-Last: Lu Author-Name: Y.-P. Wang Author-X-Name-First: Y.-P. Author-X-Name-Last: Wang Author-Name: W. Hong Author-X-Name-First: W. Author-X-Name-Last: Hong Title: NUFFT-based fast reconstruction for sparse microwave imaging Abstract: Compressive sensing (CS) theory has been applied to sparse microwave imaging in many ways that provide better performance and significantly reduce the sampling rate. However, the computational complexity of reconstruction puts strict constraint on some practical applications with large-scale problems in radar imaging. In this paper, we propose a novel fast reconstruction scheme by realizing the traditional matched filtering with CS technique, which maintains the good performance of matched filtering with a reduced number of observations. Meanwhile, a new sparse basis is formed which offers excellent potential for reducing the computational complexity in reconstruction with fast Fourier transform (FFT) and nonuniform FFT, i.e. NUFFT, where the computational complexity can decrease from to . The feasibility and efficiency of the proposed scheme are validated as well through both numerical simulations and raw data processing results. Journal: Journal of Electromagnetic Waves and Applications Pages: 485-495 Issue: 4 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.753661 File-URL: http://hdl.handle.net/10.1080/09205071.2013.753661 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:4:p:485-495 Template-Type: ReDIF-Article 1.0 Author-Name: Y.-L. Cui Author-X-Name-First: Y.-L. Author-X-Name-Last: Cui Author-Name: B. Chen Author-X-Name-First: B. Author-X-Name-Last: Chen Author-Name: R. Xiong Author-X-Name-First: R. Author-X-Name-Last: Xiong Author-Name: Y.-F. Mao Author-X-Name-First: Y.-F. Author-X-Name-Last: Mao Title: Application of the Z-transform technique to modeling the linear lumped networks in the HIE-FDTD method Abstract: In this work, a new lumped-network hybrid implicit–explicit finite-difference time-domain (LN-HIE-FDTD) method has been proposed. This method is derived from combining the 3D HIE-FDTD method with the Z-transform technique for the hybrid system including linear lumped networks. It possesses the advantage of deriving the updating equations immediately for complex circuits. The accuracy of the proposed method is verified from the comparison of calculated results given by the proposed method and the conventional lumped-network FDTD (LN-FDTD) method. The efficiency of the proposed method is verified from the comparison of the CPU time by the two methods. It is demonstrated that the proposed method is numerically efficient while time-saving. Journal: Journal of Electromagnetic Waves and Applications Pages: 529-538 Issue: 4 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.756375 File-URL: http://hdl.handle.net/10.1080/09205071.2013.756375 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:4:p:529-538 Template-Type: ReDIF-Article 1.0 Author-Name: Q. He Author-X-Name-First: Q. Author-X-Name-Last: He Author-Name: Y. A. Liu Author-X-Name-First: Y. A. Author-X-Name-Last: Liu Author-Name: S. L. Li Author-X-Name-First: S. L. Author-X-Name-Last: Li Author-Name: M. Su Author-X-Name-First: M. Author-X-Name-Last: Su Author-Name: Y. L. Wu Author-X-Name-First: Y. L. Author-X-Name-Last: Wu Title: A novel 180° rat-race hybrid with arbitrary power division for complex impedances Abstract: A generalized compact rat-race 180° hybrid with arbitrary power division ratio for matching complex impedance loads is presented in this paper. The proposed structure consists of four-section transmission lines, which is similar to the shape of the traditional hybrid. Compared with the conventional hybrid coupler, this design can be terminated with arbitrary complex impedances and realize high power-split ratio. Because of the symmetry of the proposed structure, it can be calculated by even–odd mode analysis and matrix. The explicit closed-form equations are derived analytically. The bandwidth variations are mainly discussed and simulated. For verifying the validity of this design, a microstrip prototype for 13.98 dB power-split ratio is simulated, fabricated, and measured. The measured performance shows a good agreement with the simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 318-329 Issue: 3 Volume: 27 Year: 2013 Month: 2 X-DOI: 10.1080/09205071.2013.744713 File-URL: http://hdl.handle.net/10.1080/09205071.2013.744713 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:3:p:318-329 Template-Type: ReDIF-Article 1.0 Author-Name: F. Tan Author-X-Name-First: F. Author-X-Name-Last: Tan Author-Name: W. Huang Author-X-Name-First: W. Author-X-Name-Last: Huang Author-Name: Y. Chen Author-X-Name-First: Y. Author-X-Name-Last: Chen Author-Name: Y. Li Author-X-Name-First: Y. Author-X-Name-Last: Li Author-Name: K. Huang Author-X-Name-First: K. Author-X-Name-Last: Huang Author-Name: C. Liu Author-X-Name-First: C. Author-X-Name-Last: Liu Title: Design and implementation of compact microwave components with artificial transmission lines Abstract: In this paper, designs and implementations of a compact diplexer, a broadband balun, and a tight-coupling directional coupler based on artificial transmission lines are presented. Techniques of applying artificial transmission lines to microwave component designs are explored and discussed. All designs show good performance in their respective groups and particularly small circuit sizes at lower microwave frequencies. Those microwave components are successfully implemented using artificial transmission lines based on conventional design topology. Moreover, feasibility and advantages of artificial transmission lines over conventional microstrip lines in designs of various microwave components at lower frequencies are verified such as diplexers, baluns, and directional couplers. Artificial transmission lines have a bright future in the miniaturization of microwave components. Journal: Journal of Electromagnetic Waves and Applications Pages: 385-395 Issue: 3 Volume: 27 Year: 2013 Month: 2 X-DOI: 10.1080/09205071.2013.747122 File-URL: http://hdl.handle.net/10.1080/09205071.2013.747122 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:3:p:385-395 Template-Type: ReDIF-Article 1.0 Author-Name: X.-H. Wang Author-X-Name-First: X.-H. Author-X-Name-Last: Wang Author-Name: L. Zhang Author-X-Name-First: L. Author-X-Name-Last: Zhang Author-Name: Y.-F. Bai Author-X-Name-First: Y.-F. Author-X-Name-Last: Bai Author-Name: Y. Xu Author-X-Name-First: Y. Author-X-Name-Last: Xu Author-Name: H. Xu Author-X-Name-First: H. Author-X-Name-Last: Xu Author-Name: X.-W. Shi Author-X-Name-First: X.-W. Author-X-Name-Last: Shi Title: Compact tunable dual-band filter using SIRs without extra blocking capacitances Abstract: A tunable dual-band microstrip filter using step-impedance resonators with harmonic suppression and compact size is presented in this paper. The second passband frequency of the filter can be flexibly controlled by tuning the bias voltage across the varactor whereas the first passband frequency is fixed. The structure is composed of couple lines and capacitive-loaded stepped-impedance resonator to provide frequency tunability and folded to reduce the size of the filter. The coupling scheme applied in this paper helps to reduce insertion loss and eliminate parasitic parameters, which is due to that extra blocking capacitances that are needless compared with the conventional coupling structure. To certify the validity, a prototype dual-band filter is designed, fabricated, and measured. The measured results show good agreement with the simulated ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 544-551 Issue: 5 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.756381 File-URL: http://hdl.handle.net/10.1080/09205071.2013.756381 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:5:p:544-551 Template-Type: ReDIF-Article 1.0 Author-Name: H. Lee Author-X-Name-First: H. Author-X-Name-Last: Lee Author-Name: I. Jung Author-X-Name-First: I. Author-X-Name-Last: Jung Author-Name: M. Seo Author-X-Name-First: M. Author-X-Name-Last: Seo Author-Name: H. Kim Author-X-Name-First: H. Author-X-Name-Last: Kim Author-Name: J. Ham Author-X-Name-First: J. Author-X-Name-Last: Ham Author-Name: J. Gu Author-X-Name-First: J. Author-X-Name-Last: Gu Author-Name: Y. Yang Author-X-Name-First: Y. Author-X-Name-Last: Yang Title: 400 W broadband power amplifier using transmission-line transformers with 1:8 impedance transformation ratio Abstract: This paper presents a broadband high-power amplifier using transmission-line transformers with a high impedance transformation ratio. Two series-connected transformers with 1:8 and 1:1 impedance transformation ratios are used at the load network of a single-balanced high-power amplifier to match the low load impedance in broadband. The same transformer configuration is also used at the input network. A negative feedback is applied to improve the gain flatness and to increase the stability over the broadband. In order to validate the proposed circuit structure, a broadband high-power amplifier is designed and implemented to achieve an output power of more than 400 W in the frequency band of 30 to 500 MHz. The implemented power amplifier exhibits a flat gain response within 1.80 dB at an average of 19.1 dB and high power-added efficiencies of 28.0 to 56.9 at an output power of 400 W over the entire frequency band. Journal: Journal of Electromagnetic Waves and Applications Pages: 1429-1438 Issue: 11 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.811122 File-URL: http://hdl.handle.net/10.1080/09205071.2013.811122 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:11:p:1429-1438 Template-Type: ReDIF-Article 1.0 Author-Name: Hongwei Yang Author-X-Name-First: Hongwei Author-X-Name-Last: Yang Author-Name: Zhen Wang Author-X-Name-First: Zhen Author-X-Name-Last: Wang Author-Name: Shuning Jiang Author-X-Name-First: Shuning Author-X-Name-Last: Jiang Author-Name: Zhenfeng Mu Author-X-Name-First: Zhenfeng Author-X-Name-Last: Mu Title: Study on the propagation properties of one-dimensional photonic crystal with oblique incidence by the precise integration method Abstract: Propagation properties of one-dimensional photonic crystal with oblique incidence are simulated and analyzed using precise integration method in the paper. The variational principle based on the single variable in conditions of the oblique incidence is derived. Then, the dual variables are introduced and the equations are derived to the Hamiltonian system formulation. A precise integration method based on the Riccati equations is used to generate the export stiffness matrices. The problem can be solved by merging the export stiffness matrices and using the boundary conditions. Numerical examples demonstrate the high accuracy and efficiency of this method for solving problems of transmission property of one-dimensional photonic crystal. Journal: Journal of Electromagnetic Waves and Applications Pages: 1830-1840 Issue: 14 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.825889 File-URL: http://hdl.handle.net/10.1080/09205071.2013.825889 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:14:p:1830-1840 Template-Type: ReDIF-Article 1.0 Author-Name: Y.-L. Lin Author-X-Name-First: Y.-L. Author-X-Name-Last: Lin Author-Name: S.-W. Lan Author-X-Name-First: S.-W. Author-X-Name-Last: Lan Author-Name: R.-Y. Yang Author-X-Name-First: R.-Y. Author-X-Name-Last: Yang Author-Name: C.-Y. Hung Author-X-Name-First: C.-Y. Author-X-Name-Last: Hung Title: Design of a high band-isolation diplexer based on asymmetric stepped-impedance resonators with side-coupling structure Abstract: In this paper, a high band-isolation diplexer based on two bandpass filters (BPFs) formed using asymmetric stepped-impedance resonators is presented. The passbands of the diplexer are operated at 1.8 GHz for global system for mobile communications (GSM) and 2.4 GHz for wireless local area network (WLAN). Side-coupling structure is adopted in BPFs to create two additional transmission zeros, thus enhancing the band isolation and stopband region. The measured results of the proposed diplexer show the passband at 1.8 GHz with a low insertion loss of 1.09 dB, a 3 dB fractional bandwidth (FBW) of 9.4% in the first channel and a passband at 2.4 GHz with an insertion loss of 2.6 dB, a 3 dB FBW of 6.2% in the second channel. The measured results of the fabricated diplexer also show a good agreement with the simulated ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 48-58 Issue: 1 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.737912 File-URL: http://hdl.handle.net/10.1080/09205071.2013.737912 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:1:p:48-58 Template-Type: ReDIF-Article 1.0 Author-Name: Makoto Ikeda Author-X-Name-First: Makoto Author-X-Name-Last: Ikeda Author-Name: Maxim Ignatenko Author-X-Name-First: Maxim Author-X-Name-Last: Ignatenko Author-Name: Atsushi Mase Author-X-Name-First: Atsushi Author-X-Name-Last: Mase Author-Name: Kiichiro Uchino Author-X-Name-First: Kiichiro Author-X-Name-Last: Uchino Title: Modeling and experimental detection of resonance frequency shift of a microwave cavity caused by a small conductive particle Abstract: Owing to recent progress in the manufacturing of electrical devices, the detection of metal dust on/in thin films or cloths has become crucial as they are used for separators or insulators. This paper considers the detection of metal particles less than 100 μm in size by monitoring the resonance frequency of a microwave cavity. Metal particles shift the resonance frequency, but the shift is less than the resonance frequency by many orders of magnitude when the cavity consists of an X-band waveguide. This makes it challenging to detect small metal particles in industrial environments. To overcome this difficulty, a new method of detecting small frequency shifts is proposed. First, transmission measurements are performed at a fixed frequency where the resonance peak has the steepest slope. Second, a Mexican hat filter is applied to the measured signal in order to distinguish frequency shifts from background noise and ambient conditions. Experimental detection of a 48 μm stainless steel sphere is demonstrated. The threshold level affects the minimum level of the sphere’s size and false positive signal. The paper also assesses the ability of available commercial software to accurately predict frequency shifts. The calculated results are compared with experimental data, which should be adjusted for the ambient temperature owing to thermal expansion of the cavity. The corrected experimental shifts agreed with the calculated shifts, demonstrating that the simulation can be used for future studies to improve this method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1114-1126 Issue: 9 Volume: 27 Year: 2013 Month: 6 X-DOI: 10.1080/09205071.2013.801041 File-URL: http://hdl.handle.net/10.1080/09205071.2013.801041 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:9:p:1114-1126 Template-Type: ReDIF-Article 1.0 Author-Name: Yun-Long Lu Author-X-Name-First: Yun-Long Author-X-Name-Last: Lu Author-Name: Gao-Le Dai Author-X-Name-First: Gao-Le Author-X-Name-Last: Dai Author-Name: Er-Ping Li Author-X-Name-First: Er-Ping Author-X-Name-Last: Li Author-Name: Kai Li Author-X-Name-First: Kai Author-X-Name-Last: Li Title: Dual-band bandpass filter using centrally coupled resonators (CCRs) Abstract: In this paper, a compact dual-band bandpass filter using novel centrally coupled resonators (CCRs) is presented. The proposed CCR is composed of a meandered microstrip line with a centrally coupled section and two lumped capacitors, which are loaded at the ends of the coupled lines. Based on the theoretical analysis, a key merit of the proposed resonator is found that both even- and odd-mode resonances can be separately controlled by altering the values of the relative loading capacitors. Benefitting from this feature, a dual-passband filter with two independent operating frequencies can be designed and a sample topology is demonstrated. The measured results exhibit good agreement with the full-wave simulation results, validating the proposed design concept. Journal: Journal of Electromagnetic Waves and Applications Pages: 1059-1067 Issue: 8 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.799446 File-URL: http://hdl.handle.net/10.1080/09205071.2013.799446 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:8:p:1059-1067 Template-Type: ReDIF-Article 1.0 Author-Name: S.P. Gao Author-X-Name-First: S.P. Author-X-Name-Last: Gao Author-Name: Q.S. Cao Author-X-Name-First: Q.S. Author-X-Name-Last: Cao Author-Name: J. Ding Author-X-Name-First: J. Author-X-Name-Last: Ding Author-Name: M. Zhu Author-X-Name-First: M. Author-X-Name-Last: Zhu Author-Name: Y.L. Lu Author-X-Name-First: Y.L. Author-X-Name-Last: Lu Title: A hybrid DGTD-TDIE method for solving complex electromagnetic problems Abstract: This paper presents a novel hybrid method that effectively combines two capable numerical methods – the discontinuous Galerkin time domain (DGTD) method and the time domain integral equation (TDIE) method. The hybrid DGTD-TDIE method is highly applicable to the interaction problem between arbitrarily shaped thin wires and dielectric structures with complex media compositions. The Huygens equivalence principle is employed to divide the original problem into two subproblems: (1) the region containing the thin wires, which is calculated by using the TDIE method, and (2) the dielectric region modeled by unstructured grids and analyzed by the DGTD method. A time-stepping scheme is used to match the different time steps between the DGTD and TDIE methods. To validate the hybrid method, several numerical results have been presented, which prove it a promising scheme to solve the complex coupling problems. Journal: Journal of Electromagnetic Waves and Applications Pages: 1017-1027 Issue: 8 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.797371 File-URL: http://hdl.handle.net/10.1080/09205071.2013.797371 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:8:p:1017-1027 Template-Type: ReDIF-Article 1.0 Author-Name: Li Xi Author-X-Name-First: Li Author-X-Name-Last: Xi Author-Name: Yang Lin Author-X-Name-First: Yang Author-X-Name-Last: Lin Author-Name: Wang Min Author-X-Name-First: Wang Author-X-Name-Last: Min Title: Novel design of multilayer wideband shorted annular stacked patch antenna for GNSS application with dual layer strip lines fed Abstract: Novel design of compact circularly polarized shorted annular stacked patch antenna has been proposed for global navigation satellite system in this study. The antenna has been designed to operate for the satellite navigation frequencies, including GPS, GLONASS, Galileo and Compass (1100–1600 MHz). Dual-layer strip lines that being composed of one broadband 180° hybrid and two wideband 90° hybrids are introduced as feeding network. As a result, the antenna has a 50.8% 10-dB return loss bandwidth from 1.1 to 1.85 GHz, and 45.5% 3-dB axial ratio bandwidth from 1.07 to 1.7 GHz, respectively. The designed antenna occupies a compact size of 70 mm × 70 mm × 28.5 mm. In this study, shorted annular stacked patch is introduced to obtain stable gain bandwidth, broad beam width characteristics, and good axial ratio at low elevation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1187-1195 Issue: 9 Volume: 27 Year: 2013 Month: 6 X-DOI: 10.1080/09205071.2013.803444 File-URL: http://hdl.handle.net/10.1080/09205071.2013.803444 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:9:p:1187-1195 Template-Type: ReDIF-Article 1.0 Author-Name: Joon-Ho Lee Author-X-Name-First: Joon-Ho Author-X-Name-Last: Lee Author-Name: Sung-Woo Cho Author-X-Name-First: Sung-Woo Author-X-Name-Last: Cho Author-Name: Hyun-Jin Moon Author-X-Name-First: Hyun-Jin Author-X-Name-Last: Moon Title: Application of the alternating projection strategy to the Capon beamforming and the MUSIC algorithm for azimuth/elevation AOA estimation Abstract: In this paper, the alternating projection (AP) scheme is applied to get the initial and the final estimates of the Capon beamforming algorithm and the MUSIC algorithm. In a previous paper, the AP scheme has been proposed as a computationally efficient method for the initialization and optimization of the cost function for the ML-based angle of arrival (AOA) estimation problem. We call the AP scheme in the previous paper the brute-force AP strategy. To improve the brute-force AP, we suggest the Newton AP which consists of the successive one-dimensional Newton search. The brute-force AP can be used for the initialization and the optimization of the cost function of AOA estimation, and the Newton AP can be used for the optimization of the cost function for the AOA problem. We compare the performance of the AP-based approach with the conventional implementation of the AOA estimation algorithm using two-dimensional brute-force search. Journal: Journal of Electromagnetic Waves and Applications Pages: 1439-1454 Issue: 12 Volume: 27 Year: 2013 Month: 8 X-DOI: 10.1080/09205071.2013.802657 File-URL: http://hdl.handle.net/10.1080/09205071.2013.802657 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:12:p:1439-1454 Template-Type: ReDIF-Article 1.0 Author-Name: Jinquan Lu Author-X-Name-First: Jinquan Author-X-Name-Last: Lu Author-Name: Dongsheng La Author-X-Name-First: Dongsheng Author-X-Name-Last: La Title: Novel band-pass filters using E-shape resonators Abstract: A class of band-pass filters using E-shape resonators is proposed in this paper. The transmission and reflection property of the E-shaped resonators are analyzed with the transmission line theory. In order to verify the E-shaped resonators circuit structure and its corresponding filter design theory, the single, two-, and three-cascaded band-pass filters using E-shaped resonators are designed and simulated. The resonant characteristics of the cascaded band-pass filters show their advantages of compact size, excellent pass-band performance, and high out-band suppression. Finally, the two- and three-cascaded band-pass filters are fabricated and measured. The measured results show excellent band-pass filtering property and low insertion loss. The measured results also prove to be generally consistent with the simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 458-463 Issue: 4 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.749774 File-URL: http://hdl.handle.net/10.1080/09205071.2013.749774 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:4:p:458-463 Template-Type: ReDIF-Article 1.0 Author-Name: J.-Q. Lan Author-X-Name-First: J.-Q. Author-X-Name-Last: Lan Author-Name: K.-M. Huang Author-X-Name-First: K.-M. Author-X-Name-Last: Huang Title: Evaluation of SAR in a human head with glasses exposed to radiation of a mobile phone Abstract: In this paper, we evaluate specific absorption rates (SAR) in a human head exposed to radiation of a mobile phone at two frequencies of Global System for Mobile (GSM) Communications, when people do and don’t wear glasses. The simulation includes phone call and internet surfing states. Since the eyes are sensitive to electromagnetic radiation, we focus on the maximal SAR in eyes. Based on finite-difference time-domain (FDTD) calculation method, we find that wearing glasses obviously alters the distribution of SAR and may increase SAR. The maximal SAR in eyes with glasses is even eight times more than that without glasses. The maximal SAR is more sensitive to the frame of glasses than the spectacle lens. In all, wearing glasses may possibly induce higher risk of the health hazard to eyes exposed to the radiation of a mobile phone. The results could offer valuable results for designing glasses to reduce SAR in eyes. Journal: Journal of Electromagnetic Waves and Applications Pages: 1919-1930 Issue: 15 Volume: 27 Year: 2013 Month: 10 X-DOI: 10.1080/09205071.2013.828576 File-URL: http://hdl.handle.net/10.1080/09205071.2013.828576 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:15:p:1919-1930 Template-Type: ReDIF-Article 1.0 Author-Name: Giovanni Andrea Casula Author-X-Name-First: Giovanni Andrea Author-X-Name-Last: Casula Author-Name: Giorgio Montisci Author-X-Name-First: Giorgio Author-X-Name-Last: Montisci Author-Name: Giuseppe Mazzarella Author-X-Name-First: Giuseppe Author-X-Name-Last: Mazzarella Author-Name: Paolo Maxia Author-X-Name-First: Paolo Author-X-Name-Last: Maxia Author-Name: Alessandro Fanti Author-X-Name-First: Alessandro Author-X-Name-Last: Fanti Title: Improved analysis of high-performances planar waveguide slot arrays Abstract: An improved analysis procedure for planar waveguide slot arrays has been devised and assessed. It takes into account the main interferences between radiating and coupling slots, and between coupling slots and T-junctions, and waveguide bends used in the array feeding network. All these effects have been modeled using in-house MoM codes, and Elliott’s slot array model has been extended to include them. The results of this improved procedure have been compared with experimental data showing a very good agreement. Journal: Journal of Electromagnetic Waves and Applications Pages: 2155-2165 Issue: 17 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.834274 File-URL: http://hdl.handle.net/10.1080/09205071.2013.834274 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:17:p:2155-2165 Template-Type: ReDIF-Article 1.0 Author-Name: Yu. G. Rapoport Author-X-Name-First: Yu. G. Author-X-Name-Last: Rapoport Author-Name: S. Tretyakov Author-X-Name-First: S. Author-X-Name-Last: Tretyakov Author-Name: S. Maslovski Author-X-Name-First: S. Author-X-Name-Last: Maslovski Title: Nonlinear active Huygens metasurfaces for reflectionless phase conjugation of electromagnetic waves in electrically thin layers Abstract: A possibility of almost perfect phase conjugation in electrically thin nonlinear sheets is shown for the normal incidence of the signal wave, using either symmetrical or asymmetrical particles and nondegenerate interaction with slightly different frequencies of the incident and phase-conjugated waves. Under these conditions, the use of linear and nonlinear Huygens sources for both linear (signal) and nonlinear (phase-conjugated) waves ensures zero or very small reflection for both of them. In perspective, this can lead to realization of reflectionless superlens based on three-wave interactions, as well to other applications based on reflection-free and electrically thin nonlinear layers. Journal: Journal of Electromagnetic Waves and Applications Pages: 1309-1328 Issue: 11 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.808596 File-URL: http://hdl.handle.net/10.1080/09205071.2013.808596 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:11:p:1309-1328 Template-Type: ReDIF-Article 1.0 Author-Name: Rongqiang Li Author-X-Name-First: Rongqiang Author-X-Name-Last: Li Author-Name: Guohong Du Author-X-Name-First: Guohong Author-X-Name-Last: Du Title: Substrate integrated waveguide filter with high-design flexibility Abstract: On the basis of TE201/TE101 mode substrate integrated waveguide (SIW) cavity resonators, an advanced methodology is proposed to design filter using nonresonating node with high-design flexibility. The bypass couplings are realized with the nonresonating TE10 mode, so that arbitrarily positioned transmission zeros (TZs) can be obtained. To demonstrate the design flexibility, the approach is illustrated at example of a second-order filter providing Chebyshev, elliptic function type, and asymmetric characteristics. In addition, the modularity of the filter design is validated by the individual control of each TZ. A second-order 15 GHz SIW bandpass filter with 150 MHz bandwidth is then fabricated and measured. Comparison between the measurement values and simulation results verifies the effectiveness of the proposed configurations. Journal: Journal of Electromagnetic Waves and Applications Pages: 1751-1758 Issue: 14 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.823128 File-URL: http://hdl.handle.net/10.1080/09205071.2013.823128 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:14:p:1751-1758 Template-Type: ReDIF-Article 1.0 Author-Name: Mohsen Hayati Author-X-Name-First: Mohsen Author-X-Name-Last: Hayati Author-Name: Sobhan Roshani Author-X-Name-First: Sobhan Author-X-Name-Last: Roshani Author-Name: Saeed Roshani Author-X-Name-First: Saeed Author-X-Name-Last: Roshani Author-Name: Farzin Shama Author-X-Name-First: Farzin Author-X-Name-Last: Shama Title: A novel miniaturized Wilkinson power divider with nth harmonic suppression Abstract: In this paper, a miniaturized Wilkinson power divider using a novel technique for nth harmonic suppression is presented. In this technique, a novel low-pass filter (LPF) is inserted into each quarter-wavelength transmission line of the conventional Wilkinson power divider and open stubs are used at each port. For verification, the proposed 1 GHz power divider and the miniaturized LPF are fabricated and measured. The presented structure not only impressively suppresses the harmonics (2nd–12th) with high levels of attenuation, but also significantly reduces the size over 71% of the conventional one. The overall size of the fabricated power divider is only 14.1 mm × 18.2 mm (0.06 λg × 0.08λg). Journal: Journal of Electromagnetic Waves and Applications Pages: 726-735 Issue: 6 Volume: 27 Year: 2013 Month: 4 X-DOI: 10.1080/09205071.2013.786204 File-URL: http://hdl.handle.net/10.1080/09205071.2013.786204 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:6:p:726-735 Template-Type: ReDIF-Article 1.0 Author-Name: T.L. Yim Author-X-Name-First: T.L. Author-X-Name-Last: Yim Author-Name: S.K.A. Rahim Author-X-Name-First: S.K.A. Author-X-Name-Last: Rahim Author-Name: R. Dewan Author-X-Name-First: R. Author-X-Name-Last: Dewan Title: Reconfigurable wideband and narrowband tapered slot Vivaldi antenna with ring slot pairs Abstract: A tapered slot Vivaldi antenna with reconfigurable capability is proposed in this paper. The tapered slot length was implemented on ring slot pairs to generate narrowband multiples at 1.5, 3.24, 3.44, and 4.12 GHz. Studies on the assignment of tapered slot length to ring slot pairs on Vivaldi antennas are presented and discussed. The combination of a tapered slot Vivaldi antenna, tapered slot length, and ring slots pairs successfully produces a tunable tapered slot Vivaldi antenna that is able to operate in wideband and narrowband, allowing for wireless communication. The wideband of the proposed antenna is from 1.5 to 5 GHZ. The study is also extended to the filtering effect tapered slot length on the ring slot pair. The proposed antenna performs well in terms of radiation pattern, return loss, and gain. The measurement results of the antenna’s performance satisfactorily agree with the simulation ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 276-287 Issue: 3 Volume: 27 Year: 2013 Month: 2 X-DOI: 10.1080/09205071.2013.744124 File-URL: http://hdl.handle.net/10.1080/09205071.2013.744124 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:3:p:276-287 Template-Type: ReDIF-Article 1.0 Author-Name: C.-W. Zhang Author-X-Name-First: C.-W. Author-X-Name-Last: Zhang Author-Name: Y.-Z. Yin Author-X-Name-First: Y.-Z. Author-X-Name-Last: Yin Author-Name: P.-A. Liu Author-X-Name-First: P.-A. Author-X-Name-Last: Liu Author-Name: J.-J. Xie Author-X-Name-First: J.-J. Author-X-Name-Last: Xie Title: Compact dual band-notched UWB antenna with hexagonal slotted ground plane Abstract: A novel compact dual band-notched ultra-wide band antenna with hexagonal slotted ground is proposed. By inserting two pairs of L-shaped branches symmetrically into the slotted ground plane, two notched bands, 3.3–3.7 GHz for worldwide interoperability for microwave access and 5.15–5.825 GHz for wireless local area network, are achieved, respectively. A prototype of the proposed antenna is designed, fabricated, and tested. By optimizing the length of the L-shaped branches and the gap between them, the desired bandwidth of VSWR (voltage standing wave ratio) less than 2.0 can be achieved, ranging from 2.5 to 11 GHz, except two stop-bands of 3.1–4.0 and 5.0–6.0 GHz. The simulated and measured results of the proposed antenna have shown a reasonable agreement between them. The proposed antenna has a compact size, ultra wide bandwidth, good radiation characteristics, and good time-domain behaviors. It is very suitable for modern wireless communication applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 215-223 Issue: 2 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.743449 File-URL: http://hdl.handle.net/10.1080/09205071.2013.743449 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:2:p:215-223 Template-Type: ReDIF-Article 1.0 Author-Name: Yan Li Author-X-Name-First: Yan Author-X-Name-Last: Li Author-Name: Quanyuan Feng Author-X-Name-First: Quanyuan Author-X-Name-Last: Feng Title: A compact tri-band monopole antenna with metamaterial loaded for WLAN/WiMAX applications Abstract: An asymmetric coplanar waveguide (ACPW)-fed tri-band monopole antenna with metamaterial loaded is investigated. The designed antenna comprises of a rectangle patch radiating element, a strip, and a complementary spilt-ring resonator (CSRR)-shaped slot. By embedding a trip connected between the rectangle patch and an ACPW ground plane, an epsilon negative transmission-line metamaterial loaded is achieved to obtain a zeroth-order mode. By embedding a CSRR-shaped slot in the patch leads to another resonant frequency at high band. A prototype designed on ArlonAR350(tm) substrate with dielectric constant 3.5 occupies an overall size of 14.5 × 25 × 0.8 mm3. The measured results show that the proposed antenna operates over the frequency ranges of 2.35–2.61 GHz, 3.38–4.01 GHz, and 4.25–6.65 GHz. It is suitable for WLAN 2.45/5.2/5.8 GHz and WiMAX 3.5/5.5 GHz applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 772-782 Issue: 6 Volume: 27 Year: 2013 Month: 4 X-DOI: 10.1080/09205071.2013.786208 File-URL: http://hdl.handle.net/10.1080/09205071.2013.786208 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:6:p:772-782 Template-Type: ReDIF-Article 1.0 Author-Name: Ming Chen Author-X-Name-First: Ming Author-X-Name-Last: Chen Author-Name: Chi-Chih Chen Author-X-Name-First: Chi-Chih Author-X-Name-Last: Chen Author-Name: John L. Volakis Author-X-Name-First: John L. Author-X-Name-Last: Volakis Title: A novel textured ferrite ground plane for low-profile spiral antenna Abstract: This paper presents a novel textured ferrite ground plane for the metallic cavity used as a ground plane for spiral antennas. Impedance-matched ferrite is used at the outer rim of the ground plane, and a high impedance ferrite is employed in the inner section of the cavity. Simulations show that this textured ferrite ground plane improves the spiral performance at both low frequencies and high frequencies. Journal: Journal of Electromagnetic Waves and Applications Pages: 1720-1724 Issue: 13 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.823124 File-URL: http://hdl.handle.net/10.1080/09205071.2013.823124 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:13:p:1720-1724 Template-Type: ReDIF-Article 1.0 Author-Name: Juan F. Izquierdo Author-X-Name-First: Juan F. Author-X-Name-Last: Izquierdo Author-Name: Jesús Rubio Author-X-Name-First: Jesús Author-X-Name-Last: Rubio Title: Full modeling of wideband volumetric antennas by elementary sources placed on the ground plane Abstract: A very accurate modeling technique of volumetric antennas is presented in this work. Specifically, an equivalent model based on a set of elementary sources of infinitesimal colocalized dipoles is obtained by using a genetic algorithm jointly with the application of the translational addition theorems of spherical waves. The equivalent sources that model the whole behavior of the volumetric antenna (not only the transmitting characteristics, but also its reflection, reception, and scattering properties) are located on the metallic ground plane, i.e. a planar set of sources is achieved to model nonplanar radiating devices, which increases its efficiency significantly, since the number of infinitesimal dipoles can be reduced considerably allowing the process to be much faster. Efficient wideband modeling is achieved by means of the construction of different models at very few frequency samples. The obtained full models are valid outside of the antenna minimum sphere. This way, it can be employed to the study of near–field interactions, such as arrays of antennas whose minimum spheres do not overlap. Journal: Journal of Electromagnetic Waves and Applications Pages: 794-806 Issue: 6 Volume: 27 Year: 2013 Month: 4 X-DOI: 10.1080/09205071.2013.787376 File-URL: http://hdl.handle.net/10.1080/09205071.2013.787376 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:6:p:794-806 Template-Type: ReDIF-Article 1.0 Author-Name: H.W. Son Author-X-Name-First: H.W. Author-X-Name-Last: Son Author-Name: Y.K. Cho Author-X-Name-First: Y.K. Author-X-Name-Last: Cho Author-Name: A. Gopinath Author-X-Name-First: A. Author-X-Name-Last: Gopinath Author-Name: J.T. Vaughan Author-X-Name-First: J.T. Author-X-Name-Last: Vaughan Author-Name: C.H. Lee Author-X-Name-First: C.H. Author-X-Name-Last: Lee Author-Name: H. Yoo Author-X-Name-First: H. Author-X-Name-Last: Yoo Title: shimming with SAR reduction in high-field MRI Abstract: In high-field magnetic resonance imaging systems, parallel excitation with a multi-channel transmitter and receiver has been widely investigated to mitigate inhomogeneity. Multi-channel RF coils employed in the parallel imaging may alleviate the non-uniformity in the field and each element can be independently controlled by adjusting the phase and amplitude of the excitation. In this paper, convex optimization for each coil elements to homogenize and to reduce E fields is proposed. Improved homogeneity and reduced specific absorption rate over the whole field of view is achieved. Journal: Journal of Electromagnetic Waves and Applications Pages: 1521-1524 Issue: 12 Volume: 27 Year: 2013 Month: 8 X-DOI: 10.1080/09205071.2013.817958 File-URL: http://hdl.handle.net/10.1080/09205071.2013.817958 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:12:p:1521-1524 Template-Type: ReDIF-Article 1.0 Author-Name: GuoHua Lin Author-X-Name-First: GuoHua Author-X-Name-Last: Lin Author-Name: YeRong Zhang Author-X-Name-First: YeRong Author-X-Name-Last: Zhang Author-Name: YongJian Zhi Author-X-Name-First: YongJian Author-X-Name-Last: Zhi Title: Effects of pantograph arcing on railway systems with auto transformers Abstract: Conducted and radiated electromagnetic interferences on auto transformer (AT) caused by pantograph arcing in electrified railway system are investigated. The overhead lines of electrified railway system can be simplified by three parallel overhead conductor lines. The model of AT in this paper is situated at the end of lines. The propagation of electromagnetic waves along the three conductors is solved by using finite-difference time-domain (FDTD) method. The circuit model for AT is created by state variable equations, and the equations are discretized by backward Euler method. The pantograph arcing is represented by a trapezoidal voltage pulse which has a wide band of frequency just like an arcing has; the rise and fall time are determined by the main frequency. The voltages across the AT windings are computed by the final FDTD iterative equations when all factors are considered. Journal: Journal of Electromagnetic Waves and Applications Pages: 1686-1693 Issue: 13 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.823120 File-URL: http://hdl.handle.net/10.1080/09205071.2013.823120 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:13:p:1686-1693 Template-Type: ReDIF-Article 1.0 Author-Name: M. Koba Author-X-Name-First: M. Author-X-Name-Last: Koba Author-Name: J. Suffczyński Author-X-Name-First: J. Author-X-Name-Last: Suffczyński Title: Magneto-optical effects enhancement in DMS layers utilizing 1-D photonic crystal Abstract: We propose a theoretical design of a structure combining a diluted magnetic semiconductor (DMS) layer with one-dimensional photonic crystal and show that it allows for a sizable (a few-fold) enhancement of the magneto-optical Kerr effect (MOKE) magnitude. We base our calculations on the transfer matrix method assuming realistic, and optimal with respect to a sample growth, parameters. We investigate representative cases of (Ga, Mn)N or (Cd, Mn)Te DMS layers deposited on the top of a respectively GaN- or CdTe-based distributed Bragg reflector, and highlight the applicability of the proposed design for both: III–V wurtzite and II–VI zinc-blende DMS. Journal: Journal of Electromagnetic Waves and Applications Pages: 700-706 Issue: 6 Volume: 27 Year: 2013 Month: 4 X-DOI: 10.1080/09205071.2013.762726 File-URL: http://hdl.handle.net/10.1080/09205071.2013.762726 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:6:p:700-706 Template-Type: ReDIF-Article 1.0 Author-Name: L. Sun Author-X-Name-First: L. Author-X-Name-Last: Sun Author-Name: B. Du Author-X-Name-First: B. Author-X-Name-Last: Du Author-Name: B.-H. Sun Author-X-Name-First: B.-H. Author-X-Name-Last: Sun Title: Inductively loaded and magnetically coupled small antenna with circular polarization Abstract: A magnetically coupled small antenna with circular polarization is presented. The antenna is composed of two orthogonal magnetic dipoles with inductively loaded hats, four capacitively loaded gaps, and a rotated driven semi-loop. Electronically, small size is implemented by employing a new inductively loaded technique. This technique consists of adding short circuited cylindrical covers to extremes of the structure, making the elements be inductively loaded, and as a result, increases the electronic length. The principle of implementing this antenna is presented in an equivalent circuit. An antenna prototype resonating at 1.3218 GHz with size of ( is proposed to verify this method. An effective volume reduction of about 17% is achieved by comparing with the newest published paper. Journal: Journal of Electromagnetic Waves and Applications Pages: 539-543 Issue: 5 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.756380 File-URL: http://hdl.handle.net/10.1080/09205071.2013.756380 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:5:p:539-543 Template-Type: ReDIF-Article 1.0 Author-Name: J. Niitsuma Author-X-Name-First: J. Author-X-Name-Last: Niitsuma Title: Generalized integral formulation of electromagnetic Cartesian multipole moments Abstract: We study integral expressions of electromagnetic multipole moments of arbitrary order in Cartesian coordinates. The volume and surface integrals of charge-induced and current-induced multipole moment tensors are formulated and the relationship between them is discussed. Full surface integral expressions for the multipole moment are also obtained. We further extend the formulation to introduce another kind of dipole moment, which is similar to the charge-induced and current-induced multipole moments and is found in a vector decomposition formula Journal: Journal of Electromagnetic Waves and Applications Pages: 1525-1533 Issue: 12 Volume: 27 Year: 2013 Month: 8 X-DOI: 10.1080/09205071.2013.819473 File-URL: http://hdl.handle.net/10.1080/09205071.2013.819473 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:12:p:1525-1533 Template-Type: ReDIF-Article 1.0 Author-Name: T. Drizdal Author-X-Name-First: T. Author-X-Name-Last: Drizdal Author-Name: M.M. Paulides Author-X-Name-First: M.M. Author-X-Name-Last: Paulides Author-Name: J. Vrba Author-X-Name-First: J. Author-X-Name-Last: Vrba Author-Name: G.C. van Rhoon Author-X-Name-First: G.C. Author-X-Name-Last: van Rhoon Title: Waveguide-based applicators for superficial hyperthermia treatment: is tuning really required? Abstract: Waveguide-based applicators are used for hyperthermia treatment of superficial tumors, e.g. chest wall recurrences. During superficial hyperthermia treatment (SHT), the patient is in the near field of these antennas, so its radiating properties may vary. To maximize the transfer power from generators towards treatment area, waveguide-based applicators usually feature means for tuning the applicators. The purpose of this study was to investigate whether waveguide-based applicators for SHT really require such tuning. Hereto, we designed and optimized a waveguide lucite applicator at 434 MHz, applying a muscle phantom and a layered (skin, fat and muscle) phantom to mimic the patient. Applicator performance was measured for different water bolus temperatures and temperatures of the water circulating the applicator by studying impedance matching.  dB was measured for nine locations at the skin of a volunteer and three different water bolus temperatures. We conclude that tuning of waveguide-based applicators is not required when the applicator is properly designed. Journal: Journal of Electromagnetic Waves and Applications Pages: 682-690 Issue: 6 Volume: 27 Year: 2013 Month: 4 X-DOI: 10.1080/09205071.2013.762609 File-URL: http://hdl.handle.net/10.1080/09205071.2013.762609 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:6:p:682-690 Template-Type: ReDIF-Article 1.0 Author-Name: Q.-L. Zhang Author-X-Name-First: Q.-L. Author-X-Name-Last: Zhang Author-Name: W.-Y. Yin Author-X-Name-First: W.-Y. Author-X-Name-Last: Yin Author-Name: L.-S. Wu Author-X-Name-First: L.-S. Author-X-Name-Last: Wu Author-Name: B.-Z. Wang Author-X-Name-First: B.-Z. Author-X-Name-Last: Wang Title: Design of a compact rat-race coupler employing electromagnetic bandgap (EBG)-loaded and composite right/left-handed (CRLH) half-mode substrate integrated waveguides (HMSIWs) Abstract: A new type of rat-race coupler, based on electromagnetic bandgap (EBG)-loaded half-mode substrate integrated waveguide (HMSIW) and composite right/left-handed (CRLH) HMSIW, has been proposed and investigated comprehensively. It consists of three sections of EBG-loaded HMSIWs with 90° phase delay and one section of CRLH HMSIW with −90° phase advance. Due to the evanescent-mode of EBG-loaded HMSIW and the backward behavior of the CRLH HMSIW in the left-handed region, the size of such a miniaturized rat-race coupler is reduced about 65.7% in comparison with its conventional counterpart. The rat-race coupler with the central frequency of 5.5 GHz has been designed and fabricated so as to validate our method, and its good performance is demonstrated by both simulated and measured results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1028-1035 Issue: 8 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.799443 File-URL: http://hdl.handle.net/10.1080/09205071.2013.799443 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:8:p:1028-1035 Template-Type: ReDIF-Article 1.0 Author-Name: Mun Seok Choe Author-X-Name-First: Mun Seok Author-X-Name-Last: Choe Author-Name: Kwang Hoon Kim Author-X-Name-First: Kwang Hoon Author-X-Name-Last: Kim Author-Name: EunMi Choi Author-X-Name-First: EunMi Author-X-Name-Last: Choi Title: A comprehensive analysis of a TE11 to HE11 mode converter for an oversized F-band corrugated waveguide Abstract: We have investigated the mode transition behavior from approximately half- to quarter-wavelength in typical F-band (90–140 GHz) TE11 to HE11 converters of varying corrugation depths. Simulations in which the number of slots in the corrugation is varied indicate that the optimal number of slots should be greater than two, which is in excellent agreement with the experimental results. The mode content was also analyzed with and without a quarter-wavelength depth-corrugated tapered section. The electric field pattern at the exit of a quarter-wavelength tapered transition connected to a half-wavelength to quarter-wavelength TE11 to HE11 mode converter is compared with that without a converter. Electric field patterns both with and without a half- to quarter-wavelength TE11 to HE11 mode converter show a highly Gaussian field pattern with less than 35 dB of cross-polarization. Simulated field patterns are in good agreement with the experimentally measured field patterns, with the measured and simulated electric field distributions matching approximately 96.5 and 97.5%, respectively, to a pure Gaussian distribution. Journal: Journal of Electromagnetic Waves and Applications Pages: 2221-2238 Issue: 17 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.838147 File-URL: http://hdl.handle.net/10.1080/09205071.2013.838147 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:17:p:2221-2238 Template-Type: ReDIF-Article 1.0 Author-Name: Yong Zhi Cheng Author-X-Name-First: Yong Zhi Author-X-Name-Last: Cheng Author-Name: Yan Nie Author-X-Name-First: Yan Author-X-Name-Last: Nie Author-Name: Zheng Ze Cheng Author-X-Name-First: Zheng Ze Author-X-Name-Last: Cheng Author-Name: Xian Wang Author-X-Name-First: Xian Author-X-Name-Last: Wang Author-Name: Rong Zhou Gong Author-X-Name-First: Rong Zhou Author-X-Name-Last: Gong Title: Chiral metamaterials with giant optical activity and negative refractive index based on complementary conjugate-swastikas structure Abstract: A compact chiral metamaterial (CMM) based on the complementary conjugate-swastikas structure was investigated. Both numerical simulations and experiments reveal that the structure exhibits giant optical rotation as well as high transmittances when a plane wave is normally incident on it, indicating strong chirality. The retrieval results reveal that negative refractive indices of the designed CCMM also could be easily realized due to strong chirality. The physical mechanism was illustrated by simulated scattered magnetic field and surface current distributions. Further, the influences of the structural parameters of the complementary CMM to the transmissions spectra, optical activity and negative refraction have been investigated numerically. Journal: Journal of Electromagnetic Waves and Applications Pages: 1068-1076 Issue: 8 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.799447 File-URL: http://hdl.handle.net/10.1080/09205071.2013.799447 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:8:p:1068-1076 Template-Type: ReDIF-Article 1.0 Author-Name: Shobhit K. Patel Author-X-Name-First: Shobhit K. Author-X-Name-Last: Patel Author-Name: Yogeshwar Kosta Author-X-Name-First: Yogeshwar Author-X-Name-Last: Kosta Title: Investigation on radiation improvement of corner truncated triband square microstrip patch antenna with double negative material Abstract: In this paper, we have reported a truncated square microstrip patch antenna loaded with double negative material and conventional dielectric material. Metamaterials exhibit qualitatively new electromagnetic response functions that cannot be found in the nature. The inclusion of these structures allows simultaneous operation over several frequencies. We have designed an antenna loaded with metamaterial to work in three bands in the frequency range of 0.5–2.0 GHz. The designed antenna loaded with metamaterial has three working frequency bands. We have shown a comparative analysis of this metamaterial loaded antenna with conventional antenna. The designed antenna loaded with metamaterial has several wireless applications. Design results are obtained by high frequency structure simulator, which is used for simulating microwave passive components. Journal: Journal of Electromagnetic Waves and Applications Pages: 819-833 Issue: 7 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.789407 File-URL: http://hdl.handle.net/10.1080/09205071.2013.789407 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:7:p:819-833 Template-Type: ReDIF-Article 1.0 Author-Name: Jose Alfredo Tirado-Mendez Author-X-Name-First: Jose Alfredo Author-X-Name-Last: Tirado-Mendez Author-Name: Hildeberto Jardon-Aguilar Author-X-Name-First: Hildeberto Author-X-Name-Last: Jardon-Aguilar Author-Name: Roberto Linares-Miranda Author-X-Name-First: Roberto Author-X-Name-Last: Linares-Miranda Title: Reduced length strip dipole antenna with DMS and stub loading without efficiency degradation Abstract: In this work, two techniques are introduced in order to reduce the dimensions of strip antennas. As an example, reduced size dipoles with no efficiency degradation are accomplished by introducing a stub load and a defected microstrip structure. For a specific configuration, a dual frequency operation can be achieved obtaining the same gain compared to a conventional strip dipole. Moreover, this technique gives the opportunity to get the same bandwidth for certain stub dimensions. Combining both techniques, the efficiency of the antenna and the cross-polarization ratio are kept with an antenna length reduction of 33%. Journal: Journal of Electromagnetic Waves and Applications Pages: 1815-1829 Issue: 14 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.825888 File-URL: http://hdl.handle.net/10.1080/09205071.2013.825888 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:14:p:1815-1829 Template-Type: ReDIF-Article 1.0 Author-Name: Marco A. Panduro Author-X-Name-First: Marco A. Author-X-Name-Last: Panduro Author-Name: Carlos A. Brizuela Author-X-Name-First: Carlos A. Author-X-Name-Last: Brizuela Author-Name: Jesus Garza Author-X-Name-First: Jesus Author-X-Name-Last: Garza Author-Name: Sergio Hinojosa Author-X-Name-First: Sergio Author-X-Name-Last: Hinojosa Author-Name: Alberto Reyna Author-X-Name-First: Alberto Author-X-Name-Last: Reyna Title: A comparison of NSGA-II, DEMO, and EM-MOPSO for the multi-objective design of concentric rings antenna arrays Abstract: A comparison between different modern multi-objective optimization methods applied to the design of concentric rings antenna arrays is presented in this paper. This design of concentric rings antenna arrays considers the optimization of the amplitude and phase excitations across the antenna elements in order to generate the trade-off curves between side lobe level and directivity for a scannable pattern with optimal performance in the whole azimuth plane. Simulation results by using evolutionary multi-objective optimization methods, such as: NSGA-II, DEMO, and EM-MOPSO are provided in this document. Furthermore, a comparative analysis of the performance between these algorithms is presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 1100-1113 Issue: 9 Volume: 27 Year: 2013 Month: 6 X-DOI: 10.1080/09205071.2013.801040 File-URL: http://hdl.handle.net/10.1080/09205071.2013.801040 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:9:p:1100-1113 Template-Type: ReDIF-Article 1.0 Author-Name: Sun K. Hong Author-X-Name-First: Sun K. Author-X-Name-Last: Hong Author-Name: Biniyam T. Taddese Author-X-Name-First: Biniyam T. Author-X-Name-Last: Taddese Author-Name: Zachary B. Drikas Author-X-Name-First: Zachary B. Author-X-Name-Last: Drikas Author-Name: Steven M. Anlage Author-X-Name-First: Steven M. Author-X-Name-Last: Anlage Author-Name: Tim D. Andreadis Author-X-Name-First: Tim D. Author-X-Name-Last: Andreadis Title: Focusing an arbitrary RF pulse at a distance using time-reversal techniques Abstract: In this paper, we demonstrate the use of a time reversal (TR) technique to effectively focus an arbitrary RF pulse at a remote location from a single-feed aperture for directed energy applications. The TR focusing is achieved by backing the aperture with a reverberating cavity, whose multipath environment enables the reconstruction of the aperture field distribution needed for directing the energy to the target location. Here, we use the impulse response between the target location and the time-reversal mirror (TRM) located inside the cavity to enable the effective transmission of arbitrary RF pulses, which are convolved with the time-reversed impulse response before transmission. The demonstration is carried out both numerically and experimentally for various RF pulses. The results show good temporal and spatial focusing at the target location. This approach could be an efficient selective “beamforming” method for directed energy, where it only requires a single feed and the impulse response between the TRM and target location or direction to effectively deliver an RF pulse of choice within an ultra-wide bandwidth of the impulse response. Journal: Journal of Electromagnetic Waves and Applications Pages: 1262-1275 Issue: 10 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.805310 File-URL: http://hdl.handle.net/10.1080/09205071.2013.805310 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:10:p:1262-1275 Template-Type: ReDIF-Article 1.0 Author-Name: Jong-Ig Lee Author-X-Name-First: Jong-Ig Author-X-Name-Last: Lee Author-Name: Junho Yeo Author-X-Name-First: Junho Author-X-Name-Last: Yeo Title: Design of a simple three-element quasi-Yagi antenna with a broad impedance bandwidth up to 2.4 : 1 Abstract: This paper introduces a method for designing a broadband three-element quasi-Yagi antenna (QYA) with a simple geometry and compact size. The proposed QYA consists of simple strip-type elements with unequal widths and distances between them to obtain the desired performance. The proposed QYA fed by a microstrip (MS) line is compact because it has an MS line-to-coplanar strip (CPS) line transition integrated on the CPS line, without requiring additional space for the transition. When a rectangular patch-type director is placed close to the driver dipole fed by a CPS line, the antenna becomes a triple resonance structure, and the impedance bandwidth is extensively increased up to 2.4 : 1 (82.3%) for a VSWR < 2. An example design for a QYA with a gain >4 dBi and a frequency band of 1.6–3.6 GHz is presented. The optimized antenna is fabricated on an FR4 substrate with dimensions of 90 mm × 90 mm and is tested experimentally. The results demonstrate an impedance bandwidth of 2.4 : 1 (1.56–3.74 GHz, 82.3%) for a VSWR < 2, a realized gain of >4 dBi, a cross-polarization level of <−21 dB, and a front-to-back ratio of >13.6 dB within the bandwidth. Journal: Journal of Electromagnetic Waves and Applications Pages: 2247-2262 Issue: 17 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.838911 File-URL: http://hdl.handle.net/10.1080/09205071.2013.838911 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:17:p:2247-2262 Template-Type: ReDIF-Article 1.0 Author-Name: M.J. Islam Author-X-Name-First: M.J. Author-X-Name-Last: Islam Author-Name: A.W. Reza Author-X-Name-First: A.W. Author-X-Name-Last: Reza Author-Name: K.A. Noordin Author-X-Name-First: K.A. Author-X-Name-Last: Noordin Author-Name: A.S.M.Z. Kausar Author-X-Name-First: A.S.M.Z. Author-X-Name-Last: Kausar Author-Name: H. Ramiah Author-X-Name-First: H. Author-X-Name-Last: Ramiah Title: Efficient and accurate ray tracing method for indoor radio wave propagation prediction in presence of human body movement Abstract: Due to the attractive features of millimeter band, its uses are greatly expanding in the indoor wireless communication systems. As the distance between the transmitter and receiver is much shorter in indoor environments than that of the outdoor environments, the radio wave paths of the millimeter band frequencies are highly influenced by the building materials as well as by the human movements. Ray tracing is widely used method to characterize the radio wave propagation for the planning and establishment of the indoor wireless network. Precise object modeling for the real environment and computational burden are the two classical problems of the propagation model. Because, large number of rays that travels in a complex and convoluted indoor environment must be traced. Therefore, an accurate and efficient ray tracing method is proposed here, which is based on the surface separation, object address distribution, and surface skipping techniques. The proposed approach considers the effects of human body movement to provide a realistic estimation of the wave propagation. Hence, an approximated human body model is used to simulate the activities of humans, whereas three-dimensional (3-D) cube or cuboids are used for the remaining objects of the simulation environment. To prove the superiority, complexity analysis and detailed comparisons between the proposed and existing methods are presented in this paper. The results obtained will be of great interest for the proposed ray tracing method that involves human motion within the simple and complex indoor environments. Journal: Journal of Electromagnetic Waves and Applications Pages: 1566-1586 Issue: 12 Volume: 27 Year: 2013 Month: 8 X-DOI: 10.1080/09205071.2013.820653 File-URL: http://hdl.handle.net/10.1080/09205071.2013.820653 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:12:p:1566-1586 Template-Type: ReDIF-Article 1.0 Author-Name: Jin Xu Author-X-Name-First: Jin Author-X-Name-Last: Xu Author-Name: Yu-Xue Ji Author-X-Name-First: Yu-Xue Author-X-Name-Last: Ji Author-Name: Miao Chen Author-X-Name-First: Miao Author-X-Name-Last: Chen Author-Name: Wen Wu Author-X-Name-First: Wen Author-X-Name-Last: Wu Title: A novel miniaturized directly coupled UWB BPF Abstract: A novel ultra-wideband (UWB) bandpass filter (BPF) structure with directly coupled I/O ports is presented in this paper. The presented structure consists of a two-end short stepped-impedance resonator with a pair of stepped-impedance open stubs (SIOSs) and one uniform-impedance open stub (UIOS) symmetrically loaded on its high-impedance section. The presented structure has multiple resonant modes. The directly coupled configuration, the SIOSs and UIOS can provide three transmission zeros on its upper stopband, which not only improve the skirt of the upper transition band but also extend the upper stopband. As an example, an UWB BPF is designed, fabricated, and measured. The measured results show that the fabricated filter has a less than 0.7 dB insertion loss, better than 14 dB return loss and wide stopband up to 18.5 GHz. The measurement agrees well with the simulation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1301-1307 Issue: 10 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.807480 File-URL: http://hdl.handle.net/10.1080/09205071.2013.807480 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:10:p:1301-1307 Template-Type: ReDIF-Article 1.0 Author-Name: J. Laviada Author-X-Name-First: J. Author-X-Name-Last: Laviada Author-Name: Y. Álvarez-López Author-X-Name-First: Y. Author-X-Name-Last: Álvarez-López Author-Name: C. García-González Author-X-Name-First: C. Author-X-Name-Last: García-González Author-Name: C. Vázquez-Antuña Author-X-Name-First: C. Author-X-Name-Last: Vázquez-Antuña Author-Name: S. Ver-Hoeye Author-X-Name-First: S. Author-X-Name-Last: Ver-Hoeye Author-Name: M. Fernández-García Author-X-Name-First: M. Author-X-Name-Last: Fernández-García Author-Name: G. Hotopan Author-X-Name-First: G. Author-X-Name-Last: Hotopan Author-Name: R. Camblor Author-X-Name-First: R. Author-X-Name-Last: Camblor Author-Name: F. Las-Heras Author-X-Name-First: F. Author-X-Name-Last: Las-Heras Title: A novel phaseless frequency scanning based on indirect holography Abstract: A phase retrieval technique for multifrequency scattered field acquisition is presented in this paper. The proposed setup is based on indirect holography schemes so that it combines the desired signal with a known reference signal. The setup is used together with a two-dimensional frequency scanning (FS) antenna and, therefore, the positions of scatterers can be retrieved without the need of moving either the antenna or the objects. Journal: Journal of Electromagnetic Waves and Applications Pages: 430-438 Issue: 4 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.748441 File-URL: http://hdl.handle.net/10.1080/09205071.2013.748441 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:4:p:430-438 Template-Type: ReDIF-Article 1.0 Author-Name: Peng Zhao Author-X-Name-First: Peng Author-X-Name-Last: Zhao Author-Name: Da-Qing Liu Author-X-Name-First: Da-Qing Author-X-Name-Last: Liu Author-Name: Yan Shi Author-X-Name-First: Yan Author-X-Name-Last: Shi Author-Name: Chi-Hou Chan Author-X-Name-First: Chi-Hou Author-X-Name-Last: Chan Title: Improving multilevel Green’s function interpolation method with a new interpolation grid Abstract: The key factor influencing the efficiency of the full-wave multilevel Green’s function interpolation method (MLGFIM) lies in employing an appropriate interpolation scheme to efficiently approximate the Green’s function. A new interpolation grid pattern named boundary clustered staggered Tartan grid (BCSTG) is proposed to improve the Green’s function interpolation. By adopting BCSTG, the required number of interpolation points is greatly reduced and consequently, the efficiency of the MLGFIM is enhanced significantly. The examples of an array of dielectric spheres as well as an electric dipole and ring system have been calculated by the proposed algorithm and compared with previously reported results. The comparison results validate the algorithm and show the computational efficiencies have been enhanced by 30 and 50% for these two examples, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 1892-1901 Issue: 15 Volume: 27 Year: 2013 Month: 10 X-DOI: 10.1080/09205071.2013.828573 File-URL: http://hdl.handle.net/10.1080/09205071.2013.828573 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:15:p:1892-1901 Template-Type: ReDIF-Article 1.0 Author-Name: S. Das Author-X-Name-First: S. Author-X-Name-Last: Das Author-Name: P.P. Sarkar Author-X-Name-First: P.P. Author-X-Name-Last: Sarkar Author-Name: S.K. Chowdhury Author-X-Name-First: S.K. Author-X-Name-Last: Chowdhury Title: Investigations on miniaturized multifrequency microstrip patch antennas for wireless communication applications Abstract: This paper is aimed at proposing some single layer, single feed, multifrequency slotted microstrip patch antennas for wireless communication applications. Four different slotted patch antennas fabricated with FR-4 () substrate are proposed and experimentally studied. Unequal narrow rectangular slots are introduced on the respective patches to reduce the size of the antennas. Multiple resonant frequencies are also obtained by cutting unequal slots. The measured result shows that the size of the proposed antennas have been reduced by 89, 90, 92, and 67%, respectively, when compared with their respective conventional rectangular microstrip antennas with same patch areas. The proposed antenna structures also provides increased frequency ratio (the ratio of second or higher resonant frequency to the first resonant frequency). All the antenna structures are simulated using method of moment based IE3D™ software. Good agreement is achieved between simulated and measured (by vector network analyzer) results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1145-1162 Issue: 9 Volume: 27 Year: 2013 Month: 6 X-DOI: 10.1080/09205071.2013.802656 File-URL: http://hdl.handle.net/10.1080/09205071.2013.802656 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:9:p:1145-1162 Template-Type: ReDIF-Article 1.0 Author-Name: Mohamed Hussein Author-X-Name-First: Mohamed Author-X-Name-Last: Hussein Author-Name: Yohandri Author-X-Name-First: Author-X-Name-Last: Yohandri Author-Name: Josaphat Tetuko Sri Sumantyo Author-X-Name-First: Josaphat Tetuko Sri Author-X-Name-Last: Sumantyo Author-Name: Ashraf Yahia Author-X-Name-First: Ashraf Author-X-Name-Last: Yahia Title: A low sidelobe level of circularly polarized microstrip array antenna for CP-SAR sensor Abstract: In this paper, an elliptical microstrip array antenna with a low sidelobe level for circularly polarized synthetic aperture radar (CP-SAR) sensor is investigated. The low sidelobe level is obtained by implementing the Chebyshev synthesis method to distribute the power unevenly to each element of the patch. A Method of Moment is employed for optimizing the design and achieving a good circular polarization at the working frequency (L-Band). The simulated axial ratio (AR) bandwidth (<3 dB) for the five elements elliptical array antenna is around 11.2 MHz (0.88%), which is consistent with the measured value of 13.3 MHz (1.05%). The maximum sidelobe level of the proposed antenna is 23.3 and 21.4 dB for measured and simulated value, respectively. The simulated and measured results considerably agree with the theoretical design calculated using Chebyshev polynomial of 20 dB. The low sidelobe level and reasonable AR values indicate that the proposed antenna satisfies the specifications of the CP-SAR sensor. Journal: Journal of Electromagnetic Waves and Applications Pages: 1931-1941 Issue: 15 Volume: 27 Year: 2013 Month: 10 X-DOI: 10.1080/09205071.2013.828577 File-URL: http://hdl.handle.net/10.1080/09205071.2013.828577 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:15:p:1931-1941 Template-Type: ReDIF-Article 1.0 Author-Name: Wen Jiang Author-X-Name-First: Wen Author-X-Name-Last: Jiang Author-Name: Yang Zhang Author-X-Name-First: Yang Author-X-Name-Last: Zhang Author-Name: Zhao-bin Deng Author-X-Name-First: Zhao-bin Author-X-Name-Last: Deng Author-Name: Tao Hong Author-X-Name-First: Tao Author-X-Name-Last: Hong Title: Novel technique for RCS reduction of circularly polarized microstrip antennas Abstract: A novel technique for radar cross section (RCS) reduction of circularly polarized (CP) microstrip antennas is proposed in this paper. By the introduction of several circular and rectangular slots on the ground of the reference CP antenna, RCS of the CP antenna is reduced without effects on the circular polarization performances. Based on the common rectangular CP antenna, two modified antennas are proposed as the examples to validate the novel technique of RCS reduction. The simulated and measured results show that the proposed antennas have lower RCS than the reference antenna while maintaining the same CP performances, which illuminates that the proposed technique is a good candidate for CP antennas with a requirement of RCS control. Journal: Journal of Electromagnetic Waves and Applications Pages: 1077-1088 Issue: 9 Volume: 27 Year: 2013 Month: 6 X-DOI: 10.1080/09205071.2013.800461 File-URL: http://hdl.handle.net/10.1080/09205071.2013.800461 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:9:p:1077-1088 Template-Type: ReDIF-Article 1.0 Author-Name: Minyeong Yoo Author-X-Name-First: Minyeong Author-X-Name-Last: Yoo Author-Name: Sungjoon Lim Author-X-Name-First: Sungjoon Author-X-Name-Last: Lim Title: SRR- and CSRR-loaded ultra-wideband (UWB) antenna with tri-band notch capability Abstract: In this study, a novel ultra-wideband antenna with a tri-band notch capability is proposed. The proposed antenna can reject worldwide interoperability for microwave access (WiMAX, 3.3–3.7 GHz), wireless local area network (WLAN) IEEE802.11a/n (5.15–5.825 GHz), and international telecommunication union (ITU, 8.025–8.4 GHz) bands. The band notch capability is achieved by merely a split ring resonator (SRR) and complementary-SRR (CSRR) patterns. The SRR under the radiating patch, the CSRR loaded on the radiating patch, and the CSRRs on the ground of the CPW feeding reject the WiMAX, WLAN, and ITU bands, respectively. The simulation and measurement results demonstrate the performance of the proposed antenna. Journal: Journal of Electromagnetic Waves and Applications Pages: 2190-2197 Issue: 17 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.837013 File-URL: http://hdl.handle.net/10.1080/09205071.2013.837013 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:17:p:2190-2197 Template-Type: ReDIF-Article 1.0 Author-Name: X. Chen Author-X-Name-First: X. Author-X-Name-Last: Chen Author-Name: J.-Z. Xu Author-X-Name-First: J.-Z. Author-X-Name-Last: Xu Title: A novel method for waveform jamming based on millimeter-wave alternating current radiometer Abstract: On the basis of the working principle and circuit response characteristics of the millimeter-wave (MMW) alternating current radiometer, a novel method for waveform jamming is proposed. In this method, a MMW jamming source is used to transmit the narrowband signal as the heat source and then a wide-time signal is obtained through a broadband reception and detection of the radiometer. Next, the wide-time signal excites differential response of low-frequency circuit of the video amplifier to yield the splitting waveform, which is similar to the negative pulse waveform in metal-target detection, therefore achieving detection effect of cold-target from the angle of waveform simulation. Simulation results show that the average similarity of the simulation waveform and the actual waveform is 79.21%, and the processing results of experimental data demonstrate validity and feasibility of the proposed method. Journal: Journal of Electromagnetic Waves and Applications Pages: 66-76 Issue: 1 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.738465 File-URL: http://hdl.handle.net/10.1080/09205071.2013.738465 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:1:p:66-76 Template-Type: ReDIF-Article 1.0 Author-Name: Lei Wang Author-X-Name-First: Lei Author-X-Name-Last: Wang Author-Name: Yong-Xin Guo Author-X-Name-First: Yong-Xin Author-X-Name-Last: Guo Author-Name: Wen Wu Author-X-Name-First: Wen Author-X-Name-Last: Wu Title: Wideband modified L-probe fed circularly polarized patch antenna with conical beam radiation pattern Abstract: A wideband circularly polarized patch antenna with conical beam radiation pattern is presented. The antenna structure is composed of a circular patch, two modified L-shaped probes, and a wideband 90° hybrid feed network. The higher mode of TM21 mode is excited on the circular patch to produce the conical beam radiation pattern. The proposed antenna has a measured common operating bandwidth with 10-dB return loss, 3-dB axial ratio bandwidth, and good conical beam radiation pattern is about 20.1% with respect to the center frequency of 2.9 GHz from 2.6 to 3.2 GHz. The average gain of the proposed antenna is about 6.5 dBi over the operating band. Good agreement is observed between the simulated and measured results. Journal: Journal of Electromagnetic Waves and Applications Pages: 969-977 Issue: 8 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.794716 File-URL: http://hdl.handle.net/10.1080/09205071.2013.794716 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:8:p:969-977 Template-Type: ReDIF-Article 1.0 Author-Name: Junding Zhao Author-X-Name-First: Junding Author-X-Name-Last: Zhao Author-Name: Jianpeng Wang Author-X-Name-First: Jianpeng Author-X-Name-Last: Wang Author-Name: Gang Zhang Author-X-Name-First: Gang Author-X-Name-Last: Zhang Author-Name: Jia-Lin Li Author-X-Name-First: Jia-Lin Author-X-Name-Last: Li Title: Design of a microstrip triple-band bandpass filter using a variation of genetic algorithm Abstract: A new microstrip triple-band bandpass filter (BPF) using a variation of genetic algorithm (VGA) is proposed in this paper. The VGA is applied to simultaneously search for the appropriate circuit topology and the corresponding electrical parameters with a triple-band characteristic. To demonstrate the effectiveness of the VGA, a triple-band BPF is designed and fabricated. In the filter, the 3 dB fractional bandwidths for the three passbands centered at 2.05, 3.57, and 5.81 GHz are 14.63, 11.20, and 7.57%, respectively. Measurement results agree well with the design index and full-wave EM simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1293-1300 Issue: 10 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.805437 File-URL: http://hdl.handle.net/10.1080/09205071.2013.805437 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:10:p:1293-1300 Template-Type: ReDIF-Article 1.0 Author-Name: W.T. Chyla Author-X-Name-First: W.T. Author-X-Name-Last: Chyla Title: Group velocity of the electromagnetic wave packet in a relativistic dispersive medium Abstract: This paper presents the fully relativistic, general expression for the group velocity Vg of the electromagnetic wave packet in a relativistic dispersive medium. Motion of the medium is accounted for with the relativistic index of refraction. The general formula for Vg is specialized to a few particular situations that are briefly discussed. The explicit, exact, fully relativistic expression for Vg is relevant to all issues where the electromagnetic wave packet travels through a medium in motion, especially where the velocity of the medium is high or utmost accuracy is essential, e.g. it pertains to the slow light phenomenon, pulsar radiation, GPS, radar, and LIDAR technologies. Journal: Journal of Electromagnetic Waves and Applications Pages: 938-943 Issue: 7 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.792752 File-URL: http://hdl.handle.net/10.1080/09205071.2013.792752 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:7:p:938-943 Template-Type: ReDIF-Article 1.0 Author-Name: Hossam A. Saker Author-X-Name-First: Hossam A. Author-X-Name-Last: Saker Author-Name: Essmat A.F. Abdallah Author-X-Name-First: Essmat A.F. Author-X-Name-Last: Abdallah Title: Full-wave analysis of a compact bandpass meandering resonator filter using method of lines Abstract: Full-wave analysis based on the method of lines and the generalized transmission line equations is applied for the design of a small-size wide stopband bandpass filter. The analytical calculation in the direction of propagation and using nonequidistant discretization enables the analysis of the method of lines to be efficient for structures that can be divided into cascaded subsections along the propagation direction of the wave. The proposed filter consists of a pair of meandering uniform impedance resonators and feeding lines. Wide stopband and high selectivity as well as compact size of the filter are achieved due to the effect of multipath between the feeding points and the resonators that leads to suppression of the first and second harmonic of the filter. The modes distribution and the scattering parameters of the designed filter are computed and studied, leading to an achievement of a passband return loss greater than 18 dB and insertion loss about 1.7 dB. The designed filter is fabricated and tested, where good agreement is found between the numerical and experimental results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1163-1177 Issue: 9 Volume: 27 Year: 2013 Month: 6 X-DOI: 10.1080/09205071.2013.803266 File-URL: http://hdl.handle.net/10.1080/09205071.2013.803266 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:9:p:1163-1177 Template-Type: ReDIF-Article 1.0 Author-Name: Yong Zhi Cheng Author-X-Name-First: Yong Zhi Author-X-Name-Last: Cheng Author-Name: Yan Nie Author-X-Name-First: Yan Author-X-Name-Last: Nie Author-Name: Zheng Ze Cheng Author-X-Name-First: Zheng Ze Author-X-Name-Last: Cheng Author-Name: Lin Wu Author-X-Name-First: Lin Author-X-Name-Last: Wu Author-Name: Xian Wang Author-X-Name-First: Xian Author-X-Name-Last: Wang Author-Name: Rong Zhou Gong Author-X-Name-First: Rong Zhou Author-X-Name-Last: Gong Title: Broadband transparent metamaterial linear polarization transformer based on triple-split-ring resonators Abstract: In this paper, a chiral metamaterial (CMM) with triple-layer twisted split-ring resonators structure was proposed, which could exhibit a linear polarization conversion as well as asymmetric transmission only for forward and backward propagating linearly polarized waves in a broadband frequency range. The polarization of broadband linearly polarized electromagnetic waves can be rotated in a specific direction by passing it through such a CMM slab with a thickness of about one-twelfth the operational center wavelength. Experiment and simulation calculations are in good agreement, and the polarization conversion rate is above 90% in the frequency range of 5.5–11.1 GHz. The physical mechanism of the broadband linear polarization conversion effect could be further illustrated by simulated electrical field and surface current distributions. Journal: Journal of Electromagnetic Waves and Applications Pages: 1850-1858 Issue: 14 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.825891 File-URL: http://hdl.handle.net/10.1080/09205071.2013.825891 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:14:p:1850-1858 Template-Type: ReDIF-Article 1.0 Author-Name: Rajas Khokle Author-X-Name-First: Rajas Author-X-Name-Last: Khokle Author-Name: Raj Kumar Author-X-Name-First: Raj Author-X-Name-Last: Kumar Author-Name: R.V.S. Ram Krishna Author-X-Name-First: R.V.S. Author-X-Name-Last: Ram Krishna Title: Design of horizontally polarized stepped slot antenna for ultra-wideband applications Abstract: A horizontally polarized ultra wideband stepped slot antenna is proposed in this paper. First, a stepped-slot structure is fed by an L shaped microstrip feed to achieve multiple resonances. Then a parasitic slot is introduced near the vertical arm of the L-shaped feed to get better impedance matching over the bandwidth of 3.7 GHz (5.0–8.7 GHz). Further, an impedance step is introduced in the feed line and the measured −10 dB impedance bandwidth covering from 2.8 to 12.8 GHz is achieved. The measured peak gain is around 4.5 dBi throughout the band. The measured radiation patterns are bidirectional in E plane and omnidirectional in H plane. The experimental results are in close agreement with the simulated results. This antenna can be used for ultra-wideband communication devices, medical imaging and vehicular radars. Journal: Journal of Electromagnetic Waves and Applications Pages: 1246-1261 Issue: 10 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.805309 File-URL: http://hdl.handle.net/10.1080/09205071.2013.805309 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:10:p:1246-1261 Template-Type: ReDIF-Article 1.0 Author-Name: D. Jiang Author-X-Name-First: D. Author-X-Name-Last: Jiang Author-Name: Y.-H. Xu Author-X-Name-First: Y.-H. Author-X-Name-Last: Xu Author-Name: R.-M. Xu Author-X-Name-First: R.-M. Author-X-Name-Last: Xu Author-Name: W.-G. Lin Author-X-Name-First: W.-G. Author-X-Name-Last: Lin Title: Implementation of a novel broadband microstrip metamaterial power divider Abstract: A low-loss, planar, and compact metamaterial broadband power divider is presented in this paper. The power divider uses novel two parallel microstrip transmission-line coupled-line couplers with negative-refractive-index characterization allowing it to be compact in the longitudinal direction. The method of designing two turns spiral resonators (2-SRs) is detailed starting from edge-coupled split-ring resonator (SRR), and full-wave simulations of novel power divider are fulfilled by HFSS. A power divider with 5.40 GHz center frequency is fabricated for demonstration purpose. The measurement results show that a ultra-wide band of 50% is achieved with . While maintaining similar performance, a 50% reduction in impedance transformer is achieved in comparison to a conventional design. Journal: Journal of Electromagnetic Waves and Applications Pages: 591-598 Issue: 5 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.757849 File-URL: http://hdl.handle.net/10.1080/09205071.2013.757849 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:5:p:591-598 Template-Type: ReDIF-Article 1.0 Author-Name: Zaharias D. Zaharis Author-X-Name-First: Zaharias D. Author-X-Name-Last: Zaharis Author-Name: Konstantinos A. Gotsis Author-X-Name-First: Konstantinos A. Author-X-Name-Last: Gotsis Author-Name: John N. Sahalos Author-X-Name-First: John N. Author-X-Name-Last: Sahalos Title: Array beamsteering with side lobe suppression using neural networks trained by Mutated Boolean particle swarm optimized data Abstract: A beamsteering (BS) technique applied on antenna arrays is proposed. The technique is based on neural networks (NNs) and aims at estimating the array excitation weights that produce a main lobe towards every desired signal and achieve low side lobe level (SLL). Initially, the Mutated Boolean particle swarm optimization (MBPSO) is applied to a set of random directions of incoming signals in order to estimate the excitation weights that make a uniform linear array (ULA) produce one or more main lobes towards the respective incoming signals and achieve a SLL equal to or less than a desired value. The estimated weights are then used to train a NN efficiently. The trained NN is applied to a new set of random directions of incoming signals and the derived radiation patterns are compared to respective patterns derived by the MBPSO, a differential evolution based BS technique and the maximum likelihood method. The above comparisons were performed for various SLLs and for one or two desired signals received by a ULA. In the problem, the presence of additive zero-mean Gaussian noise was assumed. The comparative results show the advantages of the proposed BS technique. Journal: Journal of Electromagnetic Waves and Applications Pages: 877-883 Issue: 7 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.789412 File-URL: http://hdl.handle.net/10.1080/09205071.2013.789412 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:7:p:877-883 Template-Type: ReDIF-Article 1.0 Author-Name: Zengxu Guo Author-X-Name-First: Zengxu Author-X-Name-Last: Guo Author-Name: Kuo-Sheng Chin Author-X-Name-First: Kuo-Sheng Author-X-Name-Last: Chin Author-Name: Wenquan Che Author-X-Name-First: Wenquan Author-X-Name-Last: Che Author-Name: Chih-Chun Chang Author-X-Name-First: Chih-Chun Author-X-Name-Last: Chang Title: V-band cross-coupled SIW band-pass filter with an antisymmetric U-slot negative coupling structure Abstract: This study presents an low-temperature cofired ceramic (LTCC) V-band cross-coupled band-pass filter using substrate-integrated waveguide cavities. Two antisymmetric U-shaped slots connected by via is proposed to construct the negative coupling structure, which is simple and especially useful for 60 GHz applications. Moreover, the U-slot structure possesses a wide range of realizable coupling coefficients from −0.008 to −0.075. An experimental LTCC fourth-order filter was fabricated for demonstration, achieving a bandwidth of 12% (7.2 GHz) at 59.6 GHz with superior frequency selectivity. Journal: Journal of Electromagnetic Waves and Applications Pages: 953-961 Issue: 8 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.793620 File-URL: http://hdl.handle.net/10.1080/09205071.2013.793620 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:8:p:953-961 Template-Type: ReDIF-Article 1.0 Author-Name: Y. Li Author-X-Name-First: Y. Author-X-Name-Last: Li Author-Name: Q.-Y. Feng Author-X-Name-First: Q.-Y. Author-X-Name-Last: Feng Title: A compact composite right-/left-handed transmission line antenna with extended bandwidth Abstract: An asymmetric coplanar waveguide (ACPW)-fed antenna with extended bandwidth is investigated. The designed antenna comprises two unit cells of composite right-/left-handed transmission line (CRLH TL). The bandwidth enhancement of the designed antenna can be achieved when the zeroth-order and first-positive-order modes merge. A prototype designed on F4BM350 substrate with dielectric constant 3.5 occupies an overall size of 14 mm × 25 mm × 0.8 mm, which is approximately 0.118 λ0 × 0.211 λ0 × 0.007 λ0. The measured result shows that the operating bandwidth with 10 dB return loss is about 330 MHz (2.44–2.77 GHz), and the peak gain and radiation efficiency simulated are 1.37 dBi and 88% at 2.53 GHz, which are suitable for WiMAX (2.5–2.69 GHz) application. Journal: Journal of Electromagnetic Waves and Applications Pages: 123-130 Issue: 1 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.740778 File-URL: http://hdl.handle.net/10.1080/09205071.2013.740778 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:1:p:123-130 Template-Type: ReDIF-Article 1.0 Author-Name: Sungchan Jung Author-X-Name-First: Sungchan Author-X-Name-Last: Jung Author-Name: Youngoo Yang Author-X-Name-First: Youngoo Author-X-Name-Last: Yang Title: Miniaturized branch-line hybrid coupler with broadband impedance matching network Abstract: This paper presents a compact broadband branch-line hybrid coupler. It is composed of a miniaturized branch-line hybrid coupler and broadband impedance matching networks. A coupled-line structure is used for the broadband impedance matching network. The branch-line hybrid coupler is realized by using high-impedance transmission lines and distributed capacitors. In order to further reduce the circuit size, the distributed capacitors are placed in the center space of the hybrid coupler and the coupled lines are effectively meandered. For validation, a prototype of the compact hybrid coupler was designed and fabricated at the center frequency of 1 GHz. For given conditions, the proposed hybrid has 29.4% bandwidth which is from 870 to 1170 MHz. Compared to the conventional 3-dB branch-line hybrid coupler, it exhibited a size reduction of 50.8% and an extended operating bandwidth of 66.7%. Journal: Journal of Electromagnetic Waves and Applications Pages: 1230-1237 Issue: 10 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.805168 File-URL: http://hdl.handle.net/10.1080/09205071.2013.805168 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:10:p:1230-1237 Template-Type: ReDIF-Article 1.0 Author-Name: L.-Z. Zhang Author-X-Name-First: L.-Z. Author-X-Name-Last: Zhang Author-Name: L. Zhou Author-X-Name-First: L. Author-X-Name-Last: Zhou Author-Name: W. Jiang Author-X-Name-First: W. Author-X-Name-Last: Jiang Title: A compact dual-band coupler with arbitrary power dividing ratio using broadside-coupled microstrip Abstract: In this paper, a compact dual-band coupler with arbitrary power division ratio using broadside-coupled microstrip has been proposed, designed, and measured. The proposed coupler is formed by two three-section microstrip lines and a common ground plane with three rectangular shaped slots used for coupling. Simple analysis method based on the even-odd mode technique has been applied, design equations are then derived. With the even- and odd-mode characteristic admittances, the initial geometry parameters of the proposed coupler are obtained by using the empirical formulas. The coupler features a wide frequency ratio range, arbitrary power dividing ratio, compact size, and wide bandwidth. For verification purposes, two prototypes of the proposed couplers with a coupling ratio of 3 and 6 dB, operating at the frequency of 2.4/5.2 GHz, have been designed, simulated, fabricated, and measured. Good agreements have been shown between the simulated and the measured results. Journal: Journal of Electromagnetic Waves and Applications Pages: 140-148 Issue: 2 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.740784 File-URL: http://hdl.handle.net/10.1080/09205071.2013.740784 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:2:p:140-148 Template-Type: ReDIF-Article 1.0 Author-Name: Gianluca Gennarelli Author-X-Name-First: Gianluca Author-X-Name-Last: Gennarelli Author-Name: Giovanni Riccio Author-X-Name-First: Giovanni Author-X-Name-Last: Riccio Title: Obtuse-angled penetrable wedges: a time domain solution for the diffraction coefficients Abstract: Closed form solutions are proposed for evaluating the time domain diffraction coefficients to be used when plane waves are orthogonally incident on obtuse-angled penetrable wedges. They are obtained by performing the inverse Laplace transform of the corresponding frequency domain solutions related to the internal region of the wedge and the surrounding space. The knowledge of the analytical expressions of the diffraction coefficients allows one to evaluate the response to an arbitrary incident transient field via a convolution integral. Numerical tests and comparisons with finite-difference time-domain results confirm the effectiveness of the proposed solutions. Journal: Journal of Electromagnetic Waves and Applications Pages: 2020-2028 Issue: 16 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.831327 File-URL: http://hdl.handle.net/10.1080/09205071.2013.831327 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:16:p:2020-2028 Template-Type: ReDIF-Article 1.0 Author-Name: J. Ou Yang Author-X-Name-First: J. Author-X-Name-Last: Ou Yang Author-Name: Y. Zhang Author-X-Name-First: Y. Author-X-Name-Last: Zhang Author-Name: X. Luo Author-X-Name-First: X. Author-X-Name-Last: Luo Author-Name: K.Z. Zhang Author-X-Name-First: K.Z. Author-X-Name-Last: Zhang Author-Name: Y. Li Author-X-Name-First: Y. Author-X-Name-Last: Li Author-Name: F. Yang Author-X-Name-First: F. Author-X-Name-Last: Yang Title: A broadband and wide beam circular polarization LTCC microstrip antenna analysis and design with characteristic modes theory Abstract: In this paper, characteristic modes theory was used in analysis and design of a broad axial ratio band circular polarization LTCC microstrip antenna. An ellipse slot couple structure was proposed to take the place of traditional circular slot couple structure for enlarging circular polarization broadband. And the theory of how to improve the axial ratio band was researched in detail by characteristic mode method. The characteristic angle phase difference of two orthogonal characteristic modes and the phase difference of feed line in whole frequencies are the key points in these kind of designs. Finally, the designed broadband axial ratio band circular polarization LTCC microstrip antenna was been successfully implemented, and the experimental results are presented and discussed. Good agreement between simulation and testing was achieved. Journal: Journal of Electromagnetic Waves and Applications Pages: 671-681 Issue: 6 Volume: 27 Year: 2013 Month: 4 X-DOI: 10.1080/09205071.2013.752316 File-URL: http://hdl.handle.net/10.1080/09205071.2013.752316 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:6:p:671-681 Template-Type: ReDIF-Article 1.0 Author-Name: Li Xi Author-X-Name-First: Li Author-X-Name-Last: Xi Author-Name: Yang Lin Author-X-Name-First: Yang Author-X-Name-Last: Lin Author-Name: Wang Min Author-X-Name-First: Wang Author-X-Name-Last: Min Title: Novel design of strip line L-shape probe-fed wideband metallic contact stacked patch antenna for GNSS application Abstract: A novel design of compact circularly polarized metallic contact annular stacked patch antenna has been proposed for global navigation satellite system in this paper. In order to obtain wideband characteristics, broadband 90° hybrids have been used as a secondary network. As a result, the antenna has an effective bandwidth of 87% from 0.85 to 2.16 GHz for VSWR < 2, and 62.4% from 0.97 to 1.85 GHz for AR < 3 dB respectively, which is sufficiently enough to operate for the satellite navigation frequencies including GPS, GLONASS, Galileo and Compass (1100–1600 MHz). The designed antenna can provide stable gain bandwidths, broad beam width and good axial ratio at low elevation by introducing metallic contact annular stacked patch structure. The designed antenna occupies a compact size of 100 mm × 100 mm × 13 mm. Journal: Journal of Electromagnetic Waves and Applications Pages: 2010-2019 Issue: 16 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.830076 File-URL: http://hdl.handle.net/10.1080/09205071.2013.830076 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:16:p:2010-2019 Template-Type: ReDIF-Article 1.0 Author-Name: Qing He Author-X-Name-First: Qing Author-X-Name-Last: He Author-Name: Junyu Shen Author-X-Name-First: Junyu Author-X-Name-Last: Shen Author-Name: Qiang Liu Author-X-Name-First: Qiang Author-X-Name-Last: Liu Author-Name: Jiuchao Li Author-X-Name-First: Jiuchao Author-X-Name-Last: Li Author-Name: Liming Liang Author-X-Name-First: Liming Author-X-Name-Last: Liang Title: A simplified dual-band rat-race hybrid for arbitrary power division ratio with only single shunt stub Abstract: A planar, simplified, dual-band rat-race hybrid with arbitrary power division ratio is presented. It is accomplished by inserting only single additional shunt stub in the conventional structure and modifying the lengths and characteristic impedances of the arms. Using rigorous even- and odd-mode analysis, the explicit closed-form equations for this hybrid are derived. Based on the standard microstrip technology, the relationship between the realizable power-split ratios and the frequency ratio is investigated. As a generalized design, it is found that traditional rat-race hybrid and some previous compact structures are special cases of the proposed hybrid. With this method, a prototype operating at 1/3.5 GHz with 7.96 dB power division ratio is designed, fabricated and measured. The validity of this design has been proved by the consistency of the simulation and measurement results. Journal: Journal of Electromagnetic Waves and Applications Pages: 2101-2109 Issue: 16 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.832396 File-URL: http://hdl.handle.net/10.1080/09205071.2013.832396 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:16:p:2101-2109 Template-Type: ReDIF-Article 1.0 Author-Name: X.Q. Lin Author-X-Name-First: X.Q. Author-X-Name-Last: Lin Author-Name: J.Y. Jin Author-X-Name-First: J.Y. Author-X-Name-Last: Jin Author-Name: Y. Jiang Author-X-Name-First: Y. Author-X-Name-Last: Jiang Author-Name: Y. Fan Author-X-Name-First: Y. Author-X-Name-Last: Fan Title: Metamaterial-inspired waveguide filters with compact size and sharp skirt selectivity Abstract: In this paper, a metamaterial-inspired miniaturization method for waveguide filter design is proposed. The transmission response and effective medium parameters of I-shaped resonator in metallic rectangular waveguide are first discussed. By embedding such an I-shaped resonator, a novel λg/2-type inverter is then proposed (λg: the guided wavelength). The large effective refraction index with low loss which appears below the resonant frequency of the I-shaped resonator is skillfully exploited, and then the size of λg/2-type inverter is greatly reduced with acceptable low insertion loss. The most negative permittivity of the I-shaped resonator at its resonant frequency produces an additional transmission zero which leads to sharp skirt selectivity in the upper side band. Using the novel λg/2-type inverter, two improved waveguide filters are further designed with good performances. One has an extremely compact size. The other has further improved selectivity. Two such filters are finally fabricated and the measured results agree well with the simulated ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 224-232 Issue: 2 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.743450 File-URL: http://hdl.handle.net/10.1080/09205071.2013.743450 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:2:p:224-232 Template-Type: ReDIF-Article 1.0 Author-Name: Anirban Karmakar Author-X-Name-First: Anirban Author-X-Name-Last: Karmakar Author-Name: Rowdra Ghatak Author-X-Name-First: Rowdra Author-X-Name-Last: Ghatak Author-Name: Utsab Banerjee Author-X-Name-First: Utsab Author-X-Name-Last: Banerjee Author-Name: D.R. Poddar Author-X-Name-First: D.R. Author-X-Name-Last: Poddar Title: An UWB antenna using modified Hilbert curve slot for dual band notch characteristics Abstract: A printed dual band notched ultra wideband monopole antenna with a single perturbed Hilbert curve slot is presented which exhibits 121% impedance bandwidth. A single modified Hilbert curve slot provides dual band notch characteristics in the range of 3.3–3.7 GHz (WiMAX), 3.7–4.2 GHz (C-Band), and 5.15–5.825 GHz (WLAN) which makes the notch design process simpler than other dual band notched antennas. The gain of the proposed antenna varies from 3 to 4 dBi over its operating frequency range, except at the rejection bands. Suitable radiation characteristics are obtained throughout its operating band. Simulation and measured results of the proposed antenna are in good agreement. Journal: Journal of Electromagnetic Waves and Applications Pages: 1620-1631 Issue: 13 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.821676 File-URL: http://hdl.handle.net/10.1080/09205071.2013.821676 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:13:p:1620-1631 Template-Type: ReDIF-Article 1.0 Author-Name: L. Sang Author-X-Name-First: L. Author-X-Name-Last: Sang Author-Name: J. Wang Author-X-Name-First: J. Author-X-Name-Last: Wang Author-Name: Y. Xu Author-X-Name-First: Y. Author-X-Name-Last: Xu Author-Name: R. Xu Author-X-Name-First: R. Author-X-Name-Last: Xu Title: Extracting Volterra series representation from X-parameters for the modeling of microwave device Abstract: As a classic mathematical means, Volterra series are good representations for the description of nonlinear microwave devices and systems. However, the difficulty in extracting accurate kernel functions is the most important reason that limits wider application of Volterra series. In this research, the X-parameters proposed in recent years are used to resolve this problem for the first time. The extraction method is detailed, and the results show that it is very convenient to obtain Volterra series representation by using X-parameters. A power amplifier was measured to verify the proposed approach, and a good agreement has been achieved between the measured results and the predicted data based on the Volterra series. The method proposed in this paper is useful for accurate and fast modeling of modern microwave devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 299-308 Issue: 3 Volume: 27 Year: 2013 Month: 2 X-DOI: 10.1080/09205071.2013.744283 File-URL: http://hdl.handle.net/10.1080/09205071.2013.744283 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:3:p:299-308 Template-Type: ReDIF-Article 1.0 Author-Name: Xiao Ding Author-X-Name-First: Xiao Author-X-Name-Last: Ding Author-Name: Bingzhong Wang Author-X-Name-First: Bingzhong Author-X-Name-Last: Wang Title: A millimeter-wave pattern-reconfigurable antenna with a reconfigurable feeding network Abstract: A millimeter-wave pattern-reconfigurable antenna is proposed, which adopts a linear array structure with three radiating elements and has a reconfigurable feeding network. In order to eliminate the influence on the radiation caused by the feeding network and to conveniently reconfigure the feeding network, the feeding layer and radiation layer of the antenna are separated by a ground plane. By electrically controlling the PIN diodes integrated in the feeding network, the proposed antenna can reconfigure its radiation pattern with three reconfigurable modes. Experiment results show that the three reconfigurable patterns point to , 3°, and in the elevation plane, respectively, with a gain fluctuation less than 0.6 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 649-658 Issue: 5 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.759520 File-URL: http://hdl.handle.net/10.1080/09205071.2013.759520 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:5:p:649-658 Template-Type: ReDIF-Article 1.0 Author-Name: L.-J. Xu Author-X-Name-First: L.-J. Author-X-Name-Last: Xu Author-Name: J.P. Wang Author-X-Name-First: J.P. Author-X-Name-Last: Wang Author-Name: Y.-X. Guo Author-X-Name-First: Y.-X. Author-X-Name-Last: Guo Author-Name: W. Wu Author-X-Name-First: W. Author-X-Name-Last: Wu Title: Double-folded substrate integrated waveguide band-pass filter with transmission zeros in LTCC Abstract: A miniaturized substrate integrated waveguide (SIW) band-pass filter with two transmission zeros is proposed in low-temperature co-fired ceramic (LTCC) technology. The miniaturization of the filter is achieved by vertically stacking three double-folded SIW resonators. To strengthen the coupling between the feeding structure and the resonators, a new meandered microstrip feeding line is introduced. In addition, to realize better out-of-band rejection performance, two short-circuited lines are adopted in the filter design to achieve two transmission zeros outside the passband. To verify the design concept, an X-band LTCC band-pass filter was designed, fabricated, and measured. Both simulation and measurement results indicate that the proposed filter has good frequency response, high selectivity, and a size reduction of about 87% in comparison with conventional planar direct-coupled waveguide filter. Journal: Journal of Electromagnetic Waves and Applications Pages: 96-103 Issue: 1 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.739540 File-URL: http://hdl.handle.net/10.1080/09205071.2013.739540 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:1:p:96-103 Template-Type: ReDIF-Article 1.0 Author-Name: E.B. Manoukian Author-X-Name-First: E.B. Author-X-Name-Last: Manoukian Title: Red light, blue light, Feynman and a layer of glass: the causal propagator Abstract: A propagator–description approach of the propagation of EM waves is provided, in complex situations with underlying boundary conditions. To this end, the so-called Schwinger–Feynman causal propagator is explicitly derived, and spelled out, for the first time, for transmission of a photon through, and reflection off, a layer of glass of flat parallel surfaces. In a very general context, the corresponding transition amplitudes of a polarized or unpolarized photon are obtained, and the conservation of probabilities, and the underlying consistency conditions of the results, are established. Inspired by Feynman’s intuitive and well-publicized non-technical treatment of such a problem with red and blue light, one, in a quantum view-point, is interested in the probabilities of the events just described in determining the fate of a photon. This analysis provides an alternative way of looking at the problem in question, through propagation of photons, as a physically more appealing approach, in Feynman’s spirit, than by matching plane waves at boundaries as we often do. It also shows how a propagator may be derived, in more complex situations with specific boundary conditions, than just simply in infinite extended spaces. Finally, it is hoped that this work will be stimulating and of interest to practitioners with different emphases on EM wave propagation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1986-1996 Issue: 15 Volume: 27 Year: 2013 Month: 10 X-DOI: 10.1080/09205071.2013.832639 File-URL: http://hdl.handle.net/10.1080/09205071.2013.832639 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:15:p:1986-1996 Template-Type: ReDIF-Article 1.0 Author-Name: Masih Ghasemi Author-X-Name-First: Masih Author-X-Name-Last: Ghasemi Author-Name: P.K. Choudhury Author-X-Name-First: P.K. Author-X-Name-Last: Choudhury Title: On the sustainment of optical power in twisted clad dielectric cylindrical fibers Abstract: The paper presents an analytical investigation of twisted clad dielectric optical fiber with the emphasis on the propagation of power through the guide. The fiber structure assumes twists in the form of loading of conducting sheath helical windings with a particular value of pitch at the core–clad interface. It is assumed that the turns of right-handed helical windings are continuous in nature, but still insulated from each other. The dispersion relation is deduced for the structure followed by the evaluation of the propagation of power (in terms of power confinement factor) under different values of helix pitch angle. It has been found that the pitch plays determining role to control power confinement in the guide as the amount of power in the core section is found to be the maximum corresponding to 0° pitch and goes on decreasing with the increase in its value. It is presumed that such characteristics of the guide would be useful to device varieties of optical components wherein the need of tuning optical power propagation remains vital. Journal: Journal of Electromagnetic Waves and Applications Pages: 1382-1391 Issue: 11 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.809509 File-URL: http://hdl.handle.net/10.1080/09205071.2013.809509 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:11:p:1382-1391 Template-Type: ReDIF-Article 1.0 Author-Name: J.H. Wang Author-X-Name-First: J.H. Author-X-Name-Last: Wang Author-Name: L. Sang Author-X-Name-First: L. Author-X-Name-Last: Sang Author-Name: Z.G. Wang Author-X-Name-First: Z.G. Author-X-Name-Last: Wang Author-Name: R.M. Xu Author-X-Name-First: R.M. Author-X-Name-Last: Xu Author-Name: B. Yan Author-X-Name-First: B. Author-X-Name-Last: Yan Title: A compact high-gain patch antenna using stacked rings in LTCC technology Abstract: A compact high-gain patch antenna using stacked rings based on low-temperature co-fired ceramic (LTCC) multilayer technology is proposed in this paper. Three metal stacked rings are employed to surround the patch antenna, acting as directors to guide the electromagnetic wave radiating toward broadside and, hence, improve the antenna's gain. Also, three ground planes are connected by metallic vias to form a cavity-backed structure, which suppresses the outward propagating diffraction wave and contributes to the improvement of the antenna’s gain either. The fabricated antenna achieves a high gain of 8.1 dBi at 36.7 GHz including the loss of the feeding parts and radio-frequency (RF) probe, and the gain is relatively stable within the bandwidth. Furthermore, the antenna only occupies a compact size of mm3 which is much smaller than most of the other high-gain patch antennas on LTCC. Journal: Journal of Electromagnetic Waves and Applications Pages: 330-337 Issue: 3 Volume: 27 Year: 2013 Month: 2 X-DOI: 10.1080/09205071.2013.744714 File-URL: http://hdl.handle.net/10.1080/09205071.2013.744714 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:3:p:330-337 Template-Type: ReDIF-Article 1.0 Author-Name: K.-S. Zheng Author-X-Name-First: K.-S. Author-X-Name-Last: Zheng Author-Name: J.-Z. Li Author-X-Name-First: J.-Z. Author-X-Name-Last: Li Author-Name: G. Wei Author-X-Name-First: G. Author-X-Name-Last: Wei Author-Name: J.-D. Xu Author-X-Name-First: J.-D. Author-X-Name-Last: Xu Title: Analysis of Doppler effect of moving conducting surfaces with Lorentz-FDTD method Abstract: To analyze scattering fields from moving conducting bodies, a novel Lorentz finite-difference time-domain (FDTD) method is proposed in this paper. The transformation formulas of electromagnetic field parts, space parts, and time variable are gained by using Lorentz transformation between the rest and the moving reference frame. To calculate the scattering fields from moving conducting bodies, the total-field–scattered-field boundary condition is set up to introduce an incident plane wave in the moving reference frame. Using the interpolation method, the relation between electromagnetic fields in the moving reference frame and that of the related grids in the rest is estimated. Using the proposed Lorentz-FDTD method analyze the scattering fields from one-dimensional moving conducting surface. Thus, variations of the amplitude and frequency of scattering fields with the moving conducting surface speed are considered. Caused by the moving conducting surface, the amplitude and frequency of incident plane wave suffer a modulation shift. Numerical results are in a good agreement with analytical results for the discussed case. Journal: Journal of Electromagnetic Waves and Applications Pages: 149-159 Issue: 2 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.741042 File-URL: http://hdl.handle.net/10.1080/09205071.2013.741042 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:2:p:149-159 Template-Type: ReDIF-Article 1.0 Author-Name: L. Shi Author-X-Name-First: L. Author-X-Name-Last: Shi Author-Name: B.W. Bai Author-X-Name-First: B.W. Author-X-Name-Last: Bai Author-Name: Y.M. Liu Author-X-Name-First: Y.M. Author-X-Name-Last: Liu Author-Name: X.P. Li Author-X-Name-First: X.P. Author-X-Name-Last: Li Title: Navigation antenna performance degradation caused by plasma sheath Abstract: A plasma sheath generated around a hypersonic vehicle can be a serious obstacle to fixed-frequency communications, especially navigation systems. This paper studies the effects of a plasma sheath on a Beidou navigation circular microstrip patch antenna. The dynamic stratified medium model method, which is based on the gradient of electron density profile curve, is employed to model the nonuniform plasma sheath. Using the algorithm calculation of the time-domain finite integration, the navigation antenna radiation pattern property is obtained, along with the changes in the reflection coefficient and input impedance properties. Results show that antenna pattern distortion, resonant frequency shift, and impedance mismatch caused by plasma are proportional to the electron density. The process of reentry blackout is also reproduced from the perspective of the antenna performance degradation. The inductor L and capacitor C (LC tuning circuit) impedance mismatch compensation scheme proposed is demonstrated to be effective and it can decrease return loss by 19.4 dB under the most serious plasma environment, thus reducing signal reflection and enhancing navigation system performance. Journal: Journal of Electromagnetic Waves and Applications Pages: 518-528 Issue: 4 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.755110 File-URL: http://hdl.handle.net/10.1080/09205071.2013.755110 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:4:p:518-528 Template-Type: ReDIF-Article 1.0 Author-Name: H. Zhao Author-X-Name-First: H. Author-X-Name-Last: Zhao Author-Name: L. Yan Author-X-Name-First: L. Author-X-Name-Last: Yan Author-Name: X. Zhao Author-X-Name-First: X. Author-X-Name-Last: Zhao Author-Name: K. Huang Author-X-Name-First: K. Author-X-Name-Last: Huang Title: A compact tri-band patch antenna with notched ground for WLAN/WiMAX communication Abstract: A compact tri-band patch antenna resonant at 2.45, 3.5, and 5.5 GHz is proposed for wireless local area network (WLAN)/worldwide interoperability for microwave access (WiMax) applications in this paper. The antenna has an asymmetric structure with total dimension of 25 × 18 × 1.5 mm3, where a C-shaped metal strip and an inverted L-shaped strip are designed as radiation elements. The measured −10 dB return-loss bandwidths cover 2.35–2.5, 3.07–3.85, and 4.6–7 GHz, which meets the IEEE 802.11b/g/a standard for WLAN and IEEE 802.16e standard for WiMax applications. Measured radiation patterns at 2.45, 3.5, and 5.5 GHz also show good agreement with simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 250-256 Issue: 2 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.743498 File-URL: http://hdl.handle.net/10.1080/09205071.2013.743498 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:2:p:250-256 Template-Type: ReDIF-Article 1.0 Author-Name: A. Rezig Author-X-Name-First: A. Author-X-Name-Last: Rezig Author-Name: A. N’diye Author-X-Name-First: A. Author-X-Name-Last: N’diye Author-Name: A. Djerdir Author-X-Name-First: A. Author-X-Name-Last: Djerdir Author-Name: M.R. Mekideche Author-X-Name-First: M.R. Author-X-Name-Last: Mekideche Title: Experimental investigation of vibration monitoring technique for online detection of bearing fault in induction motors Abstract: This paper investigates the online detection of bearing fault by a vibration monitoring technique. A theoretical mechanical model for faults in bearing elements was developed. This model which is based on the nonlinear contact theory calculates the vibration of the shaft due to a defect in the ball bearing’s rolling elements. An experimental device was also installed to validate the theoretical model in which one bearing of an induction motor was drilled on its outer race. The analyses of measured vibration show that defect can be characterized by a particular signature in vibration spectrum. Journal: Journal of Electromagnetic Waves and Applications Pages: 496-506 Issue: 4 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.753662 File-URL: http://hdl.handle.net/10.1080/09205071.2013.753662 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:4:p:496-506 Template-Type: ReDIF-Article 1.0 Author-Name: S.K. Mandal Author-X-Name-First: S.K. Author-X-Name-Last: Mandal Author-Name: G.K. Mahanti Author-X-Name-First: G.K. Author-X-Name-Last: Mahanti Author-Name: Rowdra Ghatak Author-X-Name-First: Rowdra Author-X-Name-Last: Ghatak Title: A single objective approach for suppressing sideband radiations of ultra-low side lobe patterns in time-modulated antenna arrays Abstract: In this paper, a novel optimization method based on single objective, that is, minimization of sideband radiation (SBR) of ultra-low side lobe, narrow beam patterns in time modulated antenna arrays (TMAAs) is proposed. The proposed method utilizes the weighting vectors of the low side lobe Dolph-Chebyshev/Taylor series patterns as the dynamic excitation coefficients of the desired pattern at fundamental radiation. Differential evolution algorithm is employed to distribute the static amplitudes and switch-on time durations in such a way that in the optimization process, dynamic excitation distribution remains the same. Static amplitudes are perturbed in a predefined search range of (0.25, 1), whereas the weighted values of switch-on time durations are obtained by dividing dynamic excitation coefficients by static amplitudes. The technique greatly simplifies the difficulties of multi-objective TMAA synthesizing problem by reducing it to a single-objective optimization problem. Numerical examples for a 32-element linear array are presented to produce ultra low side lobe Taylor and Dolph-Chebyshev pattern with low value of maximum sideband radiation (SBRmax). The optimization results of the proposed method are also compared with those obtained by other optimization techniques, which have been reported previously. Journal: Journal of Electromagnetic Waves and Applications Pages: 1767-1775 Issue: 14 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.823360 File-URL: http://hdl.handle.net/10.1080/09205071.2013.823360 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:14:p:1767-1775 Template-Type: ReDIF-Article 1.0 Author-Name: Gyu Yeong Cho Author-X-Name-First: Gyu Yeong Author-X-Name-Last: Cho Author-Name: Hyeon Dong Cho Author-X-Name-First: Hyeon Dong Author-X-Name-Last: Cho Author-Name: Wee Sang Park Author-X-Name-First: Wee Sang Author-X-Name-Last: Park Title: Investigation of higher-order modes in finite-width parallel-plate waveguide Abstract: Transverse electric modes in finite-width parallel-plate waveguides were described and investigated. Electric and magnetic field components of the modes were evaluated, assuming that boundaries at both sides of the parallel-plate waveguide were perfect magnetic conductors. The existence of the modes was verified by simulation, experimental measurement of a parallel-plate waveguide cavity. As the cut-off frequencies of the reported transverse modes are lower than even those of TE1 and TM1 modes, which are generally considered the lowest, the characteristics of the transverse modes must be considered before using parallel-plate waveguides. Changes in the modes due to imperfect boundaries were also studied. Journal: Journal of Electromagnetic Waves and Applications Pages: 1509-1520 Issue: 12 Volume: 27 Year: 2013 Month: 8 X-DOI: 10.1080/09205071.2013.817956 File-URL: http://hdl.handle.net/10.1080/09205071.2013.817956 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:12:p:1509-1520 Template-Type: ReDIF-Article 1.0 Author-Name: S. Padhy Author-X-Name-First: S. Author-X-Name-Last: Padhy Author-Name: S. Sanyal Author-X-Name-First: S. Author-X-Name-Last: Sanyal Author-Name: R.S. Meena Author-X-Name-First: R.S. Author-X-Name-Last: Meena Author-Name: R. Chatterjee Author-X-Name-First: R. Author-X-Name-Last: Chatterjee Author-Name: A. Bose Author-X-Name-First: A. Author-X-Name-Last: Bose Title: Characterization and performance evaluation of radar absorbing materials Abstract: This paper presents characterization and performance evaluation of radar-absorbing paint (RAP) consisting of U-type Hexaferrite magnetic material Ba4 (Co1–5xP2x)2Fe36O60 for (x = 0.05) and polyimide solution. In this paper, different methods of RAP characterizations are discussed and with scattering parameter method, permittivity and permeability values are measured using Vector Network Analyser. Reflection loss of the RAP has been computed from the measured complex permittivity and permeability values. RAP has been applied on an artillery shell and its performance evaluation has been carried out using multilevel fast multipole method-based electromagnetic simulation software at various frequencies in X band. Maximum radar cross section reductions of the order of 17 dB have been observed at 10 GHz frequency range. Journal: Journal of Electromagnetic Waves and Applications Pages: 191-204 Issue: 2 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.743447 File-URL: http://hdl.handle.net/10.1080/09205071.2013.743447 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:2:p:191-204 Template-Type: ReDIF-Article 1.0 Author-Name: Nikolina Jankovic Author-X-Name-First: Nikolina Author-X-Name-Last: Jankovic Author-Name: Vasa Radonic Author-X-Name-First: Vasa Author-X-Name-Last: Radonic Author-Name: Vesna Crnojevic-Bengin Author-X-Name-First: Vesna Author-X-Name-Last: Crnojevic-Bengin Title: Compact tri-band bandpass filter based on quarter-wavelength resonators Abstract: In this work, a planar microstrip tri-band filter based on quarter-wavelength resonators is presented, which allows independent control of the positions of all three passbands. Furthermore, the topology of the filter provides five transmission zeros and thus results in a highly selective response in all passbands. A synthesis procedure of the filter is presented and used to design a tri-band filter which operates at WLAN frequencies of 2.4/3.5/5.2 GHz. The designed filter outperforms all other state-of-the-art tri-band filters in terms of compact size, high selectivity and transmission, and return-loss characteristics. Journal: Journal of Electromagnetic Waves and Applications Pages: 750-757 Issue: 6 Volume: 27 Year: 2013 Month: 4 X-DOI: 10.1080/09205071.2013.786206 File-URL: http://hdl.handle.net/10.1080/09205071.2013.786206 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:6:p:750-757 Template-Type: ReDIF-Article 1.0 Author-Name: Josefa Gómez Pérez Author-X-Name-First: Josefa Author-X-Name-Last: Gómez Pérez Author-Name: Abdelhamid Tayebi Tayebi Author-X-Name-First: Abdelhamid Author-X-Name-Last: Tayebi Tayebi Author-Name: Iván González Diego Author-X-Name-First: Iván Author-X-Name-Last: González Diego Author-Name: Felipe Cátedra Pérez Author-X-Name-First: Felipe Author-X-Name-Last: Cátedra Pérez Title: Broadband reflectarray antenna composed of single-layer concentric rings Abstract: An offset-fed reflectarray antenna composed of single-layer elements based on the combination of circular and square concentric rings of variable size is presented in this paper. The characteristics of the elementary cells have been optimized providing a lineal phase curve with a phase range higher than 360°. The 297 × 297 mm reflectarray has been designed, fabricated, and measured to operate at 16 GHz and radiates the main beam in the direction given by θ = 10° and  = 0°. In spite of utilizing a thin substrate, measured results of the linearly polarized reflectarray demonstrate a 1 dB gain bandwidth of 15.48% and radiation efficiency of 52.36% with a peak gain of 32.21 dB. Also, the measurements exhibit a cross-polar discrimination better than 27 dB in the working frequency band. Journal: Journal of Electromagnetic Waves and Applications Pages: 2166-2175 Issue: 17 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.835247 File-URL: http://hdl.handle.net/10.1080/09205071.2013.835247 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:17:p:2166-2175 Template-Type: ReDIF-Article 1.0 Author-Name: Chung-Jung Chen Author-X-Name-First: Chung-Jung Author-X-Name-Last: Chen Author-Name: Ching-Her Lee Author-X-Name-First: Ching-Her Author-X-Name-Last: Lee Author-Name: Chung-I G. Hsu Author-X-Name-First: Chung-I G. Author-X-Name-Last: Hsu Title: Balanced wideband BPF design using multi-mode slot-line resonator for MB-OFDM applications Abstract: This paper presents a new balanced wideband band-pass filter (BPF) that is designed using a multi-mode slot-line resonator (MMSLR) with microstrip feed-lines. To obtain good differential operation and meanwhile reject unwanted common-mode (CM) noises, the balanced BPF is arranged in a symmetric fashion. For differential-mode (DM) operation, by locating the first three resonant modes of the MMSLR in the desired passband and feeding the MMSLR with tightly coupled microstrip feed-lines, we obtained a wideband response that meets the requirement of the OFDM group-B bandwidth specification (4.752–6.336 GHz). For CM operation, an open-circuited stub is effectively added to the feeding lines at the output port so that the transmitted CM signals can be attenuated. The measurement agrees well with the simulation. For the designed balanced wideband BPF, the measured minimum DM insertion loss is 0.63 dB in the DM passband, in which the CM suppression is larger than 17.6 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 1419-1428 Issue: 11 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.811040 File-URL: http://hdl.handle.net/10.1080/09205071.2013.811040 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:11:p:1419-1428 Template-Type: ReDIF-Article 1.0 Author-Name: M.S.A. Rani Author-X-Name-First: M.S.A. Author-X-Name-Last: Rani Author-Name: S.K.A. Rahim Author-X-Name-First: S.K.A. Author-X-Name-Last: Rahim Author-Name: H. Rezaie Author-X-Name-First: H. Author-X-Name-Last: Rezaie Author-Name: F.D. Dahalan Author-X-Name-First: F.D. Author-X-Name-Last: Dahalan Author-Name: M.I. Sabran Author-X-Name-First: M.I. Author-X-Name-Last: Sabran Author-Name: M.Z.M. Nor Author-X-Name-First: M.Z.M. Author-X-Name-Last: Nor Author-Name: A. Zainal Author-X-Name-First: A. Author-X-Name-Last: Zainal Title: Directional UWB antenna with a parabolic ground structure and split ring resonator for a 5.8 GHz band notch Abstract: A simple and compact circular planar monopole ultra-wide band antenna with a 5.8 GHz band rejection and directional radiation pattern is proposed in this paper. The split ring resonator (SRR) technique has been utilized to produce band rejection at 5.8 GHz. Some results and analysis on several SRR placements are highlighted in this paper. The parabolic ground structure is used to produce a directional radiation pattern together with bandwidth enhancement. The proposed prototype antenna has acceptable performances in terms of gain, efficiency, and directional radiation pattern. Simulated and experimental results are discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 14-22 Issue: 1 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2012.737456 File-URL: http://hdl.handle.net/10.1080/09205071.2012.737456 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:1:p:14-22 Template-Type: ReDIF-Article 1.0 Author-Name: Humberto Lobato-Morales Author-X-Name-First: Humberto Author-X-Name-Last: Lobato-Morales Author-Name: Jim S. Sun Author-X-Name-First: Jim S. Author-X-Name-Last: Sun Author-Name: Alonso Corona-Chavez Author-X-Name-First: Alonso Author-X-Name-Last: Corona-Chavez Author-Name: Tatsuo Itoh Author-X-Name-First: Tatsuo Author-X-Name-Last: Itoh Author-Name: José Luis Olvera-Cervantes Author-X-Name-First: José Luis Author-X-Name-Last: Olvera-Cervantes Title: Novel microstrip diplexer for ultra-wide-band (UWB) and wireless LAN (WLAN) bands Abstract: A new microstrip diplexer for ultra-wide-band (UWB) and wireless LAN (WLAN) bands is presented in this paper. The proposed structure integrates a multipole directional filter operating at WLAN band coupled to a UWB filter. The prototype is capable of processing the whole UWB region (from 3.1 to 10.6 GHz) with the WLAN band notch in one channel, and the passband WLAN band in other channel with a good selectivity due to the presence of transmission zeros at both sides of the WLAN band. The proposed diplexer is simple to fabricate, as it is designed using planar microstrip technology, and presents compact dimensions, making use of a low number of elements. Moreover, it presents the capacity of processing a narrow band (WLAN with 8% bandwidth) with a wide band (UWB). Simulated and measured results are presented with good agreement and the diplexer presents a good performance up to 15 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1338-1350 Issue: 11 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.808598 File-URL: http://hdl.handle.net/10.1080/09205071.2013.808598 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:11:p:1338-1350 Template-Type: ReDIF-Article 1.0 Author-Name: E.J. Rothwell Author-X-Name-First: E.J. Author-X-Name-Last: Rothwell Author-Name: K.A. Akinlabi-Oladimeji Author-X-Name-First: K.A. Author-X-Name-Last: Akinlabi-Oladimeji Title: Effects of surface curvature and beam defocusing on the characterization of conductor-backed absorbing materials using a free-space system Abstract: Algorithms that extract the permittivity and permeability of conductor-backed absorbing materials from data obtained using a free-space system often assume plane-wave excitation and planar materials to improve the computational efficiency, even though the surfaces are usually curved and focus beam systems are used for interrogation. It is thus important to assess the effects that these assumptions have on the accuracy of the extracted material parameters. A two-dimensional model is used to determine the conditions under which the error in the extracted parameters exceeds that expected from measurement uncertainty. It is found for typical absorbers that errors introduced by the modelling assumptions are significant when the surface curvature radius is less than about 10 wavelengths or the beam is defocused by a quarter to a half of a wavelength. These results should prove useful for the design of practical free-space systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 1473-1482 Issue: 12 Volume: 27 Year: 2013 Month: 8 X-DOI: 10.1080/09205071.2013.816640 File-URL: http://hdl.handle.net/10.1080/09205071.2013.816640 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:12:p:1473-1482 Template-Type: ReDIF-Article 1.0 Author-Name: Shengjun Wei Author-X-Name-First: Shengjun Author-X-Name-Last: Wei Author-Name: Quanyuan Feng Author-X-Name-First: Quanyuan Author-X-Name-Last: Feng Title: A tunable wide-slot antenna with asymmetric Y-shaped microstrip line Abstract: In this paper, a tunable dual-band antenna with an asymmetric Y-shaped microstrip line is proposed. The proposed antenna comprises an asymmetric Y-shaped microstrip line and an isosceles triangle-wide slot carved on the ground plane. By adjusting the angle of the Y-shaped microstrip line, desired center frequency of single-band can be obtained. With loading varactors, single-band and dual-band are achieved, which can be conveniently controlled. Simultaneously, the switchable behavior between the tunable single-band and the tunable dual-band is presented. The prototype is designed on F4B-2 substrate with a dielectric constant of 2.65, which occupied an overall size of 30 × 25 × 0.5 mm3. Simulated and measured results show that low- and high-frequency bands can be controlled through two varactors. The low-frequency channel ranging from 2.6 to 3.35 GHz can be realized, while the tunable high-frequency band ranges from 4.6 to 5.12 GHz. The low-frequency band can be adjusted while keeping the high-frequency band unchanged. Further, the proposed antenna has relatively stable radiation patterns during frequency tuning. Journal: Journal of Electromagnetic Waves and Applications Pages: 1735-1742 Issue: 14 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.823126 File-URL: http://hdl.handle.net/10.1080/09205071.2013.823126 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:14:p:1735-1742 Template-Type: ReDIF-Article 1.0 Author-Name: Lanmei Wang Author-X-Name-First: Lanmei Author-X-Name-Last: Wang Author-Name: Guibao Wang Author-X-Name-First: Guibao Author-X-Name-Last: Wang Author-Name: Zhihai Chen Author-X-Name-First: Zhihai Author-X-Name-Last: Chen Title: Joint DOA-polarization estimation based on uniform concentric circular array Abstract: A joint estimation method for direction of arrival (DOA) and polarization based on uniform concentric circular array is proposed in this paper. According to the array, manifold vector relationship between electric dipoles and magnetic loops, the least squares solution to the signal polarization parameters, and DOA are given. By maximum likelihood-estimation of signal parameters via rotational invariance techniques method, the space-polarization matrix is obtained from signal subspace by decoupling data covariance matrix. The eigenvalue of space-polarization matrix is used to estimate polarization parameter and the corresponding eigenvector is the steering vector of the whole array. The phase differences between two array elements on inner circle is acquired from the steering vectors of inner circle, which can be used to give rough but unambiguous estimates of DOA; they are used as coarse references to disambiguate the cyclic phase ambiguities in phase differences between two array elements on outer ring circle. Without spectral peak searching and parameter matching, this method has advantages of the small amount of calculation and high precision. Finally, simulation results verify the effectiveness of the algorithm. Journal: Journal of Electromagnetic Waves and Applications Pages: 1702-1714 Issue: 13 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.823122 File-URL: http://hdl.handle.net/10.1080/09205071.2013.823122 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:13:p:1702-1714 Template-Type: ReDIF-Article 1.0 Author-Name: Wan Jiang Author-X-Name-First: Wan Author-X-Name-Last: Jiang Author-Name: Changjun Liu Author-X-Name-First: Changjun Author-X-Name-Last: Liu Author-Name: Chengyang Yu Author-X-Name-First: Chengyang Author-X-Name-Last: Yu Author-Name: Feifei Tan Author-X-Name-First: Feifei Author-X-Name-Last: Tan Author-Name: Xing Chen Author-X-Name-First: Xing Author-X-Name-Last: Chen Author-Name: Kama Huang Author-X-Name-First: Kama Author-X-Name-Last: Huang Title: A novel dual-frequency microwave rectifier at 2.45 and 5.8 GHz with harmonic recycling Abstract: A novel dual-frequency microwave rectifier that operates at 2.45 GHz alone, 5.8 GHz alone, or their combination has been developed in this paper. It is the first approach to microwave rectifying for a situation of the incoherent microwave power combination. We focused on the two primary components, i.e. the regulation of impedance matching and the recycling of the second harmonics. A quarter-wave short-ended microstrip line at 5.8 GHz is shunted at the input of the rectifier to enhance the impedance matching at 2.45 GHz. A microstrip line band-stop filter (BSF) and a quarter-wave short-ended microstrip line are introduced to improve the recycling of the second harmonics. The measured microwave to DC (MW-DC) conversion efficiencies are 57.5, 46.5, and 40.7% at 2.45, 5.8 GHz, and their combination, respectively, with an input microwave power at 17 dBm. It may be applied to a dual-frequency microwave power wireless transmission system. Journal: Journal of Electromagnetic Waves and Applications Pages: 707-715 Issue: 6 Volume: 27 Year: 2013 Month: 4 X-DOI: 10.1080/09205071.2013.763589 File-URL: http://hdl.handle.net/10.1080/09205071.2013.763589 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:6:p:707-715 Template-Type: ReDIF-Article 1.0 Author-Name: S.-S. Zhang Author-X-Name-First: S.-S. Author-X-Name-Last: Zhang Author-Name: B.-Y. Wen Author-X-Name-First: B.-Y. Author-X-Name-Last: Wen Author-Name: H. Zhou Author-X-Name-First: H. Author-X-Name-Last: Zhou Title: Analysis of the higher order Bragg scatter in HF radar Abstract: The higher order Bragg scatter from rough surface, which belongs to an electromagnetic scatter, is investigated with the boundary perturbation method. The equations of radar scatter cross sections for higher order Bragg scatter are deduced. The performance of higher order Bragg scatter is distinct from the sea-echo spectra in real data when at high sea states or in the upper part of the HF band. The accuracy and efficiency of the deduced formulas are compared and validated with several examples of the Ocean State Measuring and Analyzing Radar-S experiments data, which were obtained in different locations and at different operating frequencies. Journal: Journal of Electromagnetic Waves and Applications Pages: 507-517 Issue: 4 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.753844 File-URL: http://hdl.handle.net/10.1080/09205071.2013.753844 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:4:p:507-517 Template-Type: ReDIF-Article 1.0 Author-Name: Ana Vazquez Alejos Author-X-Name-First: Ana Vazquez Author-X-Name-Last: Alejos Author-Name: Francisco Falcone Author-X-Name-First: Francisco Author-X-Name-Last: Falcone Author-Name: Muhammad Dawood Author-X-Name-First: Muhammad Author-X-Name-Last: Dawood Author-Name: Erik Aguirre Author-X-Name-First: Erik Author-X-Name-Last: Aguirre Author-Name: Leire Azpilicueta Author-X-Name-First: Leire Author-X-Name-Last: Azpilicueta Title: Evaluation of the Brillouin precursor performance for ultra wide band intra-body technologies Abstract: In this letter, we describe the formation and the evolution of Brillouin precursor fields through human tissues by using a frequency-domain analysis technique and a multi-pole Cole–Cole model to characterize the dielectric properties of the human body tissues, in a frequency band designated by the FCC for ultra wide band medical applications, which extends from 0.5 to 20 GHz. A 3D representation of the human body model has been implemented by employing a discretized mesh of cuboids with a resolution of 8 mm3 in which the frequency dispersive material parameters for different tissues have been considered. The dispersive propagation is analyzed for the purposes of radar imaging and intra-body communications. The performance of a classical rectangular pulse, a Brillouin pulse and a medium-matched waveform is described. The results show the potential application of this type of communication scheme in order to improve the achievable measurement range and provide better signal to noise ratios. Journal: Journal of Electromagnetic Waves and Applications Pages: 2213-2220 Issue: 17 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.837015 File-URL: http://hdl.handle.net/10.1080/09205071.2013.837015 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:17:p:2213-2220 Template-Type: ReDIF-Article 1.0 Author-Name: C. Pan Author-X-Name-First: C. Author-X-Name-Last: Pan Author-Name: H. Zhou Author-X-Name-First: H. Author-X-Name-Last: Zhou Author-Name: B.-Y. Wen Author-X-Name-First: B.-Y. Author-X-Name-Last: Wen Title: Radio frequency interference suppression in high frequency surface wave radar based on range–domain correlation Abstract: High frequency surface wave radar (HFSWR) is often subject to the serious impact of external radio frequency interference (RFI), which must be suppressed efficiently in order to improve the viability of the radar. In this paper, we consider two different types of RFIs. One has a strong range–domain correlation at all range cells, while the other has a strong range–domain correlation only at the adjacent range cells. According to the difference on range–domain correlation between these two types of RFIs, we propose two different suppression methods based on the range–domain adaptive filtering. One is the far range cells method which uses the signals at the far range cells as the secondary data, and the other is the adjacent range cells method which uses the signals at the adjacent range cells as the secondary data. In the practical processing, we should select the far range cells method when the RFI has a strong range–domain correlation at all range cells. Otherwise, we should select the adjacent range cells method. Processing results of real data are presented to demonstrate the effectiveness of these two methods. Journal: Journal of Electromagnetic Waves and Applications Pages: 448-457 Issue: 4 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.749773 File-URL: http://hdl.handle.net/10.1080/09205071.2013.749773 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:4:p:448-457 Template-Type: ReDIF-Article 1.0 Author-Name: S. Natarajamani Author-X-Name-First: S. Author-X-Name-Last: Natarajamani Author-Name: Santanu Kumar Behera Author-X-Name-First: Santanu Kumar Author-X-Name-Last: Behera Author-Name: Sarat Kumar Patra Author-X-Name-First: Sarat Kumar Author-X-Name-Last: Patra Title: A triple band-notched planar antenna for UWB applications Abstract: A compact planar microstrip-fed ultra wideband antenna for triple bands is presented and analyzed. The proposed antenna consists of semi-circular shaped radiating patch with two I-shaped stubs. It provides a wide bandwidth of 3.05–11.7 GHz. A pair of spiral loop resonators merges with radiating patch to create the first notched band in 3.3–3.7 GHz for the WiMAX system. In addition, integrated microstrip resonators are coupled with ground to generate the second- and third-notched bands in 5.2–5.4 GHz for lower WLAN and 5.7–6 GHz for upper WLAN, respectively. Experimental results of the proposed antenna exhibit good radiation pattern, stable gain, and consistent group delay performances. The time domain behavior of the antenna with and without resonator is analyzed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1178-1186 Issue: 9 Volume: 27 Year: 2013 Month: 6 X-DOI: 10.1080/09205071.2013.803443 File-URL: http://hdl.handle.net/10.1080/09205071.2013.803443 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:9:p:1178-1186 Template-Type: ReDIF-Article 1.0 Author-Name: Bohee Suh Author-X-Name-First: Bohee Author-X-Name-Last: Suh Author-Name: Younghwan Kim Author-X-Name-First: Younghwan Author-X-Name-Last: Kim Author-Name: Taejin Kim Author-X-Name-First: Taejin Author-X-Name-Last: Kim Author-Name: Sanggeun Jeon Author-X-Name-First: Sanggeun Author-X-Name-Last: Jeon Title: K- and Ka-band miniature CMOS balun with a single spiral coupled structure Abstract: This paper presents a CMOS wideband miniature balun operating over the full K- and Ka-bands. The balun is based on a single spiral coupled structure where two symmetric spiral lines are stacked vertically (i.e. broadside-coupled) in an antipodal manner. The proposed structure provides ultra-wideband balun performance while occupying a minimal chip area compared with conventional spiral baluns. In order to offset residual inductance of the spirals, a compensation capacitor is shunted at the end of an unbalanced input line, which further improves the bandwidth. The proposed balun is implemented in a bulk 0.13-μm CMOS process. The measured insertion loss is less than 6.5 dB from 14 to 40 GHz. The amplitude and phase imbalances are less than 1 dB and 10°, respectively, over the entire bandwidth. The balun occupies an area of only 0.0095 mm2, which, to the authors’ knowledge, is significantly smaller than any previously reported CMOS baluns at similar frequency bands. Journal: Journal of Electromagnetic Waves and Applications Pages: 1910-1918 Issue: 15 Volume: 27 Year: 2013 Month: 10 X-DOI: 10.1080/09205071.2013.828575 File-URL: http://hdl.handle.net/10.1080/09205071.2013.828575 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:15:p:1910-1918 Template-Type: ReDIF-Article 1.0 Author-Name: Jui-Han Lu Author-X-Name-First: Jui-Han Author-X-Name-Last: Lu Author-Name: Bai-Fu Siao Author-X-Name-First: Bai-Fu Author-X-Name-Last: Siao Title: Planar omnidirectional tag antenna for UHF RFID system Abstract: A novel design of planar omnidirectional tag antenna for ultra high frequency (UHF) radio frequency identification (RFID) is proposed. With the use of a square loop accompanying dual dipole strips, the measured half-power bandwidth of the proposed broadband tag antenna can reach 143 MHz (857–1000 MHz), which includes the entire operating bandwidth for worldwide UHF RFID system. Meanwhile, with omnidirectional reading pattern, the measured reading distance is about 11.0 m as it is mounted on the carton. Good tag sensitivity was obtained across the desired frequency band. Journal: Journal of Electromagnetic Waves and Applications Pages: 901-910 Issue: 7 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.792749 File-URL: http://hdl.handle.net/10.1080/09205071.2013.792749 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:7:p:901-910 Template-Type: ReDIF-Article 1.0 Author-Name: Hongwei Deng Author-X-Name-First: Hongwei Author-X-Name-Last: Deng Author-Name: Yongjiu Zhao Author-X-Name-First: Yongjiu Author-X-Name-Last: Zhao Author-Name: Yong Fu Author-X-Name-First: Yong Author-X-Name-Last: Fu Author-Name: Ying He Author-X-Name-First: Ying Author-X-Name-Last: He Author-Name: Xiaojun Zhao Author-X-Name-First: Xiaojun Author-X-Name-Last: Zhao Title: High selectivity and CM suppression microstrip balanced BPF and balanced-to-balanced diplexer Abstract: In this paper, a new compact microstrip balanced bandpass filter (BPF) and balanced-to-balanced diplexer are designed with high selectivity and common-mode (CM) suppression. The equivalent differential-mode (DM) and CM half-circuits of the proposed balanced BPF and balanced-to-balanced diplexer are analyzed in detail. Under the DM excitation, the filtering topology is formed by two coupling quarter-wavelength resonators (QWR) and source-load short-ended feedlines. Two transmission zeros can be generated near the DM passband edge to achieve high selectivity. Under the CM excitation, the transmission zero generated by the coupling between the QWR and short-ended feedline can be adjusted by the shorted stub loaded at the center to the DM passband. Moreover, the mutual loading effect of the filters with two coupling uniform resonators is approximately equivalent to a uniform resonator coupling shorted stub. Hence, the mutual loading effect of two balanced BPFs can generate new transmission zeros to deepen the stopband and improve CM suppression without deterioration of high selectivity and CM suppression performance within the DM passband. Finally, the compact balanced BPF and balanced-to-balanced diplexer by combining two balanced BPFs without extra matching network are designed and fabricated, and good agreement can be obtained between the experimental and simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1047-1058 Issue: 8 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.799445 File-URL: http://hdl.handle.net/10.1080/09205071.2013.799445 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:8:p:1047-1058 Template-Type: ReDIF-Article 1.0 Author-Name: J. Ding Author-X-Name-First: J. Author-X-Name-Last: Ding Author-Name: C. Gu Author-X-Name-First: C. Author-X-Name-Last: Gu Author-Name: Z. Li Author-X-Name-First: Z. Author-X-Name-Last: Li Author-Name: Z. Niu Author-X-Name-First: Z. Author-X-Name-Last: Niu Title: Analysis of transient electromagnetic scattering using time domain equivalent dipole moment method Abstract: In this paper, an efficient technique is presented for computing the matrices in time domain integral equations (TDIE). The proposed method is the extension of the frequency domain equivalent dipole moment method to the time domain. Each matrix element does not require computing the usual surface integrals involving the expansion and testing functions, which makes the matrix generation more efficient and faster than the conventional TDIE method. Numerical results about the electromagnetic scattering from perfect electric conductor(PEC) objects are given to demonstrate the accuracy and efficiency of the proposed method. Journal: Journal of Electromagnetic Waves and Applications Pages: 39-47 Issue: 1 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.737911 File-URL: http://hdl.handle.net/10.1080/09205071.2013.737911 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:1:p:39-47 Template-Type: ReDIF-Article 1.0 Author-Name: Ming-Zhu Du Author-X-Name-First: Ming-Zhu Author-X-Name-Last: Du Author-Name: Jian-Xin Chen Author-X-Name-First: Jian-Xin Author-X-Name-Last: Chen Author-Name: Yong-Jie Yang Author-X-Name-First: Yong-Jie Author-X-Name-Last: Yang Author-Name: Zhi-Hua Bao Author-X-Name-First: Zhi-Hua Author-X-Name-Last: Bao Title: Balanced dual-band bandpass filter using stub-loaded stepped-impedance resonators Abstract: A balanced dual-band bandpass filter (BPF) based on stub-loaded stepped-impedance resonators (SIRs) is proposed in this paper. With the aid of the two open stubs loaded to the SIR symmetrically, the employed stub-loaded SIR possesses more design freedom for controlling differential-mode fundamental resonant frequency and second harmonic, as well as the ratio between them in the design of the proposed BPF. In addition, as the loaded stubs’ length increases, both fundamental resonant frequency and second harmonic can be shifted down, implying that the size reduction in this design is achieved. Finally, a two-order balanced dual-band BPF is designed and fabricated for demonstration, and the simulated and measured results are presented, showing good agreement. In addition, the centrally loaded resistor is added and optimized to achieve high common-mode suppression, especially in the two differential-mode passbands. Journal: Journal of Electromagnetic Waves and Applications Pages: 2056-2064 Issue: 16 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.831740 File-URL: http://hdl.handle.net/10.1080/09205071.2013.831740 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:16:p:2056-2064 Template-Type: ReDIF-Article 1.0 Author-Name: Sobia Shoukat Author-X-Name-First: Sobia Author-X-Name-Last: Shoukat Author-Name: Shakeel Ahmed Author-X-Name-First: Shakeel Author-X-Name-Last: Ahmed Author-Name: Muhammad Aqueel Ashraf Author-X-Name-First: Muhammad Author-X-Name-Last: Aqueel Ashraf Author-Name: Aqeel A. Syed Author-X-Name-First: Aqeel A. Author-X-Name-Last: Syed Author-Name: Q.A. Naqvi Author-X-Name-First: Q.A. Author-X-Name-Last: Naqvi Title: Scattering of electromagnetic plane wave from a chiral cylinder placed in chiral metamaterials Abstract: Analytical solution of vector wave equation describing the scattering of electromagnetic plane waves from an infinitely long circular chiral cylinder placed in another chiral metamaterial is presented. Cylindrical vector wave functions are used to express the fields both inside and outside the circular cylinder. The unknown are determined by applying the appropriate boundary conditions at the cylindrical interface. The numeric results are presented taking different combinations of metamaterials for inner and outer mediums of the cylinder. For this purpose chiral and/or chiral nihility cylinder placed in chiral and/or chiral nihility mediums are considered. Extreme cases of permittivity and permeability corresponding to PEC and PMC cylinder are also considered. Journal: Journal of Electromagnetic Waves and Applications Pages: 1127-1135 Issue: 9 Volume: 27 Year: 2013 Month: 6 X-DOI: 10.1080/09205071.2013.801042 File-URL: http://hdl.handle.net/10.1080/09205071.2013.801042 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:9:p:1127-1135 Template-Type: ReDIF-Article 1.0 Author-Name: D. Abed Author-X-Name-First: D. Author-X-Name-Last: Abed Author-Name: S. Redadaa Author-X-Name-First: S. Author-X-Name-Last: Redadaa Author-Name: H. Kimouche Author-X-Name-First: H. Author-X-Name-Last: Kimouche Title: Printed ultra-wideband stepped-circular slot antenna with different tuning stubs Abstract: This paper is aimed at proposing a novel printed microstrip-fed slot antenna suitable for wireless ultra-wideband (UWB) communication systems. The proposed antenna has been designed for operating at  GHz frequency band. The synthesis of the antenna is carried out by means of parametric study of the main parameters. The result is a printed stepped-circular-shaped slot antenna exhibiting a good impedance matching with different tuning stubs. To demonstrate the effectiveness of the proposed UWB antenna, the results from numerical validations and experimental tests are presented and discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 846-855 Issue: 7 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.789409 File-URL: http://hdl.handle.net/10.1080/09205071.2013.789409 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:7:p:846-855 Template-Type: ReDIF-Article 1.0 Author-Name: F. Cheng Author-X-Name-First: F. Author-X-Name-Last: Cheng Author-Name: X.Q. Lin Author-X-Name-First: X.Q. Author-X-Name-Last: Lin Author-Name: X.X. Liu Author-X-Name-First: X.X. Author-X-Name-Last: Liu Author-Name: K.J. Song Author-X-Name-First: K.J. Author-X-Name-Last: Song Author-Name: Y. Fan Author-X-Name-First: Y. Author-X-Name-Last: Fan Title: A compact dual-band bandpass SIW filter Abstract: A novel method for the design of substrate integrated waveguide (SIW) dual-band bandpass filter is presented in this paper. Dual-band response is achieved by TE101 mode and diagonal TE201 (TE102) mode. The resonant frequency of TE101 mode can be adjusted by the location of perturbation vias while the resonant frequency of diagonal TE201 (TE102) mode keeps unchanged. A design example with second-order filter response is given and verified by experiments. The vertically stacked SIW resonators are used here to save the size. Journal: Journal of Electromagnetic Waves and Applications Pages: 338-344 Issue: 3 Volume: 27 Year: 2013 Month: 2 X-DOI: 10.1080/09205071.2013.745387 File-URL: http://hdl.handle.net/10.1080/09205071.2013.745387 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:3:p:338-344 Template-Type: ReDIF-Article 1.0 Author-Name: Meriam Attia Author-X-Name-First: Meriam Author-X-Name-Last: Attia Author-Name: Michel Ney Author-X-Name-First: Michel Author-X-Name-Last: Ney Author-Name: Taoufik Aguili Author-X-Name-First: Taoufik Author-X-Name-Last: Aguili Title: The segmentation concept for frequency-domain TLM method combined to the variable mesh technique Abstract: In this paper, the segmentation method is implemented in the frequency-domain transmission line matrix (FD-TLM). The method is combined with the variable mesh technique. Although the procedure is general, the examples shown concern the design of waveguide discontinuities. Thus, the structure is decomposed into several sub-domains and a finer mesh is used in the computational domain around discontinuities. An important reduction in computing time and memory resources is achieved with a good accuracy. Journal: Journal of Electromagnetic Waves and Applications Pages: 2035-2048 Issue: 16 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.831329 File-URL: http://hdl.handle.net/10.1080/09205071.2013.831329 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:16:p:2035-2048 Template-Type: ReDIF-Article 1.0 Author-Name: Chien-Yuan Pan Author-X-Name-First: Chien-Yuan Author-X-Name-Last: Pan Author-Name: Bo-Yao Wu Author-X-Name-First: Bo-Yao Author-X-Name-Last: Wu Author-Name: Jen-Yea Jan Author-X-Name-First: Jen-Yea Author-X-Name-Last: Jan Title: Size reduction of circularly polarized slot antenna using open C-slot for WiMAX application Abstract: A new wideband circularly polarized (CP) open C-slot antenna fed by a microstrip line for size reduction is presented. The proposed antenna consists of an open C-slot with a straight slit on the ground plane, and a microstrip line with a semicircle-shaped patch on the other side of the substrate. The antenna size is reduced by about 35% compared with the circular slot antenna. By using the semicircle-shaped patch to disturb the magnetic current distribution on the open C-slot, a wider CP bandwidth can be achieved. The measured results show that the proposed antenna can provide a 3 dB axial ratio (AR) bandwidth of 40% (4.1–6.2 GHz) and a 10 dB return loss impedance bandwidth of 107% (2.3–7.6 GHz). The measured gain variation is from 2.8 to 4.3 dBic in the 3 dB AR bandwidth. A prototype of the proposed antenna has a simple and compact size of 30 × 55 × 1.6 mm3. Journal: Journal of Electromagnetic Waves and Applications Pages: 1640-1648 Issue: 13 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.821956 File-URL: http://hdl.handle.net/10.1080/09205071.2013.821956 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:13:p:1640-1648 Template-Type: ReDIF-Article 1.0 Author-Name: Z.X. Xia Author-X-Name-First: Z.X. Author-X-Name-Last: Xia Author-Name: Y.J. Cheng Author-X-Name-First: Y.J. Author-X-Name-Last: Cheng Author-Name: Y. Fan Author-X-Name-First: Y. Author-X-Name-Last: Fan Title: Frequency-reconfigurable TM010-mode reentrant cylindrical cavity for microwave material processing Abstract: This paper proposes a frequency-reconfigurable microwave reactor based on the reentrant cylindrical resonant cavity. It works with the TM010-associated mode and is able to resonate at every frequency in the range of 500–950 MHz, i.e., 62% tunable relative bandwidth. Considering the practical requirements of microwave processing, especially for the single processing capacity and the wide frequency bandwidth, the theory and design formula for the existing reentrant cylindrical resonant cavity are no longer applicable. Consequently, a new method to control the resonant frequency is proposed. The corresponding approximate design formulas are derived to show the relationship between cavity’s dimension and its electric properties (resonant frequency and quality factor). Their correctness is validated by the full-wave simulation. Furthermore, an effective feed method is developed to achieve good matching over a wideband frequency band. Within a volume of 502 mm3, relatively homogeneous -field can be generated at every operation frequency with the strength more than 105 V/m, while the single processed capacity keeps unchanged. Most of the microwave energy is concentrated within the processed region to achieve a high efficiency. This microwave reactor presents an excellent candidate in the application of a frequency-reconfigurable microwave processing system to recognize the optimal absorbent frequency for a special microwave reaction. Journal: Journal of Electromagnetic Waves and Applications Pages: 605-614 Issue: 5 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.758224 File-URL: http://hdl.handle.net/10.1080/09205071.2013.758224 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:5:p:605-614 Template-Type: ReDIF-Article 1.0 Author-Name: S. T. Bishay Author-X-Name-First: S. T. Author-X-Name-Last: Bishay Author-Name: O. M. Abo-Seida Author-X-Name-First: O. M. Author-X-Name-Last: Abo-Seida Author-Name: H. S. Shoeib Author-X-Name-First: H. S. Author-X-Name-Last: Shoeib Title: Wave propagation in air from a vertical magnetic dipole located in three rough-layered structures Abstract: In this paper, the field scattered in the upper medium (air) by a system composed of three homogeneous media (air–sea–ground) that are separated by two rough interfaces is derived from a perturbation technique. The source is located in the inner medium (seawater), which is a vertical magnetic dipole. Then, by applying the boundary conditions at each interface, the scattered field in each medium is derived analytically and expressed using the Hankel transformation (integral over the radial distance r). This research assumes that the modulus of the sea permittivity (> | {k_1}| ?>) is much larger than that of the air and that the parameter > \ 1 ?> (far field assumption), closed-form expressions of the involved integrals are found for the scattered field in the air by using an approximate method. No pole is considered and therefore the formulation is consistent with previous published results. Numerical results are given and represented graphically. In addition, this research presents a comparison of the results obtained here with those of one rough surface and two planar surfaces. This study will be useful for remote sensing of the ocean surface, especially when the transmitter is close to the surface. Journal: Journal of Electromagnetic Waves and Applications Pages: 911-929 Issue: 7 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.792750 File-URL: http://hdl.handle.net/10.1080/09205071.2013.792750 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:7:p:911-929 Template-Type: ReDIF-Article 1.0 Author-Name: K. Song Author-X-Name-First: K. Author-X-Name-Last: Song Author-Name: S. Hu Author-X-Name-First: S. Author-X-Name-Last: Hu Author-Name: Y. Fan Author-X-Name-First: Y. Author-X-Name-Last: Fan Author-Name: Q. Xue Author-X-Name-First: Q. Author-X-Name-Last: Xue Title: Compact ultra-wideband (UWB) slotline bandpass filter with a switchable notch band Abstract: A novel switchable slotline notch-band structure is presented and applied in the ultra-wideband (UWB) bandpass filter (BPF) to switch a notch band within the passband. The PIN diodes are used for electronic switching. Based on the equivalent-circuit method, the circuit model of the presented UWB switchable notch-band BPF has been developed. The presented UWB BPF with a switchable notch band has been designed, fabricated, and measured. The fabricated UWB filter has an extremely compact size of  mm. The measured results agree with the simulated ones closely. The simulated and measured results show that a notch band centered at around 5.66 GHz can be turned on or off with no obvious degradation of the performance of the UWB BPF. Journal: Journal of Electromagnetic Waves and Applications Pages: 691-699 Issue: 6 Volume: 27 Year: 2013 Month: 4 X-DOI: 10.1080/09205071.2013.762677 File-URL: http://hdl.handle.net/10.1080/09205071.2013.762677 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:6:p:691-699 Template-Type: ReDIF-Article 1.0 Author-Name: C. Karpuz Author-X-Name-First: C. Author-X-Name-Last: Karpuz Author-Name: A.K. Gorur Author-X-Name-First: A.K. Author-X-Name-Last: Gorur Author-Name: A.N. Basmaci Author-X-Name-First: A.N. Author-X-Name-Last: Basmaci Author-Name: A. Ozek Author-X-Name-First: A. Author-X-Name-Last: Ozek Title: Design and analysis of a compact dual-mode dual-band microstrip bandpass filter Abstract: Design and fabrication of compact dual-mode dual-band microstrip bandpass filters with a novel feed scheme is presented. The proposed filters have two square loop resonators for two passbands, and each resonator is fed by the feedlines located at the upper corners of the resonators. By using the perturbation elements such as patches or corner-cuts, two degenerate modes of each passband can be easily excited, so mode frequencies and transmission zeros of the passbands can be controlled independently. Also, the proposed feed scheme provides the harmonic suppression for the first passband. In addition, theoretical results have been obtained by using an equivalent circuit model, and a coupling scheme is also presented. The designed filters have an electrical length of for the quarter wavelength resonator, where is the guided wavelength at 1.8 GHz. Two bandpass filters having elliptical and linear phase filtering characteristics in each passband have been designed, fabricated, and tested. Measured results are in an excellent agreement with simulated and calculated ones. In all frequency responses, return losses are better than 15 dB and insertion losses are at acceptable values for both passbands. Journal: Journal of Electromagnetic Waves and Applications Pages: 180-190 Issue: 2 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.743209 File-URL: http://hdl.handle.net/10.1080/09205071.2013.743209 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:2:p:180-190 Template-Type: ReDIF-Article 1.0 Author-Name: J.A. Brandão Faria Author-X-Name-First: J.A. Author-X-Name-Last: Brandão Faria Title: A physical model of the ideal transformer based on magnetic transmission line theory Abstract: The ideal transformer is a simple device whose analysis is covered in most electrical engineering textbooks, encompassing power systems, circuit analysis, and basic electromagnetics. Ordinary analysis of ideal transformer functioning poses several delicate physical questions whose answer is given in this paper, enabling an understanding of the whole picture. On one hand, it is shown that if the magnetic stray flux is absent (as usually is assumed), then power flow between primary and secondary windings cannot occur. On the other hand, a physically correct perspective to deal with ideal transformers is developed by resorting to frequency-domain transmission line theory. This approach, based on Maxwell’s equations and Poynting’s vector, applies indistinctly to low and high frequency regimes. For analysis purposes, the ideal transformer is modeled by means of an ideal magnetic transmission line. Transverse electric and magnetic fields are obtained considering the particular example of a coaxial geometry. Ordinary results concerning the ideal transformer, i.e. voltage, current, and impedance ratios, are thoroughly discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 365-373 Issue: 3 Volume: 27 Year: 2013 Month: 2 X-DOI: 10.1080/09205071.2013.746632 File-URL: http://hdl.handle.net/10.1080/09205071.2013.746632 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:3:p:365-373 Template-Type: ReDIF-Article 1.0 Author-Name: R. Shen Author-X-Name-First: R. Author-X-Name-Last: Shen Author-Name: X.Q. Lin Author-X-Name-First: X.Q. Author-X-Name-Last: Lin Author-Name: Y. Fan Author-X-Name-First: Y. Author-X-Name-Last: Fan Title: A compact dual-band band-stop filter with high performance and controllable response Abstract: A fourth-order dual-band microstrip band-stop filter is proposed in this paper. Folded stepped impedance resonators are implemented as well as capacitive gap and inductive grounded via, thus the dual-band performance can be obtained in merely one resonator. Besides its compact size, simplicity, and good spurious band suppression, the filter also features its excellent mid-band rejection and skirt characteristic which is achieved by four reflection zeros adjacent to the dual resonating frequencies. Controllable response of filter is realized by tuning of gap capacity and via inductance, and the theory is verified by both simulation and experimental results that agree well with each other. Journal: Journal of Electromagnetic Waves and Applications Pages: 23-29 Issue: 1 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2012.737908 File-URL: http://hdl.handle.net/10.1080/09205071.2012.737908 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:1:p:23-29 Template-Type: ReDIF-Article 1.0 Author-Name: Y.L. Luo Author-X-Name-First: Y.L. Author-X-Name-Last: Luo Author-Name: L. Xu Author-X-Name-First: L. Author-X-Name-Last: Xu Author-Name: Z.Y. Xin Author-X-Name-First: Z.Y. Author-X-Name-Last: Xin Title: Compact UWB printed slot antenna with extra UMTS and Bluetooth bands Abstract: In this article, a novel compact ultra-wideband (UWB) antenna with two lower pass bands for wireless applications is presented and investigated. The low-profile antenna comprises of a pentagonal shaped patch for covering the UWB band (3.1–10.6 GHz). Two lower pass bands, 2.1 GHz The Universal Mobile Telecommunications System band and 2.4 GHz Bluetooth band, can be realized by etching two meander slots on the both sides of the ground bilaterally and adding a pair of inverted U-shaped stubs attached to the UWB antenna, respectively. The proposed antenna is designed and built on a FR-4 substrate, with a overall size of 26 mm × 37 mm. The simulated and measured results are presented and shown that the proposed compact antenna has a stable and good radiation patterns across all the relevant bands. Journal: Journal of Electromagnetic Waves and Applications Pages: 1557-1565 Issue: 12 Volume: 27 Year: 2013 Month: 8 X-DOI: 10.1080/09205071.2013.820151 File-URL: http://hdl.handle.net/10.1080/09205071.2013.820151 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:12:p:1557-1565 Template-Type: ReDIF-Article 1.0 Author-Name: Jui-Han Lu Author-X-Name-First: Jui-Han Author-X-Name-Last: Lu Author-Name: Yu-Yi Lee Author-X-Name-First: Yu-Yi Author-X-Name-Last: Lee Title: Planar compact triple-band monopole antenna for IEEE 802.16m WiMAX application Abstract: Planar compact monopole antenna design with triple-band operation for the IEEE 802.16 m worldwide interoperability for microwave access (WiMAX) system is proposed. By adding C- and L-shaped monopole strips to the antenna, excitation of multiresonant modes can approximate the 2.6, 3.5, and 5.5 GHz bands required for WiMAX (IEEE 802.16 m) operations. The obtained impedance bandwidths across the operating bands approach 168/325/1208 MHz for the 2.6/3.5/5.5 GHz bands, respectively. The proposed uniplanar antenna reduces the antenna size by at least 15%, since overall antenna volume is only 22 × 28 × 0.8 mm3 (0.19 λo × 0.243 λo × 0.007 λo, at 2.6 GHz). The measured peak gains and radiation efficiencies approximate 3.0/4.2/4.5 dBi and 77/76/83% in the 2.6/3.5/5.5 GHz band, respectively, and exhibit a nearly omni-directional pattern in the XY-plane. Journal: Journal of Electromagnetic Waves and Applications Pages: 1206-1219 Issue: 10 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.804460 File-URL: http://hdl.handle.net/10.1080/09205071.2013.804460 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:10:p:1206-1219 Template-Type: ReDIF-Article 1.0 Author-Name: Alberto Reyna Maldonado Author-X-Name-First: Alberto Author-X-Name-Last: Reyna Maldonado Author-Name: Marco A. Panduro Author-X-Name-First: Marco A. Author-X-Name-Last: Panduro Author-Name: Carlos del Rio Bocio Author-X-Name-First: Carlos Author-X-Name-Last: del Rio Bocio Author-Name: Aldo L. Mendez Author-X-Name-First: Aldo L. Author-X-Name-Last: Mendez Title: Design of concentric ring antenna array for a reconfigurable isoflux pattern Abstract: This report presents a novel design of concentric ring antenna array for a reconfigurable isoflux pattern. The array considers 61 disk patch antennas including mutual coupling by using the cavity model at the frequency of 2.8 GHz. The problem consists in finding out a few levels of excitations for the disk patch antennas. Harmony search algorithm and particle swarm optimization are implemented for this optimization problem. This novel design permits to reduce the complexity of the antenna hardware in the whole antenna system mounted in a satellite, where the volume occupation and heat dissipations are critical issues. Journal: Journal of Electromagnetic Waves and Applications Pages: 1483-1495 Issue: 12 Volume: 27 Year: 2013 Month: 8 X-DOI: 10.1080/09205071.2013.816877 File-URL: http://hdl.handle.net/10.1080/09205071.2013.816877 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:12:p:1483-1495 Template-Type: ReDIF-Article 1.0 Author-Name: D. Packiaraj Author-X-Name-First: D. Author-X-Name-Last: Packiaraj Author-Name: K.J. Vinoy Author-X-Name-First: K.J. Author-X-Name-Last: Vinoy Author-Name: M. Ramesh Author-X-Name-First: M. Author-X-Name-Last: Ramesh Author-Name: A.T. Kalghatgi Author-X-Name-First: A.T. Author-X-Name-Last: Kalghatgi Title: Analysis of multi-conductor coupled microstrip lines with an aperture in the ground plane for the design of a broadband filter Abstract: Closed-form expressions for the propagation characteristics of coupled microstrip lines with a symmetrical aperture in the ground plane are derived. Expressions for the regular microstrip coupled lines have been modified using physical insights to incorporate the effect of the aperture. The accuracy of these expressions has been verified by full-wave simulations and compared with conformal mapping analysis. These expressions are accurate within 5% for a substrate whose thickness varies from 0.2 to 1.6 mm and permittivity in the range of 2–10. Designing a broadband filter based on planar multi-conductor coupled lines with aperture in the ground plane is demonstrated in this paper using the proposed expressions for its practical use. Journal: Journal of Electromagnetic Waves and Applications Pages: 856-867 Issue: 7 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.789410 File-URL: http://hdl.handle.net/10.1080/09205071.2013.789410 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:7:p:856-867 Template-Type: ReDIF-Article 1.0 Author-Name: Younghwan Kim Author-X-Name-First: Younghwan Author-X-Name-Last: Kim Author-Name: Sungjoon Lim Author-X-Name-First: Sungjoon Author-X-Name-Last: Lim Title: Compact magnetic coupled resonator with high efficiency during misaligned wireless power transmission Abstract: A compact and high efficient magnetic coupled resonator that uses additional parallel capacitors is presented. The proposed resonators are used as a transmitter (TX) and receiver (RX) for a magnetic coupled wireless power transmission. Compared with a conventional magnetic coupled resonator, the resonator’s size is effectively decreased and the efficiency is increased by the additional capacitor at long distances. Interestingly, the proposed wireless power transmission system shows increased efficiency even when the axis between the TX and RX is misaligned, in contrast to with the conventional one. The proposed resonator has 88% maximum efficiency at a distance of 45 cm, and maintains 80% efficiency up to 25 cm offset. Journal: Journal of Electromagnetic Waves and Applications Pages: 1942-1948 Issue: 15 Volume: 27 Year: 2013 Month: 10 X-DOI: 10.1080/09205071.2013.829392 File-URL: http://hdl.handle.net/10.1080/09205071.2013.829392 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:15:p:1942-1948 Template-Type: ReDIF-Article 1.0 Author-Name: Hong-wei Deng Author-X-Name-First: Hong-wei Author-X-Name-Last: Deng Author-Name: Yong-jiu Zhao Author-X-Name-First: Yong-jiu Author-X-Name-Last: Zhao Author-Name: Yong Fu Author-X-Name-First: Yong Author-X-Name-Last: Fu Author-Name: Ying He Author-X-Name-First: Ying Author-X-Name-Last: He Author-Name: Xiao-jun Zhou Author-X-Name-First: Xiao-jun Author-X-Name-Last: Zhou Title: High selectivity and common-mode suppression combline balanced BPF Abstract: In this study, new balanced microstrip bandpass filter (BPF) based on stepped-impedance combline structure is proposed with high selectivity and high common-mode (CM) suppression performance In the beginning, a single-ended compact stepped-impedance resonator (SIR) combline BPF with enhanced performance including low insertion loss, sharp skirt and wide stopband response is designed by consisting of an array of short quarter-wavelength bi-section SIRs with a new scheme of tapped-transformer coupling at input and output ports. Under CM excitation, no special consideration or design procedure is required to suppress the CM, and the CM suppression is the nature of the parallel-coupled filter. Finally, the second- and third-order SIR combline balanced BPFs for WLAN application, without loss of generality, have been designed and implemented. The simulated and measured results show a good agreement and validate the proposed theory. Journal: Journal of Electromagnetic Waves and Applications Pages: 1008-1016 Issue: 8 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.796864 File-URL: http://hdl.handle.net/10.1080/09205071.2013.796864 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:8:p:1008-1016 Template-Type: ReDIF-Article 1.0 Author-Name: Qiusheng Li Author-X-Name-First: Qiusheng Author-X-Name-Last: Li Author-Name: Weixin Xie Author-X-Name-First: Weixin Author-X-Name-Last: Xie Title: Classification of aircraft targets with low-resolution radars based on multifractal spectrum features Abstract: The multifractal spectrum characteristics of aircraft echoes from low-resolution radars offer a fine description of dynamic characteristics which induce the echo structure; therefore, they can provide a new way for aircraft target classification and recognition with low-resolution radars. On basis of introducing the scattering mechanism of aircraft echoes from low-resolution radars, the paper analyzed the multifractal characteristics of aircraft echoes as well as the extraction method of their multifractal spectrum features by means of the multifractal analysis of measures and proposed the classification method for different types of aircraft targets from the viewpoint of pattern recognition. The classification experiment results with real recorded echo data showed the multifractal spectrum feature-based classification method can classify different types of aircraft targets effectively, so the defined characteristic parameters could be used as effective features for aircraft target classification and recognition. Journal: Journal of Electromagnetic Waves and Applications Pages: 2090-2100 Issue: 16 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.832394 File-URL: http://hdl.handle.net/10.1080/09205071.2013.832394 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:16:p:2090-2100 Template-Type: ReDIF-Article 1.0 Author-Name: F. Lin Author-X-Name-First: F. Author-X-Name-Last: Lin Author-Name: Q.-X. Chu Author-X-Name-First: Q.-X. Author-X-Name-Last: Chu Author-Name: S.W. Wong Author-X-Name-First: S.W. Author-X-Name-Last: Wong Title: A novel Gysel power divider design with uniform impedance transmission lines for arbitrary power-dividing ratios Abstract: A novel Gysel power divider with uniform impedance transmission lines is presented. The arbitrary power-dividing ratio is obtained only by adjusting the electrical lengths of the transmission lines, avoiding the use of high impedance lines that are involved in the conventional Gysel power divider design with large power-dividing ratio. All the transmission lines are with the same characteristic impedance, which is independent of the power-dividing ratio and provides a freedom to control the operation bandwidth. For verification, a 9:1 Gysel power divider operating at 1 GHz is designed, fabricated, and measured. The measured results are in good agreement with the simulated ones. The measured results show a bandwidth of 13.7% with better than 20 dB return loss and 29.2 dB isolation from 0.95 to 1.09 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 242-249 Issue: 2 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.743452 File-URL: http://hdl.handle.net/10.1080/09205071.2013.743452 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:2:p:242-249 Template-Type: ReDIF-Article 1.0 Author-Name: Shakeel Ahmed Author-X-Name-First: Shakeel Author-X-Name-Last: Ahmed Author-Name: Fazli Manan Author-X-Name-First: Fazli Author-X-Name-Last: Manan Author-Name: Aqeel A. Syed Author-X-Name-First: Aqeel A. Author-X-Name-Last: Syed Author-Name: Q.A. Naqvi Author-X-Name-First: Q.A. Author-X-Name-Last: Naqvi Title: Scattering from a buried perfect electromagnetic conductor of circular cylindrical shape and coated by a chiral material Abstract: The scattering effects of different types of chiral materials used as coating on a perfect electromagnetic conductor (PEMC) circular cylinder buried in a dielectric half space have been investigated in this paper. The coating layers of double positive (DPS) chiral, double negative (DNG) chiral, and chiral nihility have been considered in the analysis. The spectral plane wave solution is used to handle the multiple interactions between the buried cylinder and the dielectric interface separating the two half spaces. Numerical results obtained for scattering of a perpendicularly polarized electromagnetic plane wave from this configuration have been presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 1959-1975 Issue: 15 Volume: 27 Year: 2013 Month: 10 X-DOI: 10.1080/09205071.2013.832398 File-URL: http://hdl.handle.net/10.1080/09205071.2013.832398 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:15:p:1959-1975 Template-Type: ReDIF-Article 1.0 Author-Name: M. Abou El-Nasr Author-X-Name-First: M. Author-X-Name-Last: Abou El-Nasr Author-Name: H. Shaban Author-X-Name-First: H. Author-X-Name-Last: Shaban Title: Theoretical and experimental error performance and data-throughput of on-body UWB-based WBANs in the presence of timing-jitter Abstract: Recently, we have proposed using sensor nodes with rectangular template-based correlator detectors for ultra wideband (UWB) wireless body area networks (WBANs). Typically, correlator-based receive nodes have the potential for providing high data-throughput, however, they require high power consumption. On the other hand, rectangular template-based receivers are low-power alternatives that provide a bit-error-rate (BER) performance that approaches the performance of optimal detectors. This paper investigates the BER performance and maximum allowable data-throughput of equally correlated pulse position modulation (EC-PPM) scheme of the proposed receive nodes for on-body WBANs in the presence of timing-jitter. We derive closed forms for the BER performance, and provide numerical results based on theoretical analysis, Monte Carlo simulations in the industrially accepted on-body UWB IEEE 802.15.6a channel model, as well as actual on-body measurements. Numerical results show that the maximum signal-to-noise-ratio (SNR) penalty when using the rectangular template-based receive nodes is 0.5 dB, and the corresponding data-throughput degradation is 12 Mbps in the presence of timing-jitter. Moreover, the maximum allowable data-throughput at a distance of 4 m exceeds 300 Mbps, which makes the proposed low-power receive nodes a good candidate for reliable transmission of high data-rate medical data over WBANs. Journal: Journal of Electromagnetic Waves and Applications Pages: 1672-1685 Issue: 13 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.822834 File-URL: http://hdl.handle.net/10.1080/09205071.2013.822834 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:13:p:1672-1685 Template-Type: ReDIF-Article 1.0 Author-Name: A. Yilmaz Author-X-Name-First: A. Author-X-Name-Last: Yilmaz Author-Name: C. Sabah Author-X-Name-First: C. Author-X-Name-Last: Sabah Title: Diamond-shaped hole array in double-layer metal sheets for negative index of refraction Abstract: In this paper, a new design of hole array in a double-layer periodic arrangement is introduced and investigated both numerically and experimentally for the negative index of refraction. The structure shows similar behavior to that of the corresponding fishnet metamaterials. The effective constitutive parameters are revealed by using retrieval procedure to verify the negative refraction nature of the proposed structure. A relatively high figure of merit (FOM = −Re(n)/Im(n) = 70.05) is achieved at the K-band (18–26.5) frequency region. Journal: Journal of Electromagnetic Waves and Applications Pages: 413-420 Issue: 4 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.748437 File-URL: http://hdl.handle.net/10.1080/09205071.2013.748437 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:4:p:413-420 Template-Type: ReDIF-Article 1.0 Author-Name: J. Ha Author-X-Name-First: J. Author-X-Name-Last: Ha Author-Name: S. Lee Author-X-Name-First: S. Author-X-Name-Last: Lee Author-Name: J.-H. Park Author-X-Name-First: J.-H. Author-X-Name-Last: Park Author-Name: Y. Lee Author-X-Name-First: Y. Author-X-Name-Last: Lee Title: Dual-band branch-line couplers with three parallel lines for arbitrary power-split ratios Abstract: This work demonstrates the design procedure for a dual-band branch-line coupler that is capable of having an arbitrary coupling level. Simply with an additional parallel line that connect the centers of the two branch lines, the coupler can be designed to have an arbitrary power-split ratio between the through and coupled ports, while its structural simplicity is preserved. Moreover, the practical range of power-split ratio is relatively wider than previous dual-band branch-line couplers. A detailed design procedure is presented. Experimental results for dual-band couplers centered at 1 and 2.5 GHz with ±3-dB power-split ratios show great agreement with theoretical results. The power-split ratio remains within 0.5 dB from the specified, in as much as 230 MHz bandwidths at both 1 and 2.5 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1220-1229 Issue: 10 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.805167 File-URL: http://hdl.handle.net/10.1080/09205071.2013.805167 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:10:p:1220-1229 Template-Type: ReDIF-Article 1.0 Author-Name: X.-B. Wei Author-X-Name-First: X.-B. Author-X-Name-Last: Wei Author-Name: S.-L. Yuan Author-X-Name-First: S.-L. Author-X-Name-Last: Yuan Author-Name: J.-X. Liao Author-X-Name-First: J.-X. Author-X-Name-Last: Liao Author-Name: P. Wang Author-X-Name-First: P. Author-X-Name-Last: Wang Author-Name: Z.-Q. Xu Author-X-Name-First: Z.-Q. Author-X-Name-Last: Xu Author-Name: Y. Shi Author-X-Name-First: Y. Author-X-Name-Last: Shi Title: Design of a wide-stopband bandpass filter using stepped impedance resonators Abstract: In this paper, a compact bandpass filter (BPF) with improved stopband characteristics using stepped impedance resonators (SIRs) is proposed. The filter consists of two quarter-wavelength SIRs with radial stubs and a PI-network of capacitance, which is used to suppress the upper frequency spurious signals. An odd- and even-mode analysis is adopted considering the structure’s symmetry. A new BPF centered at 1.57 GHz has been designed and fabricated to verify the validity of the proposed method. Measured results are in good agreement with the electromagnetic simulation. The frequency selectivity was enhanced via introducing two finite transmission zeros (TZs) near the passband, located at 1.21 GHz with 43.5 dB rejection and 3.10 GHz with 62.3 dB rejection, respectively. The spurious frequencies of the upper stopband are suppressed better than 20 dB from 2.07 to 16.25 GHz. And the circuit only occupies 0.09 λg × 0.09 λg. Journal: Journal of Electromagnetic Waves and Applications Pages: 2029-2034 Issue: 16 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.831328 File-URL: http://hdl.handle.net/10.1080/09205071.2013.831328 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:16:p:2029-2034 Template-Type: ReDIF-Article 1.0 Author-Name: Senem Makal Yucedag Author-X-Name-First: Senem Author-X-Name-Last: Makal Yucedag Title: An artificial neural network application for buried target classification Abstract: Design of an electromagnetic target classifier is demonstrated in this study. The surface equivalence principle and the method of moment are used to calculate the electric field scattered from buried cylindrical target. A database is obtained by the scattered fields from two cylindrical targets at certain frequencies. While a portion of the database is used to train the network, the rest is used to test the performance of the neural network. Radial basis function network is proposed for target classification. This target classification process is repeated by changing the surface roughness and electrical parameters of the medium in which the target is buried, incident angle of the incident wave and cross section of the cylindrical target. Effects of these parameters to the target classification are investigated. Journal: Journal of Electromagnetic Waves and Applications Pages: 2274-2280 Issue: 17 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.840544 File-URL: http://hdl.handle.net/10.1080/09205071.2013.840544 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:17:p:2274-2280 Template-Type: ReDIF-Article 1.0 Author-Name: Hee-Do Kang Author-X-Name-First: Hee-Do Author-X-Name-Last: Kang Author-Name: Il-Young Oh Author-X-Name-First: Il-Young Author-X-Name-Last: Oh Author-Name: Jong-Gwan Yook Author-X-Name-First: Jong-Gwan Author-X-Name-Last: Yook Title: Analytic modeling of oblique penetration of early-time high altitude electromagnetic pulse into dispersive underground multilayer structures Abstract: In this paper, a formulation for obliquely incident electromagnetic wave has been presented for an analysis of high-power electromagnetic pulse penetration into multilayer dispersive media. Based on generalized models of measured dielectric constants and propagation channels reflecting the Earth’s general features, the propagation phenomenon of the obliquely incident early-time (E1) high-altitude electromagnetic pulse (HEMP) is analyzed in frequency as well as in time domains. In addition, the polarization and critical angle are also considered. It is found that the total reflection occurs at an incident angle of about 38 at the soil–rock interface, and that the parallel-polarized E1 HEMP penetrates better than the perpendicular-polarized one. The peak level of the penetrating electric field is found to be 5.6 kV/m at normal incidence, regardless of the type of polarization, and 1.1 kV/m for incidence at 30 in perpendicular case. Journal: Journal of Electromagnetic Waves and Applications Pages: 1649-1659 Issue: 13 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.821957 File-URL: http://hdl.handle.net/10.1080/09205071.2013.821957 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:13:p:1649-1659 Template-Type: ReDIF-Article 1.0 Author-Name: H. Zhou Author-X-Name-First: H. Author-X-Name-Last: Zhou Author-Name: B. Wen Author-X-Name-First: B. Author-X-Name-Last: Wen Title: Automatic antenna pattern estimation for high-frequency surface wave radars Abstract: Distortions of antenna patterns may cause big errors in direction of arrival (DOA) estimation for high-frequency surface wave radars using loop antennas and thus should be calibrated in the direction finding process. The conventional methods to acquire the actual patterns are to measure it, by either a transponder or a monotone beacon borne on a ship moving through all the look angles, leading to increased system complexity and cost. To address this, a novel method for automatic antenna pattern estimation is proposed, which is only involved with some soft computations, i.e. recursively approaching the actual patterns by the amplitude and direction parameter pairs extracted from the single-DOA sea echoes. Both simulations and real radar data processing results show the validity of the proposed method. Journal: Journal of Electromagnetic Waves and Applications Pages: 168-179 Issue: 2 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.743208 File-URL: http://hdl.handle.net/10.1080/09205071.2013.743208 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:2:p:168-179 Template-Type: ReDIF-Article 1.0 Author-Name: D.-O. Kim Author-X-Name-First: D.-O. Author-X-Name-Last: Kim Author-Name: C.-Y. Kim Author-X-Name-First: C.-Y. Author-X-Name-Last: Kim Author-Name: H.-A. Jang Author-X-Name-First: H.-A. Author-X-Name-Last: Jang Title: Analytical calculation and electromagnetic simulation of scattered magnetic field of a capacitively loaded inductive loop under resonance/nonresonance conditions Abstract: The effective permeability in a resonance situation becomes a big issue whenever it has to be negative in a metamaterial resonator. This permeability is a measure of magnetic polarization in response to a magnetic field. By using the Biot–Savart law, in this study, the magnetic field distributions inside a loop in resonance/nonresonance situations are theoretically analyzed and then simulated using a 3D electromagnetic tool. We employed a simple analytic model that considers the losses on a metallic loop. Through the exploration of the magnetic field distributions, this paper provides physical insights into the resonance mechanisms of a metamaterial resonator. The dissimilar aspects occurring in resonance and nonresonance situations are discussed in detail. Journal: Journal of Electromagnetic Waves and Applications Pages: 30-38 Issue: 1 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2012.737909 File-URL: http://hdl.handle.net/10.1080/09205071.2012.737909 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:1:p:30-38 Template-Type: ReDIF-Article 1.0 Author-Name: Y. Wu Author-X-Name-First: Y. Author-X-Name-Last: Wu Author-Name: Q. Liu Author-X-Name-First: Q. Author-X-Name-Last: Liu Author-Name: J. Shen Author-X-Name-First: J. Author-X-Name-Last: Shen Author-Name: Y. Liu Author-X-Name-First: Y. Author-X-Name-Last: Liu Title: A novel wide-band hybrid coupler using coupled-line power divider and improved coupled-line phase shifter Abstract: A novel hybrid coupler aiming for wide-band applications is proposed in this paper. This hybrid coupler consists of a broadband Wilkinson coupled-line power divider and an improved wide-band coupled-line phase shifter. Taking advantage of the coupled-line section, the power divider achieves both compact circuit configuration and wide-band performance. In lieu of patterned ground plane and lumped capacitors, the coupled-line phase shifter can be constructed on a single-layer printed circuit board for wide-band operation. For this proposed phase shifter, the scattering parameters (S-parameters) expressions are derived and the optimal structural design parameters for achieving zero reflection coefficients are highlighted. After carefully choosing the circuit parameters, a new wide-band hybrid is constructed by combining a power divider and the proposed phase shifter. To verify against the theoretical calculation in terms of S parameters and phase information, a hybrid operating at 3 GHz is designed, simulated, and fabricated through microstrip technology. Close agreement is obtained between simulation and measurement results. Journal: Journal of Electromagnetic Waves and Applications Pages: 374-384 Issue: 3 Volume: 27 Year: 2013 Month: 2 X-DOI: 10.1080/09205071.2013.746633 File-URL: http://hdl.handle.net/10.1080/09205071.2013.746633 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:3:p:374-384 Template-Type: ReDIF-Article 1.0 Author-Name: P.K. Choudhury Author-X-Name-First: P.K. Author-X-Name-Last: Choudhury Author-Name: M. Abou El-Nasr Author-X-Name-First: M. Author-X-Name-Last: Abou El-Nasr Title: Progressing electromagnetics Journal: Journal of Electromagnetic Waves and Applications Pages: 1-2 Issue: 1 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.775847 File-URL: http://hdl.handle.net/10.1080/09205071.2013.775847 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:1:p:1-2 Template-Type: ReDIF-Article 1.0 Author-Name: Rongqiang Li Author-X-Name-First: Rongqiang Author-X-Name-Last: Li Author-Name: Guohong Du Author-X-Name-First: Guohong Author-X-Name-Last: Du Title: A SIW filter with asymmetric frequency response by non-resonating node Abstract: In this paper, a novel substrate integrated waveguide (SIW) filter with asymmetric frequency response by using a non-resonating node (NRN) is proposed. The NRN was first implemented as a strongly detuned SIW resonator. This filter can realize a transmission zero either in the upper or in the lower stopband, and only positive coupling coefficient between each resonator and NRN is required. A third-order SIW filter with the center frequency of 15 GHz was constructed and measured, in which bandwidth is 300 MHz. The measured results agree well with the simulated results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1550-1556 Issue: 12 Volume: 27 Year: 2013 Month: 8 X-DOI: 10.1080/09205071.2013.820150 File-URL: http://hdl.handle.net/10.1080/09205071.2013.820150 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:12:p:1550-1556 Template-Type: ReDIF-Article 1.0 Author-Name: A.K. Mishra Author-X-Name-First: A.K. Author-X-Name-Last: Mishra Author-Name: M. Kumar Author-X-Name-First: M. Author-X-Name-Last: Kumar Author-Name: D. Kumar Author-X-Name-First: D. Author-X-Name-Last: Kumar Author-Name: O.N. Singh Author-X-Name-First: O.N. Author-X-Name-Last: Singh Title: Modal study of plasma cladded cylindrical optical fiber Abstract: A theoretical study of cylindrical dielectric waveguide having plasma in the cladding region is investigated. The eigen-value equations for the proposed waveguide and its power calculation have been evaluated using the usual boundary conditions. By using these equations modal dispersion, normalized group velocity, power confinement factor, and fractional modal power curves are drawn for some lower-order TE and TM modes. The nature and shape of the dispersion curve is usual but the group velocity of TM01 mode is largely affected in the presence of plasma. It may also be noted that for a fixed value of plasma density, the fractional modal power sustained by a particular fiber mode can be tuned at the optimum level by adjusting the operating frequency properly. Also, the maximum power is concentrated at the interface instead, at the waveguide axis. Journal: Journal of Electromagnetic Waves and Applications Pages: 868-876 Issue: 7 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.789411 File-URL: http://hdl.handle.net/10.1080/09205071.2013.789411 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:7:p:868-876 Template-Type: ReDIF-Article 1.0 Author-Name: P.H. van der Merwe Author-X-Name-First: P.H. Author-X-Name-Last: van der Merwe Author-Name: J.W. Odendaal Author-X-Name-First: J.W. Author-X-Name-Last: Odendaal Author-Name: J. Joubert Author-X-Name-First: J. Author-X-Name-Last: Joubert Title: An optimized quad-ridged horn antenna with pyramidal sidewalls Abstract: The wideband gain and voltage standing wave ratio (VSWR) performance of quad-ridged horn antennas in general are restricted due to the excitation of higher order modes in the coaxial to quad-ridged waveguide transition. This results in large gain variations vs. frequency and break-up of the radiation patterns at higher frequencies. In this paper, a quad-ridged horn antenna is presented with optimized radiation characteristics and VSWR performance. The performance of the antenna was optimized by separating the antenna into two subsections, viz. a coaxial to quad-ridged waveguide transition section and a flared quad-ridged horn section. The performance of each section was optimized individually using a numerical solver – CST Microwave Studio. Three possible configuration of the coaxial to quad-ridged waveguide transition section were considered and optimized. Four configurations for the flared quad-ridged horn section were also investigated. The best performing configuration from each one of the two sections were combined to yield the final design of the optimized quad-ridged horn antenna. The numerical performance of the quad-ridged horn antenna was validated through measurements, performed in a compact antenna test range. The optimized antenna has a 12.5:1 frequency bandwidth from 0.8 to 10 GHz. Over this frequency range, the antenna has a VSWR performance typically better than 2.5:1, stable boresight gain and radiation patterns for both ports with more than 30 dB isolation between the two ports. Journal: Journal of Electromagnetic Waves and Applications Pages: 2263-2273 Issue: 17 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.840251 File-URL: http://hdl.handle.net/10.1080/09205071.2013.840251 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:17:p:2263-2273 Template-Type: ReDIF-Article 1.0 Author-Name: H. Öztürk Author-X-Name-First: H. Author-X-Name-Last: Öztürk Author-Name: G. Çınar Author-X-Name-First: G. Author-X-Name-Last: Çınar Title: Scattering of a TEM wave by a large circumferential gap on a coaxial waveguide Abstract: In the present work, the scattering of a TEM wave by a gap on the outer wall of a coaxial waveguide is analyzed rigorously. The formulation of the related boundary-value problem in terms of Fourier integrals leads to a modified Wiener–Hopf equation which is first reduced into a pair of Fredholm integral equations of the second kind and the diffraction coefficients related to the reflected, transmitted, and radiated fields are determined explicitly for large gap width compared to the wavelength. At the end of the analysis, numerical results illustrating the effects of the cross-sectional area of the coaxial cylindrical waveguide and the gap width on the fields are presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 615-628 Issue: 5 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.758225 File-URL: http://hdl.handle.net/10.1080/09205071.2013.758225 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:5:p:615-628 Template-Type: ReDIF-Article 1.0 Author-Name: Biao Wang Author-X-Name-First: Biao Author-X-Name-Last: Wang Author-Name: Xiao-Hua Wang Author-X-Name-First: Xiao-Hua Author-X-Name-Last: Wang Author-Name: Bing-Zhong Wang Author-X-Name-First: Bing-Zhong Author-X-Name-Last: Wang Author-Name: Hualiang Zhang Author-X-Name-First: Hualiang Author-X-Name-Last: Zhang Title: Compact microstrip dual-band bandpass filter with multiple transmission zeros Abstract: A compact microstrip dual-band bandpass filter with multiple transmission zeros is proposed. This filter is composed of input/output (I/O) coupling structure with source-load cross-coupling and two pairs of short-ended resonators resonating at 2.4 and 5.8 GHz, respectively. By proper arrangement of the I/O coupling structure with source-load cross-coupling, multiple transmission zeros are introduced. In this way, high selectivity of both passbands and good out-band rejection level better than 20 dB up to 9 GHz are achieved. Good agreement can be found between the full-wave electromagnetic simulations and measured results, which verifies the proposed design concept. Journal: Journal of Electromagnetic Waves and Applications Pages: 930-937 Issue: 7 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.792751 File-URL: http://hdl.handle.net/10.1080/09205071.2013.792751 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:7:p:930-937 Template-Type: ReDIF-Article 1.0 Author-Name: Anjan Biswas Author-X-Name-First: Anjan Author-X-Name-Last: Biswas Author-Name: Dawn A. Lott Author-X-Name-First: Dawn A. Author-X-Name-Last: Lott Author-Name: Brielle Sutton Author-X-Name-First: Brielle Author-X-Name-Last: Sutton Author-Name: Kaisar R. Khan Author-X-Name-First: Kaisar R. Author-X-Name-Last: Khan Author-Name: Mohammad F. Mahmood Author-X-Name-First: Mohammad F. Author-X-Name-Last: Mahmood Title: Optical Gaussons in nonlinear directional couplers Abstract: This paper studies optical Gaussons in nonlinear directional couplers. Both twin-core couplers as well as multiple-core couplers are considered. For multiple-core couplers, coupling with nearest neighbors as well as coupling with all neighbors are considered. A closed form optical Gausson solution is obtained in all of these cases where the amplitude of the Gaussons is governed by a nonlinear difference equation. The domain restrictions naturally fall out as constraint conditions in order for the Gaussons to exist. Journal: Journal of Electromagnetic Waves and Applications Pages: 1976-1985 Issue: 15 Volume: 27 Year: 2013 Month: 10 X-DOI: 10.1080/09205071.2013.832488 File-URL: http://hdl.handle.net/10.1080/09205071.2013.832488 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:15:p:1976-1985 Template-Type: ReDIF-Article 1.0 Author-Name: Y. Yang Author-X-Name-First: Y. Author-X-Name-Last: Yang Author-Name: H. Zhou Author-X-Name-First: H. Author-X-Name-Last: Zhou Author-Name: X.-H. Wang Author-X-Name-First: X.-H. Author-X-Name-Last: Wang Author-Name: Y. Mi Author-X-Name-First: Y. Author-X-Name-Last: Mi Title: Low-pass frequency selective surface with wideband high-stop response for shipboard radar Abstract: In this paper, a compact frequency selective surface (FSS) with low-pass and wideband high-stop response is presented. The FSS is composed of hexagon rings and placed in hexagon arrangement. At low frequencies below 2.0 GHz, the insertion loss is less than 0.9 dB. While in the stopband 8.0–18.0 GHz, the transmission is below  dB. Moreover, the FSS has the merits of low profile (0.6 mm) and stable performance for various incident angles within 30 degrees and for different polarizations. Design procedure and measurement results of the FSS are presented and discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 117-122 Issue: 1 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.739547 File-URL: http://hdl.handle.net/10.1080/09205071.2013.739547 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:1:p:117-122 Template-Type: ReDIF-Article 1.0 Author-Name: Fazhong Shen Author-X-Name-First: Fazhong Author-X-Name-Last: Shen Author-Name: Tiancun Hu Author-X-Name-First: Tiancun Author-X-Name-Last: Hu Author-Name: Huan Li Author-X-Name-First: Huan Author-X-Name-Last: Li Author-Name: Jiangtao Huangfu Author-X-Name-First: Jiangtao Author-X-Name-Last: Huangfu Author-Name: Lixin Ran Author-X-Name-First: Lixin Author-X-Name-Last: Ran Title: High-order mode-matching-based single-cavity coaxial transducer for broadband measurement of complex permittivity Abstract: The broadband measurement of complex permittivity of materials based on transmission line methods has been attracting more and more interests in scientific research and industrial applications. In this paper, by removing the transition section in conventional implementations and applying high-order mode-matching theory of axisymmetric coaxial discontinuity, we propose a single-cavity coaxial transducer for broadband measurement of complex permittivity of lossy media. With an ultra simple structure, the sample holder can be designed to install any coaxial connector, and its radial and longitudinal dimensions can be arbitrarily designed to fit variant capacity demands. Full-wave simulation and experimental measurement show that the proposed transducer can obtain the same precision as previous designs. The proposed approach also applies for two-port transducers. We expect a wide range of practical applications of this general approach in scientific research and industrial applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 2049-2055 Issue: 16 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.831739 File-URL: http://hdl.handle.net/10.1080/09205071.2013.831739 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:16:p:2049-2055 Template-Type: ReDIF-Article 1.0 Author-Name: R.S. Dubey Author-X-Name-First: R.S. Author-X-Name-Last: Dubey Author-Name: P.L. Sarojini Author-X-Name-First: P.L. Author-X-Name-Last: Sarojini Title: Light trapping mechanism in one-dimensional (1D) photonic crystals for silicon-based solar cells Abstract: In the present paper, the light trapping mechanism of one-dimensional (1D) photonic crystal of uniform symmetry for TE polarization is studied. The analysis of the forbidden bands, reflectivity, and group velocity is presented which are interdependent parameters and important to tune the desired optical properties. It is observed that the group velocity is the vanishing factor within the forbidden bands due to the increased optical path length of trapped photons. For solar cells, the use of 1D structure as bottom layer assures the prevention of electron and hole pair recombination for a longer time due to optical delay. We have compared the reflectivity of prepared multilayer (1D) structure of porous silicon with simulated one and important results are presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 309-317 Issue: 3 Volume: 27 Year: 2013 Month: 2 X-DOI: 10.1080/09205071.2013.744284 File-URL: http://hdl.handle.net/10.1080/09205071.2013.744284 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:3:p:309-317 Template-Type: ReDIF-Article 1.0 Author-Name: M. Russo Author-X-Name-First: M. Author-X-Name-Last: Russo Author-Name: P. Šolić Author-X-Name-First: P. Author-X-Name-Last: Šolić Author-Name: M. Stella Author-X-Name-First: M. Author-X-Name-Last: Stella Title: Probabilistic modeling of harvested GSM energy and its application in extending UHF RFID tags reading range Abstract: Newer silicon-based consumer electronics became very popular due to its reduction in size, price, and power consumption. One of its applications today is building low-power devices for ubiquitous sensing. Although sensors are low-power devices, they need some energy source to function properly. One of the major challenges today is to develop systems where sensors do not require external power sources, and could be powered using available ambient energy. To address this power issue one could use energy harvesting concepts. In this paper, we present our probabilistic approach used for modeling the possible amount of Global System for Mobile Communication (GSM) energy that could be harvested, including a demonstration of what power levels could be harvested using GSM rectifying antenna (rectenna). In addition to harvesting approach, we propose an application of its usage in increasing the communication range between Radio Frequency Identification (RFID) reader and battery free passive RFID tags. Journal: Journal of Electromagnetic Waves and Applications Pages: 473-484 Issue: 4 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.753659 File-URL: http://hdl.handle.net/10.1080/09205071.2013.753659 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:4:p:473-484 Template-Type: ReDIF-Article 1.0 Author-Name: P.Y. Ke Author-X-Name-First: P.Y. Author-X-Name-Last: Ke Author-Name: H.-C. Chiu Author-X-Name-First: H.-C. Author-X-Name-Last: Chiu Author-Name: F.H. Huang Author-X-Name-First: F.H. Author-X-Name-Last: Huang Author-Name: Hsuan-Ling Kao Author-X-Name-First: Hsuan-Ling Author-X-Name-Last: Kao Title: A wideband and high rejection multimode 60 GHz GaAs bandpass filter using open-loop CMRC with controllable transmission zeros technique Abstract: This work presents a novel compact open-loop resonator V-band bandpass filters with compact microstrip resonator cell (CMRC) controllable transmission zeros for 60 GHz. The filter, which has a high and wide rejection band, has two functions, which are: (1) perturbation for multimode operation and (2) zero point generation at the stopband to control the stopband. Proper input/output open-loop coupling is conducted using two additional poles. The CMRC distances between resonators and the positions of the open gaps in the open-loop-coupled filter can be adjusted to change the coupling coefficients and generate controllable transmission zeros in the upper stopband. The design and fabrication of the proposed open-loop and CMRC open-loop resonator filters provide such advantages as a wider passband and a higher rejection level, and precise control of the locations of the transmission zeros. Journal: Journal of Electromagnetic Waves and Applications Pages: 1611-1619 Issue: 13 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.821675 File-URL: http://hdl.handle.net/10.1080/09205071.2013.821675 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:13:p:1611-1619 Template-Type: ReDIF-Article 1.0 Author-Name: J.J. Sánchez-Martínez Author-X-Name-First: J.J. Author-X-Name-Last: Sánchez-Martínez Author-Name: E. Márquez-Segura Author-X-Name-First: E. Author-X-Name-Last: Márquez-Segura Title: Analysis of wire-bonded multiconductor transmission line-based phase-shifting sections Abstract: The theoretical analysis of wire-bonded multiconductor transmission lines (MTL) for synthesizing phase shifters is accomplished and generalized in order to extend the traditional theory where 3-dB quarter-wavelength directional couplers are usually employed. In this paper, it is demonstrated that this kind of reflection phase shifters, where the coupled and direct ports are terminated with reactive loads, can be designed for any coupling level. Therefore, analytical design equations are derived to compute both the insertion and return losses as well as the operating frequency band as a function of the coupling factor of the MTL. Furthermore, two general equivalent circuits as a function of the number of strips are derived for two particular arrangements, when both coupled and direct ports are open- or short-circuited. These simple equivalent circuits provide some insight into the physical behavior of the MTL and are expedient to the design of filtering structures and and phase shifters. Finally, the validity of the developed theory is assessed by means of measurements. Two critical- and over-coupling open-circuited and short-circuited wire-bonded MTLs and a broadband balun with an operating fractional bandwidth higher than 92% and excellent output isolation are designed, manufactured, and measured. Journal: Journal of Electromagnetic Waves and Applications Pages: 1997-2009 Issue: 16 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.830075 File-URL: http://hdl.handle.net/10.1080/09205071.2013.830075 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:16:p:1997-2009 Template-Type: ReDIF-Article 1.0 Author-Name: Xiaojian Fu Author-X-Name-First: Xiaojian Author-X-Name-Last: Fu Author-Name: Yunsheng Guo Author-X-Name-First: Yunsheng Author-X-Name-Last: Guo Author-Name: Ji Zhou Author-X-Name-First: Ji Author-X-Name-Last: Zhou Title: Terahertz optical parameters and lattice vibration-induced resonance of Er3+-doped Y3Al5O12 crystal Abstract: In this paper, the terahertz time-domain spectra of undoped and Er3+-doped YAG crystals with the components of Y3Al5O12, (Er0.2Y0.8)3Al5O12, and (Er0.5Y0.5)3Al5O12 were detected and the corresponding frequency-domain spectra were also obtained after Fourier transform. It is shown that the three kinds of crystals are weakly dispersive and nearly transparent below 2.10 THz, whereas in the frequency region between 2.10 and 2.60 THz, dielectric resonance and obvious absorption are investigated which can be attributed to the low-frequency lattice phonon. It is also found that with the increase in Er3+ concentration, the resonant frequency exhibits a red shift and the values of refractive index show a small increase, which could be explained by the larger ionic mass and larger polarizability of Er3+ compared to Y3+, respectively. This work contributes to the research on YAG laser materials as well as novel materials applicable to THz devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 1792-1799 Issue: 14 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.823569 File-URL: http://hdl.handle.net/10.1080/09205071.2013.823569 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:14:p:1792-1799 Template-Type: ReDIF-Article 1.0 Author-Name: Jui-Han Lu Author-X-Name-First: Jui-Han Author-X-Name-Last: Lu Author-Name: Bo-Shen Chang Author-X-Name-First: Bo-Shen Author-X-Name-Last: Chang Title: Planar circularly polarized tag antenna with compact operation for UHF RFID application Abstract: A novel compact design of planar circularly polarized (CP) tag antenna for UHF RFID system is proposed. By introducing the Y-shaped slit as the feed structure, the measured half-power bandwidth of the proposed CP tag antenna can be more than 135 MHz (860–1000 MHz), which includes the entire operating bandwidth for worldwide UHF RFID system. The obtained 3 dB axial-ratio (AR) bandwidth can be about 10 MHz suitable for Taiwan UHF RFID applications. The proposed tag antenna reduces the antenna size by at least 30% since the antenna size is only 40 × 40 × π mm2. The simulated peak gain and antenna efficiency are approximately 0.4 dBic and 91% for Taiwan UHF RFID band. Meanwhile, with omnidirectional reading pattern, the measured reading distance is about 7.2 m. Good tag sensitivity was obtained across the desired frequency band. Journal: Journal of Electromagnetic Waves and Applications Pages: 1882-1891 Issue: 15 Volume: 27 Year: 2013 Month: 10 X-DOI: 10.1080/09205071.2013.827592 File-URL: http://hdl.handle.net/10.1080/09205071.2013.827592 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:15:p:1882-1891 Template-Type: ReDIF-Article 1.0 Author-Name: D. Zarifi Author-X-Name-First: D. Author-X-Name-Last: Zarifi Author-Name: H. Oraizi Author-X-Name-First: H. Author-X-Name-Last: Oraizi Author-Name: M. Soleimani Author-X-Name-First: M. Author-X-Name-Last: Soleimani Title: Electromagnetic scattering from inhomogeneous planar-layered chiral media using the finite difference method Abstract: A general method of analyzing the wave propagation and scattering problem for inhomogeneous planar-layered chiral media is presented. It is assumed that the constitutive parameters are known at all or only at some points along the thickness of the inhomogeneous chiral layer. The analysis is based on using finite difference method to solve a state vector differential equation and calculation of the transverse components of electric and magnetic fields. The presented method is applicable in the problems in which Taylor’s series expansion method cannot be used. The validity of the method is verified by considering some special types of inhomogeneous chiral media and comparing the results obtained by the presented method with those of other reported methods. Journal: Journal of Electromagnetic Waves and Applications Pages: 582-590 Issue: 5 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.757198 File-URL: http://hdl.handle.net/10.1080/09205071.2013.757198 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:5:p:582-590 Template-Type: ReDIF-Article 1.0 Author-Name: Jingjing Yao Author-X-Name-First: Jingjing Author-X-Name-Last: Yao Author-Name: Siyuan He Author-X-Name-First: Siyuan Author-X-Name-Last: He Author-Name: Chao Li Author-X-Name-First: Chao Author-X-Name-Last: Li Author-Name: Hongcheng Yin Author-X-Name-First: Hongcheng Author-X-Name-Last: Yin Author-Name: Chao Wang Author-X-Name-First: Chao Author-X-Name-Last: Wang Author-Name: Guoqiang Zhu Author-X-Name-First: Guoqiang Author-X-Name-Last: Zhu Title: An asymptotic solution of the scattering from a biaxial electric anisotropic slab with a PEC substrate Abstract: Based on spectral domain method, an asymptotic solution of the electromagnetic scattering from a biaxial electric anisotropic (BEA) slab with a perfect electric conductor (PEC) substrate is proposed. Firstly, the spectral formulas of two types of waves with different phase velocities existing in the BEA slab are proposed. Then the boundary conditions at the top and bottom interfaces of the BEA slab are employed to determine the complex amplitudes of the scattered fields in spectral domain. By means of saddle point technique, the scattered fields in space domain are asymptotically solved out, which degrade to the reflected fields. The asymptotic solution is validated by the comparisons between the numerical results from the proposed solution and Titchener’s method. Employing the asymptotic solution, the evaluation of the scattering from an electrically large and complex PEC target coated with a BEA layer is realized. Journal: Journal of Electromagnetic Waves and Applications Pages: 1534-1549 Issue: 12 Volume: 27 Year: 2013 Month: 8 X-DOI: 10.1080/09205071.2013.819474 File-URL: http://hdl.handle.net/10.1080/09205071.2013.819474 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:12:p:1534-1549 Template-Type: ReDIF-Article 1.0 Author-Name: Y.-L. Ban Author-X-Name-First: Y.-L. Author-X-Name-Last: Ban Author-Name: J.-H. Chen Author-X-Name-First: J.-H. Author-X-Name-Last: Chen Author-Name: J.L.-W. Li Author-X-Name-First: J.L.-W. Author-X-Name-Last: Li Author-Name: W. Hu Author-X-Name-First: W. Author-X-Name-Last: Hu Title: Printed wideband notched antenna for wireless USB dongle attached to laptop computer Abstract: In the paper, a printed notched antenna for eight-band long term evolution (LTE)/global system for mobile communications (GSM)/universal mobile telecommunications system (UMTS) wireless universal serial bus (USB) dongle application is proposed. As a low profile and easily fed by a 50- microstrip feed line, the presented antenna comprises a matching network (including a serial chip capacitance 3 pF and a parallel chip inductance 8.5 nH) and a big radiating patch with a notch in the design, totally occupying a size of Based on the USB dongle system ground plane and laptop system ground plane, the radiating patch along the gap between the radiating patch and USB dongle system ground plane can generate a foundational resonant mode at about 750 MHz to cover lower bandwidth of 698–960 MHz, while the desired upper operating bands (DCS1800/PCS1900/UMTS2100/LTE2300/2500) can be obtained by the radiating patch (the notch separates the big radiating patch into two portions in order to excite another resonant mode at about 2650 MHz). Experimental results show that very good total power radiation characteristics and an adequate coverage of the whole 698–960 and 1710–2690 MHz bands are achieved, making it promising for USB dongle in laptop computer. Journal: Journal of Electromagnetic Waves and Applications Pages: 257-266 Issue: 2 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.743499 File-URL: http://hdl.handle.net/10.1080/09205071.2013.743499 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:2:p:257-266 Template-Type: ReDIF-Article 1.0 Author-Name: Han-Lim Lee Author-X-Name-First: Han-Lim Author-X-Name-Last: Lee Author-Name: Seong-Mo Moon Author-X-Name-First: Seong-Mo Author-X-Name-Last: Moon Author-Name: Moon-Que Lee Author-X-Name-First: Moon-Que Author-X-Name-Last: Lee Author-Name: Jong-Wo Yu Author-X-Name-First: Jong-Wo Author-X-Name-Last: Yu Title: K-band reflection-type phase shifter using phase-shift range enhancement technique Abstract: This letter presents a simple but efficient phase shift range enhancement technique for a reflection type phase shifter (RTPS). The proposed structure consists of a 3-dB coupler and a pair of back-to-back diodes connected with a pair of series and parallel inductors and a pair of parallel resistors. The parallel inductors are inserted to widen relative phase shift range compared to regularly used RTPS and Lange coupler is used as the 3-dB coupler. The proposed circuit is implemented in 0.15 -μm GaAs low noise pHEMT process and provides a measured phase shifting range of 227° at 24 GHz with a measured insertion loss of 4.6 ± 1.3 dB. The input and output return losses are better than 18 dB and 17 dB, respectively. The size of the fabricated phase shifter MMIC chip is 2.2×1.5 mm2 including test pads. Journal: Journal of Electromagnetic Waves and Applications Pages: 2135-2144 Issue: 16 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.833063 File-URL: http://hdl.handle.net/10.1080/09205071.2013.833063 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:16:p:2135-2144 Template-Type: ReDIF-Article 1.0 Author-Name: N.-Z. Wang Author-X-Name-First: N.-Z. Author-X-Name-Last: Wang Author-Name: L. Talbi Author-X-Name-First: L. Author-X-Name-Last: Talbi Author-Name: Q.-S. Zeng Author-X-Name-First: Q.-S. Author-X-Name-Last: Zeng Author-Name: J.-D. Xu Author-X-Name-First: J.-D. Author-X-Name-Last: Xu Title: Wideband ring-slot coupled patch antenna with enhanced gain Abstract: A wideband ring-slot coupled patch antenna is presented in this paper. A microstrip line feeding network is used for impedance matching. Additionally, in order to depress the backward radiation caused by the resonance of the ring-slot, a reflector is introduced to obtain unidirectional radiation patterns, while a dielectric cover is adopted to alleviate the deterioration in impedance caused by the reflector. A prototype is fabricated and measured. The measured results are in good agreement with those simulated, which indicates that the antenna operates well with a relative bandwidth of 55% for reflection coefficient less than −10 dB, an enhanced gain of 8–11 dBi, unidirectional radiation patterns, as well as low cross-polarization. Journal: Journal of Electromagnetic Waves and Applications Pages: 572-581 Issue: 5 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.757194 File-URL: http://hdl.handle.net/10.1080/09205071.2013.757194 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:5:p:572-581 Template-Type: ReDIF-Article 1.0 Author-Name: Y.J. Cheng Author-X-Name-First: Y.J. Author-X-Name-Last: Cheng Author-Name: C.A. Zhang Author-X-Name-First: C.A. Author-X-Name-Last: Zhang Title: Miniaturized half mode substrate integrated waveguide cavity resonator and filter with good spurious suppression Abstract: A miniaturized cavity resonator based on the half mode substrate integrated waveguide (HMSIW) technology is proposed and investigated in this paper to reduce the circuit area of a conventional substrate integrated waveguide (SIW) cavity resonator much more. Such a miniaturized resonator is built up by a two-layer HMSIW cavity loaded with a modified complementary split ring resonator (CSRR) etched on its middle conductor plate. Then, the proposed miniaturized cavity resonator is employed to design an S-band fourth-element bandpass filter. The center frequency is 3 GHz and the average insertion loss is 1.2 dB within the in-band. The total circuit area is only , i.e., 7% of the size of a conventional SIW fourth-element bandpass filter. It presents a good and wideband spurious suppression because the first higher order resonant mode of the used resonator is far away from the operation band. Experimental and simulated results are in good agreement, both validating our design concept. Journal: Journal of Electromagnetic Waves and Applications Pages: 396-404 Issue: 3 Volume: 27 Year: 2013 Month: 2 X-DOI: 10.1080/09205071.2013.747124 File-URL: http://hdl.handle.net/10.1080/09205071.2013.747124 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:3:p:396-404 Template-Type: ReDIF-Article 1.0 Author-Name: C.-Y. Lee Author-X-Name-First: C.-Y. Author-X-Name-Last: Lee Author-Name: S.-J. Ha Author-X-Name-First: S.-J. Author-X-Name-Last: Ha Author-Name: C.W. Jung Author-X-Name-First: C.W. Author-X-Name-Last: Jung Author-Name: Y.J. Kim Author-X-Name-First: Y.J. Author-X-Name-Last: Kim Title: A CPWG-fed reconfigurable 3D beam-steering antenna with directive radiation pattern Abstract: A reconfigurable beam-steering antenna using a coplanar waveguide with ground with directive radiation pattern is presented. The switchable beam steering antenna composed of a loop and two dipole structures with four switches to generate six different radiation beam patterns is proposed. The antenna can select desired beam pattern by controlling switching configurations. The proposed antenna is designed to operate at 2.65 GHz with 4.2 dBi maximum gain for wireless communications. Maximum beam direction can be steered by switch on/off configurations with ±30° in the H-plane and E-plane. Journal: Journal of Electromagnetic Waves and Applications Pages: 59-65 Issue: 1 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.737971 File-URL: http://hdl.handle.net/10.1080/09205071.2013.737971 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:1:p:59-65 Template-Type: ReDIF-Article 1.0 Author-Name: Subash Vegesna Author-X-Name-First: Subash Author-X-Name-Last: Vegesna Author-Name: Fahmida Irin Author-X-Name-First: Fahmida Author-X-Name-Last: Irin Author-Name: Micah Green Author-X-Name-First: Micah Author-X-Name-Last: Green Author-Name: Mohammad Saed Author-X-Name-First: Mohammad Author-X-Name-Last: Saed Title: Non-destructive technique for broadband characterization of carbon nanotubes at microwave frequencies Abstract: This paper presents a broadband microwave non-destructive technique for characterization of carbon nanotubes (CNTs). Typically, commercially available carbon nanotubes are powder-like samples and, therefore, in this paper, a broadband characterization technique to extract electrical conductivity of powder materials is developed. The technique uses a microstrip line configuration in conjunction with a cavity resonator technique. The electrical conductivity of CNTs is extracted from the measured attenuation in the signal response (|S21|dB) for the microstrip configuration with a signal trace made of copper and a ground plane filled with CNT samples. A resonant cylindrical cavity is also used in the measurement process to help determine a correction factor for the surface roughness of the CNT microstrip ground plane. A novel method to take attenuation due to surface roughness into account to determine conductivity of CNTs is introduced. Experimental and numerical verification of the proposed method is provided. The method developed in this work provides a cost-effective solution where significant amount of time and cost are reduced in the sample preparation process. Measurement results for the electrical conductivity of single-walled CNTs and multi-walled CNTs are presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 1372-1381 Issue: 11 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.808968 File-URL: http://hdl.handle.net/10.1080/09205071.2013.808968 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:11:p:1372-1381 Template-Type: ReDIF-Article 1.0 Author-Name: Y.-J. Huang Author-X-Name-First: Y.-J. Author-X-Name-Last: Huang Author-Name: G.-J. Wen Author-X-Name-First: G.-J. Author-X-Name-Last: Wen Author-Name: J. Li Author-X-Name-First: J. Author-X-Name-Last: Li Author-Name: W.-R. Zhu Author-X-Name-First: W.-R. Author-X-Name-Last: Zhu Author-Name: P. Wang Author-X-Name-First: P. Author-X-Name-Last: Wang Author-Name: Y.-H. Sun Author-X-Name-First: Y.-H. Author-X-Name-Last: Sun Title: Wide-angle and polarization-independent metamaterial absorber based on snowflake-shaped configuration Abstract: A metamaterial absorber (MA) based on snowflake-shaped resonators is designed and experimentally demonstrated in this paper. Such an MA possesses a nearly perfect absorption with wide angle of incidence and polarization independence. The measurement in a rectangular waveguide system shows the absorptivity as high as 99.5% at 11.28 GHz. Furthermore, the operating frequency can be flexibly controlled by adjusting the lengths of the snowflake's branches, while keep the peak absorptivities nearly uniform (>97.5%). The proposed MA is sure to find wide applications in, for instance, stealth technology, thermal detector and imaging. Journal: Journal of Electromagnetic Waves and Applications Pages: 552-559 Issue: 5 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.756383 File-URL: http://hdl.handle.net/10.1080/09205071.2013.756383 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:5:p:552-559 Template-Type: ReDIF-Article 1.0 Author-Name: Z. Guo Author-X-Name-First: Z. Author-X-Name-Last: Guo Author-Name: K.-S. Chin Author-X-Name-First: K.-S. Author-X-Name-Last: Chin Author-Name: W. Che Author-X-Name-First: W. Author-X-Name-Last: Che Author-Name: C.-C. Chang Author-X-Name-First: C.-C. Author-X-Name-Last: Chang Title: Cross-coupled bandpass filters using QMSIW cavities and S-shaped slot coupling structures Abstract: This paper presents a novel cross-coupled bandpass filter using quarter-mode substrate integrated waveguide (QMSIW) cavities. QMSIWs with fictitious magnetic walls on two sides retain similar performances of the conventional SIW, but are almost one fourth the size. The dominant resonant mode of the proposed resonator is the TE101 mode. A special negative coupling scheme with symmetrical S-shaped slots on the top and bottom metal planes connected by metallic vias is developed. The proposed structure provides more design flexibility in arranging the pitch of vias owing to the extended slot length. The experimental filter has a measured fractional bandwidth of 7.44% at 5.57 GHz with a return loss better than −18.1 dB and an insertion loss less than −2 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 160-167 Issue: 2 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.741514 File-URL: http://hdl.handle.net/10.1080/09205071.2013.741514 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:2:p:160-167 Template-Type: ReDIF-Article 1.0 Author-Name: X.-F. Lu Author-X-Name-First: X.-F. Author-X-Name-Last: Lu Author-Name: G.-H. Wei Author-X-Name-First: G.-H. Author-X-Name-Last: Wei Author-Name: X.-D. Pan Author-X-Name-First: X.-D. Author-X-Name-Last: Pan Title: A directional-coupler-based injection device aimed at radiated susceptibility verification of antenna systems against HIRF Abstract: In this paper, a current injection method is proposed to substitute equivalently for high-level field strength radiation, when the antenna and the cable are the main coupling path. This is done by adopting differential-mode current injection, which is achieved by employing a coupling device composed of cascaded directional couplers. When the device is connected to the antenna system, the equivalent relationship between the radiated field strength and the injected voltage is analyzed. It is verified that this relationship is linear even if the EUT response is nonlinear. Therefore, linear extrapolation is employed to obtain the injected voltage which is equivalent to high-level radiated field strength. With a typical antenna system under test, the experimental results show that the proposed method is highly accurate and is fit for radiated susceptibility verification of antenna systems against high-intensity radiated field in microwave frequency band. Journal: Journal of Electromagnetic Waves and Applications Pages: 1351-1364 Issue: 11 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.808599 File-URL: http://hdl.handle.net/10.1080/09205071.2013.808599 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:11:p:1351-1364 Template-Type: ReDIF-Article 1.0 Author-Name: A. Hammami Author-X-Name-First: A. Author-X-Name-Last: Hammami Author-Name: R. Ghayoula Author-X-Name-First: R. Author-X-Name-Last: Ghayoula Author-Name: A. Gharsallah Author-X-Name-First: A. Author-X-Name-Last: Gharsallah Title: Design of concentric ring arrays for low side lobe level using SQP algorithm Abstract: In this paper, an efficient method based on the sequential quadratic programming (SQP) algorithm for the pattern synthesis of concentric rings antenna arrays to reduce side lobe levels (SLL) by controlling only the amplitude excitations of each array element was presented. SQP algorithm is a deterministic method of multi-objective optimization. It is the most widely used for the resolution of nonlinear problems. It consists of transforming the nonlinear problem to sequence of quadratic sub-problems by using a quadratic approximation of the Lagrangian function. In order to illustrate the performance of the proposed method, several examples of planar concentric rings antenna array patterns with almost one-half wavelength spaced isotropic elements to reduce the SLL and to norrow the half power beam width are presented. The results shown in this paper and compared with those obtained by the application of uniform, Hamming and Blackman weighting, demonstrate the effectiveness of this optimization method based on the SQP algorithm. Journal: Journal of Electromagnetic Waves and Applications Pages: 807-818 Issue: 7 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.787375 File-URL: http://hdl.handle.net/10.1080/09205071.2013.787375 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:7:p:807-818 Template-Type: ReDIF-Article 1.0 Author-Name: S.-L. Yuan Author-X-Name-First: S.-L. Author-X-Name-Last: Yuan Author-Name: X.-B. Wei Author-X-Name-First: X.-B. Author-X-Name-Last: Wei Author-Name: G.-T. Yue Author-X-Name-First: G.-T. Author-X-Name-Last: Yue Author-Name: B. Fu Author-X-Name-First: B. Author-X-Name-Last: Fu Title: Design of compact bandpass filter with enhanced stopband characteristics Abstract: In this paper, a compact third-order bandpass filter with enhanced stopband characteristics is proposed. The filter consists of three stepped impedance resonators, where one is embedded into the other two resonators for compact size. Multiple transmission zeros (TZs) can be realized near the passband by introducing frequency-dependent coupling between the nonadjacent resonators for enhanced frequency selectivity. Besides, defected ground structure is employed to suppress the harmonics over a broad bandwidth. A new filter centered at 1.51 GHz has been analyzed, simulated, and fabricated to verify the validity of the proposed method. The measured results show that there are three finite TZs near the passband, which are located at 1.1 GHz with 62.1 dB rejection, 1.76 GHz with 34.2 dB rejection, and 2.48 GHz with 37.2 dB rejection, respectively. And, the spurious frequencies of the upper stopband are suppressed below 20 dB from 1.7 to 25 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1743-1750 Issue: 14 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.823127 File-URL: http://hdl.handle.net/10.1080/09205071.2013.823127 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:14:p:1743-1750 Template-Type: ReDIF-Article 1.0 Author-Name: Hui Chen Author-X-Name-First: Hui Author-X-Name-Last: Chen Author-Name: Pu Tang Author-X-Name-First: Pu Author-X-Name-Last: Tang Author-Name: Ke-song Chen Author-X-Name-First: Ke-song Author-X-Name-Last: Chen Author-Name: Hong-fei Zhao Author-X-Name-First: Hong-fei Author-X-Name-Last: Zhao Author-Name: Hong-sheng Zhong Author-X-Name-First: Hong-sheng Author-X-Name-Last: Zhong Title: Wideband dual-mode bandpass filter using a modified right-triangular patch resonator overlapped with input/output DMS Abstract: A novel and compact dual-mode wideband bandpass filter (BPF) with multiple transmission zeros is designed, fabricated, and measured in this paper. This filter consists of a modified right-triangle patch resonator with two orthogonal narrow-strip stubs and improved input/output defected microstrip structure (DMS). The designed resonator and DMS show dual-mode and dual-bandgap characteristics, respectively. The equivalent circuit models are described and their element values are also extracted by the full-wave EM simulator. The presented BPF is constructed by cascading the stub of patch resonator with the input/output DMS and overlapping partly with each other between the stub of resonator and middle conductor strip of input/output DMS. The EM simulated result has been confirmed by an experimental one and they have shown good agreement with each other. The measured result exhibits wide passband and low insertion loss characteristics for the proposed filter. Journal: Journal of Electromagnetic Waves and Applications Pages: 1365-1371 Issue: 11 Volume: 27 Year: 2013 Month: 7 X-DOI: 10.1080/09205071.2013.808600 File-URL: http://hdl.handle.net/10.1080/09205071.2013.808600 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:11:p:1365-1371 Template-Type: ReDIF-Article 1.0 Author-Name: Kaijun Song Author-X-Name-First: Kaijun Author-X-Name-Last: Song Author-Name: Fan Zhang Author-X-Name-First: Fan Author-X-Name-Last: Zhang Author-Name: Fulong Chen Author-X-Name-First: Fulong Author-X-Name-Last: Chen Author-Name: Yong Fan Author-X-Name-First: Yong Author-X-Name-Last: Fan Title: Wideband millimetre-wave four-way spatial power combiner based on multilayer SIW Abstract: A hybrid rectangular waveguide/multilayer substrate integrated waveguide (SIW) spatial power divider/combiner has been presented. The rectangular waveguide/four-layer SIW transition is applied to implement the four-way power-dividing/combining function. A millimetre-wave four-way multilayer-SIW power divider/combiner is designed, fabricated and measured. The measured 15 dB return loss and 3 dB insertion loss bandwidth are demonstrated from 29 GHz to 37 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1715-1719 Issue: 13 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.823123 File-URL: http://hdl.handle.net/10.1080/09205071.2013.823123 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:13:p:1715-1719 Template-Type: ReDIF-Article 1.0 Author-Name: HaiFeng Zhang Author-X-Name-First: HaiFeng Author-X-Name-Last: Zhang Author-Name: ShaoBin Liu Author-X-Name-First: ShaoBin Author-X-Name-Last: Liu Author-Name: XiangKun Kong Author-X-Name-First: XiangKun Author-X-Name-Last: Kong Title: Investigation of Faraday effects in photonic band gap for tunable three-dimensional magnetized plasma photonic crystals containing the anisotropic material in diamond arrangement Abstract: In this paper, the properties of photonic band gaps (PBGs) for three-dimensional (3-D) magnetized plasma photonic crystals (MPPCs) composed of homogeneous magnetized plasma spheres immersed in the anisotropic dielectric (the uniaxial material) background with diamond lattices are theoretically studied by the plane wave expansion method, as the Faraday effects of magnetized plasma are considered. The equations for calculating the anisotropic PBGs in the first irreducible Brillouin zone are theoretically deduced. The anisotropic PBG and one flatbands region can be achieved. The effects of the ordinary-refractive index, extraordinary-refractive index, plasma filling factor, plasma frequency, and the external magnetic field on the characteristics of first anisotropic PBG are studied in detail, respectively, and some corresponding physical explanations are also given. The numerical results show that the anisotropy can open partial band gaps in diamond lattices, and the complete PBG can be obtained compared to the conventional 3-D MPPCs doped by the isotropic material (the relative bandwidth of PBG is increased by 0.1108). The bandwidth of PBG also can be enlarged by introduced the magnetized plasma into 3-D PCs containing the uniaxial material, and the relative bandwidth of PBG is increased by 0.0266. It also is shown that the first anisotropic PBG can be manipulated by the ordinary-refractive index, extraordinary-refractive index, plasma filling factor, plasma frequency, and the external magnetic field, respectively. The PBG can be enlarged by introducing the uniaxial material into 3-D MPPCs as the Faraday effects are considered. It also provides a way to enlarge the complete PBG for the 3-D MPPCs. Journal: Journal of Electromagnetic Waves and Applications Pages: 1776-1791 Issue: 14 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.823361 File-URL: http://hdl.handle.net/10.1080/09205071.2013.823361 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:14:p:1776-1791 Template-Type: ReDIF-Article 1.0 Author-Name: Zewei Wu Author-X-Name-First: Zewei Author-X-Name-Last: Wu Author-Name: Hao Li Author-X-Name-First: Hao Author-X-Name-Last: Li Author-Name: Biao Hu Author-X-Name-First: Biao Author-X-Name-Last: Hu Author-Name: Jianhua Xu Author-X-Name-First: Jianhua Author-X-Name-Last: Xu Author-Name: Tianming Li Author-X-Name-First: Tianming Author-X-Name-Last: Li Title: Design of a circular TE5,1 mode generator for gyrotrons low-power measurement Abstract: To test quasi-optical mode converters for gyrotrons, an efficient low-power generator for rotating high-order modes with high purity is necessary. A W-band mode generator which converts a TE1,0 rectangular waveguide mode into either a linearly or a circularly polarized TE5,1 circular mode is designed, fabricated, and measured. The generator consists of a mode converter, a waveguide transition, and a polarization converter. The converting process in each section is displayed and the working principles are discussed. The back-to-back measured results show that the conversion efficiency exceeds 63% with −2 dB from 92 to 95 GHz is obtained. The angle-independent transmissions demonstrate high-mode purity and the field pattern is directly demonstrated on a temperature-sensitive liquid-crystal sheet. The proposed mode generator features high-mode purity, easy to construct, and polarization controllability. Journal: Journal of Electromagnetic Waves and Applications Pages: 1660-1671 Issue: 13 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.822338 File-URL: http://hdl.handle.net/10.1080/09205071.2013.822338 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:13:p:1660-1671 Template-Type: ReDIF-Article 1.0 Author-Name: Daryoush Mortazavi Author-X-Name-First: Daryoush Author-X-Name-Last: Mortazavi Author-Name: Abas Z. Kouzani Author-X-Name-First: Abas Z. Author-X-Name-Last: Kouzani Author-Name: Ladislau Matekovits Author-X-Name-First: Ladislau Author-X-Name-Last: Matekovits Author-Name: Wei Duan Author-X-Name-First: Wei Author-X-Name-Last: Duan Title: Localized surface plasmon resonance: nano-sinusoid arrays Abstract: A new nano-sinusoid shape has recently been proposed, which offers the advantage of more resonance wavelength tunability than that offered by other sharp-tip nano-particles. In this paper, a one-dimensional (1D) chain of the nano-sinusoids is modelled, and results are compared with those describing chains of nano-triangles and nano-diamonds. It is demonstrated that the chain of nano-sinusoids provides more enhancement at hot spots than other examined nano-particle shapes. This enhancement is analytically quantified using the coupling constant values used in the electrostatic eigenmode method for analytically solving Maxwell's equations for the nano-plasmonic devices. In addition, investigating LSPR spectrum of two-dimensional (2D) arrays of NPs demonstrates existence of enhanced surface electric fields on hot spots of the outer rows of the array. Journal: Journal of Electromagnetic Waves and Applications Pages: 638-648 Issue: 5 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.759519 File-URL: http://hdl.handle.net/10.1080/09205071.2013.759519 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:5:p:638-648 Template-Type: ReDIF-Article 1.0 Author-Name: Luděk Klimeš Author-X-Name-First: Luděk Author-X-Name-Last: Klimeš Title: Relation between the propagator matrix of geodesic deviation and the second-order derivatives of the characteristic function Abstract: In the Finsler geometry, which is a generalization of the Riemann geometry, the metric tensor also depends on the direction of propagation. The basics of the Finsler geometry were formulated by William Rowan Hamilton in 1832. Hamilton’s formulation is based on the first-order partial differential Hamilton–Jacobi equations for the characteristic function which represents the distance between two points. The characteristic function and geodesics together with the geodesic deviation in the Finsler space can be calculated efficiently by Hamilton’s method. The Hamiltonian equations of geodesic deviation are considerably simpler than the Riemannian or Finslerian equations of geodesic deviation. The linear ordinary differential equations of geodesic deviation may serve to calculate geodesic deviations, amplitudes of waves and the second-order spatial derivatives of the characteristic function or action. The propagator matrix of geodesic deviation contains all the linearly independent solutions of the equations of geodesic deviation. In this paper, we use the Hamiltonian formulation to derive the relation between the propagator matrix of geodesic deviation and the second-order spatial derivatives of the characteristic function in the Finsler geometry. We assume that the Hamiltonian function is a positively homogeneous function of the second degree with respect to the spatial gradient of the characteristic function, which corresponds to the Riemannian or Finslerian equations of geodesics and of geodesic deviation. The derived equations, which represent the main result of this paper, are applicable to the Finsler geometry, the Riemann geometry, and their various applications such as general relativity or the high-frequency approximations of wave propagation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1589-1601 Issue: 13 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.808595 File-URL: http://hdl.handle.net/10.1080/09205071.2013.808595 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:13:p:1589-1601 Template-Type: ReDIF-Article 1.0 Author-Name: I.Y. Park Author-X-Name-First: I.Y. Author-X-Name-Last: Park Author-Name: D. Kim Author-X-Name-First: D. Author-X-Name-Last: Kim Title: High-gain antenna using an intelligent artificial magnetic conductor ground plane Abstract: We propose a high-gain antenna using an intelligent ground plane composed of artificial magnetic conductors (AMCs). The main role of the ground plane is removing difference in phase delays caused by different path lengths from a signal-feeding dipole onto each AMC cell. Hence, the ground plane consists of AMC cells with different lengths corresponding to the phase delays to be compensated. As a consequence, we can obtain a planar wave front of a reflected wave, which is perpendicular to a boresight direction. By maximizing constructive interference between the reflected waves and direct waves from the dipole, we can significantly increase our antenna gain without deteriorating impedance matching bandwidth behavior. Experimental data has shown good agreement with the prediction, which validates the accuracy and effectiveness of our proposal. Journal: Journal of Electromagnetic Waves and Applications Pages: 1602-1610 Issue: 13 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.817957 File-URL: http://hdl.handle.net/10.1080/09205071.2013.817957 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:13:p:1602-1610 Template-Type: ReDIF-Article 1.0 Author-Name: Xiaolong Wang Author-X-Name-First: Xiaolong Author-X-Name-Last: Wang Author-Name: Iwata Sakagami Author-X-Name-First: Iwata Author-X-Name-Last: Sakagami Author-Name: Atsushi Mase Author-X-Name-First: Atsushi Author-X-Name-Last: Mase Title: A compact dual-band Wilkinson power divider with two design approaches Abstract: A compact dual-band Wilkinson power divider with coupled open stubs is newly presented. Coupled open stubs are not only used for miniaturization but also used to get isolation between two output ports. Based on an even- and odd-mode analysis, the proposed model provides two different design approaches. The design charts, coupling coefficients, and bandwidths between two design approaches are discussed and compared under the same conditions. For verification, experimental results are also presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 758-771 Issue: 6 Volume: 27 Year: 2013 Month: 4 X-DOI: 10.1080/09205071.2013.786207 File-URL: http://hdl.handle.net/10.1080/09205071.2013.786207 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:6:p:758-771 Template-Type: ReDIF-Article 1.0 Author-Name: V. Gahlaut Author-X-Name-First: V. Author-X-Name-Last: Gahlaut Author-Name: S.M. Sharma Author-X-Name-First: S.M. Author-X-Name-Last: Sharma Author-Name: P.A. Alvi Author-X-Name-First: P.A. Author-X-Name-Last: Alvi Author-Name: S.K. Ghosh Author-X-Name-First: S.K. Author-X-Name-Last: Ghosh Title: Thermal management of helix used in high-power high-efficiency traveling-wave tubes Abstract: In this paper, an approach has been presented to estimate thermal contact resistance (TCR) between helix slow-wave structure to support rod and support rod to metal envelope to study the effective heat dissipation from the helix. Based on this method, TCRs are optimized by comparing analytically and experimentally estimated helix temperature with those obtained from ANSYS simulation. Helix temperature, at a given power loss in the helix, is obtained by varying the fraction of effective resistance between helix and support rod for a given fraction of effective resistance between support rod to barrel envelope and vice versa. This helix temperature has been compared with the measured temperature to predict the TCRs. Journal: Journal of Electromagnetic Waves and Applications Pages: 1861-1868 Issue: 15 Volume: 27 Year: 2013 Month: 10 X-DOI: 10.1080/09205071.2013.823570 File-URL: http://hdl.handle.net/10.1080/09205071.2013.823570 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:15:p:1861-1868 Template-Type: ReDIF-Article 1.0 Author-Name: Vesna Crnojević-Bengin Author-X-Name-First: Vesna Author-X-Name-Last: Crnojević-Bengin Author-Name: Nikolina Janković Author-X-Name-First: Nikolina Author-X-Name-Last: Janković Author-Name: Norbert Cselyuszka Author-X-Name-First: Norbert Author-X-Name-Last: Cselyuszka Author-Name: Riana H. Geschke Author-X-Name-First: Riana H. Author-X-Name-Last: Geschke Title: Mu-near-zero propagation in quasi-TEM microstrip circuits Abstract: This paper presents the theoretical analysis and experimental demonstration of mu-near-zero (MNZ) propagation in quasi-TEM microstrip circuits achieved by using metamaterials of the resonant type. We show that two frequencies exist which may support MNZ propagation and how the actual operating of MNZ frequency depends on the properties of the host. The phenomena of MNZ propagation is then used to propose an entirely new class of MNZ bandpass filters characterized by significantly reduced variation of group delay in comparison to conventional solutions. Journal: Journal of Electromagnetic Waves and Applications Pages: 2198-2212 Issue: 17 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.837014 File-URL: http://hdl.handle.net/10.1080/09205071.2013.837014 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:17:p:2198-2212 Template-Type: ReDIF-Article 1.0 Author-Name: Milad Mirzaee Author-X-Name-First: Milad Author-X-Name-Last: Mirzaee Title: A novel compact UWB BPF with independently controllable double notched bands and super wide upper stopband Abstract: This paper presents a novel compact ultra-wideband bandpass filter without and with single or multiple notched bands with significant improvements in size reduction and upper stopband enhancement in comparison with its classical counterparts. A new multiple-mode resonator capable of producing multiple transmission zeros is exploited in the filter structure to produce notch bands and improve performance of the upper stopband. A parallel-coupled structure with tapped-line input/output is applied to significantly improve the selectivity and out-of-band rejection. The proposed filter achieves outstanding electrical performance, with wide passband from 2.93 to 10.64 GHz, two notched bands centered at 5.68 and 8 GHz with rejection level better than 40 dB, low insertion loss, high passband return loss, and wide stopband with suppression level better than −25 dB up to 30 GHz. These attractive features make the proposed filter a viable candidate for any number of broadband wireless communications and radar systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 77-86 Issue: 1 Volume: 27 Year: 2013 Month: 1 X-DOI: 10.1080/09205071.2013.738466 File-URL: http://hdl.handle.net/10.1080/09205071.2013.738466 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:1:p:77-86 Template-Type: ReDIF-Article 1.0 Author-Name: Hui Chen Author-X-Name-First: Hui Author-X-Name-Last: Chen Author-Name: Hong-Fei Zhao Author-X-Name-First: Hong-Fei Author-X-Name-Last: Zhao Author-Name: Ke-Song Chen Author-X-Name-First: Ke-Song Author-X-Name-Last: Chen Author-Name: Y.-H. Wu Author-X-Name-First: Y.-H. Author-X-Name-Last: Wu Author-Name: Pu Tang Author-X-Name-First: Pu Author-X-Name-Last: Tang Author-Name: Hong-Sheng Zhong Author-X-Name-First: Hong-Sheng Author-X-Name-Last: Zhong Title: A high selectivity quad-band bandpass filter based on hybrid-coupled microstrip/slotline quad-mode resonator Abstract: A sharp-rejection and high-isolation quad-band bandpass filter with ellipse response using hybrid microstrip/slotline quad-mode resonator is proposed in this paper. The presented composite quad-mode resonator consists of a narrow L-shaped slot in the ground plane and a broadside microstrip L-shaped structure loaded by the two orthogonal narrow-stripline stubs. The dual-metal-plane resonator on a single substrate is employed to obtain a quad-frequency response. Based on this quad-mode resonator, a filter with four passbands centering at 3.86, 6.93, 10.13, and 12.58 GHz is designed, fabricated, and measured. Simulated results from the full-wave electromagnetic software and measured results show a good agreement. The measured inter-band isolations among the quad-frequency passbands with multi-transmission zeros are greater than 22 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 1902-1909 Issue: 15 Volume: 27 Year: 2013 Month: 10 X-DOI: 10.1080/09205071.2013.828574 File-URL: http://hdl.handle.net/10.1080/09205071.2013.828574 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:15:p:1902-1909 Template-Type: ReDIF-Article 1.0 Author-Name: Guo Liu Author-X-Name-First: Guo Author-X-Name-Last: Liu Author-Name: Jianxun Wang Author-X-Name-First: Jianxun Author-X-Name-Last: Wang Author-Name: Yong Luo Author-X-Name-First: Yong Author-X-Name-Last: Luo Title: Comparative analysis on TM110-2π-mode and TM110-π-mode as the operating mode for W-band sheet beam klystron Abstract: Multicavity multigap sheet beam klystron in W-band is an ideally portable coherent radiation source for nonlethal warfare system. In general, the beam–wave interaction circuit employs multigap structures operating with TM110-2π-mode. In this paper, compared investigation of TM110-2π-mode and TM110-π-mode interacting with sheet beam is demonstrated. Analysis indicates that although TM110-2π-mode has higher cavity impendence R/Q, TM110-π-mode possesses wider frequency spacing interval with the adjacent competition modes, larger beam–wave coupling coefficient M and M2(R/Q), which is profitable to improve beam–wave interaction efficiency, reduce mode oscillation and shorten the circuit length. Furthermore, cold characteristics, including R/Q, M, M2(R/Q), operating frequency, and electric-field uniformity, with different gap distance and variable displacements along electron beam propagation and the perpendicular direction are explained in detail. It also turns out TM110-π-mode is not sensitive to the fluctuations of cold characteristics as TM110-2π-mode. This paper provides a confident evidence for TM110-π-mode interacting with sheet beam in the WSBK design. Journal: Journal of Electromagnetic Waves and Applications Pages: 1089-1099 Issue: 9 Volume: 27 Year: 2013 Month: 6 X-DOI: 10.1080/09205071.2013.800462 File-URL: http://hdl.handle.net/10.1080/09205071.2013.800462 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:9:p:1089-1099 Template-Type: ReDIF-Article 1.0 Author-Name: T. Li Author-X-Name-First: T. Author-X-Name-Last: Li Author-Name: H.-Q. Zhai Author-X-Name-First: H.-Q. Author-X-Name-Last: Zhai Author-Name: C. Zhu Author-X-Name-First: C. Author-X-Name-Last: Zhu Author-Name: L. Li Author-X-Name-First: L. Author-X-Name-Last: Li Author-Name: C.-H. Liang Author-X-Name-First: C.-H. Author-X-Name-Last: Liang Author-Name: Y.-F. Han Author-X-Name-First: Y.-F. Author-X-Name-Last: Han Title: Design and analysis of compact printed dual band-notched ultrawideband (UWB) antenna Abstract: A compact printed ultrawideband (UWB) antenna with dual band-notched characteristics is proposed for UWB integration communication system. The presented design, having a total size of 30 × 25 mm, consists of a folded fork-shaped radiator fed by a microstrip line and a modified ground plane with trapezoid-shaped slots on its top edge, which can effectively increase the bandwidth of the proposed antenna. To avoid potential interferences, a straight, open-ended quarter-wavelength slot and a semicircular half-wavelength slot are etched in the radiating patch to generate dual notched bands in 3.3–3.6 GHz for WiMAX and 5.15–5.825 GHz for WLAN. Lumped-element equivalent circuit model is carried out to comprehend and predict the dual band-notched properties. Good agreement is achieved between the simulation and measurement, which shows that the proposed antenna provides an impedance bandwidth of more than 145% between 2.7 and 17 GHz, two independently controllable notched bands and good omnidirectional radiation patterns. Journal: Journal of Electromagnetic Waves and Applications Pages: 560-571 Issue: 5 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.756796 File-URL: http://hdl.handle.net/10.1080/09205071.2013.756796 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:5:p:560-571 Template-Type: ReDIF-Article 1.0 Author-Name: X.-R. Guo Author-X-Name-First: X.-R. Author-X-Name-Last: Guo Author-Name: Z. Zhang Author-X-Name-First: Z. Author-X-Name-Last: Zhang Author-Name: J.-H. Wang Author-X-Name-First: J.-H. Author-X-Name-Last: Wang Author-Name: J.-J. Zhang Author-X-Name-First: J.-J. Author-X-Name-Last: Zhang Title: The design of a triple-band wide-angle metamaterial absorber based on regular pentagon close-ring Abstract: We present three implementation methods and structures using regular pentagon close-ring (PCR) to obtain the characters of triple-band wide-angle metamaterial (MTM) absorber. The proposed metamaterial absorbers are composed of a periodic array with single layer or multi-layer ultrathin dielectric substrates, PCRs, and metal ground. By parametric simulation and optimization, the metamaterial absorbers have significant achievements that perform three distinct absorption peaks for different resonant frequencies. All the absorption rates of emerging peaks with normal incidence are greater than 99% as well as absorptivity for wide incident angles are excellent in both simulated and experimental data. The method utilizing PCRs puts forward a flexible way to design and fabricate multi-band, wide-angle, and ultrathin metamaterial absorbers. Journal: Journal of Electromagnetic Waves and Applications Pages: 629-637 Issue: 5 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.758317 File-URL: http://hdl.handle.net/10.1080/09205071.2013.758317 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:5:p:629-637 Template-Type: ReDIF-Article 1.0 Author-Name: Zi Han Wu Author-X-Name-First: Zi Han Author-X-Name-Last: Wu Author-Name: Feng Wei Author-X-Name-First: Feng Author-X-Name-Last: Wei Author-Name: Yan Yi Wang Author-X-Name-First: Yan Yi Author-X-Name-Last: Wang Author-Name: Xiao Wei Shi Author-X-Name-First: Xiao Wei Author-X-Name-Last: Shi Title: A tunable dual-passband filter based on improved ring resonator Abstract: A miniaturized varactor-tuned microstrip bandpass filter (BPF) based on an improved ring resonator is presented in this paper. The proposed BPF is comprised of a ring as 1/2 λ resonator with two varactors in the middle section and a coupling scheme. The variation of coupling coefficient can be controlled by using a capacitor. The center frequency of the lower passband can be tuned from 3.2 to 3.9 GHz, while the center frequency of the upper passband is at 4.9 GHz and it is fixed during the process. Theoretical analysis and design approach are demonstrated. Finally, the predicted results are compared with measured data and good agreement is reported. Journal: Journal of Electromagnetic Waves and Applications Pages: 2239-2246 Issue: 17 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.838148 File-URL: http://hdl.handle.net/10.1080/09205071.2013.838148 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:17:p:2239-2246 Template-Type: ReDIF-Article 1.0 Author-Name: S. Habib Mazharimousavi Author-X-Name-First: S. Author-X-Name-Last: Habib Mazharimousavi Author-Name: Ashkan Roozbeh Author-X-Name-First: Ashkan Author-X-Name-Last: Roozbeh Author-Name: M. Halilsoy Author-X-Name-First: M. Author-X-Name-Last: Halilsoy Title: Electromagnetic wave propagation through inhomogeneous material layers Abstract: We use Maxwell’s equations in a sourceless, inhomogeneous medium with continuous permeability and permittivity to study the wave propagation. The general form of the wave equation is derived and by virtue of some physical assumptions, including and as functions of the equation has been simplified. Finally, by introducing a smooth step dielectric variable, we solve the wave equation in the corresponding medium which is in conform with the well-known results. Exact double-layer solution in analytic form has been given in terms of the Heun functions. Journal: Journal of Electromagnetic Waves and Applications Pages: 2065-2074 Issue: 16 Volume: 27 Year: 2013 Month: 11 X-DOI: 10.1080/09205071.2013.831741 File-URL: http://hdl.handle.net/10.1080/09205071.2013.831741 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:16:p:2065-2074 Template-Type: ReDIF-Article 1.0 Author-Name: Wei Li Author-X-Name-First: Wei Author-X-Name-Last: Li Author-Name: Jianguo Guan Author-X-Name-First: Jianguo Author-X-Name-Last: Guan Title: Transforming complex space: a general strategy to compensate loss of transformation optical media Abstract: We propose a general theoretical solution by transforming to the loss problem of transformation media complex coordinates. In particular, this universal schematic has been demonstrated by two design examples of a loss compensated invisibility cloak and a loss compensated superlens with simple material parameters and structures. In such designs, the gain materials, which amplify the wave as opposed to the traditional lossy materials, are properly manipulated so as to compensate the inherent loss. The complex transformation method proposed here paves an effective path of addressing the inevitable loss problem in general transformational optical devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 834-845 Issue: 7 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.789408 File-URL: http://hdl.handle.net/10.1080/09205071.2013.789408 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:7:p:834-845 Template-Type: ReDIF-Article 1.0 Author-Name: Feng Wei Author-X-Name-First: Feng Author-X-Name-Last: Wei Author-Name: Lei Chen Author-X-Name-First: Lei Author-X-Name-Last: Chen Author-Name: Yingfang Guo Author-X-Name-First: Yingfang Author-X-Name-Last: Guo Author-Name: Wentao Li Author-X-Name-First: Wentao Author-X-Name-Last: Li Author-Name: Xiaowei Shi Author-X-Name-First: Xiaowei Author-X-Name-Last: Shi Title: Compact UWB directional coupler with one notch-band Abstract: An ultra-wideband (UWB) parallel coupled-line directional coupler (DC) with one notch-band based on folded stepped impedance resonator (SIR) is investigated in this paper. The proposed UWB DC is comprised of one conventional microstrip directional coupler, two folded shunt quarter-wavelength short-circuited stubs and one SIR with metalized via hole to ground. The SIR is studied and employed to generate one desired notched band. The predicted results are compared with measured data and good agreement is reported. Journal: Journal of Electromagnetic Waves and Applications Pages: 599-604 Issue: 5 Volume: 27 Year: 2013 Month: 3 X-DOI: 10.1080/09205071.2013.757853 File-URL: http://hdl.handle.net/10.1080/09205071.2013.757853 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:5:p:599-604 Template-Type: ReDIF-Article 1.0 Author-Name: Biao Hu Author-X-Name-First: Biao Author-X-Name-Last: Hu Author-Name: Jiayin Li Author-X-Name-First: Jiayin Author-X-Name-Last: Li Author-Name: Xinhui Wu Author-X-Name-First: Xinhui Author-X-Name-Last: Wu Author-Name: Tianming Li Author-X-Name-First: Tianming Author-X-Name-Last: Li Author-Name: Yihong Zhou Author-X-Name-First: Yihong Author-X-Name-Last: Zhou Title: Design of a large-orbit electron gun with gradual reversal magnetic field for a W-band permanent magnet peniotron Abstract: This paper demonstrates the operating characteristics of an axis-encircling large-orbit electron gun and a corresponding permanent magnet system of a W-band peniotron. The practical novel large-orbit electron beam with axial velocity spread of 5.17%, transverse velocity spread of 1.28%, guiding center deviation ratio 10.7%, and high velocity ratio 2 is designed. The main advantages of such a peniotron in the large-orbit configuration with a permanent magnet system are its compact size, reduced operational gap, and lower cost. Critical characteristics, such as acceleration voltage and the relative axial position of the magnetic system and electrode system have also been well examined and it is shown that a careful control of them is important for the device performance. Journal: Journal of Electromagnetic Waves and Applications Pages: 1136-1144 Issue: 9 Volume: 27 Year: 2013 Month: 6 X-DOI: 10.1080/09205071.2013.801043 File-URL: http://hdl.handle.net/10.1080/09205071.2013.801043 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:9:p:1136-1144 Template-Type: ReDIF-Article 1.0 Author-Name: Da Peng Author-X-Name-First: Da Author-X-Name-Last: Peng Author-Name: Xingji Tang Author-X-Name-First: Xingji Author-X-Name-Last: Tang Author-Name: Hu Yang Author-X-Name-First: Hu Author-X-Name-Last: Yang Author-Name: Jianguo He Author-X-Name-First: Jianguo Author-X-Name-Last: He Title: Dissipative scheme for discontinuous Galerkin time-domain method based on Verlet time-stepping Abstract: A dissipative scheme based on the Verlet time-stepping algorithm is proposed to decrease the numerical dispersive error and eliminate spurious modes in unstructured grid-based discontinuous Galerkin time-domain (DGTD) method. The dissipative terms are only added in the first line of each time-step to yield a totally explicit algorithm. Combined with this time integration algorithm, we perform a numerical Fourier analysis of the discrete scheme to investigate the dispersion and dissipation properties of DGTD. Numerical results show that more accurate solutions can be obtained by using the dissipative Verlet scheme in the DG method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1800-1814 Issue: 14 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.825887 File-URL: http://hdl.handle.net/10.1080/09205071.2013.825887 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:14:p:1800-1814 Template-Type: ReDIF-Article 1.0 Author-Name: N. Purushothaman Author-X-Name-First: N. Author-X-Name-Last: Purushothaman Author-Name: S.K. Ghosh Author-X-Name-First: S.K. Author-X-Name-Last: Ghosh Title: Performance improvement of helix TWT using metamaterial helix-support structure Abstract: An analysis to determine performance parameters for dispersion characteristics and interaction impedance of helix traveling-wave tube using metamaterial is presented. The conventional positive dielectric supports of the helix slow-wave structure have been replaced by an equivalent homogeneous metamaterial medium. The analysis has been carried out in tape helix model, to include the effects of space harmonics. Structure characteristics, namely, dispersion and interaction impedance have been studied, as the former predicts the phase velocity of the RF wave and the latter has direct relevance to the device gain. It has been observed that, with metamaterial supported helix, both phase velocity and interaction impedance increase as compared to conventional positive dielectric supports. The results have been presented for fundamental space harmonic mode. Journal: Journal of Electromagnetic Waves and Applications Pages: 890-900 Issue: 7 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.792748 File-URL: http://hdl.handle.net/10.1080/09205071.2013.792748 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:7:p:890-900 Template-Type: ReDIF-Article 1.0 Author-Name: A. Freni Author-X-Name-First: A. Author-X-Name-Last: Freni Author-Name: A. Mazzinghi Author-X-Name-First: A. Author-X-Name-Last: Mazzinghi Author-Name: M. Albani Author-X-Name-First: M. Author-X-Name-Last: Albani Title: Comments on “A novel technique in simplifying the fabrication process and improving the reflection coefficient of the linear polarized radial line slot array (LP-RLSA) antennas” Journal: Journal of Electromagnetic Waves and Applications Pages: 1859-1860 Issue: 14 Volume: 27 Year: 2013 Month: 9 X-DOI: 10.1080/09205071.2013.823837 File-URL: http://hdl.handle.net/10.1080/09205071.2013.823837 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:14:p:1859-1860 Template-Type: ReDIF-Article 1.0 Author-Name: Min-Ho Ka Author-X-Name-First: Min-Ho Author-X-Name-Last: Ka Author-Name: A.I. Baskakov Author-X-Name-First: A.I. Author-X-Name-Last: Baskakov Title: Enhancement of the sensitivity of the dual-frequency correlation radar over sea surface roughness in a small satellite Abstract: The possibility of sea surface roughness estimation using the dual-frequency cross-correlation function of reflected signals with the correlation radar in a small satellite was analyzed. We showed the possibility of reducing the influence of the decorrelation factor on the dual-frequency correlation function, by synthesizing the antenna aperture in each frequency channel and by constructing a cross-track linear antenna array which is perpendicular to the flight direction of the satellite. Finally, we achieved enhancement of the sensitivity of the measurement characteristic with an array of small antennas, which is particularly important for the remote sensing system in a small satellite. Journal: Journal of Electromagnetic Waves and Applications Pages: 1036-1046 Issue: 8 Volume: 27 Year: 2013 Month: 5 X-DOI: 10.1080/09205071.2013.799444 File-URL: http://hdl.handle.net/10.1080/09205071.2013.799444 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:27:y:2013:i:8:p:1036-1046 Template-Type: ReDIF-Article 1.0 Author-Name: Zi-Fan Meng Author-X-Name-First: Zi-Fan Author-X-Name-Last: Meng Author-Name: Zhi Tao Author-X-Name-First: Zhi Author-X-Name-Last: Tao Author-Name: Feng Lan Author-X-Name-First: Feng Author-X-Name-Last: Lan Author-Name: Jiu-Fu Ruan Author-X-Name-First: Jiu-Fu Author-X-Name-Last: Ruan Author-Name: Fei Cai Author-X-Name-First: Fei Author-X-Name-Last: Cai Author-Name: Tao Wang Author-X-Name-First: Tao Author-X-Name-Last: Wang Title: Frequency selective surface based on Ti3C2Tx MXene for dual band Wi-Fi applications Abstract: A dual-band frequency selective surface (FSS) employing Ti3C2Tx deposited on a polyethylene terephthalate (PET) layer is proposed for Wi-Fi applications. The structure can afford dual-frequency passbands with central frequencies of 2.4 GHz and 5.5 GHz and realize large bandwidths covering 1.7-2.9 GHz and 4.9-6 GHz for -3 dB reference, which are bands of Wi-Fi communication. Featured by the use of 4.3 μm-thick Ti3C2Tx, the FSS reduces the thickness by 16% compared to that using 35 μm thick copper, which renders it preferable for flexible and ultrathin applications. Moreover, the proposed FSS has the advantages of polarization and incident-angle insensitivity as well as the ease of fabrication. The proposed FSS based on Ti3C2Tx MXene for the first time may provide a further step in the development of ultrathin, lightweight and flexible devices for wireless communication, such as filters, absorbers and modulators. Journal: Journal of Electromagnetic Waves and Applications Pages: 1130-1140 Issue: 8 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.2007505 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2007505 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:8:p:1130-1140 Template-Type: ReDIF-Article 1.0 Author-Name: Nikesh Kumar Sahu Author-X-Name-First: Nikesh Kumar Author-X-Name-Last: Sahu Author-Name: Gourab Das Author-X-Name-First: Gourab Author-X-Name-Last: Das Author-Name: Ravi Kumar Gangwar Author-X-Name-First: Ravi Kumar Author-X-Name-Last: Gangwar Title: A simple conformal-strip fed composite antenna with wideband & enhanced isolation for MIMO applications Abstract: A composite antenna with wide impedance bandwidth and enhanced isolation for multiple-input-multiple-output (MIMO) applications is introduced in this article. A simple conformal-strip fed rectangular dielectric resonator (rDR) with a conducting conformal-patch, which provides wide impedance bandwidth (3.21-6.19 GHz), is utilized as an antenna element. The proposed MIMO antenna is formed by arranging two symmetrical composite antenna elements side by side along with a simple decoupling structure (based on a wide rectangular slot and two metallic strips) in between them. The proposed MIMO antenna delivers good inter-port isolation (greater than 18 dB) over the entire operating bandwidth. Also, a well satisfactory outcome of the envelope correlation coefficient (ECC) is obtained over this bandwidth. Moreover, the proposed antenna exhibits a stable broadside directional radiation pattern over the entire operating bandwidth. Journal: Journal of Electromagnetic Waves and Applications Pages: 1173-1187 Issue: 8 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.2009382 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2009382 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:8:p:1173-1187 Template-Type: ReDIF-Article 1.0 Author-Name: Yu-Jen Chi Author-X-Name-First: Yu-Jen Author-X-Name-Last: Chi Title: An automatic polarization switching antenna structure for batteryless IoT devices Abstract: Microwave power transmission (MPT) has many advantages. However, previous studies have indicated that MPT interferes with wireless data communication. In this paper, an adaptive polarization switchable rectenna architecture is proposed for simultaneous wireless information and power transfer. When the rectenna is activated by a wireless energy transmitter, the antenna automatically switches to another quadrature polarization state for wireless data communication. The experimental results show that the adaptive switching characteristic provides a wireless channel isolation of more than 23 dB between wireless power transfer and data communication. In a practical indoor environment, the measurement of packet error rate of the communication link shows that the power level of MPT could be increased by 16 dB and still keep the wireless connectivity. Thus, the proposed design is suitable for devices powered by MPT and for simultaneous wireless information and power transfer applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1141-1153 Issue: 8 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.2007506 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2007506 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:8:p:1141-1153 Template-Type: ReDIF-Article 1.0 Author-Name: Babar Kamal Author-X-Name-First: Babar Author-X-Name-Last: Kamal Author-Name: Jingdong Chen Author-X-Name-First: Jingdong Author-X-Name-Last: Chen Author-Name: Yingzeng Yin Author-X-Name-First: Yingzeng Author-X-Name-Last: Yin Author-Name: Jian Ren Author-X-Name-First: Jian Author-X-Name-Last: Ren Author-Name: Sadiq Ullah Author-X-Name-First: Sadiq Author-X-Name-Last: Ullah Author-Name: Bilawal Khan Author-X-Name-First: Bilawal Author-X-Name-Last: Khan Title: Broad-band and broad-angle linear and circular polarization converting metasurface Abstract: This paper presents a broad-band and broad-angle anisotropic reflective polarization converting metasurface (PCMS) for C- and X-band applications, which is composed of square split ring resonators. Such PCMS can be used in a wide range of applications such as satellite antennas, navigation systems, and biomedical devices, to name but a few. The performance of the presented PCMS is analyzed theoretically, numerically, and experimentally. The results at normal and oblique incidences demonstrate that the PCMS achieves broad-band linear polarization (LP) transformation within an operating bandwidth of 5.3 GHz (5.3–10.6 GHz), covering the C-band and a portion of the X-band. The broad-band performance of the PCMS sustains from $ {0}^\circ $ 0∘ to $ {60}^\circ $ 60∘. Moreover, the PCMS achieves polarization conversion for circularly polarized (CP) waves in the same bands. The polarization conversion ratio is more than $ 90\% $ 90% for both LP and CP incident waves. Journal: Journal of Electromagnetic Waves and Applications Pages: 1102-1112 Issue: 8 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.2005696 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2005696 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:8:p:1102-1112 Template-Type: ReDIF-Article 1.0 Author-Name: Yujiao Ding Author-X-Name-First: Yujiao Author-X-Name-Last: Ding Author-Name: Yue Wang Author-X-Name-First: Yue Author-X-Name-Last: Wang Author-Name: Yuchen Yang Author-X-Name-First: Yuchen Author-X-Name-Last: Yang Author-Name: Cong Du Author-X-Name-First: Cong Author-X-Name-Last: Du Author-Name: Wei Dong Author-X-Name-First: Wei Author-X-Name-Last: Dong Title: An adaptive microwave photonic filter with LMS algorithm Abstract: A microwave photonic filter (MPF) with an adaptive algorithm is proposed and theoretically analyzed. The structure combines the finite impulse response (FIR) MPF with the adaptive algorithm. The FIR MPF includes variable optical attenuators (VOAs) and variable optical delay lines (VDLs). The least mean square (LMS) algorithm can calculate the weight coefficient of each tap in FIR MPF, which can influence the VOA to realize the adaptive filtering process. This adaptive MPF can extract the desired signal from noise precisely. The noise signal can be well suppressed and the signal-to-noise ratio (SNR) can be developed from 4.15 to 25.5 dB. In addition, this adaptive MPF can be suitable for a wide range of signals. Journal: Journal of Electromagnetic Waves and Applications Pages: 1076-1088 Issue: 8 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.2003258 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2003258 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:8:p:1076-1088 Template-Type: ReDIF-Article 1.0 Author-Name: Ahmet Sefer Author-X-Name-First: Ahmet Author-X-Name-Last: Sefer Author-Name: Ali Yapar Author-X-Name-First: Ali Author-X-Name-Last: Yapar Title: Reconstruction algorithm for impenetrable rough surface profile under Neumann boundary condition Abstract: In this paper, an algorithm to reconstruct one-dimensional impenetrable rough surface from the knowledge of scattering field is presented. The rough surface is considered as locally perturbed and the scattering field data are collected above the roughness in a simple non-magnetic medium considering Neumann boundary condition. First, the surface integral equation constituted via the Neumann boundary condition is solved and scattering field data are observed synthetically. Then, the same surface integral equation together with the data equation are solved in an iterative fashion to reconstruct the surface variation. In the numerical implementation, the so-called ill-posed inverse problem is regularized with Tikhonov method and a least-squares solution is obtained by using Gaussian-type basis function. Finally, numerical examples are carried out to illustrate effectiveness of the method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1154-1172 Issue: 8 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.2009381 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2009381 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:8:p:1154-1172 Template-Type: ReDIF-Article 1.0 Author-Name: Soumendu Ghosh Author-X-Name-First: Soumendu Author-X-Name-Last: Ghosh Author-Name: Sourav Roy Author-X-Name-First: Sourav Author-X-Name-Last: Roy Author-Name: Ujjal Chakraborty Author-X-Name-First: Ujjal Author-X-Name-Last: Chakraborty Author-Name: Abhishek Sarkhel Author-X-Name-First: Abhishek Author-X-Name-Last: Sarkhel Title: An ELC meta-resonator inspired wideband wearable MIMO antenna system for biotelemetry applications Abstract: A compact wideband multiple-input multiple-output (MIMO) antenna for body-centric communication is presented in this article. Initially, an electric field-driven LC metamaterial resonator inspired monopole antenna is developed that exhibits 122.19 % (1.28–5.30 GHz) bandwidth covering 2.4 GHz WLAN and 3.5 GHz WiMAX application bands. Thereafter, the MIMO antenna is proposed, and a pair of meander line structure as a wideband decoupling network is introduced on the ground plane to reduce the inter-element coupling. The proposed antenna holds a reduced mutual coupling and low envelope correlation coefficient over the wideband. To explain the wideband antenna response and its decoupling mechanism, a circuit model analysis is incorporated. Moreover, the proposed antenna demonstrates a robust performance under complex bending and crumpling conditions with an acceptable specific absorption rate (SAR <1.6) during the on-body conditions. Besides, a high data rate link-margin analysis makes the antenna suitable for wireless biotelemetry. Journal: Journal of Electromagnetic Waves and Applications Pages: 1113-1129 Issue: 8 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.2005697 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2005697 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:8:p:1113-1129 Template-Type: ReDIF-Article 1.0 Author-Name: Edward Michaelchuck Jr. Author-X-Name-First: Edward Author-X-Name-Last: Michaelchuck Jr. Author-Name: Scott Ramsey Author-X-Name-First: Scott Author-X-Name-Last: Ramsey Author-Name: Troy Mayo Author-X-Name-First: Troy Author-X-Name-Last: Mayo Author-Name: Sarah Thompson Author-X-Name-First: Sarah Author-X-Name-Last: Thompson Author-Name: Samuel Lambrakos Author-X-Name-First: Samuel Author-X-Name-Last: Lambrakos Title: Apparent reflectance modeling for camouflage pattern comparison metrics Abstract: Camouflage patterns consist of specified complex patterning where the reflectance, as a function of wavelength, of each pattern segment is specified. Camouflage complexity establishes a need to determine camouflage pattern reflectance characteristics as a function of observer distance. The apparent reflectance spectrum, the combination of all wavelengths of light reflected from large sample sizes for a given standoff distance, can serve as an evaluation tool for camouflage fabrics. Apparent reflectance spectrum is based on far-field and statistical characteristics of camouflage patterns due to diffuse scattering properties of electromagnetic waves. This report describes modeling and simulation of apparent reflectance spectra to be adopted as a foundation for multiple metrics used in evaluating camouflage patterns in terms of their far-field characteristics over the visible and shortwave infrared wavelengths. This approach allows for direct, numerical suitability comparisons between various fabrics that can be used to optimize camouflage selection for various operational environments. Journal: Journal of Electromagnetic Waves and Applications Pages: 1060-1075 Issue: 8 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.2002728 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2002728 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:8:p:1060-1075 Template-Type: ReDIF-Article 1.0 Author-Name: Minxing Wang Author-X-Name-First: Minxing Author-X-Name-Last: Wang Author-Name: Zewei Wu Author-X-Name-First: Zewei Author-X-Name-Last: Wu Author-Name: Xiaoyi Liao Author-X-Name-First: Xiaoyi Author-X-Name-Last: Liao Author-Name: Ran Zhang Author-X-Name-First: Ran Author-X-Name-Last: Zhang Author-Name: Yong Luo Author-X-Name-First: Yong Author-X-Name-Last: Luo Title: Selective mode filtering for gyrotron traveling-wave tube systems Abstract: In this paper, a method to filter the parasitic modes for gyrotron traveling-wave tube (gyro-TWT) system is proposed. The difference of surface current between the operating TE01 mode and the parasitic modes is analyzed to achieve the mode discrimination. Based on the analysis, a slot array with high mode-selectivity is introduced, and a Ka-band oversized waveguide mode filter is designed to attenuate the parasitic modes. A prototype is fabricated and measured for validation purpose. The measurement of S-parameter demonstrates that parasitic modes can be effectively suppressed by the mode filter, while the TE01 mode suffers little attenuation after propagating through the proposed device. The high-power capacity of the mode filter is verified by a high-power test based on a gyro-TWT. The proposed mode filter features high performance in purifying TE01 mode as well as a high-power capacity, which makes it suitable for gyro-TWT systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 1089-1101 Issue: 8 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.2004558 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2004558 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:8:p:1089-1101 Template-Type: ReDIF-Article 1.0 Author-Name: Hamdy M. Youssef Author-X-Name-First: Hamdy M. Author-X-Name-Last: Youssef Author-Name: Najat A. Alghamdi Author-X-Name-First: Najat A. Author-X-Name-Last: Alghamdi Title: Irreversible thermal damage due to a laser pulse on the human breast tumour Abstract: The essential target of the tumour’s treatment is how to destroy its tissues. So, the main objective of this paper is how to invent an effective method to get enough irreversible damage by using a different type of therapy. A new thermal model of a human breast has been developed by considering three layers: skin, fat, and tumour. The internal heat source due to the chemical reactions has been considered to discuss the response time due to the perturbation based on non-classical Fourier’s law with one relaxation time. A thermal incident due to laser pulse with different values of time, depth, relaxation time, and power density have been discussed. The quantity of the thermal damage has been computed to the three layers by applying the Arrhenius burn integration formula. The time, depth, relaxation time, and power density have significant effects on the three layers of the human breast. Journal: Journal of Electromagnetic Waves and Applications Pages: 1043-1059 Issue: 8 Volume: 36 Year: 2022 Month: 05 X-DOI: 10.1080/09205071.2021.2002727 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2002727 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:8:p:1043-1059 Template-Type: ReDIF-Article 1.0 Author-Name: Tathababu Addepalli Author-X-Name-First: Tathababu Author-X-Name-Last: Addepalli Author-Name: Jagadeesh Babu Kamili Author-X-Name-First: Jagadeesh Author-X-Name-Last: Babu Kamili Author-Name: Kiran Kumar Bandi Author-X-Name-First: Kiran Author-X-Name-Last: Kumar Bandi Author-Name: Anveshkumar Nella Author-X-Name-First: Anveshkumar Author-X-Name-Last: Nella Author-Name: Manish Sharma Author-X-Name-First: Manish Author-X-Name-Last: Sharma Title: Lotus flower-shaped 4/8-element MIMO antenna for 5G n77 and n78 band applications Abstract: This paper reports a 4 × 4 and 8 × 8 MIMO antenna configuration on FR4 substrate occupying the area of 1.43λo × 1.43λo mm2 (f = 3.58 GHz) and 2.14λo × 2.14λo mm2 (f = 3.50 GHz). The proposed design is exclusively developed for 5G: n77/n78 wireless band applications. The MIMO antenna comprises of Lotus-shaped radiating element with DGS (defected-ground-structure) in-ground and the addition of slits providing boresight radiation. All the radiating elements are placed orthogonally in a 4 × 4 configuration while pairs of antennas are also placed in the same fashion for 8 × 8 MIMO antenna configuration. The high isolation of more than 16 dB is achieved by using a novel decoupling structure in the ground. Also, the MIMO antenna are characterized with diversity performance including ECC, DG, TARC, CCL and MEG achieving permissible values of <0.005, ∼10 dB, <0 dB, <0.10b/s/Hz and ∼ −3 dB respectively. The peak gain corresponds to 4.51 and 5.02 dBi with radiation efficiency of more than 80% for 4 × 4/8 × 8 MIMO antenna configuration. The proposed antenna also offers desired 2D radiation patterns in principal planes. Journal: Journal of Electromagnetic Waves and Applications Pages: 1404-1422 Issue: 10 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2028683 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2028683 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:10:p:1404-1422 Template-Type: ReDIF-Article 1.0 Author-Name: Chengzhu Du Author-X-Name-First: Chengzhu Author-X-Name-Last: Du Author-Name: Hongye Liu Author-X-Name-First: Hongye Author-X-Name-Last: Liu Author-Name: Xun Wang Author-X-Name-First: Xun Author-X-Name-Last: Wang Author-Name: Yu Nie Author-X-Name-First: Yu Author-X-Name-Last: Nie Author-Name: Zhipeng Yang Author-X-Name-First: Zhipeng Author-X-Name-Last: Yang Title: Compact CPW-fed triple-band MIMO antenna for wireless body area network based on flexible liquid crystal polymer Abstract: A compact coplanar waveguide-fed triple-band multiple input multiple output (MIMO) antenna is designed based on flexible substrate named liquid crystal polymer in this work. The proposed antenna comprises two antenna elements placed side by side. By adding a double Y-shaped branch between two antenna elements, good isolation is achieved successfully, which is better than 21 dB. According to the measured results, it can operate bandwidth covering 2.263–2.925, 3.063–4.5 and 4.588–7.25 GHz, meeting the radio spectrum, including 5G, WLAN and WiMAX. Moreover, the proposed antenna also has virous suitable characteristics including envelope correlation coefficient (<0.01), diversity gain (>9.99), channel capacity loss (<0.4 bits/s/Hz), the difference of mean effective gain (<0.15 dB) and total active reflection coefficient (<−10 dB). The bending test and the effect of human body have also been analyzed. The actual measurement indicates that the presented MIMO antenna is desirable for integration in wearable 5G/WLAN/WiMAX devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 1436-1450 Issue: 10 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2030807 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2030807 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:10:p:1436-1450 Template-Type: ReDIF-Article 1.0 Author-Name: Erdem Aslan Author-X-Name-First: Erdem Author-X-Name-Last: Aslan Author-Name: Ekin Aslan Author-X-Name-First: Ekin Author-X-Name-Last: Aslan Title: Engineering the boosting of the magnetic Purcell factor with a composite structure based on nanodisk and ring resonators Abstract: The dependence of the optical communication interconnects on the electronics technology is a limitation for ultra-high-speed communications. Nanophotonics promises intriguing technologies to exceed these limitations. In this context, a silicon-based composite nanostructure is proposed to boost the magnetic Purcell enhancement one order of magnitude higher than a single hollow-disk resonator. The boosting effect relies on the near-field interaction between a hollow disk resonator and two larger rings. The engineering of the device is presented via simulations with the aim of obtaining the highest Purcell enhancement. Additionally, to reveal the underlying mechanism, the contribution of each multipole mode to the scattered intensity and near-field enhancement properties are analysed. Finally, the dependence of the Purcell factor on the position of the source is investigated. The results of this study may have a great potential to realize nanoscale light sources to be used in all-photonic chips for ultra-high-speed optical networks. Journal: Journal of Electromagnetic Waves and Applications Pages: 1339-1351 Issue: 10 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2021.2024891 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2024891 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:10:p:1339-1351 Template-Type: ReDIF-Article 1.0 Author-Name: B. Prudhvi Nadh Author-X-Name-First: B. Author-X-Name-Last: Prudhvi Nadh Author-Name: B. T. P. Madhav Author-X-Name-First: B. T. P. Author-X-Name-Last: Madhav Author-Name: M. Siva Kumar Author-X-Name-First: M. Author-X-Name-Last: Siva Kumar Author-Name: T. Anil Kumar Author-X-Name-First: T. Author-X-Name-Last: Anil Kumar Author-Name: M. Venkateswara Rao Author-X-Name-First: M. Author-X-Name-Last: Venkateswara Rao Author-Name: S.S. Mohan Reddy Author-X-Name-First: S.S. Author-X-Name-Last: Mohan Reddy Title: MEMS-based reconfigurable and flexible antenna for body-centric wearable applications Abstract: The current study presents an MEMS switche-based frequency reconfigurable antenna for conformal and wearable applications. This is a circular ring-shaped monopole antenna loaded with spokes attached to the circular ring and fed by co-planar waveguide feeding (CPW). The antenna is designed on the flexible Liquid crystal polymer substrate material with 40 × 28 × 0.1 mm3. The reconfigurability of the antenna was achieved by placing RF MEMS SP4 T (ADGM 1304) switches. The antenna has a dual-band with reconfigurability at 2.5 GHz (2.12–2.9 GHz) and 5.4 GHz (4.5–5.8 GHz). The measured results demonstrate the antenna operates at 1.73–3.2 GHz and 4.54–6.3 GHz with resonating frequencies of 2.5 and 5.6 GHz. When placed on the human body, the gain of the antenna variesg from 5.32 to 8.38 dBi for different reconfigurable conditions. SAR analysis results in between 0.15 W/Kg and 1.37 W/Kg for different switching conditions, and the simulation results match with the measurements. Journal: Journal of Electromagnetic Waves and Applications Pages: 1389-1403 Issue: 10 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2028682 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2028682 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:10:p:1389-1403 Template-Type: ReDIF-Article 1.0 Author-Name: Debasish Nath Author-X-Name-First: Debasish Author-X-Name-Last: Nath Author-Name: Udaya Kumar Author-X-Name-First: Udaya Author-X-Name-Last: Kumar Title: Induction mechanism and propagation characteristics of current in line conductors due to an electron avalanche Abstract: Transfer of bulk electric power required in the modern world can be realized only through Extra High Voltage and Ultra High Voltage transmission lines. The scenario is dominated by overhead lines in which electromagnetic noise generated by corona is an important concern. Corona-induced currents propagate along line conductors producing electromagnetic noise, which is essential to be quantified. Towards this end, the present work aims to investigate basic mechanism of current induction using an isolated avalanche developing under space charge modulated background field. Beginning with the complete electric field produced by an avalanche, the corresponding induced currents are quantified, and the structure of electric and magnetic fields is extracted. The well-known time-domain electric field integral equation is employed for the purpose. The basic issue with long transmission line modelling is amply demonstrated. Since single avalanche is the basic mechanism behind corona, general inferences drawn are applicable for corona on transmission lines. Journal: Journal of Electromagnetic Waves and Applications Pages: 1368-1388 Issue: 10 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2028268 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2028268 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:10:p:1368-1388 Template-Type: ReDIF-Article 1.0 Author-Name: Soheyl Soodmand Author-X-Name-First: Soheyl Author-X-Name-Last: Soodmand Author-Name: Kevin A. Morris Author-X-Name-First: Kevin A. Author-X-Name-Last: Morris Author-Name: Mark A. Beach Author-X-Name-First: Mark A. Author-X-Name-Last: Beach Title: On the effect of S-parameter stability of antenna and coupler on electrical balance duplexing Abstract: Electrical Balance Duplexers (EBDs) provide transmit-receive isolation to implement a form of self-interference cancellation to facilitate simultaneous transmission and reception from a single antenna in systems like In-Band Full-duplex (IBFD) transceivers. EBD works by coupling transmitter, receiver, antenna, and balancing impedance using a hybrid coupler. In recent pieces of literature, antenna impedance variations are considered the main factor limiting the EBD isolation bandwidth, while the EBD balancing impedance needs to be equal as much as possible to the antenna impedance to achieve high isolation. But hybrid couplers are also not ideal elements, and their S-parameters are not stable in the frequency domain. In this work, five broadband RF devices (two antennas, two couplers, and a 50-Ohm RF-load) are used to form four EBD set-ups. One of the antennas, designed by the authors, has more impedance stability in the frequency domain than the other one, which is a commercial antenna. Also, one of the couplers, designed by the authors, has more S-parameter stability in Ultra-Wideband (UWB) frequency domain than the other one, which is a commercial UWB coupler. The implemented EBDs show that when both antenna and coupler have strong S-parameter stabilities in the frequency domain, wider isolation bandwidth (UWB 1.5–3.5 GHz range) and higher EBD isolation are obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 1352-1367 Issue: 10 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2026258 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2026258 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:10:p:1352-1367 Template-Type: ReDIF-Article 1.0 Author-Name: Mstislav E. Kaliberda Author-X-Name-First: Mstislav E. Author-X-Name-Last: Kaliberda Author-Name: Leonid M. Lytvynenko Author-X-Name-First: Leonid M. Author-X-Name-Last: Lytvynenko Author-Name: Sergey A. Pogarsky Author-X-Name-First: Sergey A. Author-X-Name-Last: Pogarsky Title: Electromagnetic wave scattering by half-plane and disk placed in the same plane or circular hole in half-plane Abstract: The scattering by a half-plane and circular disk placed in the same plane is considered. The scattering by a circular hole in the half-plane is also considered as a dual problem. The operator equations for relative unknown Fourier amplitudes of the scattered field are presented. They use known reflection operators of the isolated half-plane and isolated disk. After the regularization procedure involving integration over the contour in the complex plane, operator equations are reduced to the singular integral equations. The discretization is discussed. The near and far field patterns are presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 1463-1483 Issue: 10 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2032379 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2032379 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:10:p:1463-1483 Template-Type: ReDIF-Article 1.0 Author-Name: Gokhan Ozturk Author-X-Name-First: Gokhan Author-X-Name-Last: Ozturk Title: Ultra-thin, wide-angle and bandwidth-enhanced linear and circular metasurface-based reflection-type polarization converter at X-band microwave frequency Abstract: In this study, a low-profile ultra-thin metasurface-based reflection-type polarization converter with enhanced bandwidth for X-band (8.2–12.4 GHz) applications is proposed. The designed converter, which has a cell topology above a substrate (FR-4) material terminated in a metal conductor with overall thickness of 1.2 mm corresponding to a thickness of $ 0.042\lambda $ 0.042λ in terms of wavelength (ultra-thin), indicates the cross polarization performance with a polarization converter ratio (PCR) value of 90% in a wide (9–12 GHz) frequency range (normal incidence) and linear to circular polarization performance with left-handed circular polarization between 8.44 and 8.58 GHz and between 12.74 and 13.14 GHz. It is observed that the converter has a PCR value of 80% for incidence angles up to $ 60^\circ $ 60∘. Simulations of the designed converter performed by a commercial electromagnetic simulation program (CST Microwave Studio) were validated by free-space measurements. Journal: Journal of Electromagnetic Waves and Applications Pages: 1423-1435 Issue: 10 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2029722 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2029722 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:10:p:1423-1435 Template-Type: ReDIF-Article 1.0 Author-Name: Xiaoyi Liao Author-X-Name-First: Xiaoyi Author-X-Name-Last: Liao Author-Name: Zewei Wu Author-X-Name-First: Zewei Author-X-Name-Last: Wu Author-Name: Minxing Wang Author-X-Name-First: Minxing Author-X-Name-Last: Wang Title: Investigation of the curvature distribution for TE01-to-TM11 mode converter Abstract: An oversized TE $ _{01} $ 01-to-TM $ _{11} $ 11 mode converter based on waveguide bend structure is designed for high power transmission line. The curvature distribution of the waveguide bend is analyzed and optimized using mode coupling theory. Analysis results show that the curvature near the output port plays a decisive role in the content of the parasitic modes, which indicates that the restriction on curvature far from output port could be relaxed. Therefore, the asymmetric waveguide axis with enhanced curvature near the front end and lessened curvature near the output port will have a high conversion efficiency and a broad bandwidth. Combining the curvature optimization and the phase rematching technology proposed in our preliminary work, the TE $ _{01} $ 01-to-TM $ _{11} $ 11 mode converter realizes a 90 $ ^\circ $ ∘ bend with a conversion efficiency over 95% in the range of 26–32.2 GHz (the relative bandwidth over 21%). To verify the designed mode converter, a prototype is manufactured and measured. Journal: Journal of Electromagnetic Waves and Applications Pages: 1451-1462 Issue: 10 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2032378 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2032378 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:10:p:1451-1462 Template-Type: ReDIF-Article 1.0 Author-Name: Pujayita Saha Author-X-Name-First: Pujayita Author-X-Name-Last: Saha Author-Name: Debasis Mitra Author-X-Name-First: Debasis Author-X-Name-Last: Mitra Author-Name: Susanta Kumar Parui Author-X-Name-First: Susanta Kumar Author-X-Name-Last: Parui Title: A circularly polarized implantable rectenna for self-charging pacemaker Abstract: Pacemakers have existed for years for patients with heart failure to re-establish cardiac electrical pulses. However, the main complication related to a traditional pacemaker is its limited battery life. To circumvent such problems, wireless battery charging technology is one of the emergent applications for cardiac pacing. In this paper, an implantable rectenna, consisting of a circularly polarized (CP) monopole antenna, matching circuit and a rectifier, is proposed for pacemaker battery charging. To reduce the impedance mismatch loss, the matching network is incorporated between the antenna and the rectifier. A pair of T-shaped slots are introduced in the ground plane of the antenna to achieve the desired CP operation. The resonant frequency of the rectenna is 2.45 GHz with an impedance bandwidth of 28.45% and 5.73% 3 dB AR bandwidth. At −10 dBm input power, the rectenna output is 0.3 V with a rectenna efficiency of 41%. Journal: Journal of Electromagnetic Waves and Applications Pages: 1576-1588 Issue: 11 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2037107 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2037107 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:11:p:1576-1588 Template-Type: ReDIF-Article 1.0 Author-Name: Hasan Önder Yılmaz Author-X-Name-First: Hasan Önder Author-X-Name-Last: Yılmaz Author-Name: Fatih Yaman Author-X-Name-First: Fatih Author-X-Name-Last: Yaman Title: Reconstructions of effective parameters for a metamaterial antenna via 3D-printed components Abstract: This study presents the reconstruction of effective medium parameters for a double negative metamaterial slab from the knowledge of the measured/simulated S-matrix. The structure initially has been designed to embed into a patch antenna for a radar application. To observe the medium characteristics, we locate the slab in a rectangular waveguide for various orientations. The waveguide-based retrieval method is applied to find parameters regarding the biaxial anisotropic medium. Fundamental mode is used for the excitation. Additive printing technology is employed to manufacture a rectangular waveguide and its adapters for the experiments. The metallization is achieved by coating the printed structures with conductive thin layers. Experimental setups for each orientation are simulated as well. We illustrate good agreements between simulation and measurements under the fabrication tolerances. The feasibility and applicability of the additive printing technology for the investigations of the metamaterial anisotropic/bianisotropic nature is reported. Journal: Journal of Electromagnetic Waves and Applications Pages: 1613-1631 Issue: 11 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2037470 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2037470 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:11:p:1613-1631 Template-Type: ReDIF-Article 1.0 Author-Name: Fereshteh Salemi Author-X-Name-First: Fereshteh Author-X-Name-Last: Salemi Author-Name: Hamid Reza Hassani Author-X-Name-First: Hamid Reza Author-X-Name-Last: Hassani Author-Name: Sajad Mohammad-Ali-Nezhad Author-X-Name-First: Sajad Author-X-Name-Last: Mohammad-Ali-Nezhad Title: Mutual coupling reduction in linearly polarized compact extended C-shaped chipless RFID tag Abstract: Compact chipless RFID tags suffer from the mutual coupling between neighboring elements that have close resonant frequencies. In such tags, it is difficult for the words including zero bits to be detected by a reader, leading to false detection. In this paper, two techniques to reduce the mutual coupling effect based on rearrangement of the extended elements with reduced size are proposed. These techniques are applied to a compact chipless RFID tag, which has several nested C-shaped strips placed on both surfaces of the substrate. Top and bottom strips are connected through vias, and slots are placed in the middle of the bottom strips. The resonant frequencies are adjusted by varying the slot lengths in the first technique and variable vias position in the second technique. Through these techniques, the neighboring resonant frequencies can be placed farther apart. In doing so, the stability of the RCS frequency response is improved, which enables a reliable reading where zero bits are coded. For a 9-bit tag, the radius of the substrate is 7.8 mm, equivalent to 0.097λg operating over 2-9 GHz. A prototype is fabricated and measured. Journal: Journal of Electromagnetic Waves and Applications Pages: 1559-1575 Issue: 11 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2036252 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2036252 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:11:p:1559-1575 Template-Type: ReDIF-Article 1.0 Author-Name: Amar D. Chaudhari Author-X-Name-First: Amar D. Author-X-Name-Last: Chaudhari Author-Name: K. P. Ray Author-X-Name-First: K. P. Author-X-Name-Last: Ray Title: A compact five-element printed MIMO antenna with pattern and polarization diversity for 2.45 GHz WLAN applications Abstract: A five-element pattern and polarization (linear/circular) diversity multiple-input-multiple-output (MIMO) antenna system has been presented in this article for application in 2.45 GHz WLAN. The proposed configuration consists of a circularly polarized (CP) patch antenna element and four monopole antenna elements placed orthogonal to each other. Broadside CP characteristics are achieved by using a square patch antenna with circular chamfered corners and central axis feed. Simple rectangular monopole antenna elements with microstrip line feed produce four linearly polarized (LP) end-fire directive radiation patterns. It achieves a bandwidth (BW) of 24.1% and 5.1% for the end-fire LP antenna element and broadside CP antenna element (corresponding axial ratio BW is 1.64%), respectively, with minimum port isolation of 15 dB. The ECC and CLL are below 0.03 and 0.5 bits/s/Hz, respectively, showing good MIMO performance. Due to its simple design, compact footprint (93 × 93 mm2), planar structure, and competitive features, the proposed antenna is suited for practical WLAN applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1531-1543 Issue: 11 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2034128 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2034128 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:11:p:1531-1543 Template-Type: ReDIF-Article 1.0 Author-Name: Wenjun Zhu Author-X-Name-First: Wenjun Author-X-Name-Last: Zhu Author-Name: Lixin Guo Author-X-Name-First: Lixin Author-X-Name-Last: Guo Author-Name: Shaolin He Author-X-Name-First: Shaolin Author-X-Name-Last: He Title: Research on HF antenna blockage effects and their alleviation Abstract: In this paper, blockage effects on high-frequency antennas are studied and their influence on the voltage standing wave ratio, gain, and radiation patterns is analysed. By simulating different blockage effects, the relationship between the antenna and the size of the blockage is clarified. It finds that radiation patterns are usually affected more seriously than other coefficients. The impact on the pattern is greater if the size or height of the blockage is larger than half of the wavelength. Two methods relating to the modification of the angle and height of the antenna are proposed that can reduce the influence of blockage effects. These are verified using a simulation and one is further demonstrated using a practical application. Journal: Journal of Electromagnetic Waves and Applications Pages: 1544-1558 Issue: 11 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2036251 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2036251 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:11:p:1544-1558 Template-Type: ReDIF-Article 1.0 Author-Name: Vyacheslav V. Komarov Author-X-Name-First: Vyacheslav V. Author-X-Name-Last: Komarov Author-Name: Valeriy P. Meschanov Author-X-Name-First: Valeriy P. Author-X-Name-Last: Meschanov Author-Name: Nataliya F. Popova Author-X-Name-First: Nataliya F. Author-X-Name-Last: Popova Title: Extension of operating ranges of coaxial matched loads Abstract: The new coaxial matched load design with chip resistor and stepped transformer is described in this study. The proposed structure exhibits lower reflection and a wider range of operating frequencies than standard coaxial loads. Electromagnetic energy is absorbed in this design by a tantalum resistor on an Al2O3 substrate, which makes the manufacturing process simple and inexpensive. The reflection characteristics of the load under study were simulated numerically using a simplified model that included only the main parts of the load structure. Additional experimental studies made it possible to find the dimensions of the chip and other parts of the load design that provide improved electromagnetic characteristics. Journal: Journal of Electromagnetic Waves and Applications Pages: 1604-1612 Issue: 11 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2037469 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2037469 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:11:p:1604-1612 Template-Type: ReDIF-Article 1.0 Author-Name: Xu Han Author-X-Name-First: Xu Author-X-Name-Last: Han Author-Name: Xiaomin Luo Author-X-Name-First: Xiaomin Author-X-Name-Last: Luo Author-Name: Yanxiao Huang Author-X-Name-First: Yanxiao Author-X-Name-Last: Huang Author-Name: Zhaojun Zhu Author-X-Name-First: Zhaojun Author-X-Name-Last: Zhu Author-Name: Qiaoli Zhang Author-X-Name-First: Qiaoli Author-X-Name-Last: Zhang Author-Name: Zihao Feng Author-X-Name-First: Zihao Author-X-Name-Last: Feng Author-Name: Sipei Li Author-X-Name-First: Sipei Author-X-Name-Last: Li Author-Name: Shuai Ding Author-X-Name-First: Shuai Author-X-Name-Last: Ding Title: Design of high-power dual-frequency rectifier circuit Abstract: The microwave wireless power transmission system avoids the problems of large consumables, complex construction, and high maintenance costs caused by the cable. It can be seen that this method has specific demands and is worthy of deep research. This paper designs a high-power dual-frequency rectifier circuit that works at 1.15 and 1.7 GHz for wireless energy transmission. Using GaN HEMT as the rectifier, the output DC power reaches 6.5W, far beyond the conventional diode rectifier circuit in terms of power capacity. Journal: Journal of Electromagnetic Waves and Applications Pages: 1589-1603 Issue: 11 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2037108 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2037108 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:11:p:1589-1603 Template-Type: ReDIF-Article 1.0 Author-Name: D. Poljak Author-X-Name-First: D. Author-X-Name-Last: Poljak Author-Name: S. Antonijevic Author-X-Name-First: S. Author-X-Name-Last: Antonijevic Author-Name: E. K. Miller Author-X-Name-First: E. K. Author-X-Name-Last: Miller Title: Transient analysis of multiple straight wires in the presence of a half-space using different time-domain measures Abstract: The paper deals with a direct time-domain (TD) analysis of multiple wire configurations using various TD measures based on the energy stored in the near field. The currents along the wires are obtained solving the coupled Hallen integral equations. Once the current distribution is determined it is possible to calculate the charge via continuity equation. Knowing the distribution of current and charge along the wires, TD energy measures involving spatial integrals of squared values of transient current and charge, the energy stored in the electric and magnetic fields of wires are evaluated. Then total TD power measure defined as the time derivative of the total energy measure is computed. Finally, according to the definition stemming from the circuit theory the distribution of root-mean-square (RMS) values of transient current is calculated. Some computational examples for transient current, TD energy, and power measures, respectively, and RMS distribution along the wires are presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 1485-1530 Issue: 11 Volume: 36 Year: 2022 Month: 07 X-DOI: 10.1080/09205071.2022.2032842 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2032842 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:11:p:1485-1530 Template-Type: ReDIF-Article 1.0 Author-Name: Yilin Zhu Author-X-Name-First: Yilin Author-X-Name-Last: Zhu Author-Name: Qi Chen Author-X-Name-First: Qi Author-X-Name-Last: Chen Author-Name: Kun Li Author-X-Name-First: Kun Author-X-Name-Last: Li Author-Name: Wei Yang Author-X-Name-First: Wei Author-X-Name-Last: Yang Author-Name: Yun Huang Author-X-Name-First: Yun Author-X-Name-Last: Huang Title: Parameter identification of interior permanent magnet synchronous based on local search-based hybrid genetic algorithm Abstract: A hybrid genetic algorithm (Is-hGA) parameter identification method based on local search was proposed to solve the anti-salient characteristics of interior permanent magnet synchronous motor (IPMSM) and the defects of traditional genetic algorithm (GA) parameter identification method. In this hybrid optimization method, genetic algorithm is used for global search and hill-climbing algorithm is used for local search. This can not only improve the poor local search ability of genetic algorithm, but also greatly save calculation time. This method can identify four parameters of stator resistance, d-q axis inductance and permanent magnet flux linkage simultaneously. The performance of traditional GA and proposed Is-hGA in IPMSM parameter identification is compared by constructing an experimental platform. As a result, the proposed method can have more accurate identification precise. Journal: Journal of Electromagnetic Waves and Applications Pages: 1311-1322 Issue: 9 Volume: 36 Year: 2022 Month: 06 X-DOI: 10.1080/09205071.2021.2022004 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2022004 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:9:p:1311-1322 Template-Type: ReDIF-Article 1.0 Author-Name: Yuanyuan Li Author-X-Name-First: Yuanyuan Author-X-Name-Last: Li Author-Name: Guodong Han Author-X-Name-First: Guodong Author-X-Name-Last: Han Author-Name: Guoguang Cao Author-X-Name-First: Guoguang Author-X-Name-Last: Cao Author-Name: Xiaochong Zhang Author-X-Name-First: Xiaochong Author-X-Name-Last: Zhang Author-Name: Zhou Zhang Author-X-Name-First: Zhou Author-X-Name-Last: Zhang Title: A 2.5D miniaturized low-profile ultra-wideband band-stop frequency selective surface Abstract: This paper proposes a miniaturized UWB band-stop frequency selection surface based on metalized via technology, aiming at the problem of the large cell size and thick profile of the UWB band-stop frequency selection surface. By studying the principle of miniaturization of 2.5D frequency selective surface, a 2.5D ultra-wideband band-stop miniaturized frequency selective surface with high angular stability and low profile is designed. The simulation and test results show that the designed structure can cover the ultra-wideband frequency range of 2.36 GHz ∼ 11.36 GHz, the −10 dB percentage bandwidth is 161.9%, the unit size is $ 0.15\lambda \times 0.15\lambda $ 0.15λ×0.15λ, and the thickness is $ 0.009\lambda $ 0.009λ, where $ \lambda $ λ represents the resonance wavelength in free space. The maximum incident angle can reach 60 degrees for TE and TM polarization. Compared with the existing literature, the designed ultra-wideband band-stop miniaturization frequency selection surface miniaturization is better, and the profile is lower. Journal: Journal of Electromagnetic Waves and Applications Pages: 1212-1228 Issue: 9 Volume: 36 Year: 2022 Month: 06 X-DOI: 10.1080/09205071.2021.2011788 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2011788 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:9:p:1212-1228 Template-Type: ReDIF-Article 1.0 Author-Name: Anjitha Vadukkoot Author-X-Name-First: Anjitha Author-X-Name-Last: Vadukkoot Author-Name: Karella Ravi Shankar Author-X-Name-First: Karella Author-X-Name-Last: Ravi Shankar Author-Name: Sunitha Karakkad Author-X-Name-First: Sunitha Author-X-Name-Last: Karakkad Title: Influence of meteorological parameters on the propagation of lightning electromagnetic fields Abstract: Lightning electromagnetic field computation is essential in determining the impact of lightning discharge on various systems, equipment, and structures. In this regard, it is essential to know the factors affecting field propagation, and among these, the climatic conditions are essential to consider. This paper discusses the effect of different meteorological parameters on the propagation of lightning electromagnetic fields.The effect of temperature, vapor pressure, and relative humidity fluctuation on the change in the medium parameter is assessed, and the electric and magnetic field alteration is calculated. From the analysis, inconsequential variation is noted in permittivity for a temperature change from $ 5^{\circ } $ 5∘C to $ 100^{\circ } $ 100∘C and relative humidity from 0% to full saturation of 100%. Upon computing the variation in the field, the peak value of electric field and its time of arrival shows insignificant change. In line with this, the magnetic field propagation also remains unaffected by the weather conditions. Journal: Journal of Electromagnetic Waves and Applications Pages: 1323-1338 Issue: 9 Volume: 36 Year: 2022 Month: 06 X-DOI: 10.1080/09205071.2021.2024456 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2024456 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:9:p:1323-1338 Template-Type: ReDIF-Article 1.0 Author-Name: Han Wu Author-X-Name-First: Han Author-X-Name-Last: Wu Author-Name: Shijun Ji Author-X-Name-First: Shijun Author-X-Name-Last: Ji Author-Name: Ji Zhao Author-X-Name-First: Ji Author-X-Name-Last: Zhao Author-Name: Zhiyou Luo Author-X-Name-First: Zhiyou Author-X-Name-Last: Luo Author-Name: Handa Dai Author-X-Name-First: Handa Author-X-Name-Last: Dai Title: Design and analysis of a five-band metamaterial absorber Abstract: In the microwave band, we designed a new multi-band metamaterial absorber (MMA) consisting of a Buddhist logo metal resonator enclosed by a non-closed rectangular frame and a metal soleplate, separated by a dielectric layer. Through calculation, five near-perfect absorption peaks were obtained at 5.24, 8.84, 14.28, 15.96 and 18.6 GHz, with absorption rates of 96.39%, 98.13%, 98.26%, 98.07% and 99.75%, respectively. By analyzing the distribution of electromagnetic field and surface current, the absorption mechanism is further explored. Experimental results are consistent with the calculated results. Furthermore, how design parameters affect absorb property has been studied. The MMA has the characteristics of flexible structure and relatively higher absorption rates, which makes it have good potential in stealth materials, radar detection, electromagnetic sensing and other fields. Journal: Journal of Electromagnetic Waves and Applications Pages: 1273-1284 Issue: 9 Volume: 36 Year: 2022 Month: 06 X-DOI: 10.1080/09205071.2021.2020690 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2020690 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:9:p:1273-1284 Template-Type: ReDIF-Article 1.0 Author-Name: Raktim Guha Author-X-Name-First: Raktim Author-X-Name-Last: Guha Author-Name: Xin Wang Author-X-Name-First: Xin Author-X-Name-Last: Wang Author-Name: Xianfeng Tang Author-X-Name-First: Xianfeng Author-X-Name-Last: Tang Author-Name: Amit Kumar Varshney Author-X-Name-First: Amit Kumar Author-X-Name-Last: Varshney Author-Name: Sanjay Kumar Ghosh Author-X-Name-First: Sanjay Kumar Author-X-Name-Last: Ghosh Author-Name: Subrata Kumar Datta Author-X-Name-First: Subrata Kumar Author-X-Name-Last: Datta Author-Name: Michael A. Shapiro Author-X-Name-First: Michael A. Author-X-Name-Last: Shapiro Author-Name: Edl Schamiloglu Author-X-Name-First: Edl Author-X-Name-Last: Schamiloglu Author-Name: Zhaoyun Duan Author-X-Name-First: Zhaoyun Author-X-Name-Last: Duan Author-Name: B. N. Basu Author-X-Name-First: B. N. Author-X-Name-Last: Basu Title: Metamaterial assisted microwave tubes: a review Abstract: The paper has reviewed the worldwide attempts to improve the performance of microwave tube (MWT) interaction structures and MWTs employing them, accruing the exotic properties of metamaterials (MTMs). The review has encompassed the investigations based on theoretical study, using electromagnetic analysis and/or simulation, as well as experimental study. The success of and challenges to face in developing MTM assisted MWTs have also been highlighted. Journal: Journal of Electromagnetic Waves and Applications Pages: 1189-1211 Issue: 9 Volume: 36 Year: 2022 Month: 06 X-DOI: 10.1080/09205071.2021.2016499 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2016499 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:9:p:1189-1211 Template-Type: ReDIF-Article 1.0 Author-Name: Changsheng Liu Author-X-Name-First: Changsheng Author-X-Name-Last: Liu Author-Name: Zhuowei Li Author-X-Name-First: Zhuowei Author-X-Name-Last: Li Author-Name: Jianglan Bai Author-X-Name-First: Jianglan Author-X-Name-Last: Bai Author-Name: Jie Liang Author-X-Name-First: Jie Author-X-Name-Last: Liang Author-Name: Shuxu Liu Author-X-Name-First: Shuxu Author-X-Name-Last: Liu Title: Design of an airborne concentric frequency-domain electromagnetic induction system for shallow subsurface geophysical exploration Abstract: For the exploration of shallow and small subsurface targets, rigid-beam helicopter-borne electromagnetic systems are often inconvenient or costly, whereas man-portable or ground-based systems are difficult to operate in complex terrain. An airborne concentric frequency-domain electromagnetic system with an unmanned rotorcraft as a flying platform is proposed to avoid the problems of low security in conventional helicopter-borne electromagnetic method and low efficiency in ground-based electromagnetic method for the exploration of shallow subsurface targets. Compared with the series mode of man-portable system, the currents of transmitting and bucking coils are assumed to be separately and continuously adjustable, which can reduce sensitivity of the small errors of the system. In this paper, the principle of canceling the primary magnetic field is analyzed. The design index of the physical parameters of the sensor is determined. The simulation experiment of layered earth model is carried out to verify the feasibility of the proposed system. Journal: Journal of Electromagnetic Waves and Applications Pages: 1229-1243 Issue: 9 Volume: 36 Year: 2022 Month: 06 X-DOI: 10.1080/09205071.2021.2014362 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2014362 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:9:p:1229-1243 Template-Type: ReDIF-Article 1.0 Author-Name: Qian-Qian Li Author-X-Name-First: Qian-Qian Author-X-Name-Last: Li Author-Name: Hao Pan Author-X-Name-First: Hao Author-X-Name-Last: Pan Author-Name: Zhen-Hua Zhao Author-X-Name-First: Zhen-Hua Author-X-Name-Last: Zhao Author-Name: Hai-Feng Zhang Author-X-Name-First: Hai-Feng Author-X-Name-Last: Zhang Title: A circularly polarized antenna array with sequential-phase feed network Abstract: In this paper, a simple broadband circularly polarized (CP) patch antenna design is proposed. The antenna uses a 2 × 2 array fed by a sequential-phase feed network to improve the axial ratio (AR) bandwidth and gain, and an L-shaped slot is used to remove the coupling between the feed network and the radiation patches. Similarly, to reduce coupling, the height between two substrates is discussed as an important parameter. The proposed antenna is fabricated to verify the simulated results. Measured results show that the impedance bandwidth is 65.2% (1.68–3.31 GHz), the AR bandwidth obtained at the same time is 61.6% (1.86–3.39 GHz), and the effective relative bandwidth is 58% (1.86–3.31 GHz), and the peak gain is about 7.13 dBi at 2.7 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 1244-1256 Issue: 9 Volume: 36 Year: 2022 Month: 06 X-DOI: 10.1080/09205071.2021.2014363 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2014363 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:9:p:1244-1256 Template-Type: ReDIF-Article 1.0 Author-Name: Stepan Piltyay Author-X-Name-First: Stepan Author-X-Name-Last: Piltyay Title: Electromagnetic and bandwidth performance optimization of new waveguide polarizers with septum of a stepped-thickness type for satellite systems Abstract: Development and optimization of new waveguide polarizers with conducting stepped-thickness septum were performed in the article. Matching and polarization performance of novel microwave devices were accurately modelled using numerical finite elements method. An experimental prototype of the developed waveguide polarization converter with the suggested configuration of a septum was manufactured and measured. It was demonstrated that the application of a stepped-thickness conducting septum with 3 sections instead of a constant-thickness conducting septum improves return losses and cross-polarization isolation of the square waveguide polarization converter by 5 and 7 dB, respectively. In addition, measured cross-polarization isolation of the developed septum waveguide polarizer in an assembled antenna feed network is > 30 dB. Therefore, designed compact stepped-thickness septum polarization converter can be effectively applied in modern dual-polarization antenna systems for satellite communications and radar appliances. Journal: Journal of Electromagnetic Waves and Applications Pages: 1257-1272 Issue: 9 Volume: 36 Year: 2022 Month: 06 X-DOI: 10.1080/09205071.2021.2016500 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2016500 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:9:p:1257-1272 Template-Type: ReDIF-Article 1.0 Author-Name: Miraç Dilruba Geyikoğlu Author-X-Name-First: Miraç Dilruba Author-X-Name-Last: Geyikoğlu Author-Name: Bülent Çavuşoğlu Author-X-Name-First: Bülent Author-X-Name-Last: Çavuşoğlu Title: Microwave hyperthermia with X band flexible hyperthermia applicator for bone and joint cancer treatment Abstract: The microwave hyperthermia technique is proposed for bone and joint cancer with a flexible hyperthermia applicator operating in the X-band. The proposed approach consists of two steps. First, EM focus analysis is performed to optimize the phase value of antenna array elements’ excitation properties to concentrate the electromagnetic power at the tumor position while keeping the electromagnetic power level in healthy tissues at minimum values. Second, thermal analysis is performed by optimizing the amplitude value of the antenna elements’ excitation properties to achieve the required temperature at the tumor location. The proposed treatment technique is tested in a realistic simulation environment. The results obtained for different bone and joint models using the optimization technique for the excitation properties confirm the applicability of the proposed treatment method. In addition, the wideband frequency simulations show that frequencies around 10.4 GHz are the optimum values for treating bone and joint cancer. Journal: Journal of Electromagnetic Waves and Applications Pages: 1285-1297 Issue: 9 Volume: 36 Year: 2022 Month: 06 X-DOI: 10.1080/09205071.2021.2020691 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2020691 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:9:p:1285-1297 Template-Type: ReDIF-Article 1.0 Author-Name: Mekala Harinath Reddy Author-X-Name-First: Mekala Harinath Author-X-Name-Last: Reddy Author-Name: Chunwei Min Author-X-Name-First: Chunwei Author-X-Name-Last: Min Author-Name: Nick Howland Author-X-Name-First: Nick Author-X-Name-Last: Howland Author-Name: Nick R. Potts Author-X-Name-First: Nick R. Author-X-Name-Last: Potts Title: A high gain 16 × 16 Ka-band circularly polarized planar array antenna Abstract: In this article, a wide band circularly polarized microstrip array antenna with a gain of 26.5 dBiC at 29 GHz is developed and presented. The antenna structure contains six layers including the feeding and radiating layer. Modelling and experimental validations are performed on a 256 elements (16-by-16) antenna array. The proposed antenna comprises of corner truncated square patches that are fed at one feed point using the bottom layer corporate-feed network. The array exhibits S11<-10 dB over the frequency range 25–32.6 GHz (26.4%), axial ratio (AR) < 3 dB over 26.9–32 (17.3%) GHz and < 6° Half-Power Beamwidth (HPBW). The array antenna is fabricated through a multi-layer PCB process and has a size of 120 × 150 × 0.863 mm3. The measured results prove that the proposed antenna is a promising candidate for popular Ka-band applications like 5G and satellite communications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1298-1310 Issue: 9 Volume: 36 Year: 2022 Month: 06 X-DOI: 10.1080/09205071.2021.2022002 File-URL: http://hdl.handle.net/10.1080/09205071.2021.2022002 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:9:p:1298-1310 Template-Type: ReDIF-Article 1.0 Author-Name: Samuel Ngoho Author-X-Name-First: Samuel Author-X-Name-Last: Ngoho Author-Name: Mariam Dème Camara Author-X-Name-First: Mariam Dème Author-X-Name-Last: Camara Author-Name: Yuandan Dong Author-X-Name-First: Yuandan Author-X-Name-Last: Dong Author-Name: Alexandre Douyère Author-X-Name-First: Alexandre Author-X-Name-Last: Douyère Author-Name: Nour Mohammad Murad Author-X-Name-First: Nour Mohammad Author-X-Name-Last: Murad Author-Name: Preeti Thakur Author-X-Name-First: Preeti Author-X-Name-Last: Thakur Author-Name: Atul Thakur Author-X-Name-First: Atul Author-X-Name-Last: Thakur Author-Name: Rivo Randriatsiferana Author-X-Name-First: Rivo Author-X-Name-Last: Randriatsiferana Author-Name: Blaise Ravelo Author-X-Name-First: Blaise Author-X-Name-Last: Ravelo Title: S-matrix-based bandpass negative group delay innovative model of inverted parallel arm distributed topology Abstract: This paper develops an innovative model of bandpass (BP) negative group delay (NGD) inverted arm topology of parallel lines. The S-matrix model is established from impedance and admittance matrix operations of elementary transmission lines constituting the topology. Parametric analysis is performed to assess the influence of inverted arm structure sizes on the BP NGD specifications. To validate the theoretical concept, a proof of concept is designed in microstrip technology. The calculated and simulated results are in very good agreement. NGD value, center frequency and bandwidth of about −8 ns, 3.6 GHz and 4 MHz, respectively, are observed with insertion loss better than 1 dB and reflection loss better than 18 dB. The innovative NGD physical structure could be an important asset to reduce propagation delay in the upcoming telecommunications systems as the 5G system. Journal: Journal of Electromagnetic Waves and Applications Pages: 1745-1759 Issue: 12 Volume: 36 Year: 2022 Month: 08 X-DOI: 10.1080/09205071.2022.2043191 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2043191 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:12:p:1745-1759 Template-Type: ReDIF-Article 1.0 Author-Name: Vishakha Thakur Author-X-Name-First: Vishakha Author-X-Name-Last: Thakur Author-Name: Naveen Jaglan Author-X-Name-First: Naveen Author-X-Name-Last: Jaglan Author-Name: Samir Dev Gupta Author-X-Name-First: Samir Dev Author-X-Name-Last: Gupta Title: Side edge printed eight-element compact MIMO antenna array for 5G smartphone applications Abstract: A compact eight-element antenna array based on loop antennas to be utilized in 5G mobile applications is presented in this paper. The individual antenna elements are installed on the side frames of the main circuit board. The array operates over LTE 42 (3.4–3.6 GHz) band with a compact size of $ 9.5 \times 3 $ 9.5×3 mm $ ^{2} $ 2. The performance parameters that characterize the proposed array such as, isolation (>14.8 dB), Envelop correlation coefficient ( $ {\rm ECC}<0.1 $ ECC<0.1) are presented. The proposed array has decent channel capacity of 41 bps/Hz. The effects of installing battery and plastic frame have been discussed. In addition, the user's hand proximity effect on the proposed antenna array performance is presented. The array design was fabricated and its radiation characteristics are experimentally verified. The simulated and measured results are in good agreement with each other. Journal: Journal of Electromagnetic Waves and Applications Pages: 1685-1701 Issue: 12 Volume: 36 Year: 2022 Month: 08 X-DOI: 10.1080/09205071.2022.2040057 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2040057 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:12:p:1685-1701 Template-Type: ReDIF-Article 1.0 Author-Name: Dania Covarrubias-Martínez Author-X-Name-First: Dania Author-X-Name-Last: Covarrubias-Martínez Author-Name: Humberto Lobato-Morales Author-X-Name-First: Humberto Author-X-Name-Last: Lobato-Morales Author-Name: Juan M. Ramírez-Cortés Author-X-Name-First: Juan M. Author-X-Name-Last: Ramírez-Cortés Author-Name: Germán A. Álvarez-Botero Author-X-Name-First: Germán A. Author-X-Name-Last: Álvarez-Botero Title: Classification of plastic materials using machine-learning algorithms and microwave resonant sensor Abstract: The identification of different plastic materials in pellet form using a microwave negative-order-resonance sensor along with the evaluation of classification algorithms from machine learning is presented in this paper. Operation of the sensor is within the unlicensed ISM 2.5 GHz band, and identification of the materials is based on the measured resonant parameters from the sensor. Several classifiers are used to process the resonant parameters having uncertainty factors involved in pellet measurements (air gaps, pellet positions, dimensions and shapes), and performance comparison between the algorithms is carried out in terms of accuracy in the classification. Moreover, the presented measurement method is proposed as a fast, non-destructive, and low-power consumption way to identify plastic raw materials using a low-profile circuit having a high potential of being used in industrial processes. Journal: Journal of Electromagnetic Waves and Applications Pages: 1760-1775 Issue: 12 Volume: 36 Year: 2022 Month: 08 X-DOI: 10.1080/09205071.2022.2043192 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2043192 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:12:p:1760-1775 Template-Type: ReDIF-Article 1.0 Author-Name: Zhuopeng Wang Author-X-Name-First: Zhuopeng Author-X-Name-Last: Wang Author-Name: Zhen Zhang Author-X-Name-First: Zhen Author-X-Name-Last: Zhang Author-Name: Yan Hu Author-X-Name-First: Yan Author-X-Name-Last: Hu Author-Name: Hao Zhang Author-X-Name-First: Hao Author-X-Name-Last: Zhang Author-Name: Xia Wang Author-X-Name-First: Xia Author-X-Name-Last: Wang Title: Design of a novel compact and flexible chipless RFID tag based on an improved U-shaped resonator Abstract: Miniaturization, flexibility and high coding capacity design are very important while considering the development of chipless tags. In this paper, a flexible high-encoding capacity chipless radio frequency identification (RFID) tag with a compact structure is designed using Polyimide, a flexible material with high-temperature resistance as the substrate. The tag works in the band of 1.5∼10.5 GHz, the coding density of 4.348 bits/cm2 is obtained with four alternating nested improved U-shaped resonance structures. Frequency shift coding is realized by changing the structural parameters of the resonator. The production process is simple because only one conductive layer is needed. Because of its flexible and low-cost characteristics, it provides more possibilities for the promotion of RFID technology. A good agreement between simulation and measurement validates the feasibility of the design concept. Journal: Journal of Electromagnetic Waves and Applications Pages: 1672-1684 Issue: 12 Volume: 36 Year: 2022 Month: 08 X-DOI: 10.1080/09205071.2022.2038688 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2038688 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:12:p:1672-1684 Template-Type: ReDIF-Article 1.0 Author-Name: Praveen Kumar Author-X-Name-First: Praveen Author-X-Name-Last: Kumar Author-Name: Rashmi Sinha Author-X-Name-First: Rashmi Author-X-Name-Last: Sinha Author-Name: Arvind Choubey Author-X-Name-First: Arvind Author-X-Name-Last: Choubey Author-Name: Santosh Kumar Mahto Author-X-Name-First: Santosh Kumar Author-X-Name-Last: Mahto Title: A miniaturized rectangular shape narrowband MIMO antenna with reduced mutual coupling for C-band applications Abstract: A miniaturized rectangular shape narrow band multiple-input multiple-output (MIMO) antenna with I-shaped slot defected ground structure (DGS) for isolation improvement is discussed in this paper. To limit the surface waves between the adjacent patches, the DGS is etched between them. Antenna elements next to each other have a significantly reduced edge-to-edge spacing of 7.12 mm ( $ 0.18\lambda _{0} $ 0.18λ0). The complete size of the proposed MIMO antenna is $ 11.9 \times 18.9 \times 1.6\, {\rm mm}^{3} $ 11.9×18.9×1.6mm3. The MIMO antenna has a return loss less than $ -10 $ −10 dB over the operating band (7.41–7.91 Ghz ) with a lowest value of −46.77 dB. A comparative analysis of ECC (less than 0.32), DG (greater than 9.45), TARC (less than $ -5 $ −5 dB), and MEG (less than $ -3 $ −3 dB) are shown to validate the diversity performance of the proposed design. The performance parameters measured are in close agreement with the simulated result. The proposed MIMO antenna finds application in C band. Journal: Journal of Electromagnetic Waves and Applications Pages: 1717-1730 Issue: 12 Volume: 36 Year: 2022 Month: 08 X-DOI: 10.1080/09205071.2022.2041492 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2041492 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:12:p:1717-1730 Template-Type: ReDIF-Article 1.0 Author-Name: Budhadeb Maity Author-X-Name-First: Budhadeb Author-X-Name-Last: Maity Author-Name: Sisir Kumar Nayak Author-X-Name-First: Sisir Kumar Author-X-Name-Last: Nayak Title: Design of compact microstrip-fed triple-band slot antenna with defected ground structure for wireless communications Abstract: This article presents the design of a compact microstrip-fed triple-band slot antenna for WLAN/WiMAX/C-band downlink satellite communications. The newly designed proposed simple structure has a considerably high-center frequency ratio and can significantly suppress cross-polarization levels. This antenna consists of a double annular-ring slot (DARS), two L- and one I-shaped slot on the radiator, and an ellipse-shaped-slit (ESS) based defective ground structure (DGS) is imposed. Furthermore, to achieve a better impedance bandwidth and impedance matching, an insert-fed has been implemented on the proposed structure. The proposed antenna has the advantages of the easy tuned of individual resonant frequency and relatively simple antenna structure. The fabricated prototype resonates at 11.13% (2.257–2.523 GHz), 5.63% (3.455–3.655 GHz) and 6.05% (4.012–4.262 GHz) and gives a gain of 4.05, 2.52 and 2.15 dBi, respectively, and cross-polarization nearly −38.85 dB. The transmission line model of the proposed antenna is presented, and it shows the antenna behavior based on the effect of each element. It is observed that the characteristics of the RLC circuit model result is close to the simulated results using the CST simulator. Journal: Journal of Electromagnetic Waves and Applications Pages: 1702-1716 Issue: 12 Volume: 36 Year: 2022 Month: 08 X-DOI: 10.1080/09205071.2022.2041491 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2041491 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:12:p:1702-1716 Template-Type: ReDIF-Article 1.0 Author-Name: P. Prabhu Author-X-Name-First: P. Author-X-Name-Last: Prabhu Author-Name: S. Malarvizhi Author-X-Name-First: S. Author-X-Name-Last: Malarvizhi Title: 3D asymmetric super wide band (SWB) MIMO antenna system with band notch for antenna-in-package (A-I-P) applications Abstract: A UWB/SWB asymmetric 3D MIMO antenna with triple-band notch characteristics is proposed for Antenna-in-Package (A-I-P) applications. The proposed UWB/SWB radiators are placed on every side of a 3D cube-shaped polystyrene material. Each side of the cube contains two square UWB/SWB antennas with a hexagonal loop decoupling structure. Further, to reduce the mutual coupling between the radiators, each pair of antennas is placed asymmetrically on alternating sides of the cube block. The size of each pair of antennas is $ 30\,{\rm mm}\times 18\,{\rm mm}\times 1.6\,{\rm mm} $ 30mm×18mm×1.6mm, and the overall size of the antenna is $ 36\,{\rm mm}\times 36\,{\rm mm}\times 18\,{\rm mm} $ 36mm×36mm×18mm. The most significant properties of the antenna such as $ S_{{\rm ii}} $ Sii, $ S_{{\rm ij}} $ Sij, and radiation pattern are studied, Moreover, MIMO parameters such as ECC, DG, TARC, and CCL are analyzed. Therefore, the proposed asymmetric 3D antenna is suitable for off-device applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1656-1671 Issue: 12 Volume: 36 Year: 2022 Month: 08 X-DOI: 10.1080/09205071.2022.2038279 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2038279 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:12:p:1656-1671 Template-Type: ReDIF-Article 1.0 Author-Name: Anton S. Kupriianov Author-X-Name-First: Anton S. Author-X-Name-Last: Kupriianov Author-Name: Alexander Trubin Author-X-Name-First: Alexander Author-X-Name-Last: Trubin Author-Name: Vladimir R. Tuz Author-X-Name-First: Vladimir R. Author-X-Name-Last: Tuz Title: Coupling coefficient of two rotated cylindrical dielectric resonators disposed in free space Abstract: The coupled-mode theory is an established and important tool in the electromagnetic theory which describes the exchange of energy between modes of a given system. In the framework of this theory, the coupling coefficient is the main parameter that quantifies the intermode interaction strength. In this paper, we introduce practical formulas for calculating the mutual coupling coefficient between two cylindrical dielectric resonators arbitrarily oriented in free space relative to each other. The correctness of the solution is validated against the full-wave numerical simulations performed with the COMSOL Multiphysics electromagnetic solver. In particular, the obtained formulas are suitable to analyze the gain/directivity and transmission/reflection properties of dielectric antennas and metasurfaces consisting of a large but finite number of dielectric resonators. Journal: Journal of Electromagnetic Waves and Applications Pages: 1731-1744 Issue: 12 Volume: 36 Year: 2022 Month: 08 X-DOI: 10.1080/09205071.2022.2042859 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2042859 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:12:p:1731-1744 Template-Type: ReDIF-Article 1.0 Author-Name: S. I. Piltyay Author-X-Name-First: S. I. Author-X-Name-Last: Piltyay Author-Name: A. V. Bulashenko Author-X-Name-First: A. V. Author-X-Name-Last: Bulashenko Author-Name: Ye. I. Kalinichenko Author-X-Name-First: Ye. I. Author-X-Name-Last: Kalinichenko Title: Analysis of waveguide polarizers using equivalent network and finite elements methods Abstract: Current research is dedicated to the development of new theoretical model for guide polarization converter with irises. New created model is derived based on the equivalent circuits and transmission line representations. Specific feature of the model consists in the possibility of account of irises thickness in the simulations by approximate single-mode method. Using equivalent lumped elements of the circuits we obtained general scattering matrices of the polarization transformer for fundamental modes of vertical and horizontal linear polarizations. Besides, numerical simulations and optimization of the device were carried out by finite elements method. Good agreement of obtained optimal sizes and polarization characteristics is observed. Provided by the polarizer phase difference between two orthogonal polarizations falls within range 90°±5° in the operating Ku-band. Calculated ellipticity coefficient is better than 1.5 dB. Developed model can be applied for designing of new waveguide polarization converters, filters and other waveguide components with irises. Journal: Journal of Electromagnetic Waves and Applications Pages: 1633-1655 Issue: 12 Volume: 36 Year: 2022 Month: 08 X-DOI: 10.1080/09205071.2022.2037471 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2037471 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:12:p:1633-1655 Template-Type: ReDIF-Article 1.0 # input file: catalog-resolver602699808714026468.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220713T202513 git hash: 99d3863004 Author-Name: Shuvodip Majumdar Author-X-Name-First: Shuvodip Author-X-Name-Last: Majumdar Author-Name: Amitabha Bhattacharya Author-X-Name-First: Amitabha Author-X-Name-Last: Bhattacharya Title: A novel approach for approximating the average field diffracted from a double-layered dielectric wedge with Gaussian rough inner wedge face Abstract: This article studies the phenomenon of diffraction from a double-layered dielectric wedge that has roughness on the inner wedge face. For realizing the practical significance of this study, a hilly terrain may be imagined where the hills act as obstacles in the path of radiowave propagation and they are covered with snow or forest. Since generally, the hill surfaces are rough, these snow or forest covered hills can be approximated by double-layered dielectric wedges with a rough inner wedge face. Hence, this novel approach for approximating the average field diffracted from such wedges will be helpful to those involved in propagation channel modeling, especially for hilly and mountainous terrain. Journal: Journal of Electromagnetic Waves and Applications Pages: 1912-1923 Issue: 13 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2049895 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2049895 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:13:p:1912-1923 Template-Type: ReDIF-Article 1.0 # input file: catalog-resolver7806148056537697764.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220713T202513 git hash: 99d3863004 Author-Name: Nrusingha Charan Pradhan Author-X-Name-First: Nrusingha Charan Author-X-Name-Last: Pradhan Author-Name: Karthikeyan Sholampettai Subramanian Author-X-Name-First: Karthikeyan Author-X-Name-Last: Sholampettai Subramanian Author-Name: Rusan Kumar Barik Author-X-Name-First: Rusan Kumar Author-X-Name-Last: Barik Author-Name: Qingsha S. Cheng Author-X-Name-First: Qingsha S. Author-X-Name-Last: Cheng Title: A shielded QMSIW ultra-compact self-diplexing antenna for WiMAX/WLAN applications Abstract: In this contribution, novel design is presented for a very compact shielded quarter-mode substrate-integrated waveguide (S-QMSIW) based self-diplexing antenna (SDA) for WiMAX/WLAN applications. In order to achieve dual-band features, a slot is etched onto the top of the metal. Two orthogonal microstrip feed lines in the full-wave EM-simulator (HFSS) simulate the S-QMSIW resonator at two different frequencies (3.45 and 5.45 GHz). The proposed antenna pattern is extremely adaptable, allowing for simple frequency adjustments for each resonant frequency. A lumped circuit model is expected to be used to assess the antenna structure. A self-diplexing antenna based on S-QMSIW was designed, fabricated and tested to claim the proposed concept. At 3.45 and 5.45 GHz, the proposed antenna peak gains are 4.7 and 5.6 dBi, respectively. It offered port isolation better than 38 dB. The antenna front-to-back ratio was greater than 19.5 dB in each band. The proposed antenna circuit size was very compact ( $ 0.08\lambda _g^2 $ 0.08λg2). Journal: Journal of Electromagnetic Waves and Applications Pages: 1869-1881 Issue: 13 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2046179 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2046179 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:13:p:1869-1881 Template-Type: ReDIF-Article 1.0 # input file: catalog-resolver1435478194949745663.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220713T202513 git hash: 99d3863004 Author-Name: Jung-Hyeon Kim Author-X-Name-First: Jung-Hyeon Author-X-Name-Last: Kim Author-Name: Soo-Jin Joo Author-X-Name-First: Soo-Jin Author-X-Name-Last: Joo Author-Name: Yong-Hoon Kim Author-X-Name-First: Yong-Hoon Author-X-Name-Last: Kim Author-Name: Tae-Hoon Yoo Author-X-Name-First: Tae-Hoon Author-X-Name-Last: Yoo Title: Visualization of 5G antenna radiation characteristics using 3D printed models – focusing on busting the myths and finding out the truth about 5G health issues Abstract: The developments of mobile communication technology accompanied by increase in the number of high frequency bands and antennas, gave the public a negative perception that 5G is harmful to human health. Recently, rumors circulated on social media that 5G spreads COVID-19 and the pandemic. Leaving this situation untouched will hinder the successful landing of 5G and the development of 6G technology. Hence, the misunderstanding and groundless belief in 5G need to be corrected. We believe that misunderstanding and myths about 5G communications stem from fears of invisible electromagnetic waves. We visualize and compare the 5G and 4G antennas’ radiation properties by creating models with 3D printing technology to offer an intuitive impression of antenna characteristics and dispel the invisible fear. The radiation characteristics of the antennas used in 5G and 4G base stations and smartphones and their impacts on the human body are analyzed by using the electromagnetic simulator, HFSS. Journal: Journal of Electromagnetic Waves and Applications Pages: 1924-1934 Issue: 13 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2049896 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2049896 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:13:p:1924-1934 Template-Type: ReDIF-Article 1.0 # input file: catalog-resolver-4985518276310361043.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220713T202513 git hash: 99d3863004 Author-Name: Yunus Emre Yamac Author-X-Name-First: Yunus Emre Author-X-Name-Last: Yamac Author-Name: Ahmet Kizilay Author-X-Name-First: Ahmet Author-X-Name-Last: Kizilay Title: EFIE analyses of 3-D scattering from an object above arbitrarily rough periodic surfaces by current decomposition method Abstract: This paper addresses a three-dimensional scattering problem from a PEC object above a periodic conductive rough surface by using a decomposition method based on the separation of equivalent current density on the periodic surface as induced and perturbed current densities. The infinite solution domain is forcibly bounded by assuming that the perturbed current density caused by the object is intensively dominant in only a limited area on the periodic surface. The proposed decomposition method achieves considerable accuracy while providing an effortless computation without attempting a half-space Green's function or exercising a tapered wave illumination. This method provides a significantly superior solution to the tapered wave approach in illumination at low-grazing angles, although a plane wave is harnessed. Also, this proposed method can handle an arbitrary degree of roughness since the solution method does not contain an approximation of the surface roughness. Journal: Journal of Electromagnetic Waves and Applications Pages: 1882-1898 Issue: 13 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2046507 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2046507 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:13:p:1882-1898 Template-Type: ReDIF-Article 1.0 # input file: catalog-resolver8955949349225617318.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220713T202513 git hash: 99d3863004 Author-Name: Peiyu Wu Author-X-Name-First: Peiyu Author-X-Name-Last: Wu Author-Name: Xin Wang Author-X-Name-First: Xin Author-X-Name-Last: Wang Author-Name: Yongjun Xie Author-X-Name-First: Yongjun Author-X-Name-Last: Xie Author-Name: Haolin Jiang Author-X-Name-First: Haolin Author-X-Name-Last: Jiang Author-Name: Toshiaki Natsuki Author-X-Name-First: Toshiaki Author-X-Name-Last: Natsuki Title: Narrow-band anisotropic magnetized ferrite material simulation by approximate Crank–Nicolson procedure with improved nearly absorbing condition Abstract: To simulate magnetized ferrite with unique anisotropic property, unconditionally stable implementation is proposed with improved absorbing condition. To be more particular, unconditionally stable scheme is based on the Crank-Nicolson (CN) procedure with approximatefactorization-splitting (AFS) scheme, higher-order nearly perfectly matched layer (NPML) formulation and complex envelope (CE) method. Simulation formulation of anisotropic ferrite material is modified according to both CN procedure and CE method. The accuracy, efficiency and absorption can be demonstrated through numerical examples. Compared with the theory resolution and simulation results, the proposed scheme can receive considerable performance with larger CFLNs from the aspects of decreased error and enhanced accuracy. By employing the higher-order formulation, absorption can be improved significantly especially in the low-frequency band. It can also maintain the unconditional stability when the time step surpasses the stability condition. Most importantly, it can solve time increment problem among the implicit algorithms with lower CFLNs in narrow-band simulation. Journal: Journal of Electromagnetic Waves and Applications Pages: 1813-1837 Issue: 13 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2043782 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2043782 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:13:p:1813-1837 Template-Type: ReDIF-Article 1.0 # input file: catalog-resolver-485942788421042190.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220713T202513 git hash: 99d3863004 Author-Name: Julio R. Claeyssen Author-X-Name-First: Julio R. Author-X-Name-Last: Claeyssen Author-Name: Rosemaira Dalcin Copetti Author-X-Name-First: Rosemaira Author-X-Name-Last: Dalcin Copetti Author-Name: Daniela de Rosso Tolfo Author-X-Name-First: Daniela de Author-X-Name-Last: Rosso Tolfo Title: Waves and heaviside propagator in transmission lines Abstract: We characterize all plane and modal waves of lossy multiconductor lines. They are obtained by solving matrix dierential equations in closed-form. First-order and second-order telegraph formulations are considered. Wavesare described in terms of a scalar basis coupled with a nite number of matrixiterates. Modal waves are decomposed in forward and backward propagators. This decomposition can be applied in obtaining transmission and reection matrices at junctions. Eects due to initial, boundary or external inputs are described in terms of an integral contribution due to initial data, a convolution due to external disturbances and a bilinear term involving boundary values. For a two conductor transmission line satisfying the Heaviside condition, the fundamental response is obtained for the rst-order system and for the telegraph formulation. Numerical examples are given for lossy and lossless transmission lines and for determination of initial values of steady solutions. Journal: Journal of Electromagnetic Waves and Applications Pages: 1777-1812 Issue: 13 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2043781 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2043781 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:13:p:1777-1812 Template-Type: ReDIF-Article 1.0 # input file: catalog-resolver4710438655722120224.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220713T202513 git hash: 99d3863004 Author-Name: Zeeshan Zahid Author-X-Name-First: Zeeshan Author-X-Name-Last: Zahid Author-Name: Longyue Qu Author-X-Name-First: Longyue Author-X-Name-Last: Qu Title: A novel dual-loop ground-radiation antenna for circularly polarized GNSS applications Abstract: In this investigation, a circularly polarized (CP) dual-loop ground-radiation antenna has been proposed for GPS applications using a transverse loop and a longitudinal loop. The transverse loop is designed within an 8 mm × 4.5 mm (0.042λ × 0.024λ) clearance, installed at the horizontal edge of the ground plane for excitation of the ground mode along the y-axis, whereas a 1 mm × 10 mm (0.005λ × 0.053λ) longitudinal loop is etched at the vertical edge of the ground plane for excitation of the ground mode along the x-axis. In this way, the magnitudes and phases of the orthogonal components of the radiated electric field have been controlled independently, satisfying the CP conditions. The proposed antenna produced right-hand circular polarization towards the + z-axis, which has been verified using rectangular and square-shaped ground planes. Both simulation and measurement were conducted, and the measured axial ratio bandwidth with reference to 3 dB was 20 MHz (1.27%) while the impedance bandwidth with reference to −6 dB was 141 MHz (8.95%). Journal: Journal of Electromagnetic Waves and Applications Pages: 1838-1849 Issue: 13 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2044921 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2044921 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:13:p:1838-1849 Template-Type: ReDIF-Article 1.0 # input file: catalog-resolver7869075353538032151.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220713T202513 git hash: 99d3863004 Author-Name: Youngje Sung Author-X-Name-First: Youngje Author-X-Name-Last: Sung Title: A simple slot antenna for triple-polarization diversity application Abstract: A novel slot antenna with triple-polarization diversity is proposed in this paper. The proposed antenna consists of a circular slot that acts as a radiator, triple-microstrip line that acts as a feeding structure, a protruding stub, and slit applied to a GND. First, an antenna with dual-circular polarization (CP) characteristics is designed. The CP property is easily obtained using a protruding stub that acts as a perturbation in circular slots. The high isolation between two ports is achieved by the protruding stub and the slit applied to ground plane. From the measured results, the CP operating bandwidth is found to be 18.6%. The isolation is less than −14 dB within the operating bandwidth. Second, another feeding structure is implemented for linear polarization (LP). The measured CP bandwidth of the triple-polarization antenna is 12.7%, and isolation between ports is below −16.5 dB at the operating bandwidth. Journal: Journal of Electromagnetic Waves and Applications Pages: 1899-1911 Issue: 13 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2047113 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2047113 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:13:p:1899-1911 Template-Type: ReDIF-Article 1.0 # input file: catalog-resolver-698339206161116653.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220713T202513 git hash: 99d3863004 Author-Name: Amit Baran Dey Author-X-Name-First: Amit Baran Author-X-Name-Last: Dey Author-Name: Neelkamal Semwal Author-X-Name-First: Neelkamal Author-X-Name-Last: Semwal Author-Name: Wasim Arif Author-X-Name-First: Wasim Author-X-Name-Last: Arif Title: Design of a compact and efficient 2.4 GHz rectenna system for energy harvesting Abstract: This communication presents a coplanar waveguide fed rectenna system implemented for efficient Radio frequency energy harvesting at 2.4 GHz Bluetooth/WLAN applications engrossing an overall dimension of 40 × 35 mm2. The antenna is designed on a rectangular patch having four slots etched on the radiator. Also, the ground is introduced with edge slots that are close to the feed line to improve the overall impedance bandwidth providing a gain of 4.12dBi. The E-plane corresponding to the radiation showcases dipole characteristics while the H-plane follows an omnidirectional pattern. The rectifying part comprises a hybrid Tripler circuit which is well matched with the L-shaped input impedance such that most of the received power could be deliberated. The results have demonstrated that the designed rectenna exhibits high conversion efficiency of 66.7% and output DC voltage of 3.47 V for load values of 3 kΩ at 2.4 GHz under the input power of 5 dBm. Journal: Journal of Electromagnetic Waves and Applications Pages: 1850-1868 Issue: 13 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2045635 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2045635 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:13:p:1850-1868 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2054046_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Allam M. Ameen Author-X-Name-First: Allam M. Author-X-Name-Last: Ameen Author-Name: Mohamed I. Ahmed Author-X-Name-First: Mohamed I. Author-X-Name-Last: Ahmed Author-Name: Hala Elsadek Author-X-Name-First: Hala Author-X-Name-Last: Elsadek Author-Name: Wagdy R. Anis Author-X-Name-First: Wagdy R. Author-X-Name-Last: Anis Title: Design of 4-direction MIMO Vivaldi antenna system for vehicles communication in 5G applications Abstract: A MIMO antenna system that consists of four-element Vivaldi antenna for V2V communication is presented. The proposed design is realized on a substrate material of “Rogers 5880” with $ {\varepsilon _r} = 2.2 $ ϵr=2.2, $ \textrm{tan}\,\delta = 0.002 $ tanδ=0.002, and a substrate thickness equals $ 0.508\textrm{mm} $ 0.508mm. The antenna is designed to operate at a center frequency of $ 28\textrm{GHz} $ 28GHz. The designed antenna achieves a wide bandwidth of $ 1.57\textrm{GHz}({5.61\%} ) $ 1.57GHz(5.61%) around the center frequency. The radiation pattern of the proposed structure covers all the directions (a full $ {360^ \circ } $ 360∘ coverage area) with high gain. An overall realized gain of $ 9.68\textrm{dBi} $ 9.68dBi is achieved at the intended center frequency. The proposed antenna is designed and simulated using the Computer Simulation Technology MicroWave Studio software (CSTMWS). It is also fabricated using photolithography techniques and measured using an R&S vector network analyzer. Good agreement is obtained between both the CSTMWS and the measured results. Journal: Journal of Electromagnetic Waves and Applications Pages: 2027-2040 Issue: 14 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2054046 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2054046 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:14:p:2027-2040 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2050427_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Prabhakar Tripathi Author-X-Name-First: Prabhakar Author-X-Name-Last: Tripathi Author-Name: Arjun Kumar Author-X-Name-First: Arjun Author-X-Name-Last: Kumar Author-Name: Smrity Dwivedi Author-X-Name-First: Smrity Author-X-Name-Last: Dwivedi Author-Name: P. K. Jain Author-X-Name-First: P. K. Author-X-Name-Last: Jain Title: Efficiency enhancement of the reltron oscillator using four-grid asymmetrical RF interaction cavity Abstract: In this article, a modified reltron was proposed. Here an asymmetrical radio frequency (RF) modulation cavity interaction structure was used which consists of three coupled cavities instead of two used in the conventional reltron. Hence, instead of three grids in its modulation cavity, the proposed modified reltron structure consists of four grids. This additional grid inside the modulation cavity: distributes the length of the modulation cavity asymmetrically, which helps to form tight and dense electron bunches within the device. The proposed structure was designed and simulated using a CST Studio Suite. For the optimized grid spacing, the results of the PIC simulation showed the modified reltron was able to produce ∼350 MW power at 2.75 GHz frequency which was ∼100 MW more than the reltron. With the typically selected device's electric parameters the device efficiency was also found ∼41.2 % which was ∼11 % higher than previously reported results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1957-1967 Issue: 14 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2050427 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2050427 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:14:p:1957-1967 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2051756_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Wen-Ying Zhou Author-X-Name-First: Wen-Ying Author-X-Name-Last: Zhou Author-Name: Zhong-Lei Mei Author-X-Name-First: Zhong-Lei Author-X-Name-Last: Mei Author-Name: Mai Lu Author-X-Name-First: Mai Author-X-Name-Last: Lu Author-Name: Ya-Bo Zhu Author-X-Name-First: Ya-Bo Author-X-Name-Last: Zhu Title: Improved fully-connected neural network approach for decoupling microstrip antenna array design Abstract: This article presents an improved fully-connected neural network (FCNN) approach to design a decoupling microstrip antenna array. Through combing the advantage of waveguide (WG) structure and complementary double split ring resonator (CDSRRs), a novel decoupling structure is proposed, which can effectively suppress the mutual coupling between two close patches, and our improved FCNN can predict the geometry of the proposed antenna array to obtain the desired isolation. To demonstrate the validity and reliability of this method, the improved FCNN approach is used to predict the geometric parameters of the proposed antenna array when the distance of patch is reduced to 8 mm, 7mm and 6 mm. The measurement results of the predicted antenna arrays show that, their corresponding isolations are 51.16 dB, 41.99 dB and 42.43 dB respectively. The improved FCNN approach is proved to obtain the optimal isolation with lower computational complexity. Journal: Journal of Electromagnetic Waves and Applications Pages: 1996-2009 Issue: 14 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2051756 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2051756 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:14:p:1996-2009 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2052364_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Rodolfo Petrearce Author-X-Name-First: Rodolfo Author-X-Name-Last: Petrearce Author-Name: Caleb Rascon Author-X-Name-First: Caleb Author-X-Name-Last: Rascon Author-Name: Gabriel Eduardo Sandoval-Romero Author-X-Name-First: Gabriel Eduardo Author-X-Name-Last: Sandoval-Romero Title: Design and implementation of an acoustic wave measuring system based on a fiber optic sensor using multimodal interference Abstract: A system was developed that allows different acoustic parameters to be measured inside the frequency audio range and that can be used in different propagation mediums. A simple configuration of fiber optic sensors based on multimodal interference (MMI) is used, due to the advantages they provide. To perform a spatial and frequency filtering according to the characteristics of the source of interest, a beamformer is applied to the data obtained and then phase sensitive detection is used to obtain the resulting signal. The simulations were made by replicating the existing conditions in the experiments subsequently made in the laboratory. The system showed that the combination of the proposed techniques increases the signal-to-noise ratio even in cases where the ambient noise exceeds the signal of interest several times. Journal: Journal of Electromagnetic Waves and Applications Pages: 2010-2026 Issue: 14 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2052364 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2052364 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:14:p:2010-2026 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2049897_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Kalyan Sundar Kola Author-X-Name-First: Kalyan Author-X-Name-Last: Sundar Kola Author-Name: Anirban Chatterjee Author-X-Name-First: Anirban Author-X-Name-Last: Chatterjee Title: A highly-directive hybrid-fractal radiator-based printed array for X-band amateur radio applications Abstract: This article provides a 4-elements planar array of fractal patch antennas for X-band wireless communication, especially amateur-radio (10.00–10.50 GHz) applications. The single constituent of the indicated array is a freshly designed hybrid-fractal antenna with a modest gain and low cross-pol. level along the primary beam's path. The exhibited hybrid-fractal design was created using the Minkowski $ 1^{\rm st} $ 1st iteration, followed by a $ 50\% $ 50% scaling to a square geometry in the next stride. The compact planar array structure incorporates the Wilkinson power divider-based corporate feed network. The solo antenna built resonates at 10.02 GHz and offers 10.67 dBi of massive gain and 0.395 GHz of return-loss bandwidth, respectively. At 10.05 GHz resonating frequency, the array prototype gives 16.54 dBi absolute gain and 0.318 GHz impedance bandwidth. Printed prototypes achieved radiation efficiency of $ 96\% $ 96% and $ 86\% $ 86%, respectively. Both prototypes had computed aperture efficiency of $ 73\% $ 73% and $ 76\% $ 76%, respectively. There is a great deal of agreement between the prototypes' measured and simulated findings. Journal: Journal of Electromagnetic Waves and Applications Pages: 1935-1956 Issue: 14 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2049897 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2049897 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:14:p:1935-1956 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2051754_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: D. Tharani Author-X-Name-First: D. Author-X-Name-Last: Tharani Author-Name: K. Selvajyothi Author-X-Name-First: K. Author-X-Name-Last: Selvajyothi Author-Name: S. S. Karthikeyan Author-X-Name-First: S. S. Author-X-Name-Last: Karthikeyan Author-Name: R. K. Barik Author-X-Name-First: R. K. Author-X-Name-Last: Barik Author-Name: Q. S. Cheng Author-X-Name-First: Q. S. Author-X-Name-Last: Cheng Title: Compact HMSIW diplexer loaded with modified circular complementary split ring resonators for WiMAX /WLAN applications Abstract: The paper presents a miniaturized diplexer based on a half mode substrate integrated waveguide (HMSIW) loaded with a novel metamaterial unit cell. The proposed diplexer is implemented by cascading two HMSIW bandpass filters loaded with modified circular complementary split-ring resonators (MC-CSRRs) operating at distinct frequencies. The working principle behind the operation of diplexer is the theory of evanescent mode propagation that aids in the miniaturization of the diplexer in addition to the 50 % size reduction contributed by the HMSIW. The performance of the diplexer is investigated by varying the substrate thickness and substrate material. To authenticate the proposed idea, the diplexer operating at 3.5/5.8 GHz is designed using the full-wave simulator, fabricated and experimentally measured. The proposed diplexer yields the advantages of low insertion loss, smaller footprint, reasonable isolation and individual control of operating frequencies. A second-order diplexer is designed and simulated that results in improved isolation and selectivity. Journal: Journal of Electromagnetic Waves and Applications Pages: 1980-1995 Issue: 14 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2051754 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2051754 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:14:p:1980-1995 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2054730_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Abdullah Madni Author-X-Name-First: Abdullah Author-X-Name-Last: Madni Author-Name: Muhammad Rizwan Akram Author-X-Name-First: Muhammad Rizwan Author-X-Name-Last: Akram Author-Name: Kashif Riaz Author-X-Name-First: Kashif Author-X-Name-Last: Riaz Author-Name: Hamood Ur Rahman Author-X-Name-First: Hamood Ur Author-X-Name-Last: Rahman Author-Name: Mutee Ur Rehman Author-X-Name-First: Mutee Ur Author-X-Name-Last: Rehman Author-Name: Wasif Tanveer Khan Author-X-Name-First: Wasif Tanveer Author-X-Name-Last: Khan Author-Name: Muhammad Qasim Mehmood Author-X-Name-First: Muhammad Qasim Author-X-Name-Last: Mehmood Title: A compact high isolation wideband MIMO antenna for multi-band applications Abstract: Ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antennas promise a wide range of interesting applications in various radio frequency (RF) systems. However, the prime challenges in realizing such systems include achieving a wider bandwidth, significant isolation between the antennas and compactness. This research demonstrates a compact MIMO antenna having a prominent isolation level for portable UWB applications. The proposed antenna comprises two modified rectangular radiating elements with narrow slots in the ground plane, achieving an enhanced bandwidth from 2.1 to 16.9 GHz covering the S, C, X and Ku bands. Meanwhile, two inverted L-shaped stubs are introduced into the ground structure to obtain a higher isolation greater than 16 dB in the entire spectrum. The proposed antenna is of compact size (36 × 38 mm2) and exhibits excellent performance in terms of return loss, mutual coupling, envelope correlation coefficient (ECC), diversity gain (DG) and total active reflection coefficient (TARC). Journal: Journal of Electromagnetic Waves and Applications Pages: 2041-2054 Issue: 14 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2054730 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2054730 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:14:p:2041-2054 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2051755_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: C. P. do N. Silva Author-X-Name-First: C. P. do N. Author-X-Name-Last: Silva Author-Name: Moisés I. Espinosa-Espinosa Author-X-Name-First: Moisés I. Author-X-Name-Last: Espinosa-Espinosa Author-Name: Ignacio Llamas-Garro Author-X-Name-First: Ignacio Author-X-Name-Last: Llamas-Garro Author-Name: Jung-Mu Kim Author-X-Name-First: Jung-Mu Author-X-Name-Last: Kim Author-Name: M. T. de Melo Author-X-Name-First: M. T. Author-X-Name-Last: de Melo Title: Review of microwave frequency measurement circuits Abstract: In this work, microwave frequency measurement (MFM) is reviewed since the early stages using fully analog implementations, including its evolution to analog/digital implementations with high resolutions up to 1 MHz. The review includes fully digital implementations and microwave photonics techniques, with a discussion on achieved devices and the overall field of measuring and identifying unknown signals. Several microwave planar devices such as interferometers, filters, and frequency selective surfaces have been proposed to design low-cost and low-power digital MFM systems. The planar devices presented here show resolutions from 1 MHz to 940 MHz and operate in the frequency range from 0.15 GHz to 11.5 GHz, having typical bandwidths from 1 GHz to 2 GHz. MFM using microwave photonics techniques involve mapping the microwave signal into the optical spectrum to create a frequency-power function, that uniquely identifies the frequency of the unknown signal, with large bandwidths and immunity to electromagnetic interference. Journal: Journal of Electromagnetic Waves and Applications Pages: 2055-2087 Issue: 14 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2051755 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2051755 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:14:p:2055-2087 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2051211_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Pan Wang Author-X-Name-First: Pan Author-X-Name-Last: Wang Author-Name: Zhonggen Wang Author-X-Name-First: Zhonggen Author-X-Name-Last: Wang Author-Name: Yufa Sun Author-X-Name-First: Yufa Author-X-Name-Last: Sun Author-Name: Wenyan Nie Author-X-Name-First: Wenyan Author-X-Name-Last: Nie Title: A characteristic mode basis function method for solving wide-angle electromagnetic scattering problems Abstract: In the characteristic basis function method (CBFM) for the wide-angle electromagnetic scattering problems of electrically large objects, the low generation efficiency, and many characteristic basis functions exist due to the dependence on external excitation. This paper proposes a characteristic mode basis function method (CMBFM) with novel basis function construction to address this issue. In CMBFM, characteristic modes of each extended block obtained by dividing objects are calculated separately, and then the effective modes are selected as basis functions according to the modal significance. Compared with CBFM, the time performance of constructing basis functions is improved significantly. Furthermore, fewer basis functions are generated without a loss of accuracy. The corresponding numerical results demonstrate that significant efficiency and accuracy can be achieved by the proposed approach. Journal: Journal of Electromagnetic Waves and Applications Pages: 1968-1979 Issue: 14 Volume: 36 Year: 2022 Month: 09 X-DOI: 10.1080/09205071.2022.2051211 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2051211 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:14:p:1968-1979 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2070032_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Chengzhu Du Author-X-Name-First: Chengzhu Author-X-Name-Last: Du Author-Name: Xun Wang Author-X-Name-First: Xun Author-X-Name-Last: Wang Author-Name: Shunshi Zhong Author-X-Name-First: Shunshi Author-X-Name-Last: Zhong Title: A CPW-fed flexible ultra-wideband MIMO antenna based on liquid crystal polymer for IoT applications Abstract: In this study, an ultra-thin CPW-fed ultra-wideband flexible MIMO antenna for Internet of Things (IoT) applications is proposed. The antenna is etched on a liquid crystal polymer (LCP) substrate. Two antenna elements of the presented MIMO antenna are placed parallelly without an isolator. The measured S11 is less than −6 dB from 4.7 to 45 GHz, covering China’s 5G and 5G millimeter-wave bands. The measured S21 is less than −20 dB in most bands except 8.5–11.7 GHz, and the minimum |S21| is 15.7 dB at 10.5 GHz. In addition, the simulation and measurement results of flexible MIMO antenna indicate the antennas have good radiation characteristics, and the maximum gain can get 6.4 dB. Then ECC, DG and TARC are evaluated. The proposed antennas are suitable for 5G-enabled IoT applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 2198-2210 Issue: 15 Volume: 36 Year: 2022 Month: 10 X-DOI: 10.1080/09205071.2022.2070032 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2070032 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:15:p:2198-2210 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2061382_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Guanxia Yu Author-X-Name-First: Guanxia Author-X-Name-Last: Yu Author-Name: Xiaomeng Zhang Author-X-Name-First: Xiaomeng Author-X-Name-Last: Zhang Author-Name: Lei Feng Author-X-Name-First: Lei Author-X-Name-Last: Feng Author-Name: Shen Yu Author-X-Name-First: Shen Author-X-Name-Last: Yu Author-Name: Haodong Wang Author-X-Name-First: Haodong Author-X-Name-Last: Wang Author-Name: Guangyao Yuan Author-X-Name-First: Guangyao Author-X-Name-Last: Yuan Title: Tunable nonreciprocal transmission based on non-Hermitian optical system with magnetic optical materials in a one-dimensional multilayer structure Abstract: In this study, a one-dimensional composite structure composed of a PT-symmetric system and magnetic optical (MO) materials is designed. The nonreciprocal propagation of a one-dimensional multilayer structure is investigated both theoretically and numerically based on the transfer matrix theory. Different from the single nonreciprocal frequency in the parity-time (PT) system, two adjacent band gaps are changed into a pair of nonreciprocal bands under the effect of MO materials and a PT system above the PT exceptional point, and extraordinary transmissions are inspired in some nonreciprocal frequencies. At the same time, the nonreciprocal propagation bands can be tuned based on the different choices of external magnetic field directions. Furthermore, with an increase in the gain/loss factor, the two nonreciprocal band gaps both disappear and form two bands with an extraordinary transmission at certain frequencies. Such peculiar properties in the composite structure may have broad potential applications in communication and integration devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 2104-2114 Issue: 15 Volume: 36 Year: 2022 Month: 10 X-DOI: 10.1080/09205071.2022.2061382 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2061382 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:15:p:2104-2114 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2071176_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Honggang Hao Author-X-Name-First: Honggang Author-X-Name-Last: Hao Author-Name: Xuehong Ran Author-X-Name-First: Xuehong Author-X-Name-Last: Ran Author-Name: Yihao Tang Author-X-Name-First: Yihao Author-X-Name-Last: Tang Author-Name: Sen Zheng Author-X-Name-First: Sen Author-X-Name-Last: Zheng Title: Design of a high-efficiency thin-type metasurface hologram Abstract: To improve the imaging efficiency and reduce profile, a high efficiency, thin-type metasurface hologram based on induced magnetism is proposed. Both types of units consist of two asymmetric electric dipole elements printed on a thin-type dielectric substrate with only 1.3 mm thickness (λ0/6.4 at 36 GHz). By tuning the magnetic and electric responses, the transmitting phase of the units can be changed. Both types of units are designed to cover the quantized 2π phase range with the transmittance above 90%. Based on holographic theory, the target image field distribution and the incident plane wave can be regarded as object wave and reference wave respectively. A holographic metasurface is designed to record phase information of the target image. The simulation and experiment show that the designed metasurface can reproduce a clear image with a 65.86% imaging efficiency, which provides a new way to realize high-efficiency holographic imaging. Journal: Journal of Electromagnetic Waves and Applications Pages: 2227-2235 Issue: 15 Volume: 36 Year: 2022 Month: 10 X-DOI: 10.1080/09205071.2022.2071176 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2071176 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:15:p:2227-2235 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2070031_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: M. A. Al Imran Author-X-Name-First: M. A. Author-X-Name-Last: Al Imran Author-Name: E. Arık Author-X-Name-First: E. Author-X-Name-Last: Arık Author-Name: Y. Dalveren Author-X-Name-First: Y. Author-X-Name-Last: Dalveren Author-Name: M. B. Tabakcioglu Author-X-Name-First: M. B. Author-X-Name-Last: Tabakcioglu Author-Name: A. Kara Author-X-Name-First: A. Author-X-Name-Last: Kara Title: On the accuracy of an emitter localization method based on multipath exploitation in realistic scenarios Abstract: This study aims to evaluate the accuracy of a method proposed for passive localization of radar emitters around irregular terrains with a single receiver in Electronic Support Measures systems. Previously, the authors targeted only the theoretical development of the localization method. In fact, this could be a serious concern in practice since there is no evidence regarding its accuracy under the real data gathered from realistic scenarios. Therefore, an accurate ray-tracing algorithm is adapted to enable the implementation of the method in practice. Then, realistic scenarios are determined based on the geographic information system map generated to collect high-resolution digital terrain elevation data, as well as realistic localization problems for radar emitters. Next, simulations are performed to test the localization method. Thus, the performance of the method is verified for practical implementation in the electronic warfare context for the first time. Lastly, the performance bounds of the method are discussed. Journal: Journal of Electromagnetic Waves and Applications Pages: 2178-2197 Issue: 15 Volume: 36 Year: 2022 Month: 10 X-DOI: 10.1080/09205071.2022.2070031 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2070031 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:15:p:2178-2197 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2070033_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Guang-Dong Liu Author-X-Name-First: Guang-Dong Author-X-Name-Last: Liu Author-Name: Yan-Ling Hu Author-X-Name-First: Yan-Ling Author-X-Name-Last: Hu Author-Name: Jie Yin Author-X-Name-First: Jie Author-X-Name-Last: Yin Title: An improved contrast source inversion approach for the reconstruction of single-pole Cole–Cole model parameters Abstract: Single-pole Cole–Cole empirical models are often used for the high-precision description of the dispersion characteristics of common media, such as biological tissues, and water. The existing contrast source inversion (CSI) methods are not appropriate to reconstruct their frequency-dependent electrical properties. Therefore, one of them, a multi-frequency (MF) CSI method with a multiplicative regularization (MR), is modified from the direct estimation of the contrast between dispersive scatterers and their background medium, into the alternative reconstruction of three kinds of one-pole Cole–Cole model parameters, namely, the optical relative permittivity, relative permittivity difference, and static conductivity. Through two two-dimensional (2D) numerical experiments, the modified CSI method has been applied to detect breast tumors. The reconstructed results demonstrate preliminarily that the improved approach is feasible for the quantitative inversion of the internal breast compositions, and thus promising for breast cancer screening. Journal: Journal of Electromagnetic Waves and Applications Pages: 2211-2226 Issue: 15 Volume: 36 Year: 2022 Month: 10 X-DOI: 10.1080/09205071.2022.2070033 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2070033 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:15:p:2211-2226 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2060762_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Zhen Meng Author-X-Name-First: Zhen Author-X-Name-Last: Meng Author-Name: Changdi Liu Author-X-Name-First: Changdi Author-X-Name-Last: Liu Author-Name: Shijian Dong Author-X-Name-First: Shijian Author-X-Name-Last: Dong Author-Name: Xiasheng Shi Author-X-Name-First: Xiasheng Author-X-Name-Last: Shi Title: Robust widely linear beamforming method for non-circular signals Abstract: Widely linear beamforming is known to outperform the conventional adaptive beamforming by fully employing the non-circularity of non-circular signals. In this paper, a robust widely linear beamformer (WLB) is proposed to achieve satisfactory output and robustness in low computational complexity. The augmented signal-of-interest (SOI) covariance matrix is built by performing integration over SOI angular sector. The principal eigenvector of the augmented SOI covariance matrix is taken as the SOI extended steering vector. The received signal vector is projected into the interference-plus-noise subspace to remove the SOI component and derive the augmented interference covariance matrix. The augmented noise covariance matrix is added to the derived augmented interference covariance matrix so that the augmented interference-plus-noise covariance matrix can be reconstructed. The proposed WLB possesses lower computational complexity than the state-of-the-art WLBs due to the avoidance of convex optimization programming. Numerical simulations illustrate the effectiveness of the proposed WLB. Journal: Journal of Electromagnetic Waves and Applications Pages: 2089-2103 Issue: 15 Volume: 36 Year: 2022 Month: 10 X-DOI: 10.1080/09205071.2022.2060762 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2060762 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:15:p:2089-2103 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2067788_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Yuanpeng Yan Author-X-Name-First: Yuanpeng Author-X-Name-Last: Yan Author-Name: Zhuofeng Wu Author-X-Name-First: Zhuofeng Author-X-Name-Last: Wu Author-Name: Zhenyu Liu Author-X-Name-First: Zhenyu Author-X-Name-Last: Liu Title: An adaptive segmentation and template matching based on SSA for interference suppression in millimeter wave radar Abstract: The mutual interference between multiple-input multiple-output (MIMO) millimeter wave (mmWave) radars reduces the signal-to-noise ratio (SNR) of the target, which in turn affects the angle estimation of the target. The singular spectrum analysis (SSA) can be used to suppress the interference by signal reconstruction. However, when there is interference in the intermediate frequency (IF) signal, it is hard to select the principal components (PCs) to reconstruct the IF signal. Therefore, an adaptive segmentation and template matching based on SSA (ASTM-SSA) is proposed. In the adaptive segmentation, the IF signal is divided into interference and interference-free segments based on the location of the interference. In the template matching, the desired PCs of the interference-free segment are considered as the templates to match with PCs of the interference segment, and the matched PCs are used to reconstruct the IF signal. After all the interference are suppressed, the classical multiple signal classification (MUSIC) is performed to estimate the angle of the target. The simulation and field experiments are conducted to verify the effectiveness of the ASTM-SSA, and the results indicate that the ASTM-SSA can effectively suppress interference and accurately estimate the angle of the target. Journal: Journal of Electromagnetic Waves and Applications Pages: 2147-2163 Issue: 15 Volume: 36 Year: 2022 Month: 10 X-DOI: 10.1080/09205071.2022.2067788 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2067788 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:15:p:2147-2163 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2067008_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Nishant Shukla Author-X-Name-First: Nishant Author-X-Name-Last: Shukla Author-Name: Vikas Gupta Author-X-Name-First: Vikas Author-X-Name-Last: Gupta Author-Name: Praveen Ambati Author-X-Name-First: Praveen Author-X-Name-Last: Ambati Author-Name: M. Senthil Kumar Author-X-Name-First: M. Author-X-Name-Last: Senthil Kumar Author-Name: D. K. Singh Author-X-Name-First: D. K. Author-X-Name-Last: Singh Title: A method to improve the finite surface roughness of an LCP-based microstrip filter at Q-Band Abstract: In this paper, a 4-pole quasi-elliptic planar bandpass filter at Q-band on the liquid crystal polymer (LCP) is presented. The conventional design and development process of millimetre wave filters required to consider the surface roughness effects from the design stage for accurate development of filter at high frequency. Finite surface roughness of rolled copper and its impact on electrical performance are studied. Polishing is one of the methods to improve the conductor surface roughness. An improvement of 50% in surface roughness is reported for the rolled copper on the LCP, resulting in better than 1 dB insertion loss of the bandpass filter. Commensurate simulation and measurement results are presented. Journal: Journal of Electromagnetic Waves and Applications Pages: 2135-2146 Issue: 15 Volume: 36 Year: 2022 Month: 10 X-DOI: 10.1080/09205071.2022.2067008 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2067008 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:15:p:2135-2146 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2068076_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Rasoul Ebrahimzadeh Author-X-Name-First: Rasoul Author-X-Name-Last: Ebrahimzadeh Author-Name: Bijan Zakeri Author-X-Name-First: Bijan Author-X-Name-Last: Zakeri Author-Name: Amirashkan Darvish Author-X-Name-First: Amirashkan Author-X-Name-Last: Darvish Author-Name: Seyed Ehsan Hosseininejad Author-X-Name-First: Seyed Ehsan Author-X-Name-Last: Hosseininejad Title: Multi beam scanning programmable metasurface using miniaturized unit cells for 5G applications Abstract: This paper proposes a programmable reflective metasurface with a miniaturized unit cell that actively controls the scattered waves for achieving steerable multibeam radiation in sub-6 GHz 5G communication systems. The design uses array theory to provide the required phase shifts for various multibeam radiation patterns. The reconfigurability of the metasurface phase profile is attained by voltage-controlled varactor diodes embedded in the structure. Then, different unit cell arrangements are employed to achieve multibeam functionality where Pianoboard and Chessboard configurations provide one and two-dimensional multi beams, respectively. It turns out steerable multibeam radiation is achieved by dynamically change the dimension of the super unit cells. The reliability of the results is verified through analytical and numerical approaches. Moreover, the comparisons show that the proposed unit cell has more miniaturized size rather than the conventional cells, resulting in a better approximation for the ideally continuous phase profile identified by the generalized Snell’s law. Journal: Journal of Electromagnetic Waves and Applications Pages: 2164-2177 Issue: 15 Volume: 36 Year: 2022 Month: 10 X-DOI: 10.1080/09205071.2022.2068076 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2068076 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:15:p:2164-2177 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2065938_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220823T191300 git hash: 39867e6e2f Author-Name: Sergey A. Alekseytsev Author-X-Name-First: Sergey A. Author-X-Name-Last: Alekseytsev Author-Name: Victor V. Atuchin Author-X-Name-First: Victor V. Author-X-Name-Last: Atuchin Author-Name: Anatoly P. Gorbachev Author-X-Name-First: Anatoly P. Author-X-Name-Last: Gorbachev Author-Name: Yuriy N. Parshin Author-X-Name-First: Yuriy N. Author-X-Name-Last: Parshin Title: The center-end-fed dipole-like antenna excited by the cross-like reentrant in-phase power divider Abstract: The modified center-end-fed dipole-like antenna, that is fed by a novel in-phase reentrant power divider/splitter, is dwelt on in this study. Two energized splitter ports provide appropriate radiation patterns. A whole antenna prototype was simulated through the full-wave solver ‘CST Studio Suite’ and successfully implemented. The measured results confirm the proposed approach. In particular, the input reflection coefficient is less than (−10)dB in the frequency range of 0.761–0.796 GHz. Contrary to the conventional dipole antenna design, the proposed one has additional degrees of freedom, and that paves the way for the next generation of linearly polarized radiators for communication systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 2115-2134 Issue: 15 Volume: 36 Year: 2022 Month: 10 X-DOI: 10.1080/09205071.2022.2065938 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2065938 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:15:p:2115-2134 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2089600_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Abhishek Kumar Author-X-Name-First: Abhishek Author-X-Name-Last: Kumar Author-Name: Vishal Kesari Author-X-Name-First: Vishal Author-X-Name-Last: Kesari Title: Ultra-wideband TE0,1-mode dielectric window assisted with ring- based meta-surface Abstract: A novel concentric ring-based meta-surface assisted dielectric window is considered in the present study for examining its broadband response. The tolerable return loss in the Ka-Q band is taken as 20 dB for calculation of the bandwidth. The proposed window supports a bandwidth of 20.30 GHz (54.06%) for the TE0,1 mode. While comparing with a plane disk window, the bandwidth is increased by 17.55 GHz and 46.55%. On the other hand, compared with previously designed meta-surface assisted dielectric windows with square cross-sectional pillars without and with cylindrical tips, the bandwidth is increased by 1.1 GHz and 190 MHz, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 2463-2472 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2089600 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2089600 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2463-2472 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2080004_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Fatemeh Baraty Author-X-Name-First: Fatemeh Author-X-Name-Last: Baraty Author-Name: Samaneh Hamedi Author-X-Name-First: Samaneh Author-X-Name-Last: Hamedi Title: Design of a 2D photonic crystal biosensor using X-shape ring resonator based on Graphene Oxide (GO) for detection of blood components Abstract: Recent advances in photonic devices lead researches to be interested in designing all-optical biosensors as new alternatives to large laboratories. In this work, a two- dimensional photonic crystal biosensor based on Graphene Oxide (GO) is developed. The biosensing mechanism is based on the resonance wavelength shift due to refractive index changes of different blood components. The PhC waveguide is designed with an X-shape ring resonator and a hexagonal lattice of (GO) rods in the air background. In the proposed structure, the array of dielectric rods are with a total size of 21.4mm ×16.5 mm. For the optimized structure, the best calculated values of sensitivity (S), quality factor (Q), full width half maximum (FWHM), figure of merit (FOM), and transmission efficiency (TE) are 375 nm/RIU, 14665.8, 0.14nm, 2500 RIU-1, and 99.8% respectively. The important features of this biosensor are excellent FOM, acceptable sensitivity, and high transmission efficiency compared to other studies. Journal: Journal of Electromagnetic Waves and Applications Pages: 2401-2418 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2080004 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2080004 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2401-2418 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2088408_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Alireza Oruji Author-X-Name-First: Alireza Author-X-Name-Last: Oruji Author-Name: Ali Pesarakloo Author-X-Name-First: Ali Author-X-Name-Last: Pesarakloo Author-Name: Mohammad Khalaj-Amirhosseini Author-X-Name-First: Mohammad Author-X-Name-Last: Khalaj-Amirhosseini Title: Ultra-wideband bi-static RCS reduction with full angular stability using diffraction periodic symmetrical structures Abstract: In this paper, a planar, two-layer, and symmetrical structure is presented to obtain ultra-wideband bi-static RCS reduction with angular stability in azimuth and elevation directions. The proposed structure is composed of two layers. The bottom layer contains a periodic surface with periodicity larger than one wavelength to scatter multiple Floquet harmonic and thus bi-static RCS reduction. To achieve angular stability for the azimuth direction, the geometry of the unit cell is optimized with symmetry to its center. The top layer contains a substrate with high relative permittivity, which, according to refraction Snell’s law, increases the bandwidth of RCS reduction and contributes to angular stability regarding the elevation direction. The results show the RCS reduction by 10 dB over a wide frequency range from 4.2 GHz to 22.9 GHz (137%) at the normal incidence, and more than 80% for oblique incident waves within the $ 50^\circ $ 50∘ elevation angle range. Journal: Journal of Electromagnetic Waves and Applications Pages: 2450-2462 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2088408 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2088408 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2450-2462 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2095310_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: A. Nouainia Author-X-Name-First: A. Author-X-Name-Last: Nouainia Author-Name: F. Mejri Author-X-Name-First: F. Author-X-Name-Last: Mejri Author-Name: T. Aguili Author-X-Name-First: T. Author-X-Name-Last: Aguili Title: Analysis and optimization of electromagnetic leaks using genetic algorithms Abstract: The growth in the application of electronic devices across a broad spectrum of military, industrial, commercial and consumer sectors has created a new form of pollution known as noise or radio frequency interference or electromagnetic radiation or electromagnetic interference that can cause interference or malfunctioning of equipment. Therefore, there is a greater need for the effective shielding of components from its adverse effects. This review surveys the shielding materials like metals, for the control of electromagnetic radiations. These materials should exhibit effective shielding performance as well as other appropriate physical properties. To meet this challenge, in this article, a computer code based on a genetic algorithm is developed to optimize losses that come from the material surface. Journal: Journal of Electromagnetic Waves and Applications Pages: 2519-2535 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2095310 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2095310 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2519-2535 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2076158_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Tao Yin Author-X-Name-First: Tao Author-X-Name-Last: Yin Author-Name: DongYang Wu Author-X-Name-First: DongYang Author-X-Name-Last: Wu Author-Name: Ping Li Author-X-Name-First: Ping Author-X-Name-Last: Li Author-Name: Li Ding Author-X-Name-First: Li Author-X-Name-Last: Ding Title: Transmit–receive isolation improvement by a switch sequence adjustment for MMW linear-arrays imaging Abstract: High transmit-receive isolation between any two adjacent elements in sequentially switched linear arrays guarantees the performance of high-resolution close-range imaging. However, the transmit-receive antenna spacing required in wavelength order makes its isolation deteriorated rapidly in the millimeter wave and higher frequency bands. In this paper, we propose a simple yet effective method to improve transmit-receive isolation by a switch sequence adjustment on the traditional linear arrays. The new switch-mode aims to simply increase the vertical spacing between each transmit-receive pair. To maintain the densely uniform-spatial effective sampling and Fourier transform-based image reconstruction, the principle of equivalent phase center is utilized to analyze the maximum of the possible vertical spacing of each transmit-receive pair is four wavelengths. Experiments verify that the method can efficiently improve transmit-receive isolation by up to 11.5 dB and guarantee the high performance of MMW imaging. Journal: Journal of Electromagnetic Waves and Applications Pages: 2373-2383 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2076158 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2076158 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2373-2383 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2089917_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Kaijun Song Author-X-Name-First: Kaijun Author-X-Name-Last: Song Author-Name: Jia Liu Author-X-Name-First: Jia Author-X-Name-Last: Liu Author-Name: Kezhou Pu Author-X-Name-First: Kezhou Author-X-Name-Last: Pu Author-Name: Jialin Hu Author-X-Name-First: Jialin Author-X-Name-Last: Hu Title: Miniaturized cavity filters based on concentric dual-coaxial SIR Abstract: Two concentric dual-coaxial SIR filters with different structures are proposed. The first is that the upper resonant cap wraps the lower resonant cap; the second is that the cap of the upper resonator no longer wraps the lower resonator. The dual-coaxial quarter-wavelength SIR structure improves the anti-vibration capability of the resonator, and the structure makes full use of the resonator space and improves the unloaded Q value. The insertion loss of the first filter is less than 0.3 dB, and the insertion loss of the second filter is less than 1.5 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 2483-2495 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2089917 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2089917 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2483-2495 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2098539_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Sunay Güler Author-X-Name-First: Sunay Author-X-Name-Last: Güler Author-Name: Sibel Yenikaya Author-X-Name-First: Sibel Author-X-Name-Last: Yenikaya Title: Improving the shielding effectiveness of a rectangular enclosure by optimizing aperture and coating with graphene sheet Abstract: Incorporating an electric propulsion system into conventional vehicle electronic architecture makes electromagnetic compatibility (EMC) become one of the most important issues during electric vehicle design. Electromagnetic shielding is one of the compulsory preventions to protect electronic circuits against electromagnetic interference (EMI). However, apertures of the shielding enclosure reduce shielding effectiveness (SE) by permitting EMI leakage to affect the electronic circuits. When the dimensions of the enclosure remain fixed and the aperture has a particular area, studies such as optimization of the aperture dimensions or changing the enclosure material are essential. In this study, a genetic algorithm (GA) is designed initially, which improves SE by determining aperture dimensions on the front surface of the shielding enclosure. Then, obtained aperture dimensions are used in a numerical model in which the inner surfaces of the enclosure are coated with graphene sheets. It is observed that SE simulation results are in good agreement with measurement ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 2567-2581 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2098539 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2098539 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2567-2581 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2092037_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Govindam Sharma Author-X-Name-First: Govindam Author-X-Name-Last: Sharma Author-Name: Pankaj Kumar Author-X-Name-First: Pankaj Author-X-Name-Last: Kumar Author-Name: Akhlesh Lakhtakia Author-X-Name-First: Akhlesh Author-X-Name-Last: Lakhtakia Author-Name: Pradip Kumar Jain Author-X-Name-First: Pradip Kumar Author-X-Name-Last: Jain Title: Pixelated bicontrollable metasurface absorber tunable in complete X band Abstract: A pixelated bicontrollable metasurface tunable in the complete X band was designed with its meta-atoms comprising yttrium iron garnet (YIG)-patched pixels and conductive rubber (CR)-patched pixels on a metal-backed silicon substrate. Maximum absorptance of a normally incident plane wave greater than 0.99 is achievable and tunability with absorptance exceeding 0.9 is realizable, with the help of an external magnetostatic field and temperature. The YIG-patched pixels provide magnetostatic control modality with sensitivity of $ 0.04\,{\rm MHz}\,{\rm A}^{-1}\,{\rm m} $ 0.04MHzA−1m and the CR-patched pixels provide thermal control modality with sensitivity of $ 1\,{\rm MHz}\,{\rm K}^{-1} $ 1MHzK−1. The proposed metasurface absorber can be used to improve the performance of weather radar, police speed radar, and direct broadcast television. Journal: Journal of Electromagnetic Waves and Applications Pages: 2505-2518 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2092037 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2092037 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2505-2518 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2080592_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Md Danish Nadeem Author-X-Name-First: Md Danish Author-X-Name-Last: Nadeem Author-Name: Sanjeev Kumar Raghuwanshi Author-X-Name-First: Sanjeev Kumar Author-X-Name-Last: Raghuwanshi Title: Optimised design & analysis of high gain 3×3 square patch array antennas with six ports for airborne application in S-Band Abstract: The design and characteristic analysis of high isolation of 3×3 series feed square microstrip patch antenna array, having six ports, compromised with 3×3 edge feed square patches interconnected with each other are discussed in this paper. A sequential and simultaneous excitation occurs to each port/plane to achieve the beam scanning mechanism. Phase has varied each port to visualise the beam scanning phenomenon from −29.5° to +29.5°. The simulated and measured return loss result, gain profile, and radiation pattern are verified to prove the beam scanning range is ± 29.5°. The surface current distribution of each port of the proposed antenna array and the E-field and H-field radiation patterns was studied to evaluate the parameters such as reflection coefficient, individual port total gain, SLL (side lobe label),HPBW (half-power beamwidth) and FBR (front to back ratio). All vertical and horizontal ports were researched individually and together to understand the beam scanning mechanism. Journal: Journal of Electromagnetic Waves and Applications Pages: 2419-2434 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2080592 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2080592 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2419-2434 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2080003_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Praveen Chaurasia Author-X-Name-First: Praveen Author-X-Name-Last: Chaurasia Author-Name: Binod Kumar Kanaujia Author-X-Name-First: Binod Kumar Author-X-Name-Last: Kanaujia Author-Name: Santanu Dwari Author-X-Name-First: Santanu Author-X-Name-Last: Dwari Author-Name: Mukesh Kumar Khandelwal Author-X-Name-First: Mukesh Kumar Author-X-Name-Last: Khandelwal Title: Analysis and design of double negative metamaterial offering seven operating bands with minimum frequency ratio Abstract: A novel plus (+) shaped metamaterial’s (MTM) unit cell is introduced and investigated, which exhibits double negative (DNG) characteristics at seven different frequency bands of a minimal frequency ratio of 1.0953:1. DNG characteristics at seven bands are achieved in a dielectric substrate of dielectric constant 4.4. The permittivity (ε), permeability (μ) and refractive index n of the proposed MTM are extracted. Furthermore, circuit modeling of the introduced MTM is executed through transmission line theory and an equivalent circuit model (ECM) is realized for its theoretical analysis. The developed ECM is put through Keysight ADS™ software to verify the theoretical results. Dispersion equations of the invented MTM are also established, which figure out the zeroth-order frequency at its dominant mode. Simulation analysis is accomplished through Ansys HFSS™ software and both the theoretical and simulated results are verified by measured results of fabricated prototype. Journal: Journal of Electromagnetic Waves and Applications Pages: 2384-2400 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2080003 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2080003 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2384-2400 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2098063_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Kareem H. El-Gendy Author-X-Name-First: Kareem H. Author-X-Name-Last: El-Gendy Author-Name: Ahmed A. Abdel Aziz Author-X-Name-First: Ahmed A. Author-X-Name-Last: Abdel Aziz Author-Name: Mohamed F. Hagag Author-X-Name-First: Mohamed F. Author-X-Name-Last: Hagag Author-Name: Mahmoud A. Abdalla Author-X-Name-First: Mahmoud A. Author-X-Name-Last: Abdalla Title: A compact metamaterial SIW diplexer with transmission zeros Abstract: A compact low-loss microstrip diplexer with four controllable transmission zeros (TZs), all less than 41 dB, is presented. The diplexer circuit consists of two coupled gap bandpass filters with a T-junction as a combining circuit. Channels’ filters metalize SIW resonators loaded with metamaterial cells operated at zeroth order mode for compactness and low loss operation. For each channel, a fractional bandwidth of 1.9% is obtained. Also, two TZs at both sides of the resonant frequency are obtained by mixed electric and magnetic coupling between channels’ resonators. Design methodology for filtering response and placing TZs at certain frequencies are discussed in detail. There is a good agreement between simulation and measurement with isolation better than 40 dB. Moreover, the diplexer has a small size of (1.1×1.43 λg2). Lower and higher TZs are located at 4.75 and 5.69 GHz, for the lower channel, and at 5.4 GHz and 6.2 GHz for the higher channel, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 2536-2548 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2098063 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2098063 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2536-2548 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2101385_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Raghvenda Kumar Singh Author-X-Name-First: Raghvenda Kumar Author-X-Name-Last: Singh Author-Name: Ashish Gupta Author-X-Name-First: Ashish Author-X-Name-Last: Gupta Title: An asymmetric CPW-fed ultra miniaturized epsilon negative triple-band antenna with improved gain using complimentary closed ring resonators Abstract: In this paper, an ultra-miniaturized triple-band antenna based on an epsilon negative transmission line (ENG-TL) approach is presented. The proposed antenna has a miniaturized electrical size of 0.247λ0×0.185λ0×0.019λ0 at 3.71 GHz which has been achieved by means of zeroth-order resonance (ZOR). This is recognized as an attractive technique to achieve compactness. It is observed from measured results that the proposed antenna is performing well over 3.63–3.81, 5.21–5.33, and 6.79–7.09 GHz. The novelty of this work lies in the fact that the peak gain has been improved by 1.73 dBi at the lowest order resonant mode. The antenna is able to exhibit measured peak gain of 1.97, 1.09, and 3.42 dBi in the broadside direction at 3.72, 5.27, and 6.92 GHz, respectively. Hence proposed antenna is suitable to work for Wi-MAX 3.5 GHz (3.4–3.8 GHz), WLAN/Wi-Fi 5.2 GHz (5.15–5.35 GHz), mobile/satellite (E-S) (6.875–7.075 GHz) applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 2582-2599 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2101385 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2101385 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2582-2599 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2098538_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Zefei Sun Author-X-Name-First: Zefei Author-X-Name-Last: Sun Author-Name: Weiwen Li Author-X-Name-First: Weiwen Author-X-Name-Last: Li Author-Name: Qing Huo Liu Author-X-Name-First: Qing Huo Author-X-Name-Last: Liu Title: Judgment of mode crossing avoidance in characteristic mode analysis Abstract: The consistent interpretation of modes is crucial in characteristic mode analysis, which can usually be achieved by mode tracking algorithms. However, the problem of the eigenvalue crossing avoidance is still challenging to solve completely. In this paper, the possible causes of the eigenvalue crossing avoidance are discussed, and divided into two types. According to the characteristics of the modes with the cross avoidance, a comprehensive method for locating the frequency of crossing avoidance is first proposed. Since the crossing avoidance occurs in the case of degenerate mode coupling, the decoupling method is applied to eliminate the mode cross avoidance. Finally, the method’s effectiveness is verified by dealing with crossing avoidance problems of a rectangular conductor, dipole, and skewed plate structure. The proposed method is only related to the mode number to be discussed, and its calculation is time-saving. Journal: Journal of Electromagnetic Waves and Applications Pages: 2549-2566 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2098538 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2098538 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2549-2566 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2085632_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Hongling Wei Author-X-Name-First: Hongling Author-X-Name-Last: Wei Author-Name: Fuyi Cui Author-X-Name-First: Fuyi Author-X-Name-Last: Cui Author-Name: Weigang Guo Author-X-Name-First: Weigang Author-X-Name-Last: Guo Author-Name: Yinglai Wu Author-X-Name-First: Yinglai Author-X-Name-Last: Wu Author-Name: Jianxun Lu Author-X-Name-First: Jianxun Author-X-Name-Last: Lu Author-Name: Wenkang Huang Author-X-Name-First: Wenkang Author-X-Name-Last: Huang Author-Name: Libo Xu Author-X-Name-First: Libo Author-X-Name-Last: Xu Author-Name: Ruisi Li Author-X-Name-First: Ruisi Author-X-Name-Last: Li Author-Name: Chenxia Li Author-X-Name-First: Chenxia Author-X-Name-Last: Li Author-Name: Xufeng Jing Author-X-Name-First: Xufeng Author-X-Name-Last: Jing Title: Far-field scattering regulation of all dielectric material metagratings based on the addition principle of coding elements Abstract: The coding metasurface is a way of digital coding to simplify the design of the unit, which can control electromagnetic waves more simply and efficiently. To reduce ohmic losses and improve the efficiency of encoded metasurface devices, we propose all-dielectric encoded unit structure with silicon material. Based on the parameter scanning optimization method, we designed 1-bit coding unit, 2-bit coding unit and 3-bit coding unit. By rationally arranging these coding units, we construct coding metasurfaces with different sequences. In order to realize multi-angle and multi-function scattering control, we introduce the addition principle of digital codes. Two basic encoding sequences can be added to obtain a new added encoding sequence. The multi-angle and multi-function far-field control through digital code addition operation of two basic sequences of encoding metagratings can be obtained. Journal: Journal of Electromagnetic Waves and Applications Pages: 2435-2449 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2085632 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2085632 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2435-2449 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2089916_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: J. A. Ganie Author-X-Name-First: J. A. Author-X-Name-Last: Ganie Author-Name: K. R. Jha Author-X-Name-First: K. R. Author-X-Name-Last: Jha Author-Name: S. K. Sharma Author-X-Name-First: S. K. Author-X-Name-Last: Sharma Title: Sub-1 GHz and sub-6 GHz reconfigurable MIMO antenna with 28 GHz array on shared chassis for user equipment’s (UEs) Abstract: This paper presents the design of a co-located sub-1 GHz long-term evolution (LTE) and sub-6 GHz 5G band antennas implemented in multiple-input-multiple-output (MIMO) configuration. In addition, it demonstrates the integration of the millimetrewave (mm-wave) 5G band antenna arrays. Using the characteristic mode analysis (CMA), these antenna elements have been designed for the user equipment's (UEs) where they share the common ground plane of 150 mm × 70 mm size. Using the varactor and PIN diodes, band switching and frequency agility of the MIMO elements have been achieved to cover the 0.69–1.19 GHz, 2.29–3.29 GHz, 3.93–4.6 GHz, and 5.52–6.45 GHz bands with the S11 = −6.0 dB criterion. At each side of the structure, two 1 × 8 elements patch array antennas with the individual element fractional bandwidth (FBW) of 20.56% to cover 24.0–29.5 GHz band with the beam scanning angle of ±30° have been integrated. Journal: Journal of Electromagnetic Waves and Applications Pages: 2473-2482 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2089916 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2089916 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2473-2482 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2090285_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Li-Rong Tan Author-X-Name-First: Li-Rong Author-X-Name-Last: Tan Author-Name: Zhengquan Li Author-X-Name-First: Zhengquan Author-X-Name-Last: Li Author-Name: Weijia Duan Author-X-Name-First: Weijia Author-X-Name-Last: Duan Author-Name: Bin Gu Author-X-Name-First: Bin Author-X-Name-Last: Gu Author-Name: Zhaofeng Zhang Author-X-Name-First: Zhaofeng Author-X-Name-Last: Zhang Title: A novel dual-port dual-layer planar spiral slot multiband antenna Abstract: In order to realize a dual-port multiband antenna, a novel planar spiral slot antenna is proposed and analyzed. The antenna adopts a dual-layer substrate structure. A spiral slot is etched on its bottom metal surface with a ring gap beside the slot to improve the isolation and lower the frequency. An elliptical metal ring radiation unit in the middle surface of the antenna plays the role of radiating and impedance matching. Two mutually perpendicular microstrips on the upper surface are used for feeding the radiation unit. The simulation and test results show that two ports of the antenna can work at multiple frequencies with the same radiator, and the isolation is more than 13.5 dB in the working bands (1.86-1.99 GHz, 2.47-2.5 GHz, 2.57-2.64 GHz, 2.90-5.7 GHz and 6.35-9.66 GHz). The antenna has the advantages of high gain, small volume, quasi omnidirectional radiation, and so on. Journal: Journal of Electromagnetic Waves and Applications Pages: 2496-2504 Issue: 17 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2090285 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2090285 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:17:p:2496-2504 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2073475_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Ling Wang Author-X-Name-First: Ling Author-X-Name-Last: Wang Author-Name: Shuhui Yang Author-X-Name-First: Shuhui Author-X-Name-Last: Yang Author-Name: Li Zhang Author-X-Name-First: Li Author-X-Name-Last: Zhang Author-Name: Bin Li Author-X-Name-First: Bin Author-X-Name-Last: Li Title: Design of a compact quint-band bandpass filter using a symmetric dual-mode λ/4 resonator and a pair of inverted F-shaped resonators Abstract: In this paper, a compact quint-band microstrip bandpass filter (BPF) based on multiple mode resonating technology is proposed. It is composed of a symmetric dual-mode λ/4 resonator loaded with a shorted stub, two inverted F-shaped resonators, and two pairs of coupling configurations. To miniaturize the filter, the three resonators are bent and cross coupled together. Considering that the BPF has a symmetric structure, the even-odd mode analysis method is employed. On the basis of the simulation, the presented filter was fabricated by using a conventional PCB process with the substrate of Rogers RT/Duroid 5880. The measurement results are consistent well with the simulated data. The measured operating bands are centered at 1.8, 3.5, 4.5, 5.8 and 6.8 GHz, respectively, which are suitable for GSM, WiMAX, 5G, RFID and WiFi6 applications simultaneously. The measured in-band minimal return losses within five passbands are better than 15 dB. Furthermore, the filter exhibits a high selectivity with steep skirt property and the four band-to-band isolations among the five passbands are higher than 27 dB, and the out-of-band rejection is better than 25 dB. The filter’s total dimension occupies only 0.18λg × 0.15λg, where λg represents the free space wavelength corresponding to the center frequency of the lowest passband. Journal: Journal of Electromagnetic Waves and Applications Pages: 2289-2304 Issue: 16 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2073475 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2073475 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:16:p:2289-2304 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2071767_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: M. C. Kihal Author-X-Name-First: M. C. Author-X-Name-Last: Kihal Author-Name: H. Moulai Author-X-Name-First: H. Author-X-Name-Last: Moulai Author-Name: H. Azizi Author-X-Name-First: H. Author-X-Name-Last: Azizi Author-Name: C. Smartt Author-X-Name-First: C. Author-X-Name-Last: Smartt Author-Name: D.W.P. Thomas Author-X-Name-First: D.W.P. Author-X-Name-Last: Thomas Title: Sequential adaptive sampling based on cubic spline interpolation to accelerate the near field scanning Abstract: This paper describes a new automatic and adaptive sampling strategy to characterize radiated electromagnetic emissions. It is based on an optimized algorithm to accelerate near field scanning of printed and/or integrated circuits, electronic and/or power electronic systems. The algorithm sequentially defines where experimental measurements should be performed and which point must be captured. This approach is original; it combines both a deterministic mesh and a sequential scanning method enhanced by a cubic spline-based triangulation interpolation. This strategy seeks to decrease the time required to perform the electromagnetic compatibility (EMC) measurement without increasing the errors. This approach is applied to simulated and measured examples, which validates its effectiveness compared to the uniform grid sampling. Journal: Journal of Electromagnetic Waves and Applications Pages: 2237-2259 Issue: 16 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2071767 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2071767 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:16:p:2237-2259 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2076618_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Ajit Kumar Singh Author-X-Name-First: Ajit Kumar Author-X-Name-Last: Singh Author-Name: Santosh Kumar Mahto Author-X-Name-First: Santosh Kumar Author-X-Name-Last: Mahto Author-Name: Rashmi Sinha Author-X-Name-First: Rashmi Author-X-Name-Last: Sinha Title: Quad element MIMO antenna for LTE/5G (sub-6 GHz) applications Abstract: A quad-element multiple-input-multiple-output (MIMO) antenna with fractional bandwidth (FBW) of 52.42% (3.35–5.73 GHz) is proposed for LTE, WLAN (4.9/5 GHz), and 5G (sub-6 GHz) applications. The bandwidth is improved by introducing a tapered feed line and rectangular stubs in the partial ground plane. The maximum isolation of the proposed MIMO antenna is 27 dB. The diversity performance characteristics of the proposed antenna are studied in terms of the envelope correlation coefficient (ECC), diversity gain (DG), mean effective gain (MEG), total active reflection coefficient (TARC), isolation between the ports, and channel capacity loss (CCL) and the values obtained are 0.003, 9.98 dB, ±3 dB, −4 dB, −10 dB, and 0.10 bits/s/Hz respectively. A model of the proposed antenna is fabricated on the FR-4 substrate having a dielectric constant of 4.4 and a loss tangent of 0.02 with an electrical dimension of 0.45λ0 × 0.45λ0. The measured results demonstrate a decent likeness to simulated ones in the entire operating frequency range. Journal: Journal of Electromagnetic Waves and Applications Pages: 2357-2372 Issue: 16 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2076618 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2076618 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:16:p:2357-2372 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2074897_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Anıl Karatay Author-X-Name-First: Anıl Author-X-Name-Last: Karatay Title: A symmetrical self-diplexing microstrip antenna with eight-shaped defects Abstract: This article aims to demonstrate the simulation and measurement results of a two-port and symmetrical microstrip antenna operating at 6.6 and 7 GHz frequencies. The essential advantages of the antenna in terms of numerical electromagnetism are that the geometry has a small electrical length at both frequencies, does not use a structure that requires extra computational load such as substrate integrated waveguide, and is symmetrical, thus reducing the mesh requirement by half. The proposed antenna was manufactured with the chemical etching method and the measurement results were presented. In addition, varying operating frequencies are shown with the aid of liquid metal to experimentally demonstrate the independent redesign/reconfigurability feature of the antenna. To further reduce the fabrication cost, the manufacturing process of the proposed antenna with the help of a 3D printer is explained, and the performance parameters are compared. Good agreement between simulations and measurements has been reported. Journal: Journal of Electromagnetic Waves and Applications Pages: 2305-2319 Issue: 16 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2074897 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2074897 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:16:p:2305-2319 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2076159_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: R. Anandan Author-X-Name-First: R. Author-X-Name-Last: Anandan Author-Name: C. Annadurai Author-X-Name-First: C. Author-X-Name-Last: Annadurai Title: An ultrawideband miniaturized MIMO antenna with split ring Yagi like structures for S and X frequency multiband applications Abstract: A miniaturized three split ring-like Multiple-Input Multiple-Output (MIMO) antenna is presented for the S and X frequency band applications. The proposed antenna has been numerically investigated at operating frequency 1-15 gigahertz (GHz). The MIMO antenna is analyzed, and its prototype is measured in five types of structure to identify the effect of the split ring and other physical conditions. This antenna is fabricated on the FR- 4 substrates with a dimension of 25 mm × 40 mm which will provide the miniaturization factor of λ/2. The high gain of 6.61 dBi and an ultrawideband of 3.25 GHz is achieved by using split-ring resonators (SRRs) in the proposed miniaturized MIMO antenna structure. We have also analyzed the effect of the split rings on the overall radiation band and return loss on the S and X frequency band. Furthermore, the prototype measurement confirms the suggested antenna radiation characteristics. Journal: Journal of Electromagnetic Waves and Applications Pages: 2341-2356 Issue: 16 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2076159 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2076159 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:16:p:2341-2356 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2076157_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Y. Uma Maheswari Author-X-Name-First: Y. Author-X-Name-Last: Uma Maheswari Author-Name: A. Amudha Author-X-Name-First: A. Author-X-Name-Last: Amudha Author-Name: L. Ashok Kumar Author-X-Name-First: L. Author-X-Name-Last: Ashok Kumar Title: Noise mitigation in high-speed PCB applications: experimental verification and validation of electromagnetic band gap filters Abstract: Electromagnetic noise (EMI) affects efficiency of a gadget, proximity devices and human beings, necessitating the noise mitigation. Introduction of Electromagnetic Band Gap (EBG) structure in PCB as plane pairs helps for high-speed operations. In this paper, the planar L-bridge embedded pattern-type EBG structure is designed to mitigate the noise. Experimental verification of the designed EBG type with various geometrical parameters is carried out by altering the geometrical parameters of the unit cell with 18 cases. All the cases are simulated for the frequency sweep 0.1–10 GHz. Simulation results are compared with theoretical calculations and measurement results. It is found that they are in good agreement. The depth in noise levels can be efficiently altered by changing air gap, line length and unit cell width. In order to validate the EBG, a continuous plane is considered and found that EBG helps to mitigate the noise level in the higher frequency. Journal: Journal of Electromagnetic Waves and Applications Pages: 2320-2340 Issue: 16 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2076157 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2076157 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:16:p:2320-2340 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2072239_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Rimi Sengupta Author-X-Name-First: Rimi Author-X-Name-Last: Sengupta Author-Name: Ayan Chatterjee Author-X-Name-First: Ayan Author-X-Name-Last: Chatterjee Author-Name: Monojit Mitra Author-X-Name-First: Monojit Author-X-Name-Last: Mitra Author-Name: Soumen Banerjee Author-X-Name-First: Soumen Author-X-Name-Last: Banerjee Title: FSS superstrate loaded SIW circular cavity-backed cross-shaped slot antenna for wireless applications Abstract: In this paper, a low profile circular-shaped cavity-backed substrate integrated waveguide (SIW) antenna is designed and fabricated to operate at 5.38 GHz frequency in the U-NII-2B band in the dominant TM010 mode. A narrow cross-shaped slot is inserted in the ground plane of the parent antenna for radiation purposes. The antenna produces a gain of 4.7 dBi with an impedance bandwidth extending from 5.36–5.42 GHz. The gain of the antenna is augmented to 7.1 dBi through the use of a multi-layered cascaded frequency selective surface (FSS) as a superstrate. Arlon substrate materials are used to fabricate the antenna and frequency selective surface respectively. Parametric studies have been carried out in terms of return loss, antenna gain, and spacing between the antenna and FSS layer to obtain the best antenna results. All the simulation results have been carried out using HFSS v19.0. Both the simulated and the experimentally measured results show alike behavior. Journal: Journal of Electromagnetic Waves and Applications Pages: 2271-2288 Issue: 16 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2072239 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2072239 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:16:p:2271-2288 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2071768_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Khushbu Singh Raghav Author-X-Name-First: Khushbu Singh Author-X-Name-Last: Raghav Author-Name: Deepak Bansal Author-X-Name-First: Deepak Author-X-Name-Last: Bansal Title: Power optimization for self-sustained IoT enabled sensor nodes Abstract: Considering the reported existing harvested power in the microwatt (µW) range, IoT-enabled sensors cannot be operated self-sustainably pertaining to their high-milliwatt (mW) range power consumption. To mitigate this, circuit optimization and the use of deep sleep code were deployed leading to power reduction from 225 mW to 264 µW. Furthermore, an increase in the harvested power by changing the antenna design, from patch to horn has been demonstrated successfully. The horn antenna was designed and fabricated at 2.45 GHz for 15 dB gain. The analytical results show that the use of the horn antenna improves the harvested RF power by 15X compared to that of the patch antenna, which is enough for self-sustained sensor operation. Journal: Journal of Electromagnetic Waves and Applications Pages: 2260-2270 Issue: 16 Volume: 36 Year: 2022 Month: 11 X-DOI: 10.1080/09205071.2022.2071768 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2071768 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:16:p:2260-2270 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2105752_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Pravesh Pal Author-X-Name-First: Pravesh Author-X-Name-Last: Pal Author-Name: Rashmi Sinha Author-X-Name-First: Rashmi Author-X-Name-Last: Sinha Author-Name: Santosh Kumar Mahto Author-X-Name-First: Santosh Kumar Author-X-Name-Last: Mahto Title: A wideband omnidirectional planar filtenna for 5 GHz WLAN application Abstract: This paper presents a wideband planar filtenna based on the filter synthesis technique. The proposed filtenna consists of a third order hairpin line resonator filter coupled with an elliptical antenna. One arm of the last resonator of hairpin line resonator along with the extended feed arm of an antenna constitute an admittance inverter, which provides better integration between filter and antenna. The measured results show that the proposed filtenna exhibits a filtering response with impedance bandwidth of 26.5% (4.19–5.47 GHz), flat passband gain, good selectivity at band edges and omnidirectional radiation pattern well suited for WLAN application. Journal: Journal of Electromagnetic Waves and Applications Pages: 2697-2715 Issue: 18 Volume: 36 Year: 2022 Month: 12 X-DOI: 10.1080/09205071.2022.2105752 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2105752 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:18:p:2697-2715 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2106901_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Jie Yang Author-X-Name-First: Jie Author-X-Name-Last: Yang Author-Name: Shen Liu Author-X-Name-First: Shen Author-X-Name-Last: Liu Author-Name: Yue Liu Author-X-Name-First: Yue Author-X-Name-Last: Liu Author-Name: Bin Yang Author-X-Name-First: Bin Author-X-Name-Last: Yang Title: Dynamic stress intensity factor for periodic interfacial cracks in a bi-material half space disturbed by SH waves Abstract: The dynamic anti-plane properties of mode III interfacial collinear periodic cracks in a bi-material half space are investigated by the complex function and Green’s function methods. The responses of a rectangular domain under the action of an out-plane point source are solved, i.e. the required Green’s function is found. Periodic cracks at the interface are constructed by using the “cutting” method. Using the continuity conditions at the bi-material interface, the Fredholm integral equations of the first kind including the out-of-plane force system are established by the interface “conjunction” technique. Analytical expressions for the dynamic stress intensity factors (DSIFs) at crack tips are derived. Numerical analyses of DSIFs are conducted, and results discussed in depth. Journal: Journal of Electromagnetic Waves and Applications Pages: 2769-2784 Issue: 18 Volume: 36 Year: 2022 Month: 12 X-DOI: 10.1080/09205071.2022.2106901 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2106901 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:18:p:2769-2784 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2101386_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Srinivas Guthi Author-X-Name-First: Srinivas Author-X-Name-Last: Guthi Author-Name: Vakula Damera Author-X-Name-First: Vakula Author-X-Name-Last: Damera Title: Broadband and high gain circularly polarised truncated corner square patch metasurface antenna using aperture CPW feed Abstract: Broadband and the high gain circularly polarised antenna are designed in a single-layered planar substrate. An array of 3 × 3 truncated corner square patches are designed as a metasurface antenna on one side of the substrate and the metasurface antenna is fed by a stub-loaded uniform aperture CPW feed on another side of the substrate. In the metasurface antenna, the size of the central patch is increased for improving the bandwidth of impedance bandwidth and 3 dB axial ratio. Furthermore, the amount of truncation is reduced in the patches surrounding the central patch to enhance the bandwidth of impedance bandwidth and 3 dB axial ratio bandwidth. The designed metasurface antenna has achieved an impedance bandwidth of 38.2% (4.5–6.63 GHz) with an axial ratio bandwidth of 13% (5.0–5.7 GHz). Moreover, the antenna has a peak gain of 10.36dBic. The simulation and measurement results are compared. Journal: Journal of Electromagnetic Waves and Applications Pages: 2601-2613 Issue: 18 Volume: 36 Year: 2022 Month: 12 X-DOI: 10.1080/09205071.2022.2101386 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2101386 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:18:p:2601-2613 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2101387_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Piali Chakraborty Author-X-Name-First: Piali Author-X-Name-Last: Chakraborty Author-Name: Jyoti Ranjan Panda Author-X-Name-First: Jyoti Ranjan Author-X-Name-Last: Panda Author-Name: Arindam Deb Author-X-Name-First: Arindam Author-X-Name-Last: Deb Title: Design of a novel stub loaded asymmetric rectangular ring resonator based ultra-wide notched-band bandpass filter Abstract: This paper establishes a novel method to generate an ultra-wideband (UWB) bandpass filter (BPF) with four notches. Initially, this method employs a stub-loaded rectangular ring resonator (SLRRR) based compact structure to develop a UWB bandpass filter. Upgradation of the SLRRR structure into a stub-loaded asymmetric rectangular ring resonator (SLARRR) based structure in the next move facilitates the prospective filter with four notches at 4.34 GHz (S-band radar), 5.48 GHz (WLAN), 6 GHz (Wi-Fi 6E), and 9.3 GHz (X band radar) respectively possessing high rejection ability. This compact-sized (1.14λg × 0.29λg) proposed filter is characterized by a wide passband extending from 3.3 to 10.84 GHz with low insertion loss of <−0.69 dB, good selectivity of 0.8, and a 4.6 GHz wide upper stopband with −20 dB high rejection level. Structures are fabricated, measured, and compared with the obtained simulation outcomes. The resemblance between the compared results corroborates the applicability of such compact structure. Journal: Journal of Electromagnetic Waves and Applications Pages: 2614-2627 Issue: 18 Volume: 36 Year: 2022 Month: 12 X-DOI: 10.1080/09205071.2022.2101387 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2101387 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:18:p:2614-2627 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2103459_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Shreen El-Sapa Author-X-Name-First: Shreen Author-X-Name-Last: El-Sapa Author-Name: Kh. Lotfy Author-X-Name-First: Kh. Author-X-Name-Last: Lotfy Author-Name: A. El-Bary Author-X-Name-First: A. Author-X-Name-Last: El-Bary Title: Impact of laser short-pulse heating and variable thermal conductivity on photo-elasto-thermodiffusion waves of fractional heat excited semiconductor Abstract: The influence of laser short-pulse heating is utilized to investigate an elastic-mechanical-thermodiffusion (EMTD) model. The model is studied when the holes/electrons interaction of semiconductor medium is occurred with a fractional derivative of the heat equation. The governing equations describing this model are very complex, so they are studied in one dimension (1D) when the considered physical quantities are in a non-dimensional. In this case, the thermoelastic deformation (TD) due to the electronic deformation (ED) with some initial conditions is considered. Laplace transforms are used to analyze the governing equations mathematically when the thermal conductivity is variable. To obtain the complete solutions, the inverse Laplace transforms are used numerically based on the Fourier series with the application of some boundary conditions. Several comparisons of the wave propagation distribution of the fundamental fields are presented graphically according to different values of the fractional parameter, memories parameters, and thermal conductivity with discussion. Journal: Journal of Electromagnetic Waves and Applications Pages: 2628-2646 Issue: 18 Volume: 36 Year: 2022 Month: 12 X-DOI: 10.1080/09205071.2022.2103459 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2103459 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:18:p:2628-2646 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2107952_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Taner Oğuzer Author-X-Name-First: Taner Author-X-Name-Last: Oğuzer Author-Name: Deniz Kutluay Author-X-Name-First: Deniz Author-X-Name-Last: Kutluay Title: Localized Green's function using a beam-pattern for the fast modeling of 2D electromagnetic scattering Abstract: This study presents an alternative approach to the numerical solution of 2D electromagnetic scattering problems using a hybrid numerical technique based on a beam pattern function combined with the method of moments (MoM). A surface field distribution with finite width radiates outward, and it is used to define the new Green's function. This new Green's function has a beam aperture localized on the surface, and its beam width can be reduced to a few basis function levels by using a generalized pencil of beam function method (GPOF). This localization of the new Green's function brings to the sparsity in the main matrix. Then, the memory storage and the overall running times are reduced significantly by applying this localized radiation of Green's function. Numerical results have been presented in both polarizations for the single perfectly electrically conducting (PEC) strip geometry and 2D PEC objects with closed polygonal cross-sections such as square, triangle and arbitrary shapes. Journal: Journal of Electromagnetic Waves and Applications Pages: 2804-2826 Issue: 18 Volume: 36 Year: 2022 Month: 12 X-DOI: 10.1080/09205071.2022.2107952 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2107952 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:18:p:2804-2826 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2103460_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Evgenii Starodubtsev Author-X-Name-First: Evgenii Author-X-Name-Last: Starodubtsev Title: Electromagnetic waves in layered nanoresonator systems including bi-isotropic and metamaterial layers: analytical model and characteristic features of proper waves Abstract: The interaction of electromagnetic waves with multilayers of subwavelength thicknesses (nanoresonators) including the main layer made of a bi-isotropic material or metamaterial sandwiched between pairs of dielectric, epsilon-near-zero or metallic spacer layers has been modeled. The analytical model and numerical analysis are based on the exact and general solution of the electromagnetic boundary problem. The effects of birefringence, dichroism, chirality, nonreciprocity and new possibilities of their control and amplification, the conditions of excitation and features of proper waves inside of the bi-isotropic layer for various parameters of the nanoresonator geometry and components (in particular, metamaterials) and incident radiation are considered. It is shown that bi-isotropic effects in the one-layer chiral and nonreciprocal system can be significantly modified and amplified using the investigated nanoresonators. Journal: Journal of Electromagnetic Waves and Applications Pages: 2647-2671 Issue: 18 Volume: 36 Year: 2022 Month: 12 X-DOI: 10.1080/09205071.2022.2103460 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2103460 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:18:p:2647-2671 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2105753_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: T. Saiki Author-X-Name-First: T. Author-X-Name-Last: Saiki Author-Name: K. Ino Author-X-Name-First: K. Author-X-Name-Last: Ino Author-Name: M. Inada Author-X-Name-First: M. Author-X-Name-Last: Inada Title: Optimization on pole pitch of magnetic wheels and thickness of metal plate for floating and a propulsion system using permanent magnets Abstract: A magnetic-levitation system using a rotating permanent magnet has been developed. Pole pitch of the magnetic wheels and thickness of the metal plates required for levitation were investigated by experiments and computational calculation. To determine the optimum conditions, the levitation force, generated using motors with different torque and rotation speeds, was measured. These measurements clarified differences in the generated levitation force due to the different rotational speed and torque. Parameters, such as skin depth, magnetic density, eddy-current distribution density, the ratio of drag force to levitation force, and levitation force per driving power were numerically calculated from the magnetic field created by the rotating permanent magnet and effective frequency. Magnetic wheels should be designed to be large and the pole pitch of magnets was to be wide, and the levitation force per driving power will be improved in proportion to the root function of the pole pitch between magnets. Journal: Journal of Electromagnetic Waves and Applications Pages: 2716-2739 Issue: 18 Volume: 36 Year: 2022 Month: 12 X-DOI: 10.1080/09205071.2022.2105753 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2105753 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:18:p:2716-2739 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2104658_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Norsiha Zainudin Author-X-Name-First: Norsiha Author-X-Name-Last: Zainudin Author-Name: Tarik Abdul Latef Author-X-Name-First: Tarik Author-X-Name-Last: Abdul Latef Author-Name: Yoshihide Yamada Author-X-Name-First: Yoshihide Author-X-Name-Last: Yamada Author-Name: Kamilia Kamardin Author-X-Name-First: Kamilia Author-X-Name-Last: Kamardin Author-Name: Narendra Kumar Aridas Author-X-Name-First: Narendra Author-X-Name-Last: Kumar Aridas Author-Name: Nur Amalina Kamaruddin Author-X-Name-First: Nur Amalina Author-X-Name-Last: Kamaruddin Author-Name: Noorlindawaty Md Jizat Author-X-Name-First: Noorlindawaty Author-X-Name-Last: Md Jizat Title: Nearfield radio link of normal mode helical antenna for wireless capsule endoscopy Abstract: Wireless capsule endoscopy (WCE) is designed to monitor the physical data from inside human stomach and gastro intestine (GI) tract and transfer data to the receiver device. Normal mode helical antenna (NMHA) that has high efficiency at a small size is selected for WCE. To clarify the radio wave communication link budget in the dielectric environment is crucial. In this paper, NMHA for WCE system at 402 MHz along with a link budget analysis is presented. The transmitter uses NMHA embedded in a cylindrical phantom mimicking human stomach tissue, whereas the receiver uses another NMHA located outside the body. The NMHA dimension of height and diameter are 18 mm × 11 and 37 mm × 18 mm respectively. Through this study, a novel method of analytical equations for the radio wave communication link in human body are derived. From the good agreement between simulated and measured S21, the effectiveness of derived equations is ensured. Journal: Journal of Electromagnetic Waves and Applications Pages: 2672-2696 Issue: 18 Volume: 36 Year: 2022 Month: 12 X-DOI: 10.1080/09205071.2022.2104658 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2104658 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:18:p:2672-2696 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2106449_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Kegang Liu Author-X-Name-First: Kegang Author-X-Name-Last: Liu Author-Name: Qianzhong Xue Author-X-Name-First: Qianzhong Author-X-Name-Last: Xue Title: Characterization of dispersion-manipulation capability of periodic structure Abstract: Conventional analyses on dispersion tend to concentrate on the derivation and validation of closed-form solution, which is localized, viz. without an effective analysis pattern to uncover the full picture about dispersion space. This work shall provide a systematic treatment towards the panorama of dispersion space with the assistance of neural network. A thorough analysis pattern is presented to fully explore the dispersion space and gain some insight into it on the basis of several characterizations and rational-constrained analytic domain. The full picture of dispersion space and corresponding dispersion-manipulation capability are disclosed in this manner. The analysis pattern is of generality since the steps involved shall be easily transplanted to other periodic structures. Journal: Journal of Electromagnetic Waves and Applications Pages: 2756-2768 Issue: 18 Volume: 36 Year: 2022 Month: 12 X-DOI: 10.1080/09205071.2022.2106449 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2106449 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:18:p:2756-2768 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2107438_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Ghaleb Al-Duhni Author-X-Name-First: Ghaleb Author-X-Name-Last: Al-Duhni Author-Name: Nantakan Wongkasem Author-X-Name-First: Nantakan Author-X-Name-Last: Wongkasem Title: Metamaterial-inspired quintuple band printed patch antenna for dense communication networks Abstract: A compact 15 mm × 15 mm multi-band metamaterial-inspiredprinted antenna, composed of a simple microstrip antenna and a metamaterial superstate, is developed to accommodate nowadays advanced wireless communication devices and networks, where multi-functional tasks are simultaneously performed in different frequency ranges efficiently. A quintuple homocentric circular split ring resonator is explicitly designed as a band enhancer metamaterial superstate. The metamaterial geometry and orientation associated with the antenna location and radiating are optimized for the greatest consequence, where the resonances electrically and magnetically couple with the antenna radiation, generating quintuple bands in the X band: 8–12 GHz. The main lobe directions indicate an excellent directional propagation. This metamaterial-inspired antenna was designed and fabricated using a low cost commercial FR4 substrate offering a good cost margin for potential mass production. Four of five bands have a gain greater than 6dBi, which can be improved by using low-loss substrate. The measured and simulated results are in good agreement. Journal: Journal of Electromagnetic Waves and Applications Pages: 2785-2803 Issue: 18 Volume: 36 Year: 2022 Month: 12 X-DOI: 10.1080/09205071.2022.2107438 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2107438 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:18:p:2785-2803 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2106448_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Vangalla Veera Babu Author-X-Name-First: Vangalla Author-X-Name-Last: Veera Babu Author-Name: M. Thottappan Author-X-Name-First: M. Author-X-Name-Last: Thottappan Author-Name: Smrity Dwivedi Author-X-Name-First: Smrity Author-X-Name-Last: Dwivedi Title: Design and simulation investigations of a high gain millimeter wave gyro-twystron amplifier Abstract: In this paper, the design and multimode analysis of a single cavity Ka-band gyro-twystron have been presented. The present amplifier has been studied for its beam-wave interaction by using a nonlinear multimode analysis, which has also been verified with a 3D Particle-In-Cell (PIC) simulation. A single anode magnetron injection gun (MIG) has been designed with a ∼4% velocity spread using electron optics code. The PIC simulation of the current amplifier predicted an RF output power of ∼240 kW in TE01 mode at 35 GHz. The power gain, electronic efficiency, and 3-dB bandwidth were calculated as ∼53 dB, ∼37%, and ∼2 GHz, respectively, using the electron beam of 65 kV, 10 A with the velocity ratio of 1.4. Also, a collector is designed with a heat wall loading 0.116 kW/cm2 for the proposed design. Journal: Journal of Electromagnetic Waves and Applications Pages: 2740-2755 Issue: 18 Volume: 36 Year: 2022 Month: 12 X-DOI: 10.1080/09205071.2022.2106448 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2106448 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:36:y:2022:i:18:p:2740-2755 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2115947_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Bingyi Qian Author-X-Name-First: Bingyi Author-X-Name-Last: Qian Author-Name: Xiaoyu Huang Author-X-Name-First: Xiaoyu Author-X-Name-Last: Huang Author-Name: Xiaoming Chen Author-X-Name-First: Xiaoming Author-X-Name-Last: Chen Author-Name: Le Chang Author-X-Name-First: Le Author-X-Name-Last: Chang Author-Name: Kunpeng Wei Author-X-Name-First: Kunpeng Author-X-Name-Last: Wei Author-Name: Azremi Abdullah Al-Hadi Author-X-Name-First: Azremi Abdullah Author-X-Name-Last: Al-Hadi Author-Name: Ahmed A. Kishk Author-X-Name-First: Ahmed A. Author-X-Name-Last: Kishk Title: Wideband self-decoupled MIMO antenna element based on coupled-loop antenna for 5G smartphones Abstract: A novel wideband self-decoupled loop-coupled antenna element is proposed for the fifth-generation (5G) multiple-input multiple-output (MIMO) smartphones. The proposed loop-coupled antenna element generates two resonance modes of 0.75 and 1 λ. With the help of these two resonance modes, a wide bandwidth is achieved. The self-decoupled performance is realized by loading the loop antenna element with coupled lines. The common/differential mode theory is used to analyze and guide the antenna design to clarify the self-decoupling principle. At the same time, miniaturization of the proposed antenna element is also studied. The antenna element provides good isolation and diversity/multiplexing performances over N77/N78/N79 bands. An 8-port MIMO antenna is constructed using the proposed antenna element. The MIMO antenna is simulated, manufactured, and tested to verify and evaluate the performance metrics, such as isolation, envelope correlation coefficient, efficiency, and spatial multiplexing efficiency. The test results are in good agreement with the simulated ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 110-132 Issue: 1 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2115947 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2115947 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:1:p:110-132 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2109068_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Kundan Kumar Suman Author-X-Name-First: Kundan Kumar Author-X-Name-Last: Suman Author-Name: Ravi Kumar Gangwar Author-X-Name-First: Ravi Kumar Author-X-Name-Last: Gangwar Author-Name: Veer Singh Gangwar Author-X-Name-First: Veer Singh Author-X-Name-Last: Gangwar Title: A compact, low-profile, and high-performance monopulse antenna array for missile seeker Abstract: In this paper, the authors presented a compact, low-profile, and high-performance ku-band monopulse antenna array (MAA) for missile seekers with reduced complexity involved in fabrication, assembly, and installation. They investigated a multilayered microstrip patch Antenna technology by systematically developing an efficient synthesis process, high-performance design of radiating elements as well a feed network integrated with monopulse circuitry, and innovative multiple layered joining processes, which overcome limitations of the existing MAA system. Optimum aperture distribution corresponding to desired radiation characteristics is synthesized using a hybrid synthesis technique in which collapse distribution (CD) is employed to initialize the Genetic Algorithm (CD-AvGA). The authors designed the proposed MAA with computed coefficient and carried out fabrication, assembly, and functional validation. The obtained experimental results are in close agreement with simulated ones and satisfy the missile seeker’s stringent functional and platform requirements. Journal: Journal of Electromagnetic Waves and Applications Pages: 1-14 Issue: 1 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2109068 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2109068 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:1:p:1-14 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2111607_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Abhinav Bhardwaj Author-X-Name-First: Abhinav Author-X-Name-Last: Bhardwaj Author-Name: Dheeraj Pratap Author-X-Name-First: Dheeraj Author-X-Name-Last: Pratap Author-Name: Kumar Vaibhav Srivastava Author-X-Name-First: Kumar Author-X-Name-Last: Vaibhav Srivastava Author-Name: S. Anantha Ramakrishna Author-X-Name-First: S. Author-X-Name-Last: Anantha Ramakrishna Title: Analytical analysis of inhomogeneous and anisotropic metamaterial cylindrical waveguides using transformation matrix method Abstract: Several applications of a cylindrical waveguide filled with inhomogeneous materials have been demonstrated. Analytical solutions for modes, an inhomogeneous cylindrical waveguide, are available only for a few material parameters and those are also mostly approximations. We have obtained exact analytical solutions for cylindrical waveguides filled with different inhomogeneous and anisotropic material parameters. Different sets of material parameters are obtained using the geometric transformation method. The analytical and numerical modal field distributions, the value of cutoff frequencies and effective mode indices for different propagating modes are well matched to each other. The inhomogeneity can be used to miniaturize the radial dimensions of the waveguide. This is highly desirable for many applications like sensing, near-field coupling and magnetic resonance imaging (MRI). Journal: Journal of Electromagnetic Waves and Applications Pages: 53-68 Issue: 1 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2111607 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2111607 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:1:p:53-68 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2110948_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Shuqi Wang Author-X-Name-First: Shuqi Author-X-Name-Last: Wang Author-Name: Han Hao Author-X-Name-First: Han Author-X-Name-Last: Hao Author-Name: Xia Ma Author-X-Name-First: Xia Author-X-Name-Last: Ma Author-Name: Houyuan Cheng Author-X-Name-First: Houyuan Author-X-Name-Last: Cheng Author-Name: Xiaojun Huang Author-X-Name-First: Xiaojun Author-X-Name-Last: Huang Title: Wideband circularly polarized array antenna based on sequential phase feeding metasurfaces for 5G (sub-6G) applications Abstract: In this paper, a broadband circularly polarized array antenna is presented, which consists of four loop slot antennas based on metasurfaces. The antenna element is a loop slot antenna fed by a microstrip line. Cross slots are added to the loop slot to improve the antenna bandwidth, and four corner-cut square metasurfaces are loaded above it, thus generating circularly polarized radiation. The antenna adopts a sequential phase (SP) feed network to realize broadband characteristics. The antenna has been fabricated and experimented. The overall size of the antenna is 78 × 78 × 10.1 mm3 (approximately 1.22 λ0 × 1.22 λ0 × 0.15 λ0), the antenna array has a measured |S11| < −10 dB bandwidth of 3.6–6.2 GHz (53.1%) and a 3-dB axial ratio bandwidth of 3.7–4.8 GHz (28.32%). Furthermore, the antenna also has radiation with a peak gain of 5.5 dBi. Journal: Journal of Electromagnetic Waves and Applications Pages: 15-24 Issue: 1 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2110948 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2110948 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:1:p:15-24 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2113444_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: C. C. Chiu Author-X-Name-First: C. C. Author-X-Name-Last: Chiu Author-Name: T. H. Kang Author-X-Name-First: T. H. Author-X-Name-Last: Kang Author-Name: P. H. Chen Author-X-Name-First: P. H. Author-X-Name-Last: Chen Author-Name: H. Jiang Author-X-Name-First: H. Author-X-Name-Last: Jiang Author-Name: Y. K. Chen Author-X-Name-First: Y. K. Author-X-Name-Last: Chen Title: Comparison of U-Net and OASRN neural network for microwave imaging Abstract: U-Net and Object-Attentional Super-Resolution Network (OASRN) neural network for electromagnetic imaging are compared and investigated in this paper. The outcome shows that though under limited training data, the regeneration capability is still highly reliable. We first transmit the electromagnetic waves to the scatterer and use the received scattered field information to calculate the estimated permittivity distribution by Green’s function, subspace method and Dominant Current Scheme (DCS). The estimation technique can effectively reduce the training process of the neural network modules. Next, we train the U-Net and OASRN modules for real-time images. Lastly, we used Root Mean Square Error (RMSE) and Structural Similarity Index Measure (SSIM) to compare and analyze the reconstructed images of the two neural networks. Numerical results show that the reconstructed image by OASRN is better than that by U-net with 5% or 20% Gaussian noise for different dielectric constant distributions. Journal: Journal of Electromagnetic Waves and Applications Pages: 93-109 Issue: 1 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2113444 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2113444 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:1:p:93-109 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2111280_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Guan-Ren Su Author-X-Name-First: Guan-Ren Author-X-Name-Last: Su Author-Name: Eric S. Li Author-X-Name-First: Eric S. Author-X-Name-Last: Li Author-Name: Huayan Jin Author-X-Name-First: Huayan Author-X-Name-Last: Jin Author-Name: Pei-Hsin Hsu Author-X-Name-First: Pei-Hsin Author-X-Name-Last: Hsu Author-Name: Jwo-Shiun Sun Author-X-Name-First: Jwo-Shiun Author-X-Name-Last: Sun Author-Name: Kuo-Sheng Chin Author-X-Name-First: Kuo-Sheng Author-X-Name-Last: Chin Title: 79-GHz SIW slot-coupled patch antenna array with low cross polarization and wide beamwidth Abstract: A 79-GHz wide-beam patch antenna and 1×8 antenna array with low cross-polarization levels are presented for automotive radar applications. A substrate-integrated-waveguide slot-coupled scheme was employed to reduce the cross-polarization level of the patch antenna. Two parasitic elements were added to the main patch to form a three-element subarray for beamwidth enhancement. The simulated E-plane half-power beamwidth (HPBW) of the patch antenna is 148°, and the cross-polarization level is 32.5 dB less than the co-polarization level at the boresight direction. For further gain enhancement, a 1×8 patch array was designed and fabricated. The measured results show that the proposed design can offer a wide HPBW of 144° and a low cross-polarization level of 28.3 dB less than the co-polarization level at 79 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 38-52 Issue: 1 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2111280 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2111280 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:1:p:38-52 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2110949_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Baojun Li Author-X-Name-First: Baojun Author-X-Name-Last: Li Author-Name: Haorang Hua Author-X-Name-First: Haorang Author-X-Name-Last: Hua Author-Name: Jianjian She Author-X-Name-First: Jianjian Author-X-Name-Last: She Author-Name: Jiangwei Chen Author-X-Name-First: Jiangwei Author-X-Name-Last: Chen Title: Tunable transmission of a normal incidence through a double-slab structure Abstract: In this work, a double-slab structure is proposed, in which one slab is made of near-zero-real-part-of-impedance metamaterial (NZRPIM), and the other slab is made of ordinary transparent material. We shall demonstrate that, when a beam of electromagnetic wave is normally incident into the double-slab structure, the transmission may be enhanced significantly due to existence of a cross term induced by coherent superposition between forward and backward waves arising in the NZRPIM slab, thus the corresponding transmission peak may be strongly affected by the other slab and fluid arising between the two slabs, which is instructive significance for the design and application of high sensitivity refractive index sensor based on electromagnetic wave intensity detection. Our work may provide a new possible way to design and manufacture sensors by using NZRPIM. Journal: Journal of Electromagnetic Waves and Applications Pages: 25-37 Issue: 1 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2110949 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2110949 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:1:p:25-37 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2112762_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Ramyakrishna Enugonda Author-X-Name-First: Ramyakrishna Author-X-Name-Last: Enugonda Author-Name: V. K. Anandan Author-X-Name-First: V. K. Author-X-Name-Last: Anandan Author-Name: Basudeb Ghosh Author-X-Name-First: Basudeb Author-X-Name-Last: Ghosh Title: Higher order spectral analysis of weather signals Abstract: Higher Order Spectral Analysis (HOSA) is very useful technic for analysing the statistical relationships between spectral components and their distribution. HOSA can be defined in terms of bispectrum as a third order spectrum. One of the main reasons to consider HOSA on weather signals is that to characterise the Doppler spectrum obtained through the backscattered echoes which are generally skewed and having multiple peaks. The analysis also brings out any deviations from gaussianity and the performance under noisy environment. This will help in identifying and detecting the signals and their by better estimation of moments for further processing The bispectrum estimation technique has been applied to a complex time series data derived from a Polarimetric X-band Doppler Weather Radar (DWR). The results of this analysis are compared with the conventional techniques like Fourier method and pulse pair technique. It is observed that through bispectrum approach the gaussian noise components are significantly removed from the back scattered signals and improves the detectability of the weather signals under noisy condition. Journal: Journal of Electromagnetic Waves and Applications Pages: 69-92 Issue: 1 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2112762 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2112762 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:1:p:69-92 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2117102_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Durgarao Kamireddy Author-X-Name-First: Durgarao Author-X-Name-Last: Kamireddy Author-Name: Saurabh Madhukar Chavan Author-X-Name-First: Saurabh Author-X-Name-Last: Madhukar Chavan Author-Name: Arup Nandy Author-X-Name-First: Arup Author-X-Name-Last: Nandy Title: Comparative performance of novel nodal-to-edge finite elements over conventional nodal element for electromagnetic analysis Abstract: In nodal-based finite element method (FEM), degrees of freedom are associated with the nodes of the element whereas, for edge FEM, degrees of freedom are assigned to the edges of the element. Edge element is constructed based on Whitney spaces. Nodal elements impose both tangential and normal continuity of vector or scalar fields across interface boundaries. But in edge elements, only tangential continuity is imposed across interface boundaries, which is consistent with electromagnetic field problems. Therefore the required continuities in the electromagnetic analysis are directly obtained with edge elements whereas in nodal elements they are attained through potential formulations. Hence, while using edge elements, field variables are directly calculated but with nodal elements, post-processing is required to obtain the field variables from the potentials. Here, we present the finite element formulations with the edge element as well as with nodal elements. Thereafter, we have demonstrated the relative performances of different nodal and edge elements through a series of examples. All possible complexities like curved boundaries, non-convex domains, sharp corners, non-homogeneous domains have been addressed in those examples. The robustness of edge elements in predicting the singular eigen values for the domains with sharp edges and corners is evident in the analysis. A better coarse mesh accuracy has been observed for all the edge elements as compared to the respective nodal elements. Edge elements are also not susceptible to mesh distortion. Journal: Journal of Electromagnetic Waves and Applications Pages: 133-161 Issue: 1 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2117102 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2117102 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:1:p:133-161 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2118086_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Zhiyu Xing Author-X-Name-First: Zhiyu Author-X-Name-Last: Xing Author-Name: Feng Yang Author-X-Name-First: Feng Author-X-Name-Last: Yang Author-Name: Jianhua Yang Author-X-Name-First: Jianhua Author-X-Name-Last: Yang Author-Name: Xiyuan Zhu Author-X-Name-First: Xiyuan Author-X-Name-Last: Zhu Title: Low-RCS Ka-band receiving and transmitting satellite communication antennas co-designed with high-performance absorbent frequency-selective radomes Abstract: This paper investigates the low-RCS Ka-band receiving and transmitting satellite communication antennas co-designed with the high-performance absorbent frequency-selective radomes (AFSR). Consisting of the metamaterial absorber (MA) upper layer and bandpass FSS lower layer, two AFSRs operating at 19 and 29 GHz (receiving and transmitting central frequency) with low-frequency wideband absorbing and high-frequency low-insertion-loss transmission performances are proposed. To meet the needs of Ka-band satellite communication, two 4 × 4 microstrip array antennas working at the same central frequencies are co-designed with the AFSRs. We demonstrate the effectiveness of the proposed AFSRs and co-designed antenna through simulations and measurements. The results show that the gain degradations are only 0.44 dB and 0.58 dB at two central frequencies after loading the AFSRs separately, and 10-dB RCS reduction bandwidths are ranging from 6.1–16.3 GHz (relative bandwidth 91.1%) and 10.2–24.8 GHz (relative bandwidth 83.4%) individually. Journal: Journal of Electromagnetic Waves and Applications Pages: 190-206 Issue: 2 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2118086 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2118086 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:2:p:190-206 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2120419_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Adil Qayyum Author-X-Name-First: Adil Author-X-Name-Last: Qayyum Author-Name: Musarat Abbas Author-X-Name-First: Musarat Author-X-Name-Last: Abbas Title: Impact of non-linearity and non-integer dimension on the reflection and transmission coefficients Abstract: Presented manuscript is devoted to the study of reflection and transmission coefficients of a second-order nonlinear dielectric and linear dielectric NID interface excited by a P-polarized electromagnetic wave. Impact of the non-linearity of the NL medium and non-integer dimension of the NID medium are studied separately. The method of separation of variables is used to model the propagation of waves in NID medium and the solution of the non-linear wave equation is obtained by following the procedure of slowly varying amplitude approximation. We extend our analysis for special cases of the original geometry, i.e. epsilon negative non-linear, mu negative non-linear and epsilon negative NID mediums are considered in this regard. We also calculated the specific values of the permittivities, permeability and dimension of the NID medium for which maximum amplitude of the reflection and transmission coefficients can be achieved. Journal: Journal of Electromagnetic Waves and Applications Pages: 219-230 Issue: 2 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2120419 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2120419 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:2:p:219-230 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2128898_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Abdulrahman Ahmed Ghaleb Amer Author-X-Name-First: Abdulrahman Ahmed Ghaleb Author-X-Name-Last: Amer Author-Name: Syarfa Zahirah Sapuan Author-X-Name-First: Syarfa Zahirah Author-X-Name-Last: Sapuan Author-Name: Adel Y. I. Ashyap Author-X-Name-First: Adel Y. I. Author-X-Name-Last: Ashyap Title: Efficient metasurface for electromagnetic energy harvesting with high capture efficiency and a wide range of incident angles Abstract: This work introduces a miniaturized metasurface (MS) energy harvester operating at 5.54 GHz with a high capture efficiency and a wide incident angle. The proposed MS structure is comprised of an ensemble of electric ring resonator (ERR) array. The MS's impedance is engineered to match free space, so that the incident electromagnetic (EM) power is efficiently captured with minimal reflection and delivered to the optimal resistor load through an optimally positioned metallic-via. According to the simulation results obtained by CST Microwave Studio, the proposed MS harvester achieves higher conversion efficiency of about 91% under normal incidence and more than 78% across a wider incident angle up to 60°. In order to verify the simulation results, a 5×5 cell array of the proposed MS harvester is fabricated and tested. The simulation and experimental results are well match. The proposed MS configuration can be attractive for high-efficiency and compact wireless sensor network harvesting systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 245-256 Issue: 2 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2128898 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2128898 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:2:p:245-256 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2135029_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Jeeban Kumar Nayak Author-X-Name-First: Jeeban Kumar Author-X-Name-Last: Nayak Author-Name: Partha Roy Chaudhuri Author-X-Name-First: Partha Author-X-Name-Last: Roy Chaudhuri Author-Name: Satyajit Ratha Author-X-Name-First: Satyajit Author-X-Name-Last: Ratha Author-Name: Mihir Ranjan Sahoo Author-X-Name-First: Mihir Ranjan Author-X-Name-Last: Sahoo Title: A comprehensive review on effective medium theories to find effective dielectric constant of composites Abstract: We present here a selective and focused review of various Effective Medium Theories (EMT) with their progressive developments, and different mixture formulae used to calculate one of the most important optical constants, i.e. effective permittivity, for different composites. First, we visit the well-known Maxwell Garnett (MG) EMT and its variants. Thereafter, we discuss MG-EMT for the inclusions such as bi-anisotropic materials, carbon nanotube, uniaxial, and anisotropic materials. Then we emphasise the Bruggeman (Br) EMT and its variants. We have also discussed Br-EMT for uniaxial inclusions. In the next section, we analyse Bragg-Pippard (BP) EMT for anisotropic dielectric homogenized composite medium and for bi-anisotropic system. Next, we discuss on Strong Property Fluctuation Theory (SPFT) for bi-anisotropic ellipsoidal inclusions. Following this, we consider EMT for dielectric-magnetic materials, and for thin multilayer structures. Finally, we discuss different mixture formulae used for colloidal solutions, gas mixtures, solvent mixtures, and electrolyte solutions. Journal: Journal of Electromagnetic Waves and Applications Pages: 282-322 Issue: 2 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2135029 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2135029 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:2:p:282-322 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2119435_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Qi Zheng Author-X-Name-First: Qi Author-X-Name-Last: Zheng Author-Name: Chenjiang Guo Author-X-Name-First: Chenjiang Author-X-Name-Last: Guo Author-Name: Jun Ding Author-X-Name-First: Jun Author-X-Name-Last: Ding Author-Name: Peng Fei Author-X-Name-First: Peng Author-X-Name-Last: Fei Author-Name: Peyman PourMohammadi Author-X-Name-First: Peyman Author-X-Name-Last: PourMohammadi Author-Name: Guy A. E. Vandenbosch Author-X-Name-First: Guy A. E. Author-X-Name-Last: Vandenbosch Title: Wideband low-RCS circularly polarized antenna with metasurface combining wave diffusion and polarization conversion Abstract: A novel and simple low-profile high-gain wideband circularly polarized (CP) slot antenna with low radar cross section (RCS) is presented. The proposed antenna is composed of a traditional linearly polarized (LP) slot antenna and an integrated metasurface-based superstrate. The superstrate consists of a center array with metasurface (MS) unit cells and four surrounding arrays with 4×4 MS unit cells. On the one hand, a wideband and high-gain CP radiation in the frequency band of 5.27-6.18 GHz (a relative bandwidth of 15.9%) is achieved by the polarization conversion property of the MS and four surrounding arrays. On the other hand, a broadband RCS reduction in the frequency band of 4.5-20 GHz (a relative bandwidth of 126.5%) is obtained by the combination of two electromagnetic wave diffusion principles. Inspired by C-band, X-band and Ku-band radar applications, a low-cost stealthy prototype with broadband low RCS and CP radiation is realized. Journal: Journal of Electromagnetic Waves and Applications Pages: 207-218 Issue: 2 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2119435 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2119435 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:2:p:207-218 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_1760944_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: M. Norooz Oliaei Author-X-Name-First: M. Author-X-Name-Last: Norooz Oliaei Author-Name: M. Karami Author-X-Name-First: M. Author-X-Name-Last: Karami Author-Name: M. S. Abrishamian Author-X-Name-First: M. S. Author-X-Name-Last: Abrishamian Author-Name: R. A. Sadeghzadeh Author-X-Name-First: R. A. Author-X-Name-Last: Sadeghzadeh Title: 60 GHZ center fed slot array MMW antenna using hybrid standing and traveling waves Abstract: A slot array substrate integrated waveguide antenna is proposed by utilizing novel center inclined slots with non-uniform spaces for imparting feeding advantages of standing and traveling waves. This 1 × 8 array antenna introduces a 13.2 dB gain at center frequency of 59.9 GHz with −10 dB return loss from 58.9 GHz to 60.9 GHz (roughly 2 GHz) and cross-polarization levels more than 45 and 20 dB in E and H planes, respectively. The occupied volume of the antenna is 33 × 4.5 × 0.8 mm3 that shows its compactness. The analyses have been performed by two full-wave numerical electromagnetic simulator packages, namely ANSYS HFSS and CST MWS which the former collaborated with finite element method and the latter with finite integration technique. The simulation results show good coincidences between these two methods and it validates the design of proposed structure. Journal: Journal of Electromagnetic Waves and Applications Pages: 163-175 Issue: 2 Volume: 37 Year: 2023 Month: 1 X-DOI: 10.1080/09205071.2020.1760944 File-URL: http://hdl.handle.net/10.1080/09205071.2020.1760944 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:2:p:163-175 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2124197_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Zhi Tao Author-X-Name-First: Zhi Author-X-Name-Last: Tao Author-Name: Rui-Zhi Zou Author-X-Name-First: Rui-Zhi Author-X-Name-Last: Zou Author-Name: Jiu-Fu Ruan Author-X-Name-First: Jiu-Fu Author-X-Name-Last: Ruan Author-Name: Zi-Fan Meng Author-X-Name-First: Zi-Fan Author-X-Name-Last: Meng Author-Name: Sheng-Min Pan Author-X-Name-First: Sheng-Min Author-X-Name-Last: Pan Title: A metal hybrid resistive film ultra-wideband metamaterial absorber for infrared region Abstract: An ultra-wideband metamaterial absorber (MA) based on the resistive film is proposed. Unlike conventional MAs based on the resistive film, the proposed absorber features a hybrid resonant layer of resistive film and metal patch at the same top layer. The absorption of the proposed absorber exceeds 90% over the ultra-wideband frequency range of 20 –220 THz, covering most of the infrared region, while the relative absorption bandwidth is up to 167%. The coupling of resistive film and metal pattern at the same layer plays the significant role in enhancing the absorption performance, which is interpreted by the investigation of the surface current distribution. Moreover, the absorber is insensitive to polarization and incident angle. The proposed absorber with high absorption capability as well as simple and compact structure is a proper candidate for the applications in the infrared frequency regime. Journal: Journal of Electromagnetic Waves and Applications Pages: 231-244 Issue: 2 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2124197 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2124197 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:2:p:231-244 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2128899_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Muhammad Basir Abbas Author-X-Name-First: Muhammad Basir Author-X-Name-Last: Abbas Author-Name: M. A. Baqir Author-X-Name-First: M. A. Author-X-Name-Last: Baqir Author-Name: Olcay Altintaş Author-X-Name-First: Olcay Author-X-Name-Last: Altintaş Author-Name: Muharrem Karaaslan Author-X-Name-First: Muharrem Author-X-Name-Last: Karaaslan Author-Name: Musarat Abbas Author-X-Name-First: Musarat Author-X-Name-Last: Abbas Title: Tree-shaped fractal metamaterial multiband absorber for C- and X-band applications Abstract: Recently, multiband metamaterial absorbers have gained considerable attention from research and development communities due to their applications in filtering, stealth, and sensing. However, these multiband absorbers are mostly comprised of multilayered metamaterial structures that make them bulky and expensive. In this paper, we investigated a novel multiband absorber made of a single layer of the tree-shaped fractal. The proposed fractal-based metamaterial absorber (FMA) shows the polarization- and angular-sensitive features of the absorption. Furthermore, it is observed that absorptivity is attained due to electric and magnetic resonance. The proposed multiband absorber would be useful for filtering, polarization- and angle-sensing, and shielding. Furthermore, the simulation results are verified by experiments. Journal: Journal of Electromagnetic Waves and Applications Pages: 257-270 Issue: 2 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2128899 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2128899 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:2:p:257-270 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2131470_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Jyotibhusan Padhi Author-X-Name-First: Jyotibhusan Author-X-Name-Last: Padhi Author-Name: G. Shrikanth Reddy Author-X-Name-First: G. Author-X-Name-Last: Shrikanth Reddy Author-Name: Awanish Kumar Author-X-Name-First: Awanish Author-X-Name-Last: Kumar Title: Multiple stubs loaded efficient electrically small antenna for DCS/WiMAX/5G NR-n77/n78 applications Abstract: This work presents an electrically small antenna (ESA) for wireless applications, such as digital cellular systems (DCS1800), WiMAX, and sub 6 GHz – 5G new radio (NR) systems. The proposed antenna offers a triple band resonance centered at 1.825, 3.3, and 3.58 GHz. Here, impedance matching networks of printed microstrip line sections, such as inverted ‘L’, open-ended line, meandered line, and capacitive stub, are used to achieve impedance matching at the desired frequencies. The total surface area of the proposed antenna is 0.14λ × 0.06λ, where λ is the wavelength at 1.825 GHz. The designed antenna is tested for its impedance and radiation characteristics. The fabricated prototype offers fractional bandwidth (FBW, with VSWR < 2) of 1.6%, 6%, and 6.7% centered at 1.825, 3.3, and 3.58 GHz, respectively, whereas for VSWR 3:1, the achieved fraction bandwidth(s) is 8.2% and 24.5% for the DCS1800 and 3.3 GHz band, respectively. The stable and nearly omnidirectional radiation pattern for each operating frequency bands indicates the suitability of the proposed antenna for the intended application(s). Journal: Journal of Electromagnetic Waves and Applications Pages: 271-281 Issue: 2 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2131470 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2131470 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:2:p:271-281 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2118085_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Saranya Sasidharan Author-X-Name-First: Saranya Author-X-Name-Last: Sasidharan Author-Name: V. K. Anandan Author-X-Name-First: V. K. Author-X-Name-Last: Anandan Author-Name: Shivangi Mishra Author-X-Name-First: Shivangi Author-X-Name-Last: Mishra Author-Name: Sourin Mukhopadhyay Author-X-Name-First: Sourin Author-X-Name-Last: Mukhopadhyay Title: Identification, characterization and removal of anomalous propagation and ground clutter echoes using polarimetric Doppler weather radar products Abstract: This paper aims at developing an algorithm that uses polarimetric weather radar variables and its spatial variations to characterize and remove ground clutter (GC) and anomalous propagation (AP) echoes. A fuzzy logic based approach has been followed, which uses the standard deviation of differential phase (SDΦDP), vertical gradient of reflectivity (VGZ), dual pol texture ratio (DPTR) and correlation coefficient (ρhv) to discriminate precipitation echoes and non-precipitating echoes. The algorithm is tested for data of different independent events. The meteorological conditions leading to AP are also discussed. The accuracy obtained from the new algorithm is found to be better than the filtering techniques used so far. Journal: Journal of Electromagnetic Waves and Applications Pages: 176-189 Issue: 2 Volume: 37 Year: 2023 Month: 01 X-DOI: 10.1080/09205071.2022.2118085 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2118085 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:2:p:176-189 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2136040_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Weihao Zhang Author-X-Name-First: Weihao Author-X-Name-Last: Zhang Author-Name: Shuai Ding Author-X-Name-First: Shuai Author-X-Name-Last: Ding Author-Name: Yongmao Huang Author-X-Name-First: Yongmao Author-X-Name-Last: Huang Author-Name: Zhaojun Zhu Author-X-Name-First: Zhaojun Author-X-Name-Last: Zhu Author-Name: Wei He Author-X-Name-First: Wei Author-X-Name-Last: He Author-Name: Maurizio Bozzi Author-X-Name-First: Maurizio Author-X-Name-Last: Bozzi Title: Planar single-/dual-band bandpass filters based on new perturbed multi-mode SIW circular cavity Abstract: In this paper, new single- and dual-band bandpass filters are implemented based on the perturbed multi-mode substrate integrated waveguide (SIW) circular cavity. For the single-band filter, the TM $ _{010} $ 010 mode, TM $ _{110A} $ 110A mode, and TM $ _{210A} $ 210A mode are simultaneously utilized to realize the triple-mode resonance response, of which both the bandwidth and central frequency can be flexibly adjusted by allocating the perturbation position properly. Meanwhile, for the dual-band operation, the TM $ _{010} $ 010 mode, TM $ _{110A} $ 110A mode, and TM $ _{210A} $ 210A mode are arranged to realize the lower passband, whereas the TM $ _{210B} $ 210B and TM $ _{020} $ 020 modes are excited to generate the upper passband. The working principle of the filters' coupling topology is explained in detail. For concept verification, both the triple-mode single-band and multi-mode dual-band filters are designed, manufactured and measured, with the measurement results are separately in good agreement with the corresponding simulations. Journal: Journal of Electromagnetic Waves and Applications Pages: 323-334 Issue: 3 Volume: 37 Year: 2023 Month: 02 X-DOI: 10.1080/09205071.2022.2136040 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2136040 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:3:p:323-334 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2139198_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Vemula Bhanu Naidu Author-X-Name-First: Vemula Bhanu Author-X-Name-Last: Naidu Author-Name: Dipanjan Gope Author-X-Name-First: Dipanjan Author-X-Name-Last: Gope Author-Name: Subrata Kumar Datta Author-X-Name-First: Subrata Kumar Author-X-Name-Last: Datta Title: Exploration of a PBG-based cavity structure for a multiple-beam extended interaction klystron Abstract: The feasibility of a photonic band-gap (PBG)-based interaction structure was analytically explored for a multiple-beam extended interaction klystron amplifier. This configuration accrues the advantages of the multiple-defect PBG-based extended interaction structure and multiple-beam operation. The mode configurations were analysed through 3D electromagnetic simulation and the applicability of the photonic band-gap cavity was studied for the multiple-beam operation of an extended interaction klystron amplifier. A typical six-defect cavity operating at around 83 GHz was designed for electron–wave interaction at 2π mode with 6 electron beams each carrying 300 mA current at the accelerating potential of 16.5 kV. A particle-in-cell simulation shows that an output power of ∼2 kW is possible with electronic efficiency of around 6.7%. A frequency-scaled-down interaction structure at Ku-band was fabricated and cold measurements were carried out to ascertain the feasibility. The measured values of the frequency for various modes, loaded quality factor and 3 dB bandwidth were found to be within 0.36%, 5.3% and 4.07%, respectively, against those from the simulation. Journal: Journal of Electromagnetic Waves and Applications Pages: 347-358 Issue: 3 Volume: 37 Year: 2023 Month: 02 X-DOI: 10.1080/09205071.2022.2139198 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2139198 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:3:p:347-358 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2143297_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Cang Liang Author-X-Name-First: Cang Author-X-Name-Last: Liang Author-Name: Xianglin Kong Author-X-Name-First: Xianglin Author-X-Name-Last: Kong Author-Name: Fengjun Wang Author-X-Name-First: Fengjun Author-X-Name-Last: Wang Author-Name: Ruofeng Xu Author-X-Name-First: Ruofeng Author-X-Name-Last: Xu Author-Name: Yixiang Fu Author-X-Name-First: Yixiang Author-X-Name-Last: Fu Author-Name: Xiaoyu Pang Author-X-Name-First: Xiaoyu Author-X-Name-Last: Pang Author-Name: Shengjun Zhang Author-X-Name-First: Shengjun Author-X-Name-Last: Zhang Author-Name: Xiaopeng Shen Author-X-Name-First: Xiaopeng Author-X-Name-Last: Shen Author-Name: Lei Zhao Author-X-Name-First: Lei Author-X-Name-Last: Zhao Title: A broadband perfect metamaterial absorber with angle-insensitive characteristics Abstract: A broadband perfect metamaterial absorber (MA) based on bilayer resistive films with different structure units is proposed in the microwave regime. An equivalent circuit model based on transmission line theory is established to guide the absorber design and explain its broadband and perfect absorption mechanism. The absorber characters high absorptivity and stable angular. The MA displays more than 98% absorption from 4.9 to 22.6 GHz at normal incidence. The performance is suitable for transverse electric (TE) and transverse magnetic (TM) waves at normal incidence, while absorption is better than 90% (80%) within the oblique incidence 50° (60°). The measured results of absorption and 10 dB radar cross section (RCS) agree well with the simulated ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 401-410 Issue: 3 Volume: 37 Year: 2023 Month: 02 X-DOI: 10.1080/09205071.2022.2143297 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2143297 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:3:p:401-410 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2144768_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Patibandla Anilkumar Author-X-Name-First: Patibandla Author-X-Name-Last: Anilkumar Author-Name: Dobbidi Pamu Author-X-Name-First: Dobbidi Author-X-Name-Last: Pamu Author-Name: Tapeshwar Tiwari Author-X-Name-First: Tapeshwar Author-X-Name-Last: Tiwari Title: Equivalent circuit approach for the design of hole and slot bare anode block of magnetron Abstract: Magnetron is a high-power microwave source with high demand among vacuum devices. Before the design, validating it with other methods gives confidence to the designer. An equivalent circuit analysis is developed for a 16 vanes hole and slot structure yielding the design parameters, hole radius, slot length, slot width, and anode height. This method is adopted to calculate the cavity resonant frequencies preferable over the field equations, simulation, and fabrication. From inductance and capacitance definition, dispersion equation of the anode block is derived for each mode. The equivalent circuit approach is validated with the simulation to verify consistency. The resonant frequency relative difference of these two methods is 1.46%. The inductance and capacitance changes are observed by parametric variation of these structure dimensions. Strapping causes the frequency shift from 3.1685 to 2.217 GHz, and change in the cavity resonant frequency with the strap depth and strap height are plotted. Journal: Journal of Electromagnetic Waves and Applications Pages: 411-427 Issue: 3 Volume: 37 Year: 2023 Month: 02 X-DOI: 10.1080/09205071.2022.2144768 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2144768 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:3:p:411-427 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2142676_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Weaam Alhejaili Author-X-Name-First: Weaam Author-X-Name-Last: Alhejaili Author-Name: Kh Lotfy Author-X-Name-First: Kh Author-X-Name-Last: Lotfy Author-Name: A. El-Bary Author-X-Name-First: A. Author-X-Name-Last: El-Bary Author-Name: M. M. Allan Author-X-Name-First: M. M. Author-X-Name-Last: Allan Title: Response of two-temperature semiconductor model photomechanical and thermal waves during electrons-holes interaction processes Abstract: A novel mathematical-physical model is introduced in the context of the two-temperature thermoelasticity theory which describes the interaction between electrons and holes in semiconductors material. The response of the elasto-thermo- mechanical continuous waves is investigated during thermo-mass-diffusion transport processes. The photothermal (PT) technique is applied for the exciting medium. The one-dimensional (1D) Cartesian coordinate is used to describe the governing equations. Dimensionless quantity is used in the Laplace transform domain. To obtain the unknown variables, some conditions are applied at the free surface of the medium to get the main quantities analytically. The conversion of the Laplace transform technique has been employed with some numerical approximations to obtain the exact expressions of the main physical fields. The computational results have been introduced of silicon material to illustrate the impacts of the two temperature parameter and thermal memories on the wave propagation of the physical fields according to photo-thermoelasticity theory. Journal: Journal of Electromagnetic Waves and Applications Pages: 382-400 Issue: 3 Volume: 37 Year: 2023 Month: 02 X-DOI: 10.1080/09205071.2022.2142676 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2142676 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:3:p:382-400 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2139199_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Weaam Alhejaili Author-X-Name-First: Weaam Author-X-Name-Last: Alhejaili Author-Name: H. M. Atef Author-X-Name-First: H. M. Author-X-Name-Last: Atef Author-Name: Alaa A. El-Bary Author-X-Name-First: Alaa A. Author-X-Name-Last: El-Bary Title: The effect of Seebeck–Peltier on the generalized magneto thermoviscoelastic medium under five theories Abstract: This study aims to research the influence of the magnetic field on the 2-D generalized thermo-viscoelastic material in five theories. The amended Ohm Law, which includes temperature gradient (effect of Seebeck) and charging density effects and the existing Fourier Law (effect of Peltier), is adopted. In the physical domain, the analytical expressions for the physical quantities are obtained using the normal mode analysis. These expressions are measured numerically for a specific substance and graphically illustrated. Moreover, the results predicted by (C-T, L-S, G-L, G-N II and DPL) theories also examined the existence and nonexistence of the viscosity and (Seebeck–Peltier) coefficients. Journal: Journal of Electromagnetic Waves and Applications Pages: 359-381 Issue: 3 Volume: 37 Year: 2023 Month: 02 X-DOI: 10.1080/09205071.2022.2139199 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2139199 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:3:p:359-381 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2145505_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Seshagiri Duvvuri Author-X-Name-First: Seshagiri Author-X-Name-Last: Duvvuri Author-Name: Dyana Arumuganainar Author-X-Name-First: Dyana Author-X-Name-Last: Arumuganainar Author-Name: Kamla Prasan Ray Author-X-Name-First: Kamla Prasan Author-X-Name-Last: Ray Author-Name: Vengadarajan Alagarswami Author-X-Name-First: Vengadarajan Author-X-Name-Last: Alagarswami Title: Genetic algorithm-based mathematical morphology for clutter removal in airborne radars Abstract: This paper presents a novel approach for clutter removal in airborne radars using a genetic algorithm and mathematical morphology. The clutter returns are detected when constant alarm rate processing is applied on range-Doppler images. In the proposed method, mathematical morphological operations are performed on range-Doppler images to obtain clutter images. The clutter image is then applied as a mask to remove false detections due to clutter. Also, the targets embedded in clutter are detected using gray-scale morphological operations. The morphological filter and the sequence of operations are designed by a genetic algorithm. The advantage of the proposed method is that it does not require the computation of statistical measures from clutter data and filters are optimally designed using a genetic algorithm. The proposed method has shown an increase in clutter leak reduction when compared to that of a deep morphological network. Journal: Journal of Electromagnetic Waves and Applications Pages: 428-440 Issue: 3 Volume: 37 Year: 2023 Month: 02 X-DOI: 10.1080/09205071.2022.2145505 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2145505 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:3:p:428-440 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2139197_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Kaijun Song Author-X-Name-First: Kaijun Author-X-Name-Last: Song Author-Name: Qian Li Author-X-Name-First: Qian Author-X-Name-Last: Li Author-Name: Yuxuan Chen Author-X-Name-First: Yuxuan Author-X-Name-Last: Chen Title: Hybrid microstrip/SIW power divider with improved output isolation Abstract: An eight-way hybrid microstrip/substrate integrated waveguide (SIW) power divider with good output isolation performance is proposed in this paper. The circuit consists of microstrip/SIW transitions and a cross-shaped SIW cavity. The good isolation characteristics is obtained by adding the resistors between the microstrip lines and the isolation resistors on the radial slotlines. The equivalent circuit is given in this paper to analyse the proposed power divider. A prototype was fabricated and measured. The measurement results show that the insertion loss (IL) is about 1.5 dB from 9.1 GHz to 10.15 GHz, and the input return loss (RL) is higher than 20 dB. The isolation of adjacent ports on the same side, adjacent ports on the different side, and opposite ports are higher than 17.5, 19, and 15 dB, respectively. The error between measurement and simulation is acceptable. Journal: Journal of Electromagnetic Waves and Applications Pages: 335-346 Issue: 3 Volume: 37 Year: 2023 Month: 02 X-DOI: 10.1080/09205071.2022.2139197 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2139197 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:3:p:335-346 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2145506_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20220907T060133 git hash: 85d61bd949 Author-Name: Shifei Tao Author-X-Name-First: Shifei Author-X-Name-Last: Tao Author-Name: Xinyi Li Author-X-Name-First: Xinyi Author-X-Name-Last: Li Author-Name: Xiaodong Ye Author-X-Name-First: Xiaodong Author-X-Name-Last: Ye Author-Name: Hao Wang Author-X-Name-First: Hao Author-X-Name-Last: Wang Author-Name: Xiang Li Author-X-Name-First: Xiang Author-X-Name-Last: Li Title: SAR image despeckling using a CNN guided by high-frequency information Abstract: Preserving image details is a challenging and significant task for synthetic aperture radar (SAR) image despeckling. In this paper, we proposed a high-frequency information extraction module based on block-matching and 3D filtering for SAR image despeckling (SAR-BM3D) and wavelet transformation to guide the denoisers based on a convolutional neural network (CNN). Firstly, SAR-BM3D is employed to conduct the initial speckle removal, and then Haar wavelet transformation takes the task of extracting high-frequency information of the initial despeckled image. The noisy image and the high-frequency information are merged together to be the input of the CNN, which makes it easier for the CNN-based denoisers to restore the textures and details of the SAR image. Extensive experiments on synthetic and real SAR images have been validated, which show that our method can effectively remove the speckle noise and improve the detail-preserving capacity of the CNN-based denoiser. Journal: Journal of Electromagnetic Waves and Applications Pages: 441-451 Issue: 3 Volume: 37 Year: 2023 Month: 02 X-DOI: 10.1080/09205071.2022.2145506 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2145506 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:3:p:441-451 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2158138_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: S. Prasad Author-X-Name-First: S. Author-X-Name-Last: Prasad Author-Name: M. Meenakshi Author-X-Name-First: M. Author-X-Name-Last: Meenakshi Author-Name: P.H. Rao Author-X-Name-First: P.H. Author-X-Name-Last: Rao Title: Shaped beam from multiple beams using planar phased arrays Abstract: This paper proposes a synthesis and optimization procedure to generate user-specific shaped and multiple beams in any arbitrary 3D space. The synthesis method generates independently controllable multiple beams over different azimuth and elevation angles with variable peak powers. These multiple beams can form any user-defined shaped pattern with an optimum number of beams, their power, and placement in the $ \theta, \phi $ θ,ϕ angles using the proposed direct synthesis method. Different evolutionary algorithms are employed to optimize the beam peak parameters to mitigate the ripple, side lobe level, and beam spread. The synthesis method is validated on a fully functional integrated 5G mmWave phased array for various shaped beam patterns. Measured sector, isoflex beams between $ \theta =\pm 40^\circ $ θ=±40∘, $ csc^2 $ csc2, and dual beams with unequal powers are presented and compared with the shaped beam synthesis method. Journal: Journal of Electromagnetic Waves and Applications Pages: 592-604 Issue: 4 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2022.2158138 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2158138 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:4:p:592-604 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2146004_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Weirui Chen Author-X-Name-First: Weirui Author-X-Name-Last: Chen Author-Name: Xiangwen Yang Author-X-Name-First: Xiangwen Author-X-Name-Last: Yang Author-Name: Dongyang Li Author-X-Name-First: Dongyang Author-X-Name-Last: Li Author-Name: Jian Li Author-X-Name-First: Jian Author-X-Name-Last: Li Title: Model calibration for compressive sensing based linear antenna array fault diagnosis Abstract: The Compressive Sensing (CS) theory has been widely studied as it requires only a small number of measurements to identify faulty elements of antenna arrays. However, the model for linear antenna array fault diagnosis based on CS is much sensitive to model mismatch and the identification results usually turn out to be much worse than expected in the practical situation. In this study, the model mismatch for linear antenna array fault diagnosis is first analyzed and then a CS model calibration method is proposed to improve the performance of the CS-based linear antenna array fault diagnostic method by solving a convex optimization model. Numerical results demonstrate that the calibrated CS model is much more accurate in identifying faulty antenna elements under model mismatch and noise than the traditional one. Journal: Journal of Electromagnetic Waves and Applications Pages: 453-473 Issue: 4 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2022.2146004 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2146004 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:4:p:453-473 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2152390_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Mohamed Benzaghta Author-X-Name-First: Mohamed Author-X-Name-Last: Benzaghta Author-Name: Bengisu Yalcinkaya Gokdogan Author-X-Name-First: Bengisu Yalcinkaya Author-X-Name-Last: Gokdogan Author-Name: Remziye Busra Coruk Author-X-Name-First: Remziye Busra Author-X-Name-Last: Coruk Author-Name: Ali Kara Author-X-Name-First: Ali Author-X-Name-Last: Kara Title: Modeling and measurement of human body blockage loss at 28 GHz Abstract: Millimeter-wave (mm-Wave) spectrum is an essential enabler to the fifth generation (5G) wireless technology. Humans are one of the most noticeable blockers that cause temporal variation in indoor radio channels. This paper presents human blockage measurements at 28 GHz, with several humans of different sizes. The effect of the crossing orientations of the human bodies is investigated for three different transmitter heights. A human blockage model based on the Fresnel diffraction scheme is shown to be applicable in estimating the human blockage loss in indoor radio links considering various body sizes, different crossing orientations, and different transmitter heights. The findings reported in this paper could help improve indoor radio channel models at 28 GHz bands for 5G technologies considering the presence of human body blockages. Journal: Journal of Electromagnetic Waves and Applications Pages: 538-548 Issue: 4 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2022.2152390 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2152390 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:4:p:538-548 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2149354_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Kalva Nagalakshmaiah Author-X-Name-First: Kalva Author-X-Name-Last: Nagalakshmaiah Author-Name: Busineni Mahesh Kumar Author-X-Name-First: Busineni Author-X-Name-Last: Mahesh Kumar Author-Name: Jayanta Mukherjee Author-X-Name-First: Jayanta Author-X-Name-Last: Mukherjee Title: Wideband self-isolated four-element MIMO antenna based on magnetic monopole and electric monopole for sub-6 GHz 5G communication applications Abstract: A wideband antenna element is designed based on complementary antenna theory by utilizing magnetic and electric monopole antennas. By sequentially rotating the antenna element, a wideband MIMO antenna is designed with an impedance bandwidth of 51.2% (3.1–5.2 GHz), which covers the 5G sub-6 GHz bands (N48/N77/N78/N79) with isolation greater than 21.8 dB between the antenna elements over the operating band. The proposed MIMO antenna provides pattern diversity with a half-power beamwidth (HPBW) greater than $ 180^\circ $ 180∘ ( $ 180^\circ $ 180∘– $ 208^\circ $ 208∘) over the wide bandwidth. It has a stable gain of 4 dBi over the bandwidth. The proposed MIMO antenna exhibits good efficiency, low ECC, and low channel capacity loss in the operating frequency band. Journal: Journal of Electromagnetic Waves and Applications Pages: 524-537 Issue: 4 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2022.2149354 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2149354 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:4:p:524-537 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2154709_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Fatih Ozkan Alkurt Author-X-Name-First: Fatih Ozkan Author-X-Name-Last: Alkurt Author-Name: Emin Unal Author-X-Name-First: Emin Author-X-Name-Last: Unal Author-Name: Merih Palandoken Author-X-Name-First: Merih Author-X-Name-Last: Palandoken Author-Name: Gizem Altintarla Author-X-Name-First: Gizem Author-X-Name-Last: Altintarla Author-Name: Yadgar I. Abdulkarim Author-X-Name-First: Yadgar I. Author-X-Name-Last: Abdulkarim Author-Name: Uğur Cem Hasar Author-X-Name-First: Uğur Cem Author-X-Name-Last: Hasar Author-Name: Muharrem Karaaslan Author-X-Name-First: Muharrem Author-X-Name-Last: Karaaslan Title: A study on electronically controllable beamforming monopole antenna for telecommunication applications Abstract: The design, analysis, and prototyping of an electronically controllable beamforming monopole antenna (ECBMA), which could be a good candidate for ceil-mounted wireless telecommunication systems, are reported. The proposed ECBMA targeting the 2.45 GHz center frequency is based on the ‘on-off’ ground reflectors, which are connected to the main ground layer by twelve RF switches to implement digital logic states. There are twelve ground reflectors symmetrically positioned over azimuthal angle direction in the ECBMA structure controlled by RF switches and a microcontroller unit, thus resulting in a pattern change when the states of the switches change logically. The designed ECBMA has the following three main features. First, it has a good and stable reflection coefficient (S11) characteristic at the 2.45 GHz centre frequency. Second, it has a wideband characteristic between 2.15 and 2.85 GHz (700 MHz operational bandwidth). Third, it has the capability to create single, double, or multi-beam characteristics (multi-purpose) which is a highly desired feature in many modern wireless communication systems mainly suitable for indoor applications. The prototype of our ECBMA is fabricated, and the performance analysis is investigated experimentally and S11 and radiation characteristics have good performance and are in good agreement with the simulation results. The proposed ECBMA has a good candidate for wireless telecommunication purposes such as WLAN, ISM, Wi-Fi, Bluetooth and other RF peripherals like indoor applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 549-561 Issue: 4 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2022.2154709 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2154709 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:4:p:549-561 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2157760_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Mohsen Hayati Author-X-Name-First: Mohsen Author-X-Name-Last: Hayati Author-Name: Mohammad Amir Sattari Author-X-Name-First: Mohammad Amir Author-X-Name-Last: Sattari Author-Name: Sepehr Zarghami Author-X-Name-First: Sepehr Author-X-Name-Last: Zarghami Author-Name: Seyed Maziar Shah-ebrahimi Author-X-Name-First: Seyed Maziar Author-X-Name-Last: Shah-ebrahimi Title: Designing ultra-small Wilkinson power divider with multi-harmonics suppression Abstract: This paper presents a miniaturized Wilkinson Power Divider (WPD) with the capability of attenuating unwanted harmonics up to the 19th harmonic. In this study, a low pass filter was embedded as the quarter-wavelength transmission lines of the conventional WPD. To reduce the size of the proposed structure, the high impedance line is meandered. A simple T-shape resonator is added to suppress the high frequency. The even and odd mode analysis were reported as the analytical descriptions. The operational frequency of the presented WPD is 1.95GHz, and S21, S11, S22, and S23 in this frequency are -3.79dB, -15.56dB, -14.15dB, and -10.89dB, respectively. The overall size of implemented WPD is only 8.8 mm × 8.02 mm, and its normalized circuit size equals 0.078 × 0.071. The designed structure has been fabricated and measured on the RT-5880 substrate with a thickness of 20mil. The desired matching between the simulation results and the measurement ones has been evident. $ {\lambda _g} $ λg $ {\lambda _g} $ λg Journal: Journal of Electromagnetic Waves and Applications Pages: 575-591 Issue: 4 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2022.2157760 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2157760 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:4:p:575-591 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2148576_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Weijie Wang Author-X-Name-First: Weijie Author-X-Name-Last: Wang Author-Name: Guo Liu Author-X-Name-First: Guo Author-X-Name-Last: Liu Author-Name: Yingjian Cao Author-X-Name-First: Yingjian Author-X-Name-Last: Cao Author-Name: Bailiang Chen Author-X-Name-First: Bailiang Author-X-Name-Last: Chen Author-Name: Yelei Yao Author-X-Name-First: Yelei Author-X-Name-Last: Yao Author-Name: Yu Wang Author-X-Name-First: Yu Author-X-Name-Last: Wang Author-Name: Xiaoqing Gong Author-X-Name-First: Xiaoqing Author-X-Name-Last: Gong Author-Name: Wei Jiang Author-X-Name-First: Wei Author-X-Name-Last: Jiang Author-Name: Jianxun Wang Author-X-Name-First: Jianxun Author-X-Name-Last: Wang Author-Name: Yong Luo Author-X-Name-First: Yong Author-X-Name-Last: Luo Title: Theory and measurement of the single and hybrid-mode excitation and evolution in a lossy-dielectric-loaded waveguide Abstract: This paper investigates the mode excited, evolved, and propagating properties of the lossy dielectric-loaded waveguide (DLW) used in a Ku-band TE11-mode gyrotron traveling wave tube (gyro-TWT). Theoretical calculation and numerical simulation show that different DLW eigenmodes can be excited by the hollow circular waveguide as a single or hybrid-mode. This study clearly reveals the transformation conditions of the single and hybrid-mode, and the mechanism of the resulting specific dispersion, loss, and electromagnetic field distribution. According to the mode excitation principle and its evolution laws, the propagating properties can be accurately controlled by adjusting the dielectric thickness, which can effectively suppress the potential oscillations and improve the electron bunching phase in the gyro-TWT. As a result, the dielectric loading scheme can be optimized by properly arranging the DLWs, thus enhancing the stability and gain of the gyro-TWT. The theory and simulation are verified by the vector network analyzer measurement at Ku-band, and the results show a good agreement. Journal: Journal of Electromagnetic Waves and Applications Pages: 510-523 Issue: 4 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2022.2148576 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2148576 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:4:p:510-523 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2148575_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Yu-Jen Chi Author-X-Name-First: Yu-Jen Author-X-Name-Last: Chi Author-Name: Bing-Chao Huang Author-X-Name-First: Bing-Chao Author-X-Name-Last: Huang Author-Name: Chien-Wen Chiu Author-X-Name-First: Chien-Wen Author-X-Name-Last: Chiu Title: Noninvasive measurement of subcutaneous temperature using active antenna and high gain low noise microwave radiometer Abstract: This paper presents a radiometric thermometer for non-invasive measurement of the internal body temperature. The proposed radiometric thermometer designed in 1.575 GHz band consists of a near-field probe and a high gain Dick radiometer. A phantom based on Agar material was developed to emulate the real tissue of skin and muscle for experiments. The measured results show that the active probe antenna provides additional 12.5 dB gain with noise figure less than 1dB, and the radiometer has a system gain of 50 dB and total noise figure of 1.738 dB at 1.575 GHz. The output voltage measured by the proposed 1.575 GHz microwave radiometer is 2.994 V when the water temperature is set to 25 °C, while it is 3.129 V when the water temperature is set to 80 °C. The study demonstrates that using the active probe connected to the radiometer can identify temperature difference of the body. Journal: Journal of Electromagnetic Waves and Applications Pages: 490-509 Issue: 4 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2022.2148575 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2148575 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:4:p:490-509 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2156819_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Rajan Agrahari Author-X-Name-First: Rajan Author-X-Name-Last: Agrahari Author-Name: Pankaj Kumar Author-X-Name-First: Pankaj Author-X-Name-Last: Kumar Author-Name: Vikram Kumar Author-X-Name-First: Vikram Author-X-Name-Last: Kumar Title: Pixelated metasurface based wideband cross polarization converter Abstract: A wideband cross polarization converter with the pixelation approach for X, Ku, and K bands has been presented in this paper. The polarizer consists of copper FR4 combo patched pixels on an FR4 substrate backed by copper. The pixels arrangement on the meta-atom yielded polarization conversion ratio (PCR) >0.9 over a wide frequency range from 10.15 to 27.6 GHz. A broadband FWHM bandwidth of 19.87 GHz is observed for PCR which ranges from 9.26 to 29.13 GHz. The physical mechanism of the linear polarization conversion is analyzed by the spatial profile of the electric and magnetic fields. Further, to validate the simulation results a prototype of the metasurface constating of $ 17 \times 17 $ 17×17 meta-atom has been fabricated. A good agreement between the experimental and simulation results has been observed. The designed metasurface when integrated with antennas can be extensively applied for diverse microwave applications for polarization manipulation devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 562-574 Issue: 4 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2022.2156819 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2156819 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:4:p:562-574 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2147026_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Virendra Kumar Author-X-Name-First: Virendra Author-X-Name-Last: Kumar Author-Name: Rakesh Kumar Verma Author-X-Name-First: Rakesh Kumar Author-X-Name-Last: Verma Author-Name: Shreeshail Author-X-Name-First: Author-X-Name-Last: Shreeshail Author-Name: U. S. Pandey Author-X-Name-First: U. S. Author-X-Name-Last: Pandey Author-Name: K. S. Beenamole Author-X-Name-First: K. S. Author-X-Name-Last: Beenamole Author-Name: Ravi Kumar Gangwar Author-X-Name-First: Ravi Kumar Author-X-Name-Last: Gangwar Title: Investigation of active phased arrays performance deficiency due to array planarity and misalignment Abstract: This paper investigates the degradation in the electromagnetic performance of an active phased array antenna and establishes the coupling relationship between the antenna array alignment/planarity to the near-field scanner probe. An analytical framework is presented to evaluate the sensitivity of radiation parameters of active phased arrays antenna due to the deviation of complex excitation vector. A laser-based positioning metrology equipment measures the near-field scanner plane to the antenna under test (AUT) plane in a global coordinate system. The antenna array surface is adjusted and aligned to the near-field scanner probe measurement plane within 1 mm (in S-band) by employing the mechanical mechanism within the positioning accuracies of 50–100 µ $ {{\rm m}} $ m. The collimation of a perfectly aligned antenna array results in the alignment of electrical and mechanical boresight of the active phased array radar. The theoretical evidence and experimental results presented powerful tools and guidelines to set a reasonable tolerance for array alignment in the near-field test range (NFTR) to achieve high performances of the active phased array antenna. Journal: Journal of Electromagnetic Waves and Applications Pages: 474-489 Issue: 4 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2022.2147026 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2147026 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:4:p:474-489 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2188263_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Giacomo Oliveri Author-X-Name-First: Giacomo Author-X-Name-Last: Oliveri Author-Name: Nicola Anselmi Author-X-Name-First: Nicola Author-X-Name-Last: Anselmi Author-Name: Marco Salucci Author-X-Name-First: Marco Author-X-Name-Last: Salucci Author-Name: Lorenzo Poli Author-X-Name-First: Lorenzo Author-X-Name-Last: Poli Author-Name: Andrea Massa Author-X-Name-First: Andrea Author-X-Name-Last: Massa Title: Compressive sampling-based scattering data acquisition in microwave imaging Abstract: The design of systems for data acquisition in microwave imaging is addressed. First, the collection of scattering data is formulated within a Compressive Sampling (CoSamp) framework. The arising problem is then solved by minimizing the bound of the restricted isometry constant (RIC) of the observation matrix mathematically modelling the acquisition setup. Towards this end, a new incoherence-based RIC bound is derived to take into account the physics of the microwave imaging system. A set of numerical experiments is reported to assess the information acquisition capabilities of the proposed approach as well as its impact on the performance of the subsequent Compressive Sensing (CoSens)-based inversion in comparison with standard Nyquist–Shannon-based sampling techniques, as well. Journal: Journal of Electromagnetic Waves and Applications Pages: 693-729 Issue: 5 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2023.2188263 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2188263 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:5:p:693-729 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2164223_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Baoqin Lin Author-X-Name-First: Baoqin Author-X-Name-Last: Lin Author-Name: Wenzhun Huang Author-X-Name-First: Wenzhun Author-X-Name-Last: Huang Author-Name: Jianxin Guo Author-X-Name-First: Jianxin Author-X-Name-Last: Guo Author-Name: Yanwen Wang Author-X-Name-First: Yanwen Author-X-Name-Last: Wang Author-Name: Hongjun Ye Author-X-Name-First: Hongjun Author-X-Name-Last: Ye Author-Name: Xiang Ji Author-X-Name-First: Xiang Author-X-Name-Last: Ji Title: An X-shaped metasurface for high-efficiency ultra-wideband linear-to-circular and circular-to-linear polarization conversions Abstract: In this study, an X-shaped metasurface composed of an array of X-shaped metal patches printed on a grounded dielectric substrate and covered by a top dielectric layer is proposed for both linear-to-circular (LTC) and circular-to-linear (CTL) polarization conversions. Theoretical analysis and numerical simulations indicate that the metasurface can be used as both LTC and CTL reflective polarization converters. Under u- and v-polarized incidences, it can achieve LTC polarization conversion in the ultra-wide frequency band from 7.5 to 25.8 GHz with a relative bandwidth of 110%, and the polarization conversion rate (PCR) can be kept larger than 99.7% in the frequency range of 7.9-24.7 GHz. Moreover, under CP incidence, a high-efficiency ultra-wideband CTL polarization conversion can be achieved, the bandwidth and PCR are almost the same as those of the LTC polarization conversion. Finally, one experimental verification is carried out, and a reasonable agreement is observed between the simulation and experimental results. Journal: Journal of Electromagnetic Waves and Applications Pages: 661-671 Issue: 5 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2022.2164223 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2164223 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:5:p:661-671 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2158374_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Nagesh Kallollu Narayaswamy Author-X-Name-First: Nagesh Kallollu Author-X-Name-Last: Narayaswamy Author-Name: Nirupama Malavalli Prasad Author-X-Name-First: Nirupama Author-X-Name-Last: Malavalli Prasad Author-Name: Sweta Singh Author-X-Name-First: Sweta Author-X-Name-Last: Singh Author-Name: Rakesh Kumar Singh Author-X-Name-First: Rakesh Author-X-Name-Last: Kumar Singh Author-Name: Akhilesh Kumar Author-X-Name-First: Akhilesh Author-X-Name-Last: Kumar Author-Name: Brijesh Mishra Author-X-Name-First: Brijesh Author-X-Name-Last: Mishra Title: High-isolated, low correlation and wide frequency reconfigurable (2.1–4.2 GHz) MIMO antenna for cognitive radio applications Abstract: This paper proposes a unique and small (2508  mm2) penta-band frequency agile MIMO antenna based on RF switches for cognitive radio mobile, WLAN, WiMAX, and wireless sensing applications. Three RF switches generate five resonant bands at 2.1, 3, 3.5, 4, and 4.2 GHz in four usable states-100, 011, 111, 100, and 000, respectively. The proposed antenna's fractional bandwidth was 4.95 % (simulated) and 5.5 % (measured) in state-000, 3.09 % (simulated) and 2.8 % (measured) at a lower frequency (2.1 GHz), 2.12 % (simulated) and 2 % (measured) at higher frequency (4.2 GHz) in state-100, 12.5 % (simulated) and 12 % (measured) in state-011, and 4.6 % (simulated) and 4.7 % (measured) in state-111. A large peak gain of 3.6 dB at 4 GHz, maximum isolation of 32.2 dB at 3.5 GHz, significant radiation efficiency of 93.7% at 4GHz is obtained. At 4 GHz, a strong peak gain of 3.6 dB, maximum isolation of 32.2 dB at 3.5 GHz, and considerable radiation efficiency of 93.7 % are realised. For this work, MIMO parameters such as ECC (approx. 0), DG (approx.10dB), TARC (<0.5), MEG (−12 dB < MEG (dB) < −3 dB) and CCL (< 0.5 bit/s/Hz) were achieved. The suggested antenna was simulated, constructed, and tested, and the simulated results were found to be very close to the experimental findings. Journal: Journal of Electromagnetic Waves and Applications Pages: 605-628 Issue: 5 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2022.2158374 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2158374 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:5:p:605-628 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2192423_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Chao Li Author-X-Name-First: Chao Author-X-Name-Last: Li Author-Name: Hui-Chao Qi Author-X-Name-First: Hui-Chao Author-X-Name-Last: Qi Author-Name: Si-Yuan He Author-X-Name-First: Si-Yuan Author-X-Name-Last: He Title: Range profile analysis of buried objects in layered media based on efficient full-wave simulation Abstract: The high-resolution range profiles (RPs) of 3-D objects buried in layered media are investigated. In order to simulate the RPs efficiently, wideband scattered fields are calculated by a method of moments (MoM) based fast algorithm, i.e. characteristic basis function method (CBFM). To achieve fast frequency sweep, an adaptive frequency sampling strategy (AFS) is implemented to accelerate the broadband simulation. Then by using the inverse discrete Fourier transform (IDFT), RPs of the object are obtained. To validate the proposed approach, range locations are predicted qualitatively based on the ray theory. Moreover, the ray approach also enables the physical interpretation of the scattering mechanisms corresponding to the peaks, for example, the specular reflection, the edge diffraction, and the higher-order effects. Since different scattering centers (SCs) dominate in different directions, the RPs are aspect dependent. Furthermore, the RPs are also dependent on the lossy and dispersive effects of the layered medium. Numerical results demonstrate that the peaks are significantly reduced when the layered medium is lossy, especially those due to the higher-order interactions between the object and the interfaces. Journal: Journal of Electromagnetic Waves and Applications Pages: 752-765 Issue: 5 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2023.2192423 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2192423 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:5:p:752-765 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2187709_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Chengpan Yang Author-X-Name-First: Chengpan Author-X-Name-Last: Yang Author-Name: Feng Zhu Author-X-Name-First: Feng Author-X-Name-Last: Zhu Title: Time domain characteristics of lossy multiconductor transmission lines randomly excited by electromagnetic pulse Abstract: This paper provides a time domain method for solving the induced currents (and voltages) of frequency-dependent lossy multiconductor transmission lines (MTLs) model randomly excited by electromagnetic pulse (EMP) plane wave. The model is processed based on the generalized polynomial chaos expansion (gPCE) and improved finite difference time domain (FDTD). The improved FDTD method overcomes the shortcomings of the conventional method that oversimplifies the expression of conductor impedance. In addition, when quantifying the influence of uncertainty on induced values, general formula of the global sensitivity analysis is provided by defining the gPCE basis function sequence to solve the complicated search work. The verification shows that the improved FDTD method alone or combined with gPCE to solve the lossy MTLs model excited by EMP is superior to the conventional methods in solving time and accuracy. Finally, compared with the Monte Carlo method, the effectiveness of the sensitivity method is also verified. Journal: Journal of Electromagnetic Waves and Applications Pages: 672-692 Issue: 5 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2023.2187709 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2187709 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:5:p:672-692 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2164222_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Harry F. Contopanagos Author-X-Name-First: Harry F. Author-X-Name-Last: Contopanagos Title: Super-thin Frequency Selective Surfaces and waveguide filters based on Babinet-dual screens Abstract: We present a novel architecture for very thin Frequency Selective Surfaces (FSS) and waveguide passband filters based on resonantly transparent super-thin printed screens, transversely placed on the waveguide axis. The screens are based on stacked metal laminate layers where each layer is the negative print of each adjacent layer along the propagation axis. Hence, these filters are composed of stacked layers obeying the Babinet duality. We provide two optimized designs of such filters, operating both as Frequency-Selective Surfaces and as finite screens placed transversely inside a rectangular waveguide. We show that these optimized designs have very small thicknesses, relative to their performance. Therefore, they are an attractive candidate for replacing traditional bulky and heavy waveguide filters based on sparsely placed metallic posts along a substantial length of waveguide sections. Journal: Journal of Electromagnetic Waves and Applications Pages: 644-660 Issue: 5 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2022.2164222 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2164222 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:5:p:644-660 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2163191_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Saminathan Thiruvenkadam Author-X-Name-First: Saminathan Author-X-Name-Last: Thiruvenkadam Author-Name: Eswaran Parthasarathy Author-X-Name-First: Eswaran Author-X-Name-Last: Parthasarathy Title: Compact multiband monopole antenna design for IoT applications Abstract: In this work, a miniaturized quad-band monopole antenna design is presented for IoT applications. The proposed antenna comprises simple quarter-wavelength I-shaped, an inverted L-shaped, meander lines monopole radiators with microstrip feed line, tapered ground plane having dimension of $ 32 \times 15\,{\rm mm}^{2} $ 32×15mm2 and fabricated on an FR4 substrate. The radiation characteristics, such as reflection coefficient, VSWR, gain, efficiency, and radiation patterns, are analyzed from simulation and measurement results. The proposed quad-band antenna resonates at 1.8 (1.7–1.96) GHz, 2.4 (2.26–2.47) GHz, 3.35 (3.1–3.7) GHz, and 5.4 (5-5.65) GHz for GSM, WLAN, 5G, WiMAX applications respectively. Further, the proposed antenna has a fractional bandwidth of 14.4% at 1.8 GHz, 8.75% at 2.4 GHz, 17.9% at 3.35 GHz and 12.03 % at 5.4 GHz. It also exhibits omnidirectional radiation pattern with a gain of 1.5, 1.75, 2.5, and 3.7 dbi at 1.8, 2.4, 3.35, 5.4 GHz respectively and >75% total efficiency at its operating bands. The suitability of the designed antenna for IoT applications is validated through the hosting device model with copper sheet and plastic housing. The simulation and measurement results are having good agreement. Journal: Journal of Electromagnetic Waves and Applications Pages: 629-643 Issue: 5 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2022.2163191 File-URL: http://hdl.handle.net/10.1080/09205071.2022.2163191 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:5:p:629-643 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2191343_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Zhiwei Hu Author-X-Name-First: Zhiwei Author-X-Name-Last: Hu Author-Name: Haojie Zhao Author-X-Name-First: Haojie Author-X-Name-Last: Zhao Author-Name: Mark Kraman Author-X-Name-First: Mark Author-X-Name-Last: Kraman Author-Name: Wen Huang Author-X-Name-First: Wen Author-X-Name-Last: Huang Author-Name: Hao Tu Author-X-Name-First: Hao Author-X-Name-Last: Tu Author-Name: Lei Sang Author-X-Name-First: Lei Author-X-Name-Last: Sang Title: A beam-steering antenna with low deflecting-loss enabled by a miniaturized flexible lens Abstract: A miniaturized flexible lens is proposed for beam control of broadband antenna with low deflection loss. Different from traditional approaches to phase modulation, the three-segment principle presented in this article significantly lowers the maximum necessary phase difference generated by modulated waves, thus reducing the height of the lens and antenna profile. The phase modulation performance of the lens is reconfigured by adjusting the layout of the phase modulation units PMUs according to distribution requirements. Then, a Vivaldi antenna utilizing the miniaturized lens is designed, fabricated, and tested to demonstrate the system’s beam deflecting characteristics. The experimental results demonstrate the capability of the antenna to cover a deflecting range wider than [−20°, 19°] with deflecting loss below 1.4 dB throughout the entire 8–10 GHz working band. Over the operating band, the deflecting gain is greater than 8.7 dBi. Journal: Journal of Electromagnetic Waves and Applications Pages: 730-751 Issue: 5 Volume: 37 Year: 2023 Month: 03 X-DOI: 10.1080/09205071.2023.2191343 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2191343 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:5:p:730-751 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2212177_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Alexandr A. Shmat’ko Author-X-Name-First: Alexandr A. Author-X-Name-Last: Shmat’ko Author-Name: Eugene N. Odarenko Author-X-Name-First: Eugene N. Author-X-Name-Last: Odarenko Author-Name: Victoria N. Mizernik Author-X-Name-First: Victoria N. Author-X-Name-Last: Mizernik Title: Surface waves Fabry-Perot modes of the finite magnetophotonic crystal in Voigt configuration Abstract: We have solved the problem of plane wave scattering by a finite gyrotropic magnetophotonic crystal in the Voigt configuration. To find an analytical solution, the method of the Floquet-Bloch wave theory with Cauchy boundary conditions for a one-dimensional magnetophotonic crystal and the transfer matrix method were used. The reflection and transmission coefficients are obtained in analytical form for arbitrary material parameters of the gyrotropic layers of the crystal. The field distributions within the finite crystal are found in explicit form. The regime of excitation of modified Zenneck-Sommerfeld waves and a new regime of unusual gyrotropic surface waves with positive values of the effective permittivity of one of the crystal layers are revealed. The features of the distribution of surface wave fields for the considered regimes of all Fabry–Perot modes at full transmission are studied. The nonreciprocal properties of the considered crystals are established depending on the incidence angle sign. Journal: Journal of Electromagnetic Waves and Applications Pages: 827-851 Issue: 6 Volume: 37 Year: 2023 Month: 04 X-DOI: 10.1080/09205071.2023.2212177 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2212177 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:6:p:827-851 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2204405_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: D. Zh. Kurzhumbaev Author-X-Name-First: D. Zh. Author-X-Name-Last: Kurzhumbaev Author-Name: E. B. Mitberg Author-X-Name-First: E. B. Author-X-Name-Last: Mitberg Author-Name: D. S. Kalenov Author-X-Name-First: D. S. Author-X-Name-Last: Kalenov Author-Name: M. P. Parkhomenko Author-X-Name-First: M. P. Author-X-Name-Last: Parkhomenko Author-Name: I. S. Eremin Author-X-Name-First: I. S. Author-X-Name-Last: Eremin Author-Name: S. A. Urvanov Author-X-Name-First: S. A. Author-X-Name-Last: Urvanov Author-Name: A. R. Karaeva Author-X-Name-First: A. R. Author-X-Name-Last: Karaeva Author-Name: V. Z. Mordkovich Author-X-Name-First: V. Z. Author-X-Name-Last: Mordkovich Author-Name: S. V. von Gratowski Author-X-Name-First: S. V. Author-X-Name-Last: von Gratowski Title: Carbon nanotube thread as a material for flexible microwave absorbers Abstract: Microwave absorption properties are studied for flexible materials based on periodic gratings made of carbon nanotube (CNT) threads. Resonant absorption is observed by free space measurements in the frequency range from 26.5 to 40 GHz. Materials comprised of CNT thread gratings with different periods, a metal backplate, and an intermediate dielectric layer exhibit significant reflection losses (less than −45 dB). The shifts of peaks on the absorption spectra caused by changes in the thickness and rotations of the samples indicate the high sensitivity of the obtained results. Journal: Journal of Electromagnetic Waves and Applications Pages: 767-781 Issue: 6 Volume: 37 Year: 2023 Month: 04 X-DOI: 10.1080/09205071.2023.2204405 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2204405 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:6:p:767-781 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2204407_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Junwan Zhu Author-X-Name-First: Junwan Author-X-Name-Last: Zhu Author-Name: Jingrui Duan Author-X-Name-First: Jingrui Author-X-Name-Last: Duan Author-Name: Zhigang Lu Author-X-Name-First: Zhigang Author-X-Name-Last: Lu Author-Name: Zhanliang Wang Author-X-Name-First: Zhanliang Author-X-Name-Last: Wang Author-Name: Huarong Gong Author-X-Name-First: Huarong Author-X-Name-Last: Gong Author-Name: Yubin Gong Author-X-Name-First: Yubin Author-X-Name-Last: Gong Title: An elliptical beam-tunnel sine waveguide slow wave structure for G-band elliptical beam traveling wave tube Abstract: In order to improve the performance of sine waveguide (SW) traveling wave tube (TWT), an elliptical beam-tunnel sine waveguide (EBTSW) slow wave structure (SWS) is proposed. EBTSW-SWS not only has high interaction impedance in a relatively wide frequency band but also has an elliptical beam-tunnel. The simulation results of high-frequency characteristics show that, under the same dispersion, the passband of EBTSW-SWS increases by 30% compared to the SW-SWS, and the average interaction impedance of EBTSW-SWS is higher than that of SW-SWS in almost the whole passband. Moreover, the particle-in-cell (PIC) simulation results reveal that under the operating voltage of 20.8 kV and beam current of 150 mA, EBTSW-TWT can provide more than 70 W of saturated output power in the frequency range of 200-260 GHz, reaching the maximum power of 151 W at 220 GHz with the maximum electronic efficiency of 4.85%. Journal: Journal of Electromagnetic Waves and Applications Pages: 794-802 Issue: 6 Volume: 37 Year: 2023 Month: 04 X-DOI: 10.1080/09205071.2023.2204407 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2204407 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:6:p:794-802 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2204408_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Mustafa Kirlar Author-X-Name-First: Mustafa Author-X-Name-Last: Kirlar Author-Name: Mustafa Turkmen Author-X-Name-First: Mustafa Author-X-Name-Last: Turkmen Title: Ultra narrowband perfect absorber for refractive index sensing applications in mid-infrared region Abstract: In this study, a novel narrowband perfect absorber (NPA) with dual band resonance frequencies is presented. The proposed NPA absorbs over 99% of the incident laser beam in both resonance modes and it indicates high quality factor (Q = 135.2) resonance which is the highest for a perfect absorber performing in the mid-infrared region. In this work, the charge and current distributions for the corresponding resonance modes are investigated. The absorbance spectrum of the electric and magnetic field distributions is also obtained for the corresponding resonance modes. Furthermore, the detecting performance of the NPA is analyzed by covering the proposed device with a cladding layer. The figure of merit (FOM) and refractive index sensitivity (RIS) of the structure are calculated. Due to its high quality factor, enhanced electric and magnetic field responses, near unity absorbance for both resonance modes and tunable detecting characteristics the proposed NPA can be used in spectroscopy applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 803-813 Issue: 6 Volume: 37 Year: 2023 Month: 04 X-DOI: 10.1080/09205071.2023.2204408 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2204408 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:6:p:803-813 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2211282_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: T. Mary Neebha Author-X-Name-First: T. Mary Author-X-Name-Last: Neebha Author-Name: A. Diana Andrushia Author-X-Name-First: A. Diana Author-X-Name-Last: Andrushia Author-Name: P. Malin Bruntha Author-X-Name-First: P. Author-X-Name-Last: Malin Bruntha Author-Name: Atul Varshney Author-X-Name-First: Atul Author-X-Name-Last: Varshney Author-Name: R. Manjith Author-X-Name-First: R. Author-X-Name-Last: Manjith Author-Name: S. Dhanasekar Author-X-Name-First: S. Author-X-Name-Last: Dhanasekar Title: On the design of miniaturized C-shaped antenna based on artificial transmission line loading technique Abstract: This article presents an effective miniaturized antenna based on an artificial transmission line loading approach. The proposed antenna is a compact C-shaped radiating element backed by defected ground plane structure and fed by a line transition structure. The antenna is modelled to operate at 2.4 GHz with −32.99 dB return loss and operates from 2.33 GHz to 2.52 GHz with 77.55% fractional bandwidth and a gain value of 2.1 dBi. Equivalent circuits are extracted using the transmission line modelling technique. Moreover, the design has an overall substrate dimension of (20 × 30 × 1.6) mm3, which is suitable for compact wireless devices. Here antenna miniaturization is carried out through patch and ground extensions along with artificial transmission line structures incorporated. The antenna is fabricated and the measured result is in good agreement with the calculated and simulated results. In addition, by transmission line loading in the proposed design, the radiator is configured to work at 2.4 and 3.7 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 814-826 Issue: 6 Volume: 37 Year: 2023 Month: 04 X-DOI: 10.1080/09205071.2023.2211282 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2211282 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:6:p:814-826 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2204406_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Semih Korkmaz Author-X-Name-First: Semih Author-X-Name-Last: Korkmaz Author-Name: Mustafa Turkmen Author-X-Name-First: Mustafa Author-X-Name-Last: Turkmen Title: Dual-band plasmonic perfect absorber for refractive index sensing from mid- to near infrared region Abstract: A plasmonic perfect absorber (PA) utilizes high absorption of incident radiation and near-field enhancement which is so advantageous for many applications such as solar cell, infrared (IR) spectroscopy, and refractive index (RI) sensitivity. In this study, the numerically presented PA system has resonances from mid-infrared (MIR) to near-infrared (NIR) regions for different periodicities at 2.0, 2.4, and 2.8 µm. A fine-tuning mechanism is obtained to control the spectral response of PA through the geometrical parameters. Dual-band plasmonic resonances have nearly 98% absorption. Near-field intensity distributions are shown with the enhancement factor of 103 at the resonance frequencies. Refractive index sensitivity is also analyzed by embedding PA in different cladding mediums to show the sensing performance. Relationship between resonance wavelength and refractive index of the medium is observed for all resonant modes. The highest sensitivity value is 2382.48 nm/RIU and the figure of merit reaches as high as 28.29  RIU−1. Journal: Journal of Electromagnetic Waves and Applications Pages: 782-793 Issue: 6 Volume: 37 Year: 2023 Month: 04 X-DOI: 10.1080/09205071.2023.2204406 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2204406 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:6:p:782-793 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2214321_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Ankit Bhattacharjee Author-X-Name-First: Ankit Author-X-Name-Last: Bhattacharjee Author-Name: Santanu Dwari Author-X-Name-First: Santanu Author-X-Name-Last: Dwari Title: Active frequency selective surface-based 360° beam steering in two switchable frequency bands independently Abstract: A reconfigurable antenna with frequency agility and pattern-switching ability is presented in this paper. The proposed design comprises a planar and compact frequency reconfigurable monopole antenna and an active frequency selective surface (AFSS) with reconfigurable transmission and reflection properties in dual bands. The AFSS screen is divided into four sections and each section is composed of four FSS elements with only one PIN diode in each unit cell. The monopole antenna, which is situated at the center of the box-shaped AFSS to illuminate , can reconfigure its resonating frequency between 2.5 and 3.6 GHz with the help of only one PIN diode. With the help of this transformation ability of AFSS behavior electronically, the pattern can be steered across the entire X–Z plane in eight steps at two different operating frequencies independently. This antenna can be very useful in various wireless applications such as drones, small base stations, etc. Journal: Journal of Electromagnetic Waves and Applications Pages: 853-870 Issue: 7-9 Volume: 37 Year: 2023 Month: 06 X-DOI: 10.1080/09205071.2023.2214321 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2214321 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:7-9:p:853-870 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2216391_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: A. Torabi Author-X-Name-First: A. Author-X-Name-Last: Torabi Title: An efficient derivation of spatial Green's function of open-radiating rectangular cavity using CGF-CI technique Abstract: A new technique for efficient calculation of spatial Green's function of open-radiating rectangular cavity is presented. The method is based on separability assumption of the original structure and characteristic Green's function method. Using complex image (CI) technique in spectral domain and well-known Weyl's identity, a closed-form relation for spatial Green's function can be derived. To obtain more accurate closed-form Green's function, before applying CI, discrete spectrum contribution part of the derived relation is modified by replacing more accurate reflection coefficients of surface wave modes from walls of the open-radiating cavity. Verification of the derivations of the proposed method is shown for dielectric loaded metallic box which is a separable structure. Method of moment + multilevel fast multipole method solution and also exact numerical integration approach for open-radiating rectangular cavity are considered to search the accuracy as well as speed of the proposed method. It is shown that the main advantage of the proposed method lies in its speed as well as its simple implementation while the accuracy is preserved. Journal: Journal of Electromagnetic Waves and Applications Pages: 909-922 Issue: 7-9 Volume: 37 Year: 2023 Month: 06 X-DOI: 10.1080/09205071.2023.2216391 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2216391 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:7-9:p:909-922 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2214683_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Chenyin Yu Author-X-Name-First: Chenyin Author-X-Name-Last: Yu Author-Name: Shuhui Yang Author-X-Name-First: Shuhui Author-X-Name-Last: Yang Author-Name: Yinchao Chen Author-X-Name-First: Yinchao Author-X-Name-Last: Chen Author-Name: Wensong Wang Author-X-Name-First: Wensong Author-X-Name-Last: Wang Title: Investigation of a quad-band microstrip antenna using a DNG-MTM radiation patch Abstract: A compact quad-band microstrip antenna based on double-negative metamaterial (DNG-MTM) is proposed in this letter. To realize miniaturization and multi-band characteristics, a novel coplanar tri-band DNG-MTM unit, consisted of an epsilon negative (ENG) MTM and a mu negative (MNG) MTM, is firstly designed and employed as the antenna radiator. The antenna’s electrical dimension is 0.23λ0 × 0.37λ0, where λ0 is the free space wavelength at 3.5 GHz. The peak gain is 5.3, 6.3, 5.8, and 3.4 dBi and the radiation efficiency reaches 96%, 82%, 91% and 86% for 2.84–3.55 (22.2%), 6.6–7.18 (8.4%), 7.44–9.08 (19.9%), and 11.1–14.74 (28.2%) GHz, respectively. These four bands have effectively covered 5G (3.5-GHz), C-band, X-band, and Ku-band for satellite systems. The size of the proposed antenna has been reduced by about 55% in comparison to the traditional method. Journal: Journal of Electromagnetic Waves and Applications Pages: 871-883 Issue: 7-9 Volume: 37 Year: 2023 Month: 06 X-DOI: 10.1080/09205071.2023.2214683 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2214683 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:7-9:p:871-883 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2216390_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Wentao Yang Author-X-Name-First: Wentao Author-X-Name-Last: Yang Author-Name: Xi Zeng Author-X-Name-First: Xi Author-X-Name-Last: Zeng Author-Name: Lei Zheng Author-X-Name-First: Lei Author-X-Name-Last: Zheng Author-Name: Xian Wang Author-X-Name-First: Xian Author-X-Name-Last: Wang Author-Name: Rongzhou Gong Author-X-Name-First: Rongzhou Author-X-Name-Last: Gong Title: Oblique incidence-insensitive metamaterial absorber using strong magnetic coupling resonance for low-frequency microwave absorption Abstract: In this work, we presented an oblique incidence-insensitive metamaterial absorber (MA) based on the strong magnetic coupling resonance using the printed circuit board process, and the spacer is produced by a typical magnetic absorber material (MAM). As for reflection loss (RL) at oblique angles, it can achieve high-efficiency absorption for both transverse-electric (TE) and transverse-magnetic (TM) polarizations with a wide angular range from 0° to 60° in the low frequency of 2.33 GHz to 3.44 GHz. In addition, the magnetic coupling mechanism of the metamaterial absorber was deeply analyzed. Comparing the results of the simulation and experiment, it displays excellent absorption performance of the proposed absorber in TE and TM modes under large oblique incidence angles. Journal: Journal of Electromagnetic Waves and Applications Pages: 898-908 Issue: 7-9 Volume: 37 Year: 2023 Month: 06 X-DOI: 10.1080/09205071.2023.2216390 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2216390 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:7-9:p:898-908 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2216392_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Niten Kumar Panda Author-X-Name-First: Niten Kumar Author-X-Name-Last: Panda Author-Name: Sudhakar Sahu Author-X-Name-First: Sudhakar Author-X-Name-Last: Sahu Author-Name: Sraddhanjali Mohapatra Author-X-Name-First: Sraddhanjali Author-X-Name-Last: Mohapatra Title: Polarization insensitive multiband metasurface absorber for L, C, and X band applications Abstract: An ultrathin, multiband, polarization insensitive with wide angle stability metasurface absorber having unitcell dimension $ 0.119\lambda _{0} \times 0.119\lambda _{0} \times 0.022\lambda _{0} $ 0.119λ0×0.119λ0×0.022λ0 $ {\rm mm}^{3} $ mm3 is proposed ( $ \lambda _{0} $ λ0 is the free space wavelength at 1.6 GHz). The four-fold symmetry of the unitcell makes it insensitive to TE and TM polarizations. This metasurface follows the sub-quarter wavelength thickness including an air gap of 2.5 mm and metal backing. The proposed unitcell of the metamaterial absorber (MMA) is designed by parametric optimization and has absorption peaks in L, C, and X bands. This absorber is suitable for applications like radar cross section reduction, isolation, and stealth technologies. The lumped SMD resistors are used to enhance absorption peaks simultaneously in all bands mentioned above. This metasurface has absorptivity of 95%, 99%, 97% & 94% at 1.6 GHz, 5 GHz, 7.5 GHz and 10.2 GHz respectively. This is a polarization-insensitive absorber showing stable absorption for different incidence angles between $ 0^{\circ } $ 0∘ and $ 90^{\circ } $ 90∘ at the above-given frequencies. The absorption effect has been studied by investigating the filter effect from the equivalent circuit modeling using surface current distribution and normalized impedance. The proposed structure has been fabricated and its measurement results agree well with the simulated one. Journal: Journal of Electromagnetic Waves and Applications Pages: 923-937 Issue: 7-9 Volume: 37 Year: 2023 Month: 06 X-DOI: 10.1080/09205071.2023.2216392 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2216392 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:7-9:p:923-937 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2214684_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Diptiranjan Samantaray Author-X-Name-First: Diptiranjan Author-X-Name-Last: Samantaray Author-Name: Somak Bhattacharyya Author-X-Name-First: Somak Author-X-Name-Last: Bhattacharyya Title: A metasurface-backed planar low-profile dual-band monopole antenna Abstract: This paper discusses a low-profile, planar, efficient, and directed CPW-fed monopole antenna with a metasurface (MS) for WLAN as well as modern civil and military applications. A stacked 7 × 7 order metasurface (MS) and CPW-fed slotted patch antenna are sandwiched together to create the metasurface antenna (MSA). The overall size of the proposed prototype is 0.25λ0 × 0.25λ0 × 0.06λ0 only, where λ0 is the free-space wavelength at 2.34 GHz. This antenna has fractional bandwidths of 6.8% and 53.8% at two different frequencies of 2.34 and 8.94 GHz, respectively. With a peak gain of 8.7 dBi and radiation efficiency of 91.1% at 11.51 GHz, the antenna offers directional radiation characteristics in both the E- and H-planes. A comparable circuit model for the proposed prototype has also been described in order to analyze the outcomes of the electromagnetic simulation. The intended prototype has been fabricated, and the experimentally measured results closely resemble the simulated ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 884-897 Issue: 7-9 Volume: 37 Year: 2023 Month: 06 X-DOI: 10.1080/09205071.2023.2214684 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2214684 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:7-9:p:884-897 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2220145_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Mohammad Ahmad Salamin Author-X-Name-First: Mohammad Ahmad Author-X-Name-Last: Salamin Author-Name: Asmaa Zugari Author-X-Name-First: Asmaa Author-X-Name-Last: Zugari Author-Name: Mohammad Alibakhshikenari Author-X-Name-First: Mohammad Author-X-Name-Last: Alibakhshikenari Author-Name: Chan Hwang See Author-X-Name-First: Chan Hwang Author-X-Name-Last: See Author-Name: Raed Abd-Alhameed Author-X-Name-First: Raed Author-X-Name-Last: Abd-Alhameed Author-Name: Ernesto Limiti Author-X-Name-First: Ernesto Author-X-Name-Last: Limiti Title: Compact highly isolated dual-band 4-port MIMO antenna for sub-6 GHz applications Abstract: In this work, a compact 4-element multiple-input multiple-output (MIMO) antenna system is presented for sub-6 GHz applications. A modified M-shaped strip is used to form each antenna element in the MIMO system. To improve performance, a rectangular-shaped area is etched on the opposite side of each element in the ground plane. The antenna size is 100 × 60 mm2. Most interestingly, the port isolation is improved by rotating the etched areas and the corresponding radiating elements. This one-of-a-kind approach aided in the development of a highly isolated MIMO antenna with a small footprint. The theory of characteristic modes (TCM) is used to analyze the behavior of rotating the etched areas in the ground of the antenna. The antenna provides significant port isolation above 20 dB, stable radiation patterns, and an outstanding ECC less than 0.01. The design is simple and compact, making it suitable for MIMO operation in handheld devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 1023-1043 Issue: 10-12 Volume: 37 Year: 2023 Month: 08 X-DOI: 10.1080/09205071.2023.2220145 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2220145 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:10-12:p:1023-1043 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2218559_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Guilherme L. F. Brandão Author-X-Name-First: Guilherme L. F. Author-X-Name-Last: Brandão Author-Name: Elson J. Silva Author-X-Name-First: Elson J. Author-X-Name-Last: Silva Author-Name: Ursula C. Resende Author-X-Name-First: Ursula C. Author-X-Name-Last: Resende Title: A semi-analytical method to extract the characterization parameters of artificial magnetic conductor metasurfaces using generalized boundary conditions Abstract: In this work, a characterization procedure of Artificial Magnetic Conductor (AMC) metasurfaces based on analytical expressions developed using the Generalized Boundary Conditions (GBCs) model is presented. The correlation between the surface susceptibilities of the PEC scatterers and the main frequency points used in the characterization of AMCs are established. Then the susceptibilities of square patch, square loop, Jerusalem cross and second iteration Minkowski fractal PEC scatterers are obtained by two sets of simulations and are used to calculate profiling frequencies and stability parameters. The detailed characterization procedure is presented and the flexibility and effectiveness of the proposed method are compared to full-wave numerical simulations. Journal: Journal of Electromagnetic Waves and Applications Pages: 999-1010 Issue: 10-12 Volume: 37 Year: 2023 Month: 08 X-DOI: 10.1080/09205071.2023.2218559 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2218559 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:10-12:p:999-1010 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2216394_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Soni Singh Author-X-Name-First: Soni Author-X-Name-Last: Singh Author-Name: S. P. Singh Author-X-Name-First: S. P. Author-X-Name-Last: Singh Author-Name: Dharmendra Singh Author-X-Name-First: Dharmendra Author-X-Name-Last: Singh Title: Compact conformal metasurface antenna for hyperthermia applications Abstract: In this paper, the design, analysis and evaluation of a new compact conformal metasurface (MTS)-based bow-tie slot antenna is presented for hyperthermia treatment of cancer. A bow-tie slot antenna in close proximity with tissue designed at 2.45 GHz was used to excite the MTS layer, which is made of a 4 × 4 uniform array of square unit cells. The proposed MTS-based antenna is compact and provides enhanced penetration depth in the tissue medium as compared to the bow-tie antenna only. To verify the design concept, both the proposed MTS-based antenna and bow-tie antenna were fabricated, and the measured results are well anticipated. Finally, the MTS applicator is terminated with water bolus and tissue to characterize its hyperthermia performance in a real scenario. The key features of the proposed MTS applicator include wide impedance bandwidth (stable hyperthermia performance), enhanced penetration depth and effective field size, single-layer structure and ease of fabrication. Journal: Journal of Electromagnetic Waves and Applications Pages: 950-965 Issue: 10-12 Volume: 37 Year: 2023 Month: 08 X-DOI: 10.1080/09205071.2023.2216394 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2216394 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:10-12:p:950-965 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2216393_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Wenbin Yan Author-X-Name-First: Wenbin Author-X-Name-Last: Yan Author-Name: Qunsheng Cao Author-X-Name-First: Qunsheng Author-X-Name-Last: Cao Author-Name: Yi Wang Author-X-Name-First: Yi Author-X-Name-Last: Wang Title: Analysis of electromagnetic/thermal coupling of Debye media using HIE-FDTD method Abstract: In this paper, the multi-physical working mechanism of the Debye dispersive media is studied in detail, and the coupling analysis of Maxwell's and heat conduction equations is carried out. The hybrid-implicit-explicit finite difference time domain (HIE-FDTD) method is applied to accelerate calculation of the electromagnetic(EM). The Debye model, introduced to HIE-FDTD through the auxiliary difference equation (ADE) technique by utilizing polarization current, describes the dispersion characteristics of a water-based absorber. In addition, a new expression of transient power loss density is proposed with the polarization current, which overcomes the negative power loss in the traditional method and makes the computation more accurate. Finally, the analysis proves that the ADE-HIE-FDTD method has good performance in the EM-thermal coupling calculation, and the absorption rate of the absorber shows the interaction effect between temperature distribution and dielectric material. Journal: Journal of Electromagnetic Waves and Applications Pages: 939-949 Issue: 10-12 Volume: 37 Year: 2023 Month: 08 X-DOI: 10.1080/09205071.2023.2216393 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2216393 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:10-12:p:939-949 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2220091_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Mettu Goutham Reddy Author-X-Name-First: Mettu Goutham Author-X-Name-Last: Reddy Author-Name: Nrusingha Charan Pradhan Author-X-Name-First: Nrusingha Charan Author-X-Name-Last: Pradhan Author-Name: S. S. Karthikeyan Author-X-Name-First: S. S. Author-X-Name-Last: Karthikeyan Title: Investigation on tuning capabilities of self-diplexing antenna using different liquid dielectrics Abstract: This article investigates the possibilities of frequency tuning of a Self-diplexing antenna (SDA) using different liquid dielectrics. Tuning analysis is carried out using the fluidic pockets introduced into the substrate by drilling blind vias starting at the bottom layer. To examine the frequency tuning, the pockets can be filled with either air, olive oil, transformer oil, acetone, or distilled water and sealed with copper tape. The experimental results demonstrate that the proposed antenna can be configured to operate in the 3.25 to 3.52 GHz and 4.5 to 5.04 GHz bands. The proposed SDA is designed and fabricated on a substrate of 1.575 mm thick Rogers 5880 ( $ \epsilon _r $ ϵr = 2.2 and tan δ = 0.0009). It is observed that frequency shift is more when using higher permittivity fluids. The proposed antenna model has competitive features such as simple design, compact size ( $ 0.34 \lambda _g^2 $ 0.34λg2), better isolation (>30 dB), and fine-tuning, which makes it suitable for modern multiband and multifunctional gadgets. The simulated and measured circuit responses are in good agreement. Journal: Journal of Electromagnetic Waves and Applications Pages: 1011-1022 Issue: 10-12 Volume: 37 Year: 2023 Month: 08 X-DOI: 10.1080/09205071.2023.2220091 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2220091 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:10-12:p:1011-1022 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2218044_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Ramyakrishna Enugonda Author-X-Name-First: Ramyakrishna Author-X-Name-Last: Enugonda Author-Name: V K Anandan Author-X-Name-First: V K Author-X-Name-Last: Anandan Author-Name: Basudeb Ghosh Author-X-Name-First: Basudeb Author-X-Name-Last: Ghosh Title: Application of empirical mode decomposition for denoising and ground clutter removal on weather radar signals Abstract: Proper detection and estimation of signal and noise power measurements are important to generate the best quality of meteorological data products such as Reflectivity, Velocity and Spectrum width. In order to obtain the best quality radar products, it is desirable to compute meteorological parameters by estimating noise power and removal of ground clutter. This paper attempts to study the Empirical Mode Decomposition (EMD) denoising techniques on weather radar signals in the presence of noise and ground clutter. Different methods of EMD based denoising techniques have been considered and applied to the weather signals to check the best performance of the denoising and clutter removal technique. The limitations of these methods are brought out through simulation analysis. To overcome these limitations, this paper proposes a new method for denoising and clutter removal in weather signals. This method is a modified version of the correlation-based EMD Interval Threshold (IT) measurements. Moments have been estimated from these techniques and compared with conventional methods like Pulse pair techniques. Journal: Journal of Electromagnetic Waves and Applications Pages: 966-998 Issue: 10-12 Volume: 37 Year: 2023 Month: 08 X-DOI: 10.1080/09205071.2023.2218044 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2218044 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:10-12:p:966-998 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2224081_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Kallollu Narayaswamy Nagesh Author-X-Name-First: Kallollu Narayaswamy Author-X-Name-Last: Nagesh Author-Name: Penmatsa Krishna Kanth Varma Author-X-Name-First: Penmatsa Author-X-Name-Last: Krishna Kanth Varma Author-Name: Brijesh Kumar Author-X-Name-First: Brijesh Author-X-Name-Last: Kumar Author-Name: Rakesh Kumar Singh Author-X-Name-First: Rakesh Kumar Author-X-Name-Last: Singh Author-Name: Brijesh Mishra Author-X-Name-First: Brijesh Author-X-Name-Last: Mishra Author-Name: Dinesh Kumar Singh Author-X-Name-First: Dinesh Kumar Author-X-Name-Last: Singh Title: 4-Port MIMO antenna with novel isolator conducting structure for sub-1 GHz/sub-6 GHz and RF-energy harvesting applications Abstract: A 4-port MIMO antenna with a novel isolator structure for sub-1GHz/sub-6GHz and RF-energy harvesting applications is presented in this research. The proposed antenna is investigated systematically at 2.6 GHz design frequency with four distinct stages: STEP-1, STEP-2, STEP-3 and STEP-4 and an optimal design (STEP-4: $ 0.5\lambda \times 0.7\lambda \times 0.014\lambda $ 0.5λ×0.7λ×0.014λ mm3) is chosen for further study. A unique isolation structure was developed between two identical elements separated by $ 0.077\lambda $ 0.077λ, resulting an improved isolation of greater than 14 dB at 0.9 GHz and greater than 18 dB at 2.6 GHz is obtained. The suggested antenna resonates at 900 MHz-simulated & measured and 2.6 GHz-simulated & 2.8 GHz-measured with simulated fractional bandwidth/resonating band of 24.6%/0.778–1 GHz & 20.7%/2.4–2.94 GHz and a measured fractional bandwidth/resonating band of 17.8%/0.83–0.99 GHz & 21%/2.41–3 GHz at lower and upper resonating frequencies respectively. A peak gain of 1.5 dB at 900 MHz and 4.2 dB at 2.8 GHz has been obtained. The SAR values of less than 0.5 and 1.6 W/kg and radiation efficiencies of 74.7% and 90% at 900 MHz and 2.8 GHz were obtained, respectively. The suggested antenna's MIMO performance is simulated using electromagnetic tool HFSS in terms of ECC, DG, TARC, MEG and CCL, and the obtained results are experimentally verified. Further, the proposed antenna is tested for harvesting applications wherein 9.5 mW of harvested power, 76.45% power conversion efficiency (PCE), 4V harvested voltage, current 2.4mA and 12.46 mW Friis equation output at 915 MHz and 26.98 mW of harvested power, 69.5% power conversion efficiency, 5V harvested voltage, current 5.4 mA and 38.8 mW Friis equation output at 2.5 GHz are recorded. Journal: Journal of Electromagnetic Waves and Applications Pages: 1082-1105 Issue: 13 Volume: 37 Year: 2023 Month: 09 X-DOI: 10.1080/09205071.2023.2224081 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2224081 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:13:p:1082-1105 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2224080_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Nicola Anselmi Author-X-Name-First: Nicola Author-X-Name-Last: Anselmi Author-Name: Paolo Rocca Author-X-Name-First: Paolo Author-X-Name-Last: Rocca Author-Name: Andrea Massa Author-X-Name-First: Andrea Author-X-Name-Last: Massa Title: Tolerance analysis of reconfigurable monopulse linear antenna arrays through interval arithmetic Abstract: The tolerance of reconfigurable monopulse linear arrays on the uncertainties of the excitation amplitudes is analyzed with a method based on the rules of the interval arithmetic (IA) and analytic bounds for the sum and the difference power patterns are computed. Thanks to the reliability and the computational efficiency of such an IA-based formulation in deriving conservative and narrow pattern bounds, which include all possible pattern deviations, an innovative strategy is proposed for the worst-case performance analysis when dealing with tolerances on different parts of the beam forming network. Representative numerical examples both validate the formulation at hand and prove the effectiveness of the arising worst-case tool. Journal: Journal of Electromagnetic Waves and Applications Pages: 1066-1081 Issue: 13 Volume: 37 Year: 2023 Month: 09 X-DOI: 10.1080/09205071.2023.2224080 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2224080 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:13:p:1066-1081 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2216389_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Chen Su Author-X-Name-First: Chen Author-X-Name-Last: Su Author-Name: Chuanyun Zou Author-X-Name-First: Chuanyun Author-X-Name-Last: Zou Author-Name: Liangyu Jiao Author-X-Name-First: Liangyu Author-X-Name-Last: Jiao Title: Chipless RFID identification based on time reversal algorithm Abstract: A chipless RFID identification based on time reversal algorithm is presented in this work. The key problems affecting the reliability of chipless RFID identification are analyzed by using the energy focusing feature of time reversal algorithm. Analysis carried out on the energy focusing model revealed that the time reversal array can realize the multi-antenna energy focusing at the tag, so as to improve the reading distance of chipless RFID tag. Furthermore, time reversal energy self-focusing algorithm was used to suppress the noise come from other scatters near the tag. Multi-tag identification can be realized by the application of selective focusing algorithm. MIMO time reveal antenna array and C shaped resonators chipless RFID tag simulation model is constructed to verify the correctness of the proposed method. The results show that two chipless RFID tags with a distance of 0.2 m in azimuth can be identified from 1 m away. Journal: Journal of Electromagnetic Waves and Applications Pages: 1045-1065 Issue: 13 Volume: 37 Year: 2023 Month: 09 X-DOI: 10.1080/09205071.2023.2216389 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2216389 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:13:p:1045-1065 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2227392_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Zhirong Li Author-X-Name-First: Zhirong Author-X-Name-Last: Li Author-Name: Min Zhong Author-X-Name-First: Min Author-X-Name-Last: Zhong Author-Name: Liangyun Zang Author-X-Name-First: Liangyun Author-X-Name-Last: Zang Author-Name: Jiaqun Chen Author-X-Name-First: Jiaqun Author-X-Name-Last: Chen Title: Optimization and modulation of a multiband multimode metamaterial absorber and its application in healthy hotel indoor gas sensing Abstract: Here, a multiple modes metamaterial absorber with four peaks was proposed and verified. All absorption peaks were excited by the multiple modes coupling between adjacent unit cells. By increasing the structural parameter D, absorption peaks were strengthened and shifteded to the low-frequency region. When the lattice constant P was increased, these peaks were decreased and shifteded to the high-frequency region. Similarly, when the dielectric layer thickness t3 was gradually increased, these absorption peaks were weakened. Temperature was gradually increased, these absorption peaks were gradually reduced and shifteded to the high-frequency region. The multi-mode coupling effetct between unit cells was important to the performance of the metamaterial absorber. Journal: Journal of Electromagnetic Waves and Applications Pages: 1122-1138 Issue: 13 Volume: 37 Year: 2023 Month: 09 X-DOI: 10.1080/09205071.2023.2227392 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2227392 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:13:p:1122-1138 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2226332_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Yanhong Xu Author-X-Name-First: Yanhong Author-X-Name-Last: Xu Author-Name: Peipei Dong Author-X-Name-First: Peipei Author-X-Name-Last: Dong Author-Name: Anyi Wang Author-X-Name-First: Anyi Author-X-Name-Last: Wang Title: Design of a high isolation tri-band MIMO antenna for coal mine applications Abstract: In this paper, a tri-band multiple-input multiple-output (MIMO) antenna with high isolation characteristic is designed and fabricated for coal mine applications. It is composed of two symmetrical trident planar monopoles which can achieve tri-band characteristics. The isolation between the elements is higher than 20 dB across the whole frequency region by firstly placing the two elements symmetrically, loading a T-shaped branch and etching two rectangular slots on the ground successively. The proposed antenna can operate at three bands, i.e., 1.85∼2.70 GHz, 3.24∼3.99 GHz and 4.65∼5.80 GHz, which simultaneously cover the operating frequency band of WiMAX, WiFi, 4G, and 5G New Radio (NR) for mining. Good agreements can be observed between the simulated and measured results. The designed tri-band MIMO antenna has the advantages of low profile, compact structure and easy to conform with the platform, thus having a broad prospect in coal mine applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1106-1121 Issue: 13 Volume: 37 Year: 2023 Month: 09 X-DOI: 10.1080/09205071.2023.2226332 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2226332 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:13:p:1106-1121 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2230183_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Jiu-Fu Ruan Author-X-Name-First: Jiu-Fu Author-X-Name-Last: Ruan Author-Name: Da-Wei Zhu Author-X-Name-First: Da-Wei Author-X-Name-Last: Zhu Author-Name: Zhi Tao Author-X-Name-First: Zhi Author-X-Name-Last: Tao Author-Name: Rui-Zhi Zou Author-X-Name-First: Rui-Zhi Author-X-Name-Last: Zou Author-Name: Sheng-Min Pan Author-X-Name-First: Sheng-Min Author-X-Name-Last: Pan Title: Wideband THz metamaterial absorber based on unpatterned resistive-sheet and water layers Abstract: A metamaterial absorber (MA) based on unpatterned resistive-sheet and water layers is proposed. It can provide wideband absorption with the absorptivity over 90% from 162 GHz to 1.5 THz and the relative bandwidth is high up to 161%. The anti-parallel surface currents between the layers of resistive-sheet and ground metal produce magnetic resonance, which contributes to a portion of the absorption. It is found that the water layer plays a leading role in the broadband strong absorption and the main power loss is concentrated in the water layer, which is mainly attributed to magnetic resonance at the border between water layer and PDMS layer. In addition, the absorber has polarization insensitivity and good stability at wide incident angles. The design of the proposed absorber is validated by the consistency between the simulated and calculated results. This work may provide a simple and time-saving approach to design wideband MAs. Journal: Journal of Electromagnetic Waves and Applications Pages: 1221-1233 Issue: 14 Volume: 37 Year: 2023 Month: 09 X-DOI: 10.1080/09205071.2023.2230183 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2230183 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:14:p:1221-1233 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2227955_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Ramesh Amugothu Author-X-Name-First: Ramesh Author-X-Name-Last: Amugothu Author-Name: Vakula Damera Author-X-Name-First: Vakula Author-X-Name-Last: Damera Title: Wide incidence angle triple-band metamaterial EM wave absorber at X and Ku frequency band applications Abstract: This paper proposes a novel design for a metamaterial-based polarisation insensitive electromagnetic wave absorber for the X- and Ku-frequency bands. The Structure consists of FR4 substrates with modified split-ring resonators operating across three frequencies. Optimal design was achieved by varying the split gap and unit cell size. The proposed design has three absorption peaks (11.6, 14.04, and 16.56 GHz) with 99.88%, 99.72%, and 96.41% absorption efficiencies, respectively. A metamaterial unit cell prototype as well as an array of 13 x 13 unit cells, measuring 170 x 170 mm, were fabricated. Simulated and measured results have shown good agreement. The performance of the metamaterial absorber array is validated through measurement results. Because of its high efficiency and good quality factor, the proposed metamaterial absorber is suited for electromagnetic shielding and sensor applications. Furthermore, simulation results are used to analyse the scalability of the proposed structure. Journal: Journal of Electromagnetic Waves and Applications Pages: 1208-1220 Issue: 14 Volume: 37 Year: 2023 Month: 09 X-DOI: 10.1080/09205071.2023.2227955 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2227955 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:14:p:1208-1220 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2227609_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Hongxin Qi Author-X-Name-First: Hongxin Author-X-Name-Last: Qi Author-Name: Zaigao Chen Author-X-Name-First: Zaigao Author-X-Name-Last: Chen Author-Name: Yu Liu Author-X-Name-First: Yu Author-X-Name-Last: Liu Author-Name: Yuheng Wang Author-X-Name-First: Yuheng Author-X-Name-Last: Wang Title: A body-of-revolution discontinuous Galerkin time domain method based on curved mesh for Maxwell equations Abstract: Numerical simulation of body-of-revolution (BoR) or axisymmetric structures for scattering and radiation problems has a broad spectrum of technology applications in microwave and optical engineering. In this work, we propose a high-order BoR discontinuous Galerkin time-domain method (BoR-DGTD) for solving Maxwell equations in the cylindrical coordinate system. The presented approach is based on $ \sin (m\varphi ) $ sin⁡(mφ) or $ \cos (m\varphi ) $ cos⁡(mφ) (m is the mode number and φ is the azimuth) expansions for different field components and thus yields a real-valued final system of equations. It saves half of the unknowns as compared to the existing method in which all the field components are assumed to have the same φ variation, i.e. $ e^{im\varphi } $ eimφ. In contrast to the common practice of deriving variational formulation for the BoR Maxwell equations on two-dimensional grids in the meridian plane, we build it on three-dimensional coaxial toroidal subdomains. As a result, the singularity difficulty induced by the cylindrical coordinates is eliminated naturally. In addition, for BoR with curved material interfaces in the angular cross-section, a solution using curved grids in conjunction with the low-storage weight-adjusted approximation scheme is provided, which significantly enhances the simulation quality. Particularly, to achieve a set of optimized interpolation shape functions for the isoparametric transformation, an essential assistant in calculating the coefficient matrices, a heuristic procedure is developed to properly position the geometric control points on the curved grids. Some numerical experiments are conducted to demonstrate the accuracy and performance of our proposed BoR-DGTD method. Journal: Journal of Electromagnetic Waves and Applications Pages: 1139-1161 Issue: 14 Volume: 37 Year: 2023 Month: 09 X-DOI: 10.1080/09205071.2023.2227609 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2227609 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:14:p:1139-1161 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2227849_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Furkan Hasan Sakaci Author-X-Name-First: Furkan Hasan Author-X-Name-Last: Sakaci Author-Name: Suayb Cagri Yener Author-X-Name-First: Suayb Cagri Author-X-Name-Last: Yener Title: Electromagnetic emission measurement prediction of buck-boost converter circuits using machine learning methods Abstract: In this paper, a prediction system has been developed using machine learning techniques to obtain the conduction emission levels ensure they remain below the limit values specified in test standards. An LED (Light-emitting diode) driver circuit based on a buck-boost type DC-DC converter has been employed in the experiments. Standards-compliant conducted emission testing processes have been performed and measurement results have been used to generate datasets. These datasets have been organized and processed according to the targeted machine learning methods. GPR, has achieved the highest success rate of 99% among ANN and regression methods. In order to improve the performance in EMI harmonic prediction, training was conducted using deep learning, and the obtained model has a mean squared error of 0.78. The harmonics are well captured with the method and the results are in good agreement with measurements. Consequently, the number of required pre-compatibility tests for a similar topology can be significantly reduced. Journal: Journal of Electromagnetic Waves and Applications Pages: 1187-1207 Issue: 14 Volume: 37 Year: 2023 Month: 09 X-DOI: 10.1080/09205071.2023.2227849 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2227849 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:14:p:1187-1207 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2227624_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Srikumar Sandeep Author-X-Name-First: Srikumar Author-X-Name-Last: Sandeep Author-Name: Albin Gasiewski Author-X-Name-First: Albin Author-X-Name-Last: Gasiewski Author-Name: Andrew F. Peterson Author-X-Name-First: Andrew F. Author-X-Name-Last: Peterson Title: Application of cylindrical IE-GSTC to physical metasurfaces Abstract: The cylindrical Integral Equation -- Generalized Sheet Transition Condition (IE-GSTC) is validated by applying it to physical metasurfaces, i.e. metasurfaces defined by material properties and dimensions rather than by susceptibility tensor components. The previously reported IE-GSTC, which was formulated for zero thickness GSTC discontinuities, is extended to handle the finite thickness of physical metasurfaces. A simple analytical approach is used to extract the bianisotropic susceptibility tensor of concentric, multilayered, magneto-dielectric shells. Plane wave scattering by a physical metasurface constructed of four segments of multilayered, magneto-dielectric metasurface scatterers is used as an example problem to validate cylindrical IE-GSTC. A second example considers an opening on the cylindrical metasurface, confirming IE-GSTC can handle metasurfaces with openings. Third example is that of plane wave scattering by an eight segment metasurface. Good agreement is obtained between IE-GSTC results and full wave simulation results for all the cases. The paper concludes with a novel technique to handle PEC segments embedded in a cylindrical metasurface. Journal: Journal of Electromagnetic Waves and Applications Pages: 1162-1186 Issue: 14 Volume: 37 Year: 2023 Month: 09 X-DOI: 10.1080/09205071.2023.2227624 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2227624 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:14:p:1162-1186 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2230494_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Liaqat Ali Author-X-Name-First: Liaqat Author-X-Name-Last: Ali Author-Name: Bilal Ahmed Author-X-Name-First: Bilal Author-X-Name-Last: Ahmed Title: Peristaltic mechanism in an inclined asymmetric channel soaked with porous media and under magnetic effects: numerical simulation equipped with finite element method Abstract: This study is proposed for the numerical simulation of the peristaltic mechanism using the finite element method with the Galerkin residual technique to explore peristaltic transportation under the action of an externally applied magnetic field passing through an inclined asymmetric channel saturated with porous media. The Navier-stokes equations are solved for the peristaltic mechanism non-linearly by the exemption of lubrication theory to study the inertial effects. The numerical simulations and results are obtained by applying the finite element method based on quadratic triangular elements. It is observed that pressure rise per wavelength is enhanced by increasing the angle of inclination $ 0.8 \le Q \le 1.4 $ 0.8≤Q≤1.4. Journal: Journal of Electromagnetic Waves and Applications Pages: 1235-1257 Issue: 15 Volume: 37 Year: 2023 Month: 10 X-DOI: 10.1080/09205071.2023.2230494 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2230494 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:15:p:1235-1257 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2234381_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Qian-Qian Li Author-X-Name-First: Qian-Qian Author-X-Name-Last: Li Author-Name: Hai-Feng Zhang Author-X-Name-First: Hai-Feng Author-X-Name-Last: Zhang Title: A high gain circularly polarized 2 × 2 antenna array based on the spoof surface plasmon polariton and spoof localized surface plasmon Abstract: Two circularly polarized (CP) 2 × 2 array antennas based on the spoof surface plasmon polariton (SPP) and spoof localized surface plasmon (LSP) are proposed. The antenna I is fed by a feed network to increase the axial-ratio (AR) bandwidth. The spoof SPP and spoof LSP are introduced to increase the gain through energy localization, and the structure can suppress the cross-polarization to a certain extent and obtain a wider axial-ratio beamwidth. In addition, the electromagnetic band gap (EBG) is used to suppress surface waves to further increase the gain. The size of antenna I is 1.27λg × 1.27λg × 0.18λg. The impedance bandwidth and the AR bandwidth of antenna I are 72% (3.15–6.75 GHz) and 55% (3.97–6.72 GHz), respectively, and the peak gain is 11.11 dBi. The antenna II optimizes the distance between the two substrates according to antenna I to further increase the gain. Journal: Journal of Electromagnetic Waves and Applications Pages: 1298-1316 Issue: 15 Volume: 37 Year: 2023 Month: 10 X-DOI: 10.1080/09205071.2023.2234381 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2234381 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:15:p:1298-1316 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2234360_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Ayşegül Pekmezci Author-X-Name-First: Ayşegül Author-X-Name-Last: Pekmezci Title: Propagation behavior in rectangular metallic waveguide periodically loaded with single negative metamaterial slabs Abstract: This paper focused on propagation characteristics of a single mode supporting waveguide enclosed by metallic sidewalls periodically loaded with lossless single negative (SNG) metamaterial slabs along axial direction. The gap between two successive SNG slabs is filled with a double positive (DPS) material. For the analysis, the periodic structure is assumed having symmetric unit cell (UC) and simplified as a two-port network which is one-half of the symmetric UC. Scattering parameters (S-parameters) are defined by even/odd mode analysis of the symmetric UC, and then the total S-parameters are calculated by solving the cascade connection of N unit cells. Eigenvalue equations are also obtained to explicit the solutions of band edge and pass/stopband diagrams in the microwave regime. Since a SNG can be either epsilon-negative (ENG) or mu-negative (MNG), S-parameters and dispersion behavior are illustrated with numerical examples and discussed for each periodic structure constructed with ENG or MNG slabs. Journal: Journal of Electromagnetic Waves and Applications Pages: 1274-1285 Issue: 15 Volume: 37 Year: 2023 Month: 10 X-DOI: 10.1080/09205071.2023.2234360 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2234360 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:15:p:1274-1285 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2234362_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Shipra Bhatia Author-X-Name-First: Shipra Author-X-Name-Last: Bhatia Author-Name: Debasish Pal Author-X-Name-First: Debasish Author-X-Name-Last: Pal Author-Name: A. K. Bandyopadhyay Author-X-Name-First: A. K. Author-X-Name-Last: Bandyopadhyay Author-Name: P. P. Sarkar Author-X-Name-First: P. P. Author-X-Name-Last: Sarkar Title: Compact and high gain slotted patch antenna with moderate bandwidth for 60 GHz applications Abstract: A compact and high gain dual semi-circular slotted patch antenna with moderate bandwidth for 60 GHz applications is presented in this article. A rectangular-shaped patch inspires this design. The slotted antenna provides an impedance bandwidth of 1.75 GHz (58.87–60.62 GHz) and a gain of 7.55 dB. The overall size of the proposed antenna is 12 × 9.5 mm2. A dielectric superstrate is used to improve the antenna bandwidth and gain. The proposed antenna with superstrate exhibits an improved bandwidth of 2.48 GHz (58.22–60.70 GHz), an enhanced gain of 11.8 dB, and an efficiency of 95%, respectively. The antenna provides stable time-domain performance (isolation, isolation phase, group delay, and fidelity factor) over the operating band. The design prototype is fabricated and tested experimentally. Measured results exhibit a good agreement with the simulated results. The proposed antenna is suitable for high data-rate radio access and high gain 60 GHz applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 1286-1297 Issue: 15 Volume: 37 Year: 2023 Month: 10 X-DOI: 10.1080/09205071.2023.2234362 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2234362 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:15:p:1286-1297 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2231934_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Raj Kumar Mistri Author-X-Name-First: Raj Kumar Author-X-Name-Last: Mistri Author-Name: Ajit Kumar Singh Author-X-Name-First: Ajit Kumar Author-X-Name-Last: Singh Author-Name: Santosh Kumar Mahto Author-X-Name-First: Santosh Kumar Author-X-Name-Last: Mahto Author-Name: Rashmi Sinha Author-X-Name-First: Rashmi Author-X-Name-Last: Sinha Title: Quad element millimetre-wave MIMO antenna for 5G communication Abstract: A multiple-input and multiple-output (MIMO) system (size 35 × 35 × 0.76 mm3) of the four-element antenna with a 4.69 GHz impedance bandwidth (23.56–28.25 GHz) (millimetre wave) is proposed for 5G communication. The band capacity and radiation properties of the antenna are enhanced by modifying rectangular radiating patches with rectangular-shaped slots in ground plane. The proposed MIMO antenna achieved the isolation of 21 dB. The mutual coupling coefficient, envelope correlation coefficient (ECC), total active reflection coefficient (TARC), diversity gain (DG), mean effective gain (MEG), and channel capacity loss (CCL) are investigated to evaluate the performance attributes of diversity, and the obtained values are −21 dB, 0.007, −10 dB, 9.99 dB, ±3 dB, and 0.30 bits/sec/Hz, respectively. The robustness of the MIMO antenna is further demonstrated in different scenario under Gaussian/uniform propagation conditions. Each antenna has an average total efficiency of 92% and a maximum gain of 6.65 dBi. The testing of fabricated antenna provides excellent experimental results in comparison with simulations. Journal: Journal of Electromagnetic Waves and Applications Pages: 1258-1273 Issue: 15 Volume: 37 Year: 2023 Month: 10 X-DOI: 10.1080/09205071.2023.2231934 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2231934 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:15:p:1258-1273 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2241862_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Christos Tsironis Author-X-Name-First: Christos Author-X-Name-Last: Tsironis Author-Name: Aristeidis Papadopoulos Author-X-Name-First: Aristeidis Author-X-Name-Last: Papadopoulos Title: Parallelization of a 3D FDTD code and physics studies of electromagnetic wave propagation in fusion plasmas Abstract: Numerical codes for electromagnetic wave propagation in magnetized plasmas are mainly based on frequency-domain asymptotic methods, which provide a fast solution and are thus valuable for experiment design and control applications. However, in several cases of practical interest (e.g. mode conversion), these tools run close to their limits of validity and should be compared to full-wave solutions. The code RFFW solves Maxwell's equations with the finite-difference time-domain method in 3D geometry, for scenarios involving high-frequency waves with arbitrary electric field spectrum in plasmas with axisymmetric equilibrium. In fusion-related problems, the code may conduct investigations of wave propagation and absorption relevant to auxiliary plasma heating and current drive, reflectometry and instability control. The code has been parallelized with a hybrid OpenMP-MPI scheme, which has allowed exploiting the much larger processing power and memory of current-day supercomputers. In this work, we present the main aspects of the physics implemented in the code, and also refer shortly to the parallelization scheme. Furthermore, we show results that exhibit the strong scaling performance of the code, and examine cases of electron-cyclotron heating application in medium-sized tokamaks. Journal: Journal of Electromagnetic Waves and Applications Pages: 1366-1393 Issue: 16 Volume: 37 Year: 2023 Month: 11 X-DOI: 10.1080/09205071.2023.2241862 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2241862 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:16:p:1366-1393 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2239808_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Babak Honarbakhsh Author-X-Name-First: Babak Author-X-Name-Last: Honarbakhsh Title: Simple, efficient, and accurate analysis of the flanged parallel-plate waveguide Abstract: The flanged parallel-plate waveguide is analysed based on the method of Kobayashi potential (KP) using Fourier function space. The presentation of the method is free from intricate mathematics. Standard integral identities are used for problem formulation, without direct use of Weber-Schafheitlin (WS) integrals. The Fourier function space is exploited for the construction of the governing linear equations instead of Jacobi polynomials. A simple strategy is suggested for the evaluation of the required improper integrals. Near-field results are validated through convergence analysis. Far-field patterns are compared with predictions of the surface equivalence theorem (SET). Journal: Journal of Electromagnetic Waves and Applications Pages: 1330-1340 Issue: 16 Volume: 37 Year: 2023 Month: 11 X-DOI: 10.1080/09205071.2023.2239808 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2239808 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:16:p:1330-1340 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2242354_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Zhonggen Wang Author-X-Name-First: Zhonggen Author-X-Name-Last: Wang Author-Name: Yongjie Ma Author-X-Name-First: Yongjie Author-X-Name-Last: Ma Author-Name: Yufa Sun Author-X-Name-First: Yufa Author-X-Name-Last: Sun Author-Name: Pan Wang Author-X-Name-First: Pan Author-X-Name-Last: Wang Author-Name: Chenlu Li Author-X-Name-First: Chenlu Author-X-Name-Last: Li Title: Accurate analysis of bistatic scattering problems using compressive sensing with a new sparse basis Abstract: Compressive sensing (CS) used as a sparse basis can enhance the characteristic basis functions (CBFs), which helps in analyzing the bistatic scattering problems of a three-dimensional (3D) object. However, a sparse basis constructed by the CBFs lacks current information under a single plane wave, leading to a low computation accuracy when analyzing complex objects. To resolve this issue, a new sparse basis construction method is presented in this work, which considers the current information under multilevel plane waves with different incident angles and different polarization modes. As this new sparse basis contains more comprehensive current information, the accuracy is considerably improved when analyzing the complex targets. Furthermore, the accuracy and efficiency of the proposed method are verified by extensive numerical simulations. Journal: Journal of Electromagnetic Waves and Applications Pages: 1394-1408 Issue: 16 Volume: 37 Year: 2023 Month: 11 X-DOI: 10.1080/09205071.2023.2242354 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2242354 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:16:p:1394-1408 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2240315_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Miguel-Antonio Romero-Ramirez Author-X-Name-First: Miguel-Antonio Author-X-Name-Last: Romero-Ramirez Author-Name: Tejinder Kaur Kataria Author-X-Name-First: Tejinder Kaur Author-X-Name-Last: Kataria Author-Name: Jose-Luis Olvera-Cervantes Author-X-Name-First: Jose-Luis Author-X-Name-Last: Olvera-Cervantes Author-Name: Alonso Corona-Chavez Author-X-Name-First: Alonso Author-X-Name-Last: Corona-Chavez Title: Design of balanced band pass filters with one transmission zero using an asynchronously coupled dual-mode resonator Abstract: A novel quasi-elliptic balanced bandpass filter (BBPF) designed on microstrip technology that uses Asynchronously Coupled Dual-Mode Resonator (ACDMR) is proposed. The filter is based on a novel Balanced Asynchronous Box (Basybox), which has five couplings and three resonators (two λ/2 resonators and a dual-mode grounded λ/2 resonator). By changing a conventional triplet with the use of dual-mode resonators, we can generate a non-resonant mode that generates a transmission zero (TZ). In addition, the filter has a balanced response. In this paper, full design methodology is presented along with a practical implementation. The filter has a center frequency in differential-mode of 950 MHz, a bandwidth of 53 MHz and a transmission zero at 975 MHz. For the common-mode, there is a rejection higher than 15 dB throughout the band up to 3 GHz. Good agreement between simulation and measurement is observed. Journal: Journal of Electromagnetic Waves and Applications Pages: 1341-1349 Issue: 16 Volume: 37 Year: 2023 Month: 11 X-DOI: 10.1080/09205071.2023.2240315 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2240315 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:16:p:1341-1349 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2240324_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Xiaoyi Liao Author-X-Name-First: Xiaoyi Author-X-Name-Last: Liao Author-Name: Zewei Wu Author-X-Name-First: Zewei Author-X-Name-Last: Wu Author-Name: Minxing Wang Author-X-Name-First: Minxing Author-X-Name-Last: Wang Author-Name: Chen Zhao Author-X-Name-First: Chen Author-X-Name-Last: Zhao Title: Theoretical investigations on cutoff wave number of quad-polar waveguide Abstract: The hollow waveguides with angular deformation are widely used in high power millimeter wave system. In this manuscript, the cutoff wave number of the quad-polar waveguide with a boundary of $ R=R_{0}(1+h\cos 4\varphi ) $ R=R0(1+hcos⁡4φ) is theoretically analyzed based on the perturbation analysis. Using the boundary condition and the orthogonal properties of the trigonometric functions, a determinant is obtained and then the exact closed-form expression of cutoff wave number is deduced from the determinant. Based on the cutoff wave number, the eigen field is calculated by nonlinear programming method. The values of the cutoff wavenumbers, eigen fields and surface currents for the first few modes are calculated and compared with the results obtained from simulation software. The high correspondence of the calculated values with the simulated results proves that the proposed method is an appropriate option for fast and precise analyzing quad-polar waveguides. Journal: Journal of Electromagnetic Waves and Applications Pages: 1350-1365 Issue: 16 Volume: 37 Year: 2023 Month: 11 X-DOI: 10.1080/09205071.2023.2240324 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2240324 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:16:p:1350-1365 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2239806_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Engin Dogan Author-X-Name-First: Engin Author-X-Name-Last: Dogan Author-Name: Ali Kursad Gorur Author-X-Name-First: Ali Kursad Author-X-Name-Last: Gorur Author-Name: Adnan Gorur Author-X-Name-First: Adnan Author-X-Name-Last: Gorur Title: Novel flexible chipless RFID tags based on five state resonators Abstract: In this paper, novel chipless radio frequency identification (RFID) tags are designed by using asymmetrical triple mode resonators constructed by an open loop resonator with two open stubs in different lengths. Three transmission zeros (bits) can be obtained by coupling a proposed resonator to a straight feeding line that connects input/output ports. Five frequency codes can be achieved with respect to the existence of the open stubs and the open loop resonator. By coupling eight asymmetrical triple mode resonators to the feeding line, a multi-resonant circuit is developed on a flexible substrate of Rogers 5870. Totally 24 bit frequencies can be achieved and it is possible to identify 58 different items. For the chipless RFID tags, two monopole wideband antennas in vertical/horizontal polarizations are integrated instead of the input/output ports. Two tags have been fabricated and tested to demonstrate the identification of different codes under smoothed and curved positions successfully. Journal: Journal of Electromagnetic Waves and Applications Pages: 1317-1329 Issue: 16 Volume: 37 Year: 2023 Month: 11 X-DOI: 10.1080/09205071.2023.2239806 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2239806 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:16:p:1317-1329 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2251956_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Shichao Jin Author-X-Name-First: Shichao Author-X-Name-Last: Jin Author-Name: Kaijun Song Author-X-Name-First: Kaijun Author-X-Name-Last: Song Author-Name: Xueyuan Ding Author-X-Name-First: Xueyuan Author-X-Name-Last: Ding Title: Miniaturized quad-band bandpass filter using quad-mode stepped impedance resonator Abstract: A miniaturized quad-band bandpass filter (BPF) using compact quad-mode stepped impedance resonator (IQMSIR) is proposed. Based on the symmetric presented by the resonator, four modes are deduced using even-and odd-mode technique. Design formulas are also derived and they are used to guide the filter design. Multiple coupling circuit technique is employed to realize the four passbands. Independent design for four passbands are achieved due to the physical dimensions and additional cross slots. Upper stopband is performed by adding open loop SIR at I/O ports. Transmission zeros among each passbands are generated, resulting in high isolation and selectivity. A quad-band filter is designed, fabricated and measured. The operating central frequencies of the fabricated filter are at 2.54/3.36/5.24/6.6 GHz. The measured 3-dB fractional bandwidths of the four passbands are about 3.9/6.4/4/4.6% and the minimum insertion losses are about 2.3/0.89/3.2/2.3 dB. Measurements correlate well with the simulation results. Journal: Journal of Electromagnetic Waves and Applications Pages: 1480-1494 Issue: 17 Volume: 37 Year: 2023 Month: 11 X-DOI: 10.1080/09205071.2023.2251956 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2251956 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:17:p:1480-1494 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2243255_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Apala Banerjee Author-X-Name-First: Apala Author-X-Name-Last: Banerjee Author-Name: Farheen Fatima Author-X-Name-First: Farheen Author-X-Name-Last: Fatima Author-Name: Nilesh K. Tiwari Author-X-Name-First: Nilesh K. Author-X-Name-Last: Tiwari Author-Name: M. J. Akhtar Author-X-Name-First: M. J. Author-X-Name-Last: Akhtar Title: Flexible printed electrically small microwave resonator for automated displacement tracking Abstract: In this paper, a planar split ring resonator-based flexible RF sensor is developed for linear and rotational position tracking of a target object. The proposed sensing scheme employs a 100 μm thin flexible printed resonator that facilitates ease of adherence to a target object than that of the conventional RF sensor. The realized printed resonator is excited by a near-field proximity coupling mechanism using a standard 50 Ω microstrip line. A detailed numerical analysis for the linear and rotational displacement of several dummy targets is carried out by recording the change in measured parameters corresponding to the relative change in position of the printed resonator attached to a dummy target under test. Afterward, the equivalent circuit and fabricated prototype of a printed flexible sensor is developed and tested for the linear and rotational displacement of several target materials under observation and an ANN model is developed to curb the uncertainty. Journal: Journal of Electromagnetic Waves and Applications Pages: 1409-1424 Issue: 17 Volume: 37 Year: 2023 Month: 11 X-DOI: 10.1080/09205071.2023.2243255 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2243255 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:17:p:1409-1424 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2243256_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Yu-Xu Chen Author-X-Name-First: Yu-Xu Author-X-Name-Last: Chen Author-Name: Guobin Wan Author-X-Name-First: Guobin Author-X-Name-Last: Wan Author-Name: Xin Ma Author-X-Name-First: Xin Author-X-Name-Last: Ma Author-Name: Bin Fu Author-X-Name-First: Bin Author-X-Name-Last: Fu Author-Name: Xinhui Jiao Author-X-Name-First: Xinhui Author-X-Name-Last: Jiao Author-Name: Nan Wang Author-X-Name-First: Nan Author-X-Name-Last: Wang Title: A single layer and very close band spacing frequency selective surface with enhanced isolation Abstract: An ultrathin and very closely located dual-band frequency selective surface (FSS) with enhanced isolation is proposed in this letter. The unit cell consists of two typical concentric hexagon rings, with several stubs loaded on each side of the inner ring. Through the stub-loaded configuration, the mutual coupling of adjacent resonators is highly decoupled and a very close band spacing FSS with better isolation can be achieved, and the ratio of the two operating bands can be as low as 1.06. Additionally, due to the independent resonant frequencies, the band ratio can be set over a wide range, from 1.06–2.43. Furthermore, the corresponding equivalent circuit model (ECM) is developed and analyzed for better comprehension of the underlying mechanisms of the proposed FSS. The validity of the design is then checked with a prototype, and the measured results show good agreement with the simulated ones. Journal: Journal of Electromagnetic Waves and Applications Pages: 1425-1434 Issue: 17 Volume: 37 Year: 2023 Month: 11 X-DOI: 10.1080/09205071.2023.2243256 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2243256 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:17:p:1425-1434 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2251984_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Dongmin Zhang Author-X-Name-First: Dongmin Author-X-Name-Last: Zhang Author-Name: Cheng Liao Author-X-Name-First: Cheng Author-X-Name-Last: Liao Author-Name: Xiaochuan Deng Author-X-Name-First: Xiaochuan Author-X-Name-Last: Deng Author-Name: Song Fu Author-X-Name-First: Song Author-X-Name-Last: Fu Title: An efficient dual-scale method for analysis of EMI problems resulted from radiation sources Abstract: An efficient dual-scale method, which integrates parabolic equation (PE) with electric field integral equation (EFIE) formulated via the Rao-Wilton-Glisson moment method (RWG-MOM), is proposed to analyze the electromagnetic interference (EMI) problems resulted from radiation sources. This method is implemented by decomposing the original intractable multi-scale problem domain into two sub-regions: (1) modeling of the complicated ambient electromagnetic fields by PE and (2) solution of the fields coupling to the exposed electronic devices by RWG-MOM. Frequency-sweep and Fourier synthesis techniques are applied to calculate the transient currents and voltages. The proposed method is able to fully model the disturbances of the electromagnetic fields by multi-path effects. Besides, it reduces the memory footprint and the CPU computing time effectively compared to the traditional full-wave electromagnetic methods. Numerical examples are presented, and the simulation results indicate that this method is well suitable for the EMI analysis of external radiation sources. Journal: Journal of Electromagnetic Waves and Applications Pages: 1463-1479 Issue: 17 Volume: 37 Year: 2023 Month: 11 X-DOI: 10.1080/09205071.2023.2251984 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2251984 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:17:p:1463-1479 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2251979_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Noureddine Boughaba Author-X-Name-First: Noureddine Author-X-Name-Last: Boughaba Author-Name: Ouarda Barkat Author-X-Name-First: Ouarda Author-X-Name-Last: Barkat Title: LMS and RLS beamforming algorithms based linear antenna array with known mutual coupling Abstract: This study explores the application of LMS and RLS algorithms in adaptive beamforming for a linear array of half wavelength dipole (HWD) antennas with known mutual coupling. The research initiates by deriving analytical expressions for the covariance matrix of signal impinging on an HWD antenna array, accounting for mutual coupling effects. Leveraging these expressions, we calculate the weights for both LMS and RLS algorithms, enabling the evaluation of the overall far-field radiation patterns of the HWD antenna array. The results demonstrate that these algorithms effectively steer the main lobe of the radiation pattern towards the desired user while creating nulls in the direction of undesired users. Notably, simulations indicate that the proposed compensation method enhances the performance of beamforming algorithms, particularly when considering mutual coupling effects. Specifically, the LMS algorithm outperforms the RLS algorithm in reducing interference, resulting in lower side lobe levels (SLL) in the radiation pattern. Journal: Journal of Electromagnetic Waves and Applications Pages: 1449-1462 Issue: 17 Volume: 37 Year: 2023 Month: 11 X-DOI: 10.1080/09205071.2023.2251979 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2251979 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:17:p:1449-1462 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2248983_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Hong Zou Author-X-Name-First: Hong Author-X-Name-Last: Zou Author-Name: Bo Wang Author-X-Name-First: Bo Author-X-Name-Last: Wang Title: Cascaded HfO2/SiO2 microstructure for symmetrical two-port beam dispersion Abstract: A new type of double-dielectric layer two-port beam splitter grating based on sandwich structure is proposed. This grating has the characteristic of zeroth order elimination. The structural parameters of the grating are optimized by the rigorous coupled-wave analysis (RCWA) and simulated annealing algorithm (SAA) to achieve the best performance of the grating. For both TE and TM polarizations, the diffraction efficiencies of ±1st orders can reach 49.34% and 49.15%, respectively. Meanwhile, the efficiency of the zeroth order is about only 0.5% for both polarizations. This novel microstructure has the significant characteristic of zeroth order elimination. Moreover, this grating has a wide incident bandwidth and excellent manufacturing tolerance. The simplified modal method (SMM) is also used to study the specific process of energy coupling in the grating. Journal: Journal of Electromagnetic Waves and Applications Pages: 1435-1448 Issue: 17 Volume: 37 Year: 2023 Month: 11 X-DOI: 10.1080/09205071.2023.2248983 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2248983 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:17:p:1435-1448 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2260385_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Marwa E. Mousa Author-X-Name-First: Marwa E. Author-X-Name-Last: Mousa Author-Name: Mohamed A. Yakout Author-X-Name-First: Mohamed A. Author-X-Name-Last: Yakout Author-Name: Haythem H. Abdullah Author-X-Name-First: Haythem H. Author-X-Name-Last: Abdullah Author-Name: M. El din Abo El-Soud Author-X-Name-First: M. El din Author-X-Name-Last: Abo El-Soud Title: An integrated spiral DGS and an open stub meander-line resonator in the 0.13-µm BiCMOS technology for a 18-GHz band oscillator Abstract: In this paper, an 18 GHz voltage-controlled oscillator (VCO) with improved phase noise (PN) and smaller size is proposed. The filter consists of an open stub resonator and an integrated spiral Defective Ground Structure (DGS) resonator. The proposed oscillator is designed in the 0.13-µm SiGe BiCMOS technology. The differential cross-coupled VCO uses a bandpass filter. In this work, the conventional large-size coil is replaced by a resonator based on our proposed open stub resonator and defected ground structure (DGS) where the filter is equivalent to the large coil and the associated capacitors. The use of the filter results in a great reduction of VCO size, low losses, and low power consumption, hence an enhancement in the quality factor. The integrated spiral DGS is etched on the third metal layer (M3) below an open stub meander line onthe top metal layer (TM2) of the 0.13-µm top metal two (TM2) BiCMOS technology. The proposed VCO has a small die area of 0.089 mm2 and has FoMA of 188.8 dB and a power consumption is 13.38 mw. The simulated carrier frequency and phase noise are 18-GHz and −123.59 dBc/Hz (−103.7 dBc/Hz) at 10-MHz (1 MHz) offset frequency, respectively, which results in a figure of merit of 177.37 dB. Journal: Journal of Electromagnetic Waves and Applications Pages: 1575-1586 Issue: 18 Volume: 37 Year: 2023 Month: 12 X-DOI: 10.1080/09205071.2023.2260385 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2260385 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:18:p:1575-1586 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2262984_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Hishem Hyani Author-X-Name-First: Hishem Author-X-Name-Last: Hyani Author-Name: Bruno Sauviac Author-X-Name-First: Bruno Author-X-Name-Last: Sauviac Author-Name: Gérard Granet Author-X-Name-First: Gérard Author-X-Name-Last: Granet Author-Name: Bernard Bayard Author-X-Name-First: Bernard Author-X-Name-Last: Bayard Author-Name: Stéphane Robert Author-X-Name-First: Stéphane Author-X-Name-Last: Robert Author-Name: Kofi Edee Author-X-Name-First: Kofi Author-X-Name-Last: Edee Title: Electromagnetic jet produced with loaded waveguide ended by an optimized multi-rectangular sections tip Abstract: Previous works have demonstrated that a parallel plate waveguide, equipped at the end with a tip, can be used to initiate an “electromagnetic jet (Ej)” (this name generalizes the photonic jet (Pj) phenomenon regardless of the wavelength). In addition to being easy to manufacture, a rectangular shape improves energy concentration, however concurrently the full-width at half maximum (FWHM) is slightly degraded. This article aims to introduce tips with multi-rectangular sections reducing the drawbacks previously mentioned. This article proposes the use of Aperiodic Polynomial Modal Method (A-PMM) as an efficient yet robust method to model and optimize an outgoing Ej, equipped with this kind of dielectric tips. Thus, a three rectangular sections tip can improve energy concentration and can reduce the FWHM beyond the diffraction limit compared to a single section tip. Journal: Journal of Electromagnetic Waves and Applications Pages: 1587-1596 Issue: 18 Volume: 37 Year: 2023 Month: 12 X-DOI: 10.1080/09205071.2023.2262984 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2262984 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:18:p:1587-1596 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2258866_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Shaochen Li Author-X-Name-First: Shaochen Author-X-Name-Last: Li Author-Name: Teng Yan Author-X-Name-First: Teng Author-X-Name-Last: Yan Author-Name: Xiao Yuhua Author-X-Name-First: Xiao Author-X-Name-Last: Yuhua Author-Name: Li Chun Author-X-Name-First: Li Author-X-Name-Last: Chun Author-Name: Bian Borui Author-X-Name-First: Bian Author-X-Name-Last: Borui Author-Name: Juan Yue Author-X-Name-First: Juan Author-X-Name-Last: Yue Author-Name: Jiang Ling Author-X-Name-First: Jiang Author-X-Name-Last: Ling Title: Design of programmable beam splitting metasurface Abstract: Metasurface has been applied as one critical platform for electromagnetic modulation devices. Here, a programmable metasurface loaded with positive-intrinsic negative (PIN) diodes is proposed to realize dynamic switching of arbitrary multi-beam. Furthermore, the multi-beam coding sequence is optimized by a genetic algorithm (GA) to achieve dual- to nine-beam with different scattering directions. As a proof of concept, a programmable metasurface prototype that operates around 8 GHz is designed and fabricated to be tested in far-field measurements. The beam splitter has been verified by theoretical analysis and numerical simulation to have a power efficiency of over 70%. In the measurement system, multi-beam splitting phenomena are obtained using DC control of the PIN diodes “on” and “off”, which is consistent with the simulation results. The proposed beam splitter can be designed with real-time multi-beam switching and intelligently provides coding sequences with multiple directive angles, thus providing potential benefits for next-generation antennas. Journal: Journal of Electromagnetic Waves and Applications Pages: 1495-1508 Issue: 18 Volume: 37 Year: 2023 Month: 12 X-DOI: 10.1080/09205071.2023.2258866 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2258866 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:18:p:1495-1508 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2260381_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: R. Viger Author-X-Name-First: R. Author-X-Name-Last: Viger Author-Name: S. Ramsey Author-X-Name-First: S. Author-X-Name-Last: Ramsey Author-Name: T. Mayo Author-X-Name-First: T. Author-X-Name-Last: Mayo Author-Name: S. G. Lambrakos Author-X-Name-First: S. G. Author-X-Name-Last: Lambrakos Title: Estimation of dielectric response functions for NIR-SWIR absorbing dyes by inverse analysis of diffuse reflectance Abstract: This study describes the estimation of dielectric response functions for NIR-SWIR absorbing dyes by inverse analysis of diffuse reflectance. The inverse analysis procedure is based on the Kramers–Kronig relations, the Kubelka–Munk model of diffuse reflectance, and the background subtraction of substrate spectra. The calculated response functions provide estimates of the dielectric response characteristics for NIR-SWIR absorbing dyes, as well as their sensitivity to material-background environments. This study demonstrates that Kramers–Kronig analysis can be adopted for calculating estimates of dielectric functions, given any reasonable estimate of absorbance. Specifically, that Kramers–Kronig analysis provides filtering of dielectric response structure with respect to spectrum artifacts due to inverse-analysis and spectroscopic-measurement procedures. This can significantly reduce the experimentation necessary to achieve desired dielectric response characteristics for NIR-SWIR dye and substrate combinations. Furthermore, these calculated response functions can support the construction of approximate effective medium models capable of estimating reflectance features for dyed fabrics. Journal: Journal of Electromagnetic Waves and Applications Pages: 1540-1574 Issue: 18 Volume: 37 Year: 2023 Month: 12 X-DOI: 10.1080/09205071.2023.2260381 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2260381 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:18:p:1540-1574 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2260367_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Protik Roy Author-X-Name-First: Protik Author-X-Name-Last: Roy Author-Name: Partha Roy Chaudhuri Author-X-Name-First: Partha Author-X-Name-Last: Roy Chaudhuri Title: Designing cladding mode interference device – a host for sensors and all-fiber inline gain-flattening component and broad-band filter Abstract: This article describes how to devise interference and self-imaging of core and cladding modes based devices using dissimilar core concatenated all-fibers. The core diameter mismatch in the structure excites the cladding modes with the core mode that leads to a progressive interference imaging between the cladding modes and the core mode yielding wavelength and refractive index dependent loss. Through a systematic study, we tune the device parameters to gauge temperature and concentration with sensitivity of 0.0713 dB/°C and 0.0372 dB/(% mL/mL) respectively as a high-performance fiber sensor. Next, optimizing the wavelength sensitive parameters of the host configuration, we investigate the transmission characteristics as gain-flattening filters (GFF) of Erbium-doped fiber amplifiers (EDFAs) with  maximum gain variations of 0.91 and 0.97 dB, for two different EDFAs respectively over a wavelength band of 33 and 25 nm. Finally, we demonstrate a tunable and two-flattop band rejection filters with rejection band of 14, 26 and 46 nm, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 1522-1539 Issue: 18 Volume: 37 Year: 2023 Month: 12 X-DOI: 10.1080/09205071.2023.2260367 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2260367 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:18:p:1522-1539 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2262985_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Muhammed Fatih Corapsiz Author-X-Name-First: Muhammed Fatih Author-X-Name-Last: Corapsiz Title: An efficient and low-profile metasurface-based polarization converter with linear and circular polarization efficiencies for X- and Ku-Band applications Abstract: In this study, a metasurface-based linear and circular polarization converter operating on the reflection mode is proposed for X- and Ku-band microwave applications. The proposed converter offers an optimum performance with a polarization conversion ratio (PCR) and polarization matching ratio (PMR) greater than 93 $ \% $ % in the $ 8.32{\mbox {--}}17.55\,{\rm GHz} $ 8.32--17.55GHz bandwidth for a linearly polarized in the y-direction and right-handed circular polarized (RHCP) incident waves. Besides, the design performs over 80 $ \% $ % PCR performance up to $ 45^\circ $ 45∘ under oblique incidence. Moreover, the proposed converter is capable of left-handed circular polarization conversion between 7.42 and 7.68 GHz for a y-polarized incident wave. The design offers a relative bandwidth (RBW) of 71.36 $ \% $ %. The converter design is constructed with metal termination, an easily accessible FR-4 substrate and a simple design metasurface. Surface currents of the polarization converter at resonance frequencies of 8.77, 12.88 and $ 16.7\,{\rm GHz} $ 16.7GHz were examined to understand its working mechanism. In addition, when the proposed design is rearranged with the appropriate geometry, the monostatic RCS reduction value in the 8.0–17.7 $ \,{\rm GHz} $ GHz range is observed to be higher than 10 dB. CST program (a commercial 3D electromagnetic simulator) was used in simulations. The simulated device was fabricated with a traditional board fabrication technique. Simulation results were verified with free space measurements calibrated by the thru-reflect-line calibration procedure. The performance and efficiency of the proposed polarization converter were compared with other converters in the literature. Journal: Journal of Electromagnetic Waves and Applications Pages: 1597-1611 Issue: 18 Volume: 37 Year: 2023 Month: 12 X-DOI: 10.1080/09205071.2023.2262985 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2262985 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:18:p:1597-1611 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2259052_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20230119T200553 git hash: 724830af20 Author-Name: Yinuo Li Author-X-Name-First: Yinuo Author-X-Name-Last: Li Author-Name: Juan Chen Author-X-Name-First: Juan Author-X-Name-Last: Chen Author-Name: Jianxing Li Author-X-Name-First: Jianxing Author-X-Name-Last: Li Title: Miniaturized near-field-focused antenna array Abstract: This paper presents a microstrip planar antenna array designed for near-field focusing operating at 10 GHz. It is a challenge to reach the phase and amplitude distribution of near-field-focused antenna arrays with small focal spots. The antenna elements of this array are arranged radially on the aperture of only 5.6λ0 × 5.6λ0, which reduces the focal spot diameter. We designed an unequal-amplitude unequal-phase power divider to reach phase distribution and binomial taper distribution. The proposed array suppresses the sidelobes on the focal plane. It increases the electric field intensity by 11.46 dB compared with the horn with the same aperture size and increases 9.42 dB compared with the equal-phase array. The focus spot diameter is only 0.33λ0. The simulated and measured results are in good agreement, which verifies the high performance of the array. This miniaturized high-focus array has a good prospect in near-field applications like wireless energy transmission and industrial detection. Journal: Journal of Electromagnetic Waves and Applications Pages: 1509-1521 Issue: 18 Volume: 37 Year: 2023 Month: 12 X-DOI: 10.1080/09205071.2023.2259052 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2259052 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:37:y:2023:i:18:p:1509-1521 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2270477_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Ahmet Aydoğan Author-X-Name-First: Ahmet Author-X-Name-Last: Aydoğan Title: An efficient determination of field distributions in E-plane dielectric loaded waveguides Abstract: This paper proposes a new, fast, and efficient method for determining the electromagnetic field distribution in two-port E-plane dielectric-loaded uniform rectangular waveguides. The analysis region is divided into individual blocks in the absence and presence of dielectric obstacles. The non-zero electric and magnetic field components are constructed throughout the system via the proposed method by utilizing the generalized scattering matrix method between blocks for unimodal or multimodal excitation. The resulting field distributions are compared to those obtained from commercial software, with very close agreement achieved, but with a significantly reduced computational time for the proposed method. The method is applicable in a straightforward manner and has been tested on both a filter device with relatively complex geometry and a disjoint system with a modal coupling challenge between its elements. The field components' accuracy is also tested by calculating the Poynting vector along the system. Additionally, this approach provides the global scattering parameters at the physical ports as a co-product. The proposed method has the potential to be applied to various two-port networks by using the proposed method according to the considered problem. Journal: Journal of Electromagnetic Waves and Applications Pages: 1-16 Issue: 1 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2270477 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2270477 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:1:p:1-16 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2270602_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Chaoxian Qi Author-X-Name-First: Chaoxian Author-X-Name-Last: Qi Author-Name: Shubin Zeng Author-X-Name-First: Shubin Author-X-Name-Last: Zeng Author-Name: Neil Jerome A. Egarguin Author-X-Name-First: Neil Jerome A. Author-X-Name-Last: Egarguin Author-Name: Daniel Onofrei Author-X-Name-First: Daniel Author-X-Name-Last: Onofrei Author-Name: Jiefu Chen Author-X-Name-First: Jiefu Author-X-Name-Last: Chen Title: Active control of electromagnetic fields in layered media Abstract: This article presents a numerical strategy for actively manipulating electromagnetic (EM) fields in layered media. In particular, we develop a scheme to characterize an EM source that will generate some predetermined field patterns in prescribed disjoint exterior regions in layered media. The proposed question of specifying such an EM source is not an inverse source problem (ISP) since the existence of a solution is not guaranteed. Moreover, our problem allows for the possibility of prescribing different EM fields in mutually disjoint exterior regions. This question involves a linear inverse problem that requires solving a severely ill-posed optimization problem (i.e. suffering from possible non-existence or non-uniqueness of a solution). The forward operator is defined by expressing the EM fields as a function of the current at the source using the layered media Green's function (LMGF), accounting for the physical parameters of the layered media. This results to integral equations that are then discretized using the method of moments (MoM), yielding an ill-posed system of linear equations. Unlike in ISPs, stability with respect to data is not an issue here since no data is measured. Rather, stability with respect to input current approximation is important. To get such stable solutions, we applied two regularization methods, namely, the truncated singular value decomposition (TSVD) method and the Tikhonov regularization method with the Morozov Discrepancy Principle. We performed several numerical simulations to support the theoretical framework and analyzes, and to demonstrate the accuracy and feasibility of the proposed numerical algorithms. Journal: Journal of Electromagnetic Waves and Applications Pages: 66-88 Issue: 1 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2270602 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2270602 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:1:p:66-88 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2270603_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Cemile Tangel Author-X-Name-First: Cemile Author-X-Name-Last: Tangel Author-Name: Nigar Berna Teşneli Author-X-Name-First: Nigar Berna Author-X-Name-Last: Teşneli Title: A wideband, thin profile and enhanced gain microstrip patch antenna modified by novel mushroom-like EBG and periodic defected ground structures Abstract: This paper presents a wideband, thin-profile and enhanced-gain microstrip patch antenna improved by using a novel mushroom-like Electromagnetic Band Gap (EBG) structure and forming periodic Defected Ground Structures (DGS) on the ground plane. The proposed antenna operates between 9.56 and 14 GHz and has 4.44 GHz–10 dB impedance bandwidth. With A4, the gain of the reference antenna is increased by 64.4%, while a 38% bandwidth is also achieved. The parametric analyses carried out on the metallic part area of the novel EBG patch indicated that when the area of the used EBG patches are approximately three quarters or less of the conventional ones, greater gain values for the designed antenna are obtained. This relation between the EBG patches and the antenna gain can be pointed out as the novelty of the study. The results were analysed by the simulations carried out with CST Microwave Studio and were verified by measurements from manufactured prototypes. Journal: Journal of Electromagnetic Waves and Applications Pages: 89-104 Issue: 1 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2270603 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2270603 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:1:p:89-104 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2270524_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Duc-Nguyen Tran Viet Author-X-Name-First: Duc-Nguyen Tran Author-X-Name-Last: Viet Author-Name: Hung Tran-Huy Author-X-Name-First: Hung Author-X-Name-Last: Tran-Huy Author-Name: Dinh Nguyen Quoc Author-X-Name-First: Dinh Nguyen Author-X-Name-Last: Quoc Author-Name: Hyun Chang Park Author-X-Name-First: Hyun Chang Author-X-Name-Last: Park Title: A novel defected ground structure for high-isolation circularly polarized MIMO patch antenna Abstract: This paper introduces a method to reduce mutual coupling in a two-element multiple-input multiple-output (MIMO) antenna, which is a significant challenge due to the need for high isolation over a wide frequency range with close element spacing. Previous works typically achieved high isolation within a narrow bandwidth. The paper presents a novel defected ground structure (DGS) with a modified I-shaped slot, which effectively minimizes mutual coupling in a dual-sense MIMO circularly polarized (CP) antenna over a broader bandwidth than the previous approaches. The fabricated 2-element prototype with an overall size of 0.98λ × 0.71λ × 0.05λ and an edge-to-edge spacing of 0.08λ at the center operating frequency has a measured bandwidth of 2.5% (5.2–5.33 GHz). Across this band, the isolation is always better than 35 dB and the gain is higher than 4.8 dBi. The MIMO parameters are also investigated, which proves the good diversity performance of the proposed design. Journal: Journal of Electromagnetic Waves and Applications Pages: 34-48 Issue: 1 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2270524 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2270524 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:1:p:34-48 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2270562_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Chan Bai Author-X-Name-First: Chan Author-X-Name-Last: Bai Author-Name: Shuai Zhang Author-X-Name-First: Shuai Author-X-Name-Last: Zhang Author-Name: Zixuan Song Author-X-Name-First: Zixuan Author-X-Name-Last: Song Author-Name: Yuguo Liu Author-X-Name-First: Yuguo Author-X-Name-Last: Liu Author-Name: Zepu Wang Author-X-Name-First: Zepu Author-X-Name-Last: Wang Title: Miniaturized wide-band dual-polarized tightly coupled array for 5G millimeter-wave smartphones Abstract: This paper presents a miniaturized wide-band dual-polarized tightly coupled dipole antenna for 5G millimeter-wave smartphones. The proposed antenna realizes miniaturization to avoid any grating lobes and achieves feed port reduction to reduce cost by utilizing the wideband balanced feeding of planar balun. The operating bandwidth of pol-x is 19.95-45.78 GHz and of pol-y is 20.11-46.32 GHz, which contains the entire dominant 5G millimeter-wave bands for mobile communication. The proposed 1 × 8 array is 23.8 mm × 3.5 mm × 1.297 mm which adapt to the size-limited of 5G smartphones. The peak gain of pol-x is 11.71 dBi and of pol-y is 12.45 dBi. The scanning performance of proposed 1 × 8 array is measured through the test feed powers dividers, which achieve wide beam scanning of around ±60°. The experimental results demonstrate that the proposed array with good performances exhibits great potential for 5G millimeter-wave smartphones application. Journal: Journal of Electromagnetic Waves and Applications Pages: 49-65 Issue: 1 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2270562 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2270562 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:1:p:49-65 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2270517_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Guo Bai Author-X-Name-First: Guo Author-X-Name-Last: Bai Author-Name: Cheng Liao Author-X-Name-First: Cheng Author-X-Name-Last: Liao Author-Name: You-Feng Cheng Author-X-Name-First: You-Feng Author-X-Name-Last: Cheng Author-Name: Yuanzhi Liu Author-X-Name-First: Yuanzhi Author-X-Name-Last: Liu Author-Name: Ju Feng Author-X-Name-First: Ju Author-X-Name-Last: Feng Author-Name: Xuanming Zhong Author-X-Name-First: Xuanming Author-X-Name-Last: Zhong Title: Failure diagnosis for time-modulated arrays based on compressed sensing Abstract: Time-modulated arrays (TMAs) have a high design degrees of freedom (DoFs) to improve radiation performance, while they are prone to failure due to their hardware characteristics. In this article, we propose a novel technique to diagnose impaired TMAs based on compressed sensing (CS). The TMA diagnosis problem is reformulated as a sparse signal recovery problem at the center frequency and sidebands. Then, a method based on the difference of convex sets theory and sequential convex programming (DCS-SCP) is developed to implement diagnosis for impaired TMAs. Using a small number of far-field measurements at the same position but different frequencies, the joint recovery of the equivalent excitations at the center frequency and sidebands is realized by a mixed $ l_{0} $ l0/ $ l_{2} $ l2-norm minimization method. The numerical simulation and the successful comparison with the state-of-the-art algorithms demonstrate the superiority of the proposed methods in terms of noise robustness and diagnosis accuracy. Journal: Journal of Electromagnetic Waves and Applications Pages: 17-33 Issue: 1 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2270517 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2270517 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:1:p:17-33 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2277188_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Pingle Liang Author-X-Name-First: Pingle Author-X-Name-Last: Liang Author-Name: Juan Chen Author-X-Name-First: Juan Author-X-Name-Last: Chen Title: An optically transparent coplanar L-probe fed antenna based on capacitively coupled array of patches Abstract: An optically transparent antenna fed by a coplanar L-probe is proposed in this paper. Indium-doped tin oxide (ITO) with a sheet resistance of 3.5 Ω/sq etched on a soda-lime glass substrate is used as radiation array and ground to achieve high optical transmittance. TM $ _{10} $ 10 and TM $ _{20} $ 20 modes are excited simultaneously to expand work bandwidth. The fabricated antenna achieves a –10 dB reflection bandwidth of 27.5% from 4.7 to 6.2 GHz with the overall size of 42 mm × 42 mm × 3.3 mm. Different from many antennas composed of ITO, the proposed antenna exhibits directional radiation patterns with the maximum realized gain of 4.6 dBi and the maximum efficiency of 61%. Meanwhile, the optical transmittance of the antenna can reach above 58%. Journal: Journal of Electromagnetic Waves and Applications Pages: 122-133 Issue: 1 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2277188 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2277188 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:1:p:122-133 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2277189_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Mehwish Nisar Author-X-Name-First: Mehwish Author-X-Name-Last: Nisar Author-Name: Sidra Batool Author-X-Name-First: Sidra Author-X-Name-Last: Batool Author-Name: Fabio Mangini Author-X-Name-First: Fabio Author-X-Name-Last: Mangini Author-Name: Henrik Wallén Author-X-Name-First: Henrik Author-X-Name-Last: Wallén Author-Name: Ari Sihvola Author-X-Name-First: Ari Author-X-Name-Last: Sihvola Author-Name: Fabrizio Frezza Author-X-Name-First: Fabrizio Author-X-Name-Last: Frezza Title: Finding the polarizability of dielectric half-ellipse Abstract: This article studies the electrostatic response of a two-dimensional dielectric half-ellipse. A semianalytical method is presented for solving the polarizability of a half-ellipse as a function of its relative permittivity. The polarizability depends on the direction of incident field, and therefore, it is written as a dyadic with two perpendicular components. These are called series and parallel polarizability, and they are solved separately. The solution requires a series expansion of the potential function, and the coefficients must be obtained numerically, through an inversion of a finite matrix equation. Numerical results are presented for the polarizability components of the half-ellipse as functions of its geometry and permittivity. Journal: Journal of Electromagnetic Waves and Applications Pages: 134-149 Issue: 1 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2277189 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2277189 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:1:p:134-149 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2272612_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Shreen El-Sapa Author-X-Name-First: Shreen Author-X-Name-Last: El-Sapa Author-Name: Alaa A. El-Bary Author-X-Name-First: Alaa A. Author-X-Name-Last: El-Bary Author-Name: Wedad Albalawi Author-X-Name-First: Wedad Author-X-Name-Last: Albalawi Author-Name: H. M. Atef Author-X-Name-First: H. M. Author-X-Name-Last: Atef Title: Modelling Pennes’, bioheat transfer equation in thermoelasticity with one relaxation time Abstract: In this study, we develop the heat conduction equation for bio-thermoelastic skin tissue with one relaxation time using Penne’s principle, the first law of thermodynamics, and the second law of thermodynamics. We use these novel governing equations to explore the influence of arterial blood temperature on physical parameters in homogeneous, isotropic, thermally conducting half-space skin tissue. Normal mode analysis is applied in the domain to acquire analytical results for measured quantities. For a given skin tissue, these expressions are numerically calculated and graphically illustrated. The findings were predicted and tested for various values of arterial blood temperature. Journal: Journal of Electromagnetic Waves and Applications Pages: 105-121 Issue: 1 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2272612 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2272612 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:1:p:105-121 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2301564_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Mingxiu Han Author-X-Name-First: Mingxiu Author-X-Name-Last: Han Author-Name: Yubiao Du Author-X-Name-First: Yubiao Author-X-Name-Last: Du Author-Name: Juan Xu Author-X-Name-First: Juan Author-X-Name-Last: Xu Title: Frequency-multiplexed multifunctional coding metasurface based on transmission and reflection modes Abstract: In this work, a frequency-multiplexed multifunctional coding metasurface is proposed, which can realize focusing lens at the lower frequency and multiple scattering beams at the higher frequency. The two functions can be manipulated independently. The proposed metasurface is composed of the top metal patch with a circular ring, two fan rings and two rectangle patches (CFRP), the bottom metal patch with C-shaped and rectangular metal slots (CRS) and a dielectric substrate. By changing the opening direction and size of CRS and the tilt direction and fan ring size of CFRP, the amplitude and phase of transmission and reflection can be modulated, respectively. The transmission mode works at 7 GHz, which can form focal points in different focal planes. The reflection mode works at 17.5 GHz, which can form multiple scattered beams in different directions in the far field. To further verify its practical feasibility, the proposed metasurface is fabricated and measured, the experimental results are in good agreement with the numerical simulation results. The proposed metasurface provides new possibilities to develop multifunctional devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 282-293 Issue: 2 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2301564 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2301564 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:2:p:282-293 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2290506_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: JiJian Meng Author-X-Name-First: JiJian Author-X-Name-Last: Meng Author-Name: ZiWen Guo Author-X-Name-First: ZiWen Author-X-Name-Last: Guo Author-Name: Yong Zhang Author-X-Name-First: Yong Author-X-Name-Last: Zhang Author-Name: JianWen Xu Author-X-Name-First: JianWen Author-X-Name-Last: Xu Author-Name: ZiHan Li Author-X-Name-First: ZiHan Author-X-Name-Last: Li Title: Analysis of electromagnetic wave ignition mechanism and calculation of power threshold in underground coal mine Abstract: This study critically assesses the potential risks associated with the implementation of 5G radio frequency signals in coal mines. The empirical findings underscore that, under uniform excitation conditions, when situating a PCB loop antenna at the focal points of maximum near-field and far-field emissions from a Yagi antenna, both simulations and analytical computations converge on a safe power threshold of 450W for the transmitting antenna in the near field. This limit augments to 7200W in the far field context. In a hypothetical scenario devoid of transmission losses, the safe power threshold for the transmitter is projected to be 100W. It is imperative to acknowledge that the safety threshold for the RF source is intricately linked to the internal resistance of the receiving antenna. As a corollary, the probability of an inadvertent high-gain conductive spark discharge is substantially minimized, intimating that real-world safe thresholds might be greater than the values proposed herein. Journal: Journal of Electromagnetic Waves and Applications Pages: 234-249 Issue: 2 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2290506 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2290506 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:2:p:234-249 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2285779_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Haoyang Fan Author-X-Name-First: Haoyang Author-X-Name-Last: Fan Author-Name: Zheng Qin Author-X-Name-First: Zheng Author-X-Name-Last: Qin Author-Name: Jian Yu Author-X-Name-First: Jian Author-X-Name-Last: Yu Title: Ultra-broadband perfect absorber based on sub-grating structure Abstract: This paper introduces an ultra-broadband perfect absorber. The absorber comprises just two layers. By introducing sub-grating structures in the groove of the rectangle grating, a broadband absorber is realized. The proposed structure operates in the wavelength range of 420nm-1543 nm, exhibiting an absorptivity greater than 90%. To enhance our comprehension of the physical mechanism behind broadband absorption, we analyze the distributions of current density, electric field, and magnetic field within the structure. The ultra-broadband absorption is achieved through multiple resonances of the structure. Additionally, the absorber demonstrates good absorption performance at large incident angles. By modifying the proposed structure to possess centrosymmetry, the absorber becomes impervious to incident waves with varying polarization angles. Owing to the simple structure, the absorber may have a wider range of applications, including photovoltaic devices and light-emitting devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 203-212 Issue: 2 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2285779 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2285779 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:2:p:203-212 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2285773_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Chengliang Wu Author-X-Name-First: Chengliang Author-X-Name-Last: Wu Author-Name: Nanguang Su Author-X-Name-First: Nanguang Author-X-Name-Last: Su Author-Name: Ge Huang Author-X-Name-First: Ge Author-X-Name-Last: Huang Title: Design and verification of a tunable single-band metamaterial based on Polymeric Methyl Methacrylate and its feasibility for temperature detection in smart packaging Abstract: Metamaterial absorbers with single resonance mode and narrow bandwidth are often used in sensing. A metamaterial absorber containing dielectric layers of the same thickness (Polymeric Methyl Methacrylate (PMMA) and strontium titanate (STO)) are proposed and confirmed. At room temperature (300 K), an individual absorption peak is excited, and the single resonance mode and narrow bandwidth characteristic are obtained. The amplitude and resonance frequency of the metamaterial samples can be controlled by changing the thickness of PMMA or STO. The metamaterial samples are placed in an environment with a gradual change in temperature. The results show that the absorptive properties of the metamaterial sample show remarkable repeatability in the process of temperature increase and decrease. Therefore, based on the properties of single resonance mode, narrow bandwidth, and reversibility, the metamaterial samples have the potential to be used in smart packaging sensing. Journal: Journal of Electromagnetic Waves and Applications Pages: 185-202 Issue: 2 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2285773 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2285773 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:2:p:185-202 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2290501_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Özgür Eriş Author-X-Name-First: Özgür Author-X-Name-Last: Eriş Author-Name: Özgür Ergül Author-X-Name-First: Özgür Author-X-Name-Last: Ergül Title: Design, simulation, and measurement of near-zero-index shells for electromagnetic beam generation Abstract: We present design and simulation of three-dimensional (3D) shell structures, which generate directional radiation patterns from isotropic sources thanks to their near-zero-index (NZI) characteristics, as well as realizations of these shells via low-cost 3D printing. Throughout the design process of NZI beam generators, both homogenized structures, for which near-zero relative permittivity and/or permeability values are enforced, and actual models involving periodic arrangements of dielectric rods are considered. Solutions of the electromagnetic problems are obtained by using rigorous implementations of the state-of-the-art surface-integral-equation (SIE) formulations in frequency domain. Iterative solutions of matrix equations derived from SIEs are accelerated by different forms of the multilevel fast multipole algorithm (MLFMA) and suitable preconditioners, when necessary. In the design process of NZI shells, alternative strategies are employed to obtain customized radiation patterns. In this context, various cavities with strong resonance behaviors are designed as source regions. At the same time, outer surfaces are modified to either enhance or suppress outgoing electromagnetic fields. In addition to comprehensive simulations and analyses of NZI beam generators, their capabilities are verified by measurements, specifically at 10.3 GHz, on different prototypes fabricated via 3D printing. Measurements of diverse NZI shell structures are presented to demonstrate that NZI properties can successfully be achieved by well-designed arrangements of dielectric rods with proper materials. The results demonstrate the feasibility of efficient, effective, low-cost, and reconfigurable NZI shells to generate alternative beam configurations that can be useful in a plethora of microwave applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 213-233 Issue: 2 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2290501 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2290501 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:2:p:213-233 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2285760_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Zhiwei Chen Author-X-Name-First: Zhiwei Author-X-Name-Last: Chen Author-Name: Zhengpan Wang Author-X-Name-First: Zhengpan Author-X-Name-Last: Wang Author-Name: Shuiqing Xu Author-X-Name-First: Shuiqing Author-X-Name-Last: Xu Author-Name: Anjiang Li Author-X-Name-First: Anjiang Author-X-Name-Last: Li Author-Name: Qipei Zhou Author-X-Name-First: Qipei Author-X-Name-Last: Zhou Author-Name: Xiang Li Author-X-Name-First: Xiang Author-X-Name-Last: Li Title: Optimization of magnetic coupling structure of electric vehicle wireless charging DD coil Abstract: The charging coil plays an important role in the wireless charging system system. However, there are still some problems in the design of the wireless charging coil, such as the low coupling coefficient. In order to improve the coupling effect, this paper proposes an optimized design scheme for the metal shielding layer structure of DD coil. Firstly, the influence of the structure size of DD coil metal plate on the coupling coefficient is studied by the mathematical modeling analysis. Futhermore, the maxwell simulation is used to study the metal plate coupling coefficients with varying structure sizes, addressing receiving uniformity issues. The optimal size of the shielding layer is designed for optimal magnetic coupling in wireless charging. Finally, this paper validates the feasibility of the improved metal shielding layer through experiments. The research in this paper may have a reference role in the wireless charging system of electric vehicles. Journal: Journal of Electromagnetic Waves and Applications Pages: 151-169 Issue: 2 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2285760 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2285760 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:2:p:151-169 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2285761_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Abdelheq Boukarkar Author-X-Name-First: Abdelheq Author-X-Name-Last: Boukarkar Author-Name: Satouh Rachdi Author-X-Name-First: Satouh Author-X-Name-Last: Rachdi Author-Name: Mohamed Amine Merabet Author-X-Name-First: Mohamed Amine Author-X-Name-Last: Merabet Author-Name: Sami Baguigui Author-X-Name-First: Sami Author-X-Name-Last: Baguigui Author-Name: Khalil Adda Benziane Author-X-Name-First: Khalil Author-X-Name-Last: Adda Benziane Title: Miniaturized frequency-reconfigurable single-feed multi-band antenna with bandwidth enhancement for wireless applications Abstract: We propose a miniaturized frequency-reconfigurable multiband antenna with bandwidth enhancement. The main radiating patch is shorted from one edge to reduce the antenna footprint. An inverted U-shape microstrip line is integrated onto the antenna structure to excite more resonant frequencies. Indeed, by shorting the U-shape's arms, seven frequency bands can be created and controlled. The activation of the two p-i-n diodes is ensured by employing a simple symmetrical DC bias network. Furthermore, by adjusting the arms’ lengths, two resonances are combined to enhance the working bandwidth. Measurements reveal that the antenna resonates around the operating frequencies of 2.91 GHz, 3.55 GHz, 3.69 GHz, 3.83 GHz, 4.14 GHz, 4.18, and 4.24 GHz. The antenna exhibits stable patterns, with a measured peak gain and efficiency of 5.5 dBi and 86%, respectively. The antenna is compact; thus, it is recommended in wireless systems requiring multiband function with stable patterns and a reduced area. Journal: Journal of Electromagnetic Waves and Applications Pages: 170-184 Issue: 2 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2285761 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2285761 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:2:p:170-184 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2301563_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Abhinav Kumar Author-X-Name-First: Abhinav Author-X-Name-Last: Kumar Author-Name: Jayanta Ghosh Author-X-Name-First: Jayanta Author-X-Name-Last: Ghosh Title: Polarization-independent wideband meta-material absorber based on resistor-loaded hexagonal ring resonators Abstract: A polarization-independent meta-material-based absorber with wideband response is presented in this study. The proposed absorber’s unit cell consists of a resistance-loaded metallic hexagonal ring and four rectangular metal strips placed inside the hexagonal ring patterned on the upper surface of a dielectric substrate. The absorber exhibits wideband absorption with absorptivity more than 90% in the frequency range 7.14 to 13.68 GHz. The Full-Width Half Maxima (FWHM) of the absorber is 8.8 GHz (5.2–14 GHz). The four-fold symmetrical structure of the absorber confirms polarization-insensitive behaviour. The absorber performance is also validated with fabrication and measurement. There is a fair degree of agreement between simulated and measured results. The novelty of the proposed absorber is having wideband absorption with high packing density due to its hexagonal shape. The metamaterial absorber finds its use in defence-related applications such as radar surveillance, stealth technology, terrestrial communications, and satellite communication. Journal: Journal of Electromagnetic Waves and Applications Pages: 264-281 Issue: 2 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2301563 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2301563 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:2:p:264-281 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2297701_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20231214T103247 git hash: d7a2cb0857 Author-Name: Chandan Kumar Author-X-Name-First: Chandan Author-X-Name-Last: Kumar Author-Name: Sanjeev Kumar Raghuwanshi Author-X-Name-First: Sanjeev Kumar Author-X-Name-Last: Raghuwanshi Author-Name: Vikram Kumar Author-X-Name-First: Vikram Author-X-Name-Last: Kumar Title: Graphene-based patch antenna array on photonic crystal substrate at terahertz frequency band Abstract: In this paper, initially a photonic crystal is proposed with a periodic air gap and its performance is investigated at terahertz frequencies by varying the radius of the air gap. Then a microstrip array antenna on the 2-D photonic crystal using graphene sheet as patch material is designed and its electromagnetic characteristics are analysed and compared with those of the existing non-air gap antenna. The suggested antenna also operates in the multi-frequency terahertz range. Using a photonic band gap (PBG), crystal substrate causes the return loss to rise from −29 to −44 dB. Additionally, the antenna array's bandwidth was increased from 40 to 110 GHz. By using PBG, the gain of the suggested antenna is increased by up to 13 dB, as opposed to 4.81 dB for a substrate that does not use PBG. Journal: Journal of Electromagnetic Waves and Applications Pages: 250-263 Issue: 2 Volume: 38 Year: 2024 Month: 01 X-DOI: 10.1080/09205071.2023.2297701 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2297701 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:2:p:250-263 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2303676_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Rakesh Kumar Chandan Author-X-Name-First: Rakesh Kumar Author-X-Name-Last: Chandan Author-Name: Srikanta Pal Author-X-Name-First: Srikanta Author-X-Name-Last: Pal Title: Modal analysis of a half-mode substrate integrated waveguide-fed slot-coupled dual-band patch antenna Abstract: This manuscript presents comprehensive modal analysis of a compact, half-mode SIW-fed slot-coupled dual-band antenna. The Characteristic Mode Analysis (CMA) is investigated in detail and presented for the first time to analyze the radiation behavior and frequency domain characteristics of the proposed structure. The number of dominant operative modes supported by the antenna is decided based on the number eigen factors, its corresponding values, and the characteristic angles. The antenna operates at 33 and 38.14 GHz with a return loss of 20.5 and 19.5 dB, a gain of 7.9 and 6.7 dBi, and an efficiency of 90% and 88%, respectively. Measured results are in close resemblance with the CMA, considering the difference between the conventional cavity modes and the characteristic modes of the proposed planar cavity configuration. The methodology can be extended to characterize any arbitrary shape radiating geometry. Journal: Journal of Electromagnetic Waves and Applications Pages: 345-354 Issue: 3 Volume: 38 Year: 2024 Month: 02 X-DOI: 10.1080/09205071.2024.2303676 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2303676 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:3:p:345-354 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2315060_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Anand Prakash Author-X-Name-First: Anand Author-X-Name-Last: Prakash Author-Name: Sharbani Roy Author-X-Name-First: Sharbani Author-X-Name-Last: Roy Author-Name: Jaisingh Thangaraj Author-X-Name-First: Jaisingh Author-X-Name-Last: Thangaraj Author-Name: Jitendra K. Mishra Author-X-Name-First: Jitendra K. Author-X-Name-Last: Mishra Title: Performance analysis of real-time multi-wavelength nonlinear DRA for the next-generation photonic network Abstract: A new disintegrated channelization approach for the backward pumped nonlinear distributed Raman amplifier is proposed by enacting the differential coupled equations of Raman amplification, in fiber, trailing by the solution of NLSE using the first integral method first time to the best of our knowledge. A nonlinear channel modeling-based simulation is adapted for the approximation of the Raman gain profile. To realize the real-time dynamic system, 16 multiplexed channels of prime C-band are employed in a QPSK/NRZ modulation environment with a 100 Gbps bit rate for optical network reconfiguration. A non-uniform gain is reported while the disparity in BER is observed from 10−12 to 10−8. Journal: Journal of Electromagnetic Waves and Applications Pages: 381-396 Issue: 3 Volume: 38 Year: 2024 Month: 02 X-DOI: 10.1080/09205071.2024.2315060 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2315060 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:3:p:381-396 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2309662_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Yulan Hu Author-X-Name-First: Yulan Author-X-Name-Last: Hu Author-Name: Dagang Liu Author-X-Name-First: Dagang Author-X-Name-Last: Liu Author-Name: Chenglin Liu Author-X-Name-First: Chenglin Author-X-Name-Last: Liu Author-Name: Laqun Liu Author-X-Name-First: Laqun Author-X-Name-Last: Liu Author-Name: Huihui Wang Author-X-Name-First: Huihui Author-X-Name-Last: Wang Title: Multi-objective design method for high-power microwave source devices based on preferred PIC/gNSGA-II Abstract: To solve the challenging problem of multi-objective optimization for high-power microwave sources, a specialized preference-based multi-objective optimization method, namely PIC/gNSGA-II, is proposed. Additionally, to achieve the quantitative optimization of the frequency spectrum and power of high-power microwave source devices, objective functions for both the spectrum and power are designed. PIC/gNSGA-II is employed to carry out structural optimization tests on relativistic backward wave oscillators (RBWO). The optimized results produced novel device structures that meet the specified frequency bands: in the X-band, the average output power is 845.85 MW, and the operating frequency is 9.53 GHz; in the Ku-band, the average output power is 167.25 MW, and the operating frequency is 14.73 GHz. This demonstrates that by controlling the parameters of such objective functions, the code can simultaneously optimize the spectrum and power of RBWOs. Comparing the optimization results of PIC/gNSGA-II with those of NSGA-II, PIC/gNSGA-II demonstrates better optimization efficiency and the ability to design device structures that meet various performance criteria. Journal: Journal of Electromagnetic Waves and Applications Pages: 355-368 Issue: 3 Volume: 38 Year: 2024 Month: 02 X-DOI: 10.1080/09205071.2024.2309662 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2309662 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:3:p:355-368 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2309674_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: I. Derafshi Author-X-Name-First: I. Author-X-Name-Last: Derafshi Author-Name: N. Komjani Author-X-Name-First: N. Author-X-Name-Last: Komjani Title: Analysis of binary huygens metasurfaces under non-planar illumination Abstract: In this article, we have investigated the effect of using a real feed on the performance of one-dimensional binary Huygens metasurfaces (BHMS). The designed structure has variable periods and each unit-cell consists of two dipoles with different lengths. Floquet theory and local constant period assumption are used to design these metasurfaces. The simulation results show the high efficiency of the designed structure and its beam squint capability. The results in this article make it possible to use this type of metasurface in real applications under the illumination of real feed sources. Journal: Journal of Electromagnetic Waves and Applications Pages: 369-380 Issue: 3 Volume: 38 Year: 2024 Month: 02 X-DOI: 10.1080/09205071.2024.2309674 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2309674 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:3:p:369-380 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2303668_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Ali Kürşad Görür Author-X-Name-First: Ali Kürşad Author-X-Name-Last: Görür Author-Name: Engin Doğan Author-X-Name-First: Engin Author-X-Name-Last: Doğan Author-Name: Adnan Görür Author-X-Name-First: Adnan Author-X-Name-Last: Görür Title: Single-wideband and dual-band bandpass filters based on compact quadruple-mode resonator Abstract: A stub-loaded U-shaped microstrip resonator (U-SLR) exciting two odd-modes and two even-modes and its applications to single-wideband and dual-band bandpass filter (DB-BPF) are introduced. The parallel-coupled lines (PCLs) at input/output (I/O) ports can provide a wideband response by exciting two additional modes in the passband, so-called PCLs modes. In addition to the transmission poles (TPs) in the passband, two transmission zeros (TZs) in the lower and upper stopbands can be created by the loaded stubs. A compact size, high-selectivity, and low insertion loss WB-BPF is designed, fabricated, and tested. Moreover, a compact and low loss DB-BPF with closely spaced passbands is designed and tested. TZ-shifting method is used to design a DB-BPF by splitting the wideband. To achieve this, it is sufficient to change the length of only one of the loaded stubs. The calculated, simulated and measured frequency responses for both single-wideband and DB-BPFs are in very good agreement. Journal: Journal of Electromagnetic Waves and Applications Pages: 327-344 Issue: 3 Volume: 38 Year: 2024 Month: 02 X-DOI: 10.1080/09205071.2024.2303668 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2303668 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:3:p:327-344 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2301577_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Zhefei Wang Author-X-Name-First: Zhefei Author-X-Name-Last: Wang Author-Name: Ziru Hou Author-X-Name-First: Ziru Author-X-Name-Last: Hou Author-Name: Junxiang Ge Author-X-Name-First: Junxiang Author-X-Name-Last: Ge Author-Name: Fayu Wan Author-X-Name-First: Fayu Author-X-Name-Last: Wan Author-Name: Qingsheng Zeng Author-X-Name-First: Qingsheng Author-X-Name-Last: Zeng Author-Name: Mingxin Song Author-X-Name-First: Mingxin Author-X-Name-Last: Song Author-Name: Jianqiang Hou Author-X-Name-First: Jianqiang Author-X-Name-Last: Hou Author-Name: Larbi Talbi Author-X-Name-First: Larbi Author-X-Name-Last: Talbi Author-Name: Tayeb A. Denidni Author-X-Name-First: Tayeb A. Author-X-Name-Last: Denidni Title: Ultra-wideband absorber based on graphene surface with polarization insensitivity under large angles Abstract: In this paper, a frequency-selective absorber with large-angular stability under oblique incidence is present. The absorptivity of the structure can be reached to maximum by impedance matching and parameter optimization method under a specific angle (40°), which ensures an excellent absorption response within 60° oblique incidence. This method solves the problem that the absorptivity of traditional absorbers deteriorates with the increase of incident angle. The absorber consists of a three-layer structure: two lossy layers and a metal ground layer, the equivalent circuit model is discussed and the operating frequency band is widened by generating electric resonances and magnetic resonances. Due to the high symmetry of the structure, the absorber has good polarization insensitivity. Numerical simulation shows that from 4.4 to 20 GHz, the absorptivity of the structure is above 90% within 40° oblique angle of incidence. Finally, the design plays an important role in military stealth and preventing electromagnetic interference. Journal: Journal of Electromagnetic Waves and Applications Pages: 313-326 Issue: 3 Volume: 38 Year: 2024 Month: 02 X-DOI: 10.1080/09205071.2023.2301577 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2301577 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:3:p:313-326 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2301559_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: J. A. López-Toledo Author-X-Name-First: J. A. Author-X-Name-Last: López-Toledo Author-Name: R. Castillo-Pérez Author-X-Name-First: R. Author-X-Name-Last: Castillo-Pérez Author-Name: H. Oviedo-Galdeano Author-X-Name-First: H. Author-X-Name-Last: Oviedo-Galdeano Title: Analysis of wave propagation through inhomogeneous left and right-handed media using the SPPS method Abstract: Solutions of the wave equation are analyzed considering the propagation of electromagnetic fields through a non-homogeneous stratified metamaterial medium. These solutions are obtained by two methods: (1) Spectral Parameter Power Series (SPPS) and (2) SPPS with Operator Transmutation (OT). This last method is considered an innovation for this application. Numerical solutions are obtained for left-handed (LH) and right-handed (RH) media, which allow their reflectance and transmittance coefficients to be calculated. The performance of each method is evaluated by comparing their solutions with the exact ones available and with those obtained by the differential transfer matrix method (DTMM). The advantages and limitations of each method are indicated. Journal: Journal of Electromagnetic Waves and Applications Pages: 295-312 Issue: 3 Volume: 38 Year: 2024 Month: 02 X-DOI: 10.1080/09205071.2023.2301559 File-URL: http://hdl.handle.net/10.1080/09205071.2023.2301559 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:3:p:295-312 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2321276_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Chung-Yi Li Author-X-Name-First: Chung-Yi Author-X-Name-Last: Li Author-Name: Yi-Jyun Liao Author-X-Name-First: Yi-Jyun Author-X-Name-Last: Liao Author-Name: Eric S. Li Author-X-Name-First: Eric S. Author-X-Name-Last: Li Author-Name: Chao-Hsiang Liao Author-X-Name-First: Chao-Hsiang Author-X-Name-Last: Liao Author-Name: Huayan Jin Author-X-Name-First: Huayan Author-X-Name-Last: Jin Author-Name: Yi-Da Chen Author-X-Name-First: Yi-Da Author-X-Name-Last: Chen Author-Name: Kuo-Sheng Chin Author-X-Name-First: Kuo-Sheng Author-X-Name-Last: Chin Title: Wideband Ka-band printed dipole array antenna with parasitic trapezoidal patch Abstract: This work presents a printed Ka-band dipole array antenna with wide bandwidth for millimeter-wave communication applications. The operating band of the proposed antenna ranges from 27.8–38.2 GHz exhibiting a wide bandwidth of 10.4 GHz. A balun structure is designed with interlaced U-shaped bending lines on the upper and lower metal layers to feed the dipole differentially. Parasitic trapezoidal patches are exquisitely placed adjacent to the driven dipoles for coupling, which can enhance bandwidth significantly through multiple resonances. The low-frequency radiation is mainly contributed by the resonance of the dipole, while the high-frequency radiation is affected by both the dipole and the parasitic trapezoidal patch. Due to the trapezoidal patch, the equivalent path length of the resonant current becomes shorter, thus supporting high-frequency resonance. A prototype of the proposed 1 × 2 dipole array antenna was fabricated for validation. The measured –10-dB impedance bandwidth is up to 27.8∼38.2 GHz (or 31.5%) and the realized gain is as high as 8 dBi, which is suitable for advanced millimeter-wave communication applications. Journal: Journal of Electromagnetic Waves and Applications Pages: 538-555 Issue: 4 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2321276 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2321276 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:4:p:538-555 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2321274_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Eric Huang Author-X-Name-First: Eric Author-X-Name-Last: Huang Author-Name: Madhavan Swaminathan Author-X-Name-First: Madhavan Author-X-Name-Last: Swaminathan Title: Efficient monostatic anisotropic point scatterer model for high performance computing Abstract: High performance computing (HPC) electromagnetic (EM) emulators are used to simulate real-time EM wave interactions between numerous radar targets. Radar Cross Section (RCS) data stores reflection profiles of radar targets as a table; however, the needed storage size increases with frequency sampling density, aspect angle sampling density, and number of target types. The large quantity of data often exceeds storage capability and limits manipulation and representation feasibility. The spherical harmonic based monostatic anisotropic point scatterer model is proposed for HPC EM simulations where scattering responses can be computed with finite impulse response (FIR) filters. An efficient algorithm constructing this model with large scale RCS data is discussed. The scatterer position and the reflection profile of each scatterer are solved using least squares methods and particle swarm optimization (PSO). In addition, the function evaluations in PSO are accelerated by taking advantage of the matrix structure, making the algorithm 22 times faster Journal: Journal of Electromagnetic Waves and Applications Pages: 522-537 Issue: 4 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2321274 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2321274 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:4:p:522-537 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2319683_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Poonam Tiwari Author-X-Name-First: Poonam Author-X-Name-Last: Tiwari Author-Name: Vishant Gahlaut Author-X-Name-First: Vishant Author-X-Name-Last: Gahlaut Author-Name: Upendra Narayan Mishra Author-X-Name-First: Upendra Author-X-Name-Last: Narayan Mishra Author-Name: Anshuman Shastri Author-X-Name-First: Anshuman Author-X-Name-Last: Shastri Author-Name: Meenu Kaushik Author-X-Name-First: Meenu Author-X-Name-Last: Kaushik Title: Polarization diversity configuration of millimeter wave MIMO antenna for Ka-band application in 5G wireless networks Abstract: A compact MIMO antenna has been designed explicitly for Ka-band for 5G wireless networks. The antenna uses four P-shaped radiating patches in E-shaped slots for polarization variety in the 20-40 GHz frequency band. The Rogers RT/duroid 5880 substrate (26 × 25 × 1.6) supports each patch and defective ground for each element. Polarization diversity lowers radiating element interference, making this antenna design advantageous. Therefore, the antenna has a wide bandwidth of 20 GHz. A high isolation level of over -20 dB has been attained by carefully examining the mutual connection between antenna radiators. After a detailed analysis of the radiation patterns, a gain of 17.6 dBi is found. Both total and radiating efficiency exceed 87% and 91%. MIMO system dependability is evaluated by assessing diversity characteristics including ECC, DG, CCL, MEG, and TARC, yielding findings of 0.0035, 9.98 dB, 0.013 bits/sec/Hz, -3 dB, and -10 dB. Simulations and observations show a significant agrement. Journal: Journal of Electromagnetic Waves and Applications Pages: 486-507 Issue: 4 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2319683 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2319683 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:4:p:486-507 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2315061_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Shengbao Yu Author-X-Name-First: Shengbao Author-X-Name-Last: Yu Author-Name: Hongwei Wang Author-X-Name-First: Hongwei Author-X-Name-Last: Wang Author-Name: Changsheng Liu Author-X-Name-First: Changsheng Author-X-Name-Last: Liu Author-Name: Ying Guo Author-X-Name-First: Ying Author-X-Name-Last: Guo Author-Name: Jinlin Huang Author-X-Name-First: Jinlin Author-X-Name-Last: Huang Author-Name: Haigen Zhou Author-X-Name-First: Haigen Author-X-Name-Last: Zhou Title: Comparative analysis of divergence of tipper imaging with natural and orthogonal electric sources Abstract: The divergence of the tipper (DT) is an important imaging method characterized by fast imaging speed and high lateral resolution. It has been recently adopted from the natural source airborne electromagnetic method to the orthogonal electric sources ground-airborne frequency-domain electromagnetic method. However, the imaging characteristics and patterns of DT in the two methods are unclear due to significant differences in the sources used. The application of DT in ground-airborne frequency-domain electromagnetic method is limited. Therefore, this study first identifies the similarities and differences between the two methods from the theory. Furthermore, based on the same simulation model, the response characteristics of the DT excited by natural and orthogonal electric sources are investigated. The similarities and differences between the two methods are clarified. It will contribute to the rapid development and application of the DT imaging in ground-airborne electromagnetic detection method. Journal: Journal of Electromagnetic Waves and Applications Pages: 397-410 Issue: 4 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2315061 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2315061 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:4:p:397-410 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2315063_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Denis Iuzvik Author-X-Name-First: Denis Author-X-Name-Last: Iuzvik Author-Name: Maksim Stepanov Author-X-Name-First: Maksim Author-X-Name-Last: Stepanov Title: Ensuring the maximum amplitude of the electric field strength in given coordinates using a linear antenna array focused on a finite distance Abstract: The paper considers the possibility of forming the maximum amplitude of the electric field strength at a given point in space using a linear antenna array focused on a finite distance. Since the location of the electric field maximum does not coincide with the point at which the antenna array is focused, two methods have been proposed to ensure the positioning of the maximum at a given point. The first method is an algorithm that allows you to determine such a large focal length at which the maximum electric field strength is positioned at the required point. The second way is to use two parallel identical antenna arrays, equidistantly located relative to the desired location of the maximum electric field strength. The limitations imposed by each of the methods are considered. Examples of the use of each of the methods for positioning the maximum electric field strength at a given point are given. Journal: Journal of Electromagnetic Waves and Applications Pages: 411-427 Issue: 4 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2315063 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2315063 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:4:p:411-427 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2315590_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Prabir Ghosh Author-X-Name-First: Prabir Author-X-Name-Last: Ghosh Author-Name: Abhik Gorai Author-X-Name-First: Abhik Author-X-Name-Last: Gorai Author-Name: Subhrakanta Behera Author-X-Name-First: Subhrakanta Author-X-Name-Last: Behera Author-Name: Rowdra Ghatak Author-X-Name-First: Rowdra Author-X-Name-Last: Ghatak Title: Design of compact UWB antenna using characteristic mode analysis and its quad-port MIMO realization with novel isolation technique Abstract: This paper presents a miniaturized Quad-Port MIMO antenna for UWB application. Employing Characteristic Mode Analysis, the single element UWB antenna is analysed to achieve a compact design. Using the Theory of Characteristic Mode, the significant modes and their current distribution are analysed, which helps to modify the radiator and ground plane to generate more significant modes to yield a wider frequency band. Four circular-shaped radiators with tapered feeds are placed orthogonally on the FR4 substrate to improve isolation, and partial ground planes are located on the opposite surface. Furthermore, a modified Pattee-cross-shaped parasitic element is introduced between the antenna elements and shorted with the ground planes via metallic shorting pins. This novel technique improves isolation compared to the conventional integration method of the partial ground planes through strip lines. The proposed antenna achieves less than −20 dB mutual coupling over most of the frequency band ranging from 2.51–18 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 443-459 Issue: 4 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2315590 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2315590 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:4:p:443-459 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2319131_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Xiuwen Tian Author-X-Name-First: Xiuwen Author-X-Name-Last: Tian Author-Name: Lizhong Song Author-X-Name-First: Lizhong Author-X-Name-Last: Song Title: A wideband 1 bit reconfigurable transmitarray antenna based on proximity-coupled feed patch element Abstract: In this paper, a wideband 1-bit reconfigurable transmit array antenna (RTA) is proposed. The 1-bit RTA element consists of a passive receiving antenna and a reconfigurable radiating antenna, which adopt a proximity-coupled feed method to broaden the transmission bandwidth. Two p-i-n diodes are integrated into the reconfigurable receiving antenna to control the current distribution. By switching the states of the p-i-n diodes, the reconfigurable radiating antenna can achieve a 1-bit phase shift. Element simulation results show that the proposed RTA element can achieve a 3 dB transmission bandwidth of 21.5%. A 100-element RTA prototype with 200 p-in diodes is designed, fabricated and measured. The measured results show that the peak gain is 18.8 dBi at 5.05 GHz, corresponding to an aperture efficiency of 20.8%, and the 3 dB gain bandwidth is 17.1%. Furthermore, the scanned beams can reach −32° and −36°, respectively, in the E- and H-planes. Journal: Journal of Electromagnetic Waves and Applications Pages: 460-472 Issue: 4 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2319131 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2319131 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:4:p:460-472 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2320742_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Azharuddin Khan Author-X-Name-First: Azharuddin Author-X-Name-Last: Khan Author-Name: Satya Kesh Dubey Author-X-Name-First: Satya Kesh Author-X-Name-Last: Dubey Author-Name: Amit Kumar Singh Author-X-Name-First: Amit Kumar Author-X-Name-Last: Singh Title: Corner T-slot antenna at 2.45 GHz for hyperthermia application Abstract: This study focuses on the design and characterization of a novel T-slot antenna for hyperthermia application at 2.45 GHz. The simulation and experimental results demonstrate that the antenna has a resonant frequency of 2.45 GHz, is found to be in good agreement and a gain of −5.1 dBi. The proposed antenna has a dimension of 26 × 26 × 1.6 mm3 with 2.85% BW. The antenna's surface current distribution and specific absorption rate (SAR) are analyzed using numerical simulations, and the results show that the antenna provides an effective heating pattern with low levels of energy deposition in the surrounding healthy tissue. Finally, a proof-of-concept hyperthermia treatment is performed on a tissue-equivalent-liquid (TEL) phantom using the proposed antenna. The proposed T-slot antenna has the potential for use in hyperthermia treatments for cancer therapy, and further studies are required to evaluate its safety and efficacy for clinical use. Journal: Journal of Electromagnetic Waves and Applications Pages: 508-521 Issue: 4 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2320742 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2320742 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:4:p:508-521 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2315578_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Chengzhu Du Author-X-Name-First: Chengzhu Author-X-Name-Last: Du Author-Name: Yongli Ren Author-X-Name-First: Yongli Author-X-Name-Last: Ren Title: A CPW-fed wideband four-port MIMO slot antenna with high isolation for sub-6G applications Abstract: This paper presents a high isolation four-port MIMO slot antenna for sub-6G applications. Four antenna elements are placed vertically to form vertical polarization. In addition, etching trapezoidal grooves on the four sides of the ground can not only improve the low-frequency isolation, but also increase the bandwidth. The measured results show that the antenna can work at 1.95–6.7GHz (109.8%), and the isolation between antenna elements is below −18 dB. The envelope coefficient (ECC) parameter of the antenna is less than 0.004, the peak gain is 7 dB, and the radiation efficiency is 90%. The results show that the antenna has high isolation and good performance, and can be applied to wireless applications such as N41/N77/N78/N7 (5G-NR) sub-6 GHz/Wi-Fi-5/V2X/DSRC. Journal: Journal of Electromagnetic Waves and Applications Pages: 428-442 Issue: 4 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2315578 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2315578 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:4:p:428-442 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2319681_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Biao Sun Author-X-Name-First: Biao Author-X-Name-Last: Sun Title: High-power ultra-wideband power-combining technique based on microstrip line and ridge waveguide Abstract: Based on microstrip-line power divider and ridge-waveguide power combiner, a high-power ultra-wideband solid-state power-combining amplifier is designed and fabricated. The Measured results show that the continuous wave output power of the ultra-wideband solid-state power-combining amplifier reaches over 100 W within the frequency range of 6–18 GHz, the maximum output power is nearly 200 W, the power-combining efficiency is approximately 80%, and the power-added efficiency is better than 14%. Journal: Journal of Electromagnetic Waves and Applications Pages: 473-485 Issue: 4 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2319681 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2319681 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:4:p:473-485 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2321283_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Kiran Ilyas Author-X-Name-First: Kiran Author-X-Name-Last: Ilyas Author-Name: Qaisar Abbas Naqvi Author-X-Name-First: Qaisar Abbas Author-X-Name-Last: Naqvi Title: Three-octave supercontinuum spanning with Z-cut lithium niobate photonic waveguide Abstract: We numerically demonstrate three-octave supercontinuum generation using the z-cut lithium niobate waveguide by dispersion engineering. The photonic waveguide structure is designed to exhibit anomalous dispersion when pumped at 1.55  $ \rmu {\rm m} $ μm wavelength. By altering the waveguide width, tunable zero-dispersion wave generation has been achieved up to 6  $ \rmu {\rm m} $ μm wavelength. Our findings show the broadest supercontinuum spanning in the mid-IR region using a lithium niobate platform, making it a promising candidate for various applications in optical communication, sensing, and imaging. Journal: Journal of Electromagnetic Waves and Applications Pages: 611-617 Issue: 5 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2321283 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2321283 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:5:p:611-617 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2321279_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Gundu Venkatesh Author-X-Name-First: Gundu Author-X-Name-Last: Venkatesh Author-Name: Surya Pal Singh Author-X-Name-First: Surya Pal Author-X-Name-Last: Singh Author-Name: M. Thottappan Author-X-Name-First: M. Author-X-Name-Last: Thottappan Title: A novel fast roll-off bandpass frequency selective surface for stealth applications Abstract: A novel frequency selective surface (FSS)-based spatial bandpass filter for TM-polarized waves is reported. The unit cell of the proposed FSS consists of a dielectric substrate with two conducting layers on opposite sides. One magnetic resonator is placed on the top conducting layer, while two pairs of electric resonators are positioned on the bottom conducting layer to provide a fast roll-off bandpass characteristic. The simulated values of the −3 dB to −10 dB roll-off factor (RF) for the proposed structure are 140 and 280 dB/GHz on the lower and upper sides of its passband, respectively. To validate the simulation results of the proposed structure, a prototype of the FSS-based filter was fabricated and tested experimentally. Furthermore, the present simulation results are benchmarked with the band-pass FSSs reported in the literature, demonstrating an advantage of the proposed filter over the filters mentioned in previous works. Journal: Journal of Electromagnetic Waves and Applications Pages: 571-581 Issue: 5 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2321279 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2321279 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:5:p:571-581 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2321281_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Z. Hamouda Author-X-Name-First: Z. Author-X-Name-Last: Hamouda Author-Name: S. Azaizia Author-X-Name-First: S. Author-X-Name-Last: Azaizia Author-Name: M. Nehaoua Author-X-Name-First: M. Author-X-Name-Last: Nehaoua Author-Name: M. F. Hammouche Author-X-Name-First: M. F. Author-X-Name-Last: Hammouche Author-Name: T. Lasri Author-X-Name-First: T. Author-X-Name-Last: Lasri Title: A miniaturized airplane blade antenna for radio navigation and communication systems Abstract: Blade antennas are preferred antenna structures for airborne applications due to their compact size, lightweight and drag-reducing aerodynamic shape. In this paper, we present the design, simulation and realization of a miniaturized blade antenna requiring a small ground plane and covering the frequency band 0.8–1.1 GHz. To reduce air drag, the proposed antenna is placed inside an aerodynamically optimized airborne radome. The return loss, the radiation patterns and the realized gain of the proposed antenna are studied using HFSS simulations. The comparison of the simulated return loss and radiation patterns to their measured counterpart demonstrates a good agreement. A minimum realized gain of 3.6 dB was achieved at the frequency of 0.9 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 595-610 Issue: 5 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2321281 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2321281 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:5:p:595-610 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2321277_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Sangeeta Das Author-X-Name-First: Sangeeta Author-X-Name-Last: Das Author-Name: Pankaj Sarkar Author-X-Name-First: Pankaj Author-X-Name-Last: Sarkar Title: Design of a fractal triple-band reconfigurable filtering antenna for multiband applications Abstract: This letter constitutes a novel triple-band reconfigurable filtering antenna used for Bluetooth, WiMAX and WLAN applications. First, a compact triple-band reconfigurable filter is instigated which is composed of two pairs of Stepped Impedance Resonators (SIRs) and a pair of Uniform Impedance Resonators (UIRs). The SIRs are entrenched at the upper and lower half of feed lines operating at 2.4 and 5.4 GHz, respectively. A pair of UIRs operating at 3.5 GHz is folded and enclosed near the upper SIR. A shunt stub is tapped at the source-load feeding lines to upgrade the selectivity of the filter. The proposed filter uses four PIN diodes to initiate different reconfigurable multiband operations. A fractal antenna is implemented with a modified binary tree topology. The ground plane of the proposed antenna is reformed with a stub. The improved antenna structure enables three radiating bands with enhanced performance. Later, the designed filter is integrated into the antenna to implement the intended triple-band reconfigurable filtering antenna. Journal: Journal of Electromagnetic Waves and Applications Pages: 557-570 Issue: 5 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2321277 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2321277 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:5:p:557-570 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2324835_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Yan Zhang Author-X-Name-First: Yan Author-X-Name-Last: Zhang Author-Name: Bin Xia Author-X-Name-First: Bin Author-X-Name-Last: Xia Author-Name: Junfa Mao Author-X-Name-First: Junfa Author-X-Name-Last: Mao Title: A novel design methodology for asymmetric coupled line passive devices and its application in impedance transformers Abstract: This article presents a novel design methodology for asymmetric coupled line passive devices. Based on the extraction of distributed parameters of coupled lines from S-parameters, we re-derived modal characteristic parameters and Z matrix of four-port asymmetric coupled lines in inhomogeneous mediums. Then, Z matrices of ten two-port asymmetric coupled line circuits are derived and their frequency responses are analyzed. Inspired by the image parameter method, image impedances are adopted for two-port device designs. Data diagrams which connect geometric parameters with impedances are provided to simplify design processes. Two impedance transformers utilizing the open-ended and short-ended coupled line circuits, respectively, producing high transforming ratios of 100 (50 Ω to 0.5 Ω) and 40 (50 Ω to 2000 Ω) are fabricated to verify the proposed analysis and design method. Excellent agreement between the simulation and measurement result proves the unique superiorities of asymmetric coupled lines with better initial values. Journal: Journal of Electromagnetic Waves and Applications Pages: 618-637 Issue: 5 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2324835 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2324835 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:5:p:618-637 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2321280_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Jinzhou Liu Author-X-Name-First: Jinzhou Author-X-Name-Last: Liu Author-Name: Xinying Yan Author-X-Name-First: Xinying Author-X-Name-Last: Yan Author-Name: Meng Jin Author-X-Name-First: Meng Author-X-Name-Last: Jin Author-Name: Xiangpeng Xin Author-X-Name-First: Xiangpeng Author-X-Name-Last: Xin Title: Localized waves and interaction solutions to an integrable variable coefficient Date-Jimbo-Kashiwara-Miwa equation Abstract: This paper initiates an exploration into the exact solutions of the variable coefficient Date-Jimbo-Kashiwara-Miwa equation, first utilizing the Painlevé analysis method to discuss the integrability of the equation. Subsequently, By employing the Hirota bilinear method, N-soliton solutions for the equation are constructed. The application of the Long wave limit method to these N-soliton solutions yields rational and semirational solutions. Various types of localized waves, encompassing solitons, lumps, breather waves, and others, emerge through the careful selection of specific parameters. By analyzing the image of the solutions, the evolution process and its dynamical behavior are studied. Journal: Journal of Electromagnetic Waves and Applications Pages: 582-594 Issue: 5 Volume: 38 Year: 2024 Month: 03 X-DOI: 10.1080/09205071.2024.2321280 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2321280 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:5:p:582-594 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2321286_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Ramya Radhakrishnan Author-X-Name-First: Ramya Author-X-Name-Last: Radhakrishnan Author-Name: Shilpi Gupta Author-X-Name-First: Shilpi Author-X-Name-Last: Gupta Title: Metasurface-inspired circularly polarized patch antenna using DGS for sub 6-GHz applications Abstract: A novel circularly polarized metasurface inspired regular triangle patch antenna (RTPA) with enhanced gain and bandwidth is proposed in this paper. The antenna is composed of a triangular patch-driven element sandwiched between a 3×3 sub-wavelength square patch metasurface array and the ground plane. Initially, the RTPA is designed, and the ground plane is etched with fractal slots to produce degenerate modes for circular polarization. A metasurface array is used as a superstrate to improve gain and bandwidth in terms of impedance and axial ratio (AR). Another advantage of using a metasurface is the reduction of cross-polar radiation, particularly when employing a triangular-shaped patch antenna. The asymmetry of this structure leads to cross-polar components contributed by dominant modes rather than higher-order modes, and the use of a metasurface markedly diminishes these components. The proposed antenna's experimental results show a 10 dB return loss (|S11|) with a metasurface demonstrates a measured impedance bandwidth and axial ratio bandwidth of 760 and 350 MHz, respectively. The antenna exhibits right-hand circular polarization with a measured gain of 5.87 dBic at the operating frequency. Journal: Journal of Electromagnetic Waves and Applications Pages: 639-651 Issue: 6 Volume: 38 Year: 2024 Month: 04 X-DOI: 10.1080/09205071.2024.2321286 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2321286 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:6:p:639-651 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2324842_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Binod Kumar Kanaujia Author-X-Name-First: Binod Kumar Author-X-Name-Last: Kanaujia Author-Name: Praveen Chaurasia Author-X-Name-First: Praveen Author-X-Name-Last: Chaurasia Title: Design and mathematical modeling of DNG metamaterial having six-band capabilities with high effective medium ratio Abstract: In this paper, six-band double negative (DNG) metamaterial with a substantially high effective medium ratio (EMR) under the S and C microwave band is designed and investigated for multiple microwave applications. The proposed metamaterial unit cell consists of four Plus Appended Split Ring Resonator (PASRR) cells, which are combined with variable sides and positions by plus (+) shape stubs at the centre. All four Plus Appended Split Ring Resonator (PASRR) cells are mutually coupled with each other to vary the electrical length to achieve hexa Bands DNG characteristics in a lossy FR-4 epoxy substrate with the thickness of 1.5748 mm. A parameter extraction method has been used to extract effective permittivity (εeff), permeability (μeff) and refractive index (n). Moreover, the equivalent circuit model is obtained. Ansys HFSSTM software & Keysight ADSTM software are used to obtain the simulated and theoretical results, respectively, which agree measured with simulated and theoretical results. Journal: Journal of Electromagnetic Waves and Applications Pages: 704-723 Issue: 6 Volume: 38 Year: 2024 Month: 04 X-DOI: 10.1080/09205071.2024.2324842 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2324842 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:6:p:704-723 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2324837_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Tian Peng Author-X-Name-First: Tian Author-X-Name-Last: Peng Author-Name: Lixia Yang Author-X-Name-First: Lixia Author-X-Name-Last: Yang Author-Name: Tianyi Zhou Author-X-Name-First: Tianyi Author-X-Name-Last: Zhou Title: Ultra-thin and omnidirectional reflectionless absorbing surface working at dual-frequency Abstract: Materials with characteristics of omnidirectional reflectionless absorption are of great importance in electromagnetic shielding and anechoic chamber. Recently emerged absorbing surfaces mostly work at a given angle, and absorbers working at a broad frequency band usually suffer from a 3-D structure. Thus, the fabrication of the ultra-thin and omnidirectional reflectionless absorber working at dual-frequency remains a technical challenge. In this work, we demonstrated the absorbing performance of an ultra-thin slab under different incident angles of the electric fields, and an approximate solution was derived to prove the realizability of the dual-frequency and omnidirectional reflectionless absorption. For illustration, a miniaturized dual-frequency anechoic chamber with a 343.8 mm diameter was constructed, and the full-wave simulations validated the results. The proposed design method is simple and robust, which provides a new clue for solving the practicability difficulty faced by existing anechoic chambers and microwave imaging systems. Journal: Journal of Electromagnetic Waves and Applications Pages: 652-661 Issue: 6 Volume: 38 Year: 2024 Month: 04 X-DOI: 10.1080/09205071.2024.2324837 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2324837 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:6:p:652-661 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2324840_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Harry F. Contopanagos Author-X-Name-First: Harry F. Author-X-Name-Last: Contopanagos Title: Multilayer printed antennas and arrays for 5G applications Abstract: In this paper we describe a class of printed patch antennas that involve 3 metal layers completely integrated within a single dielectric, which are of very high efficiency and significant gain. The antennas presented have dual linear polarization and sufficient impedance matching bandwidth to be suited for sub-6 5G applications, producing advantageous antenna arrays monolithically integrated into a single planar PCB that are thin and lightweight. The feeding mechanism of the antennas is through an intermediate dedicated metal layer designed appropriately as a coupler, coupling the input power at the feeding ports of the structure to the antenna without a direct metal contact to the radiating patch. The multilayer design allows monolithic integration of multi-element combiners and phase shifters within the PCB of antenna arrays and results in compact monolithic scanning arrays. Theoretical full-wave simulations and measurements of fabricated prototypes are in very good agreement and validate the proposed designs. Journal: Journal of Electromagnetic Waves and Applications Pages: 662-676 Issue: 6 Volume: 38 Year: 2024 Month: 04 X-DOI: 10.1080/09205071.2024.2324840 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2324840 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:6:p:662-676 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2324841_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Syed Enamur Rahaman Author-X-Name-First: Syed Enamur Author-X-Name-Last: Rahaman Author-Name: Santanu Dwari Author-X-Name-First: Santanu Author-X-Name-Last: Dwari Author-Name: Saad Mekhilef Author-X-Name-First: Saad Author-X-Name-Last: Mekhilef Title: Electromagnetics theory-based new equation to improve harmonically tuned power amplifier theory and design Abstract: Power amplifiers (PA) are used to boost the power of signals. Recently, harmonically tuned power amplifiers (HTPA) offer high efficiency and wider bandwidth than conventional PA. HTPA achieves by shaping waveforms using varying drain terminal impedance conditions (open and short-circuited etc.), but this impedance creates reflected waves at the drain. Existing HTPA methods lack a foundation in Electromagnetic Theory (EM), leading them to miss reflected waves. As a result, the existing equations show problems Type I: generate unwanted and non-required higher-order harmonics (n > 3); and Type II: they cannot link with simulated/measured results properly. This paper proposes an alternative approach by applying EM theory to develop a general HTPA equation. This equation works for any HTPA class and overcomes problems (Type I & II). To validate the proposed theory and equation, continuous mode Class F PA is designed and fabricated. Theoretical, simulation and experimental results all showed good agreement. Journal: Journal of Electromagnetic Waves and Applications Pages: 677-703 Issue: 6 Volume: 38 Year: 2024 Month: 04 X-DOI: 10.1080/09205071.2024.2324841 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2324841 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:6:p:677-703 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2330980_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Lavudya Srinivas Author-X-Name-First: Lavudya Author-X-Name-Last: Srinivas Author-Name: Gande Arun Kumar Author-X-Name-First: Gande Arun Author-X-Name-Last: Kumar Author-Name: Gopi Ram Author-X-Name-First: Gopi Author-X-Name-Last: Ram Title: A novel design of modified I-shaped low profile broadband cavity-backed SIW slot antenna Abstract: This article proposes a novel procedure to enhance the bandwidth of substrate-integrated waveguide (SIW) slotted antennas. By introducing a rectangular slot on the cavity's bottom surface, the TE210 cavity mode is perturbed, leading to the successful generation and merging of odd and even TE210 modes. This approach achieves an impedance bandwidth of 13.5%. To further enhance the bandwidth, the rectangular slot is modified into an I-shaped slot by adding vertical slits at each end, increasing the impedance bandwidth to 15.1%. Placing the modified I-shaped slot on the ground plane further enhances the impedance bandwidth to 17.2%. The constructed antenna maintains a gain of 7.83 dBi at 10.2 GHz and 7.85 dBi at 11.4 GHz, with a measured impedance bandwidth of 19.04%. The design retains several advantageous features, including lightweight construction, easy fabrication, and seamless integration. Journal: Journal of Electromagnetic Waves and Applications Pages: 724-737 Issue: 6 Volume: 38 Year: 2024 Month: 04 X-DOI: 10.1080/09205071.2024.2330980 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2330980 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:6:p:724-737 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2330997_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Hailong Li Author-X-Name-First: Hailong Author-X-Name-Last: Li Author-Name: Wenlong Li Author-X-Name-First: Wenlong Author-X-Name-Last: Li Author-Name: Dongdong Xie Author-X-Name-First: Dongdong Author-X-Name-Last: Xie Author-Name: Shibin Xu Author-X-Name-First: Shibin Author-X-Name-Last: Xu Author-Name: Xiangwei Tang Author-X-Name-First: Xiangwei Author-X-Name-Last: Tang Author-Name: Safi Ullah Author-X-Name-First: Safi Author-X-Name-Last: Ullah Author-Name: Abdur Rauf Author-X-Name-First: Abdur Author-X-Name-Last: Rauf Author-Name: Liangjie Bi Author-X-Name-First: Liangjie Author-X-Name-Last: Bi Author-Name: Bin Wang Author-X-Name-First: Bin Author-X-Name-Last: Wang Author-Name: Yong Yin Author-X-Name-First: Yong Author-X-Name-Last: Yin Author-Name: Lin Meng Author-X-Name-First: Lin Author-X-Name-Last: Meng Title: Development of a novel flattened magnetron for household microwave oven Abstract: This paper presents a design scheme of a Novel Flattened Magnetron for Household Microwave Oven, which makes a breakthrough in the magnetic circuit of the existing magnetron and adopts the symmetrical enhanced magnetic circuit design scheme. Magnetron width has been successfully reduced from 80 mm to 50 mm. The reduction is up to 37.5%. Based on the size of the flattened magnetic circuit system, the theory of magnetron noise, and the knowledge of LC low-pass filters, a filtering structure for the flattened magnetron is proposed. Electromagnetic simulation shows that the magnetron with the new magnetic circuit structure can still meet the design specifications of the magnetron used in the existing microwave oven. An experiment was conducted to verify the proposed design's performance, and it was found to be similar to the existing conventional magnetron. Journal: Journal of Electromagnetic Waves and Applications Pages: 738-751 Issue: 6 Volume: 38 Year: 2024 Month: 04 X-DOI: 10.1080/09205071.2024.2330997 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2330997 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:6:p:738-751 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2340659_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Mostafa Danaeian Author-X-Name-First: Mostafa Author-X-Name-Last: Danaeian Author-Name: Abolfazl Shokrizadeh Author-X-Name-First: Abolfazl Author-X-Name-Last: Shokrizadeh Author-Name: Mohammad Mahdi Pezhman Author-X-Name-First: Mohammad Mahdi Author-X-Name-Last: Pezhman Title: A novel compact microstrip dual-band bandpass filter with independently controlled center frequencies based on dual-mode resonators concept Abstract: This letter presents a novel ultra-compact microstrip dual-band bandpass filter (DBBPF) with independently controlled center frequencies, and high Q-factor. The recommended DBBPF is realized by combining two different microstrip dual-mode resonators. One is a short-end stub-loaded resonator used to produce the first passband and the other one is an open-end stub-loaded resonator operating at the second passband which serves as part of the feed lines for the lower passband. To validate the performance of the proposed configuration, a novel compact DBBPF with center passband frequencies of 2.4 and 3.55 GHz is designed, simulated, fabricated and tested. A good agreement has been found between the simulation and measurement results. The designed microstrip DBBPF occupies a small area which is only about 0.19 λg × 0.15 λg. The presented microstrip DBBPF has many advantages in terms of compact size, low insertion loss, good frequency selectivity, easy fabrication, and high selectivity. Journal: Journal of Electromagnetic Waves and Applications Pages: 813-831 Issue: 7 Volume: 38 Year: 2024 Month: 05 X-DOI: 10.1080/09205071.2024.2340659 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2340659 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:7:p:813-831 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2333326_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Qun Li Author-X-Name-First: Qun Author-X-Name-Last: Li Title: High-gain and high-isolation MIMO magneto-electric dipole antenna array for 5G millimeter-wave communications Abstract: This paper presents a four-port multiple-input multiple-output (MIMO) magneto-electric dipole antenna array with high gain and high isolation for 5G millimeter-wave communications. Each antenna contains an eight-way power divider, an eight-element magneto-electric dipole antenna array, a metal rectangular ring, and a dielectric slab. The proposed magneto-electric dipole antenna array has high radiation gain. The metal rectangular ring is applied to not only support the dielectric slab but suppress the surface wave propagation and thus the mutual coupling can be reduced. A further increase in the isolation performance can be realized based on the polarization diversity. The simulated and measured impedance bandwidths at 10 dB return losses are 24–31.86 GHz (28.1%) and 24.12–32 GHz (28.1%), respectively. The simulated and measured isolation levels are larger than 25 and 20 dB, respectively. The simulated and measured realized peak gains at 30 GHz are 20.5 and 19.2 dBi, respectively. Journal: Journal of Electromagnetic Waves and Applications Pages: 753-765 Issue: 7 Volume: 38 Year: 2024 Month: 05 X-DOI: 10.1080/09205071.2024.2333326 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2333326 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:7:p:753-765 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2333336_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Parthasarathy Ramanujam Author-X-Name-First: Parthasarathy Author-X-Name-Last: Ramanujam Author-Name: Manimaran Ponnusamy Author-X-Name-First: Manimaran Author-X-Name-Last: Ponnusamy Title: Design of dual circular polarized stacked patch antenna for BeiDou navigation satellite systems Abstract: In this article, a design of two-layered, dual circular-polarization (CP) and dual-band path antenna is presented for BeiDou navigation satellite (BDS) system applications. A single 50-Ω Co-axial probe feeding arrangement is employed to achieve dual-band operation and it feeds both the antennas simultaneously. This mode introduces the CP radiation on both upper (RHCP) and lower (LHCP) operation bands. The impedance bandwidth is further widened by accommodating two semi-circular stubs on the top patch. The fabricated and experimentally validated prototype radiates at 1.82 and 3.45 GHz (center frequency). The upper and lower operating band exhibits right and left-handed CP radiations, which constructs dual-band operation. The fabricated prototype has a physical size of πr2 × 0.024 λg with an antenna profile of 2.38 mm (0.024 λg). The experimentally validated upper and lower bands impedance bandwidth with |S11| < −10 dB are 21.1% and 11.1%, respectively. The fabricated prototype is a good candidate to use in BDS applications. [Q2 Journal: Journal of Electromagnetic Waves and Applications Pages: 766-777 Issue: 7 Volume: 38 Year: 2024 Month: 05 X-DOI: 10.1080/09205071.2024.2333336 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2333336 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:7:p:766-777 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2333989_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Baoqin Lin Author-X-Name-First: Baoqin Author-X-Name-Last: Lin Author-Name: Wenzhun Huang Author-X-Name-First: Wenzhun Author-X-Name-Last: Huang Author-Name: Jianxin Guo Author-X-Name-First: Jianxin Author-X-Name-Last: Guo Author-Name: Zuliang Wang Author-X-Name-First: Zuliang Author-X-Name-Last: Wang Author-Name: Kaibo Si Author-X-Name-First: Kaibo Author-X-Name-Last: Si Author-Name: Rui Zhu Author-X-Name-First: Rui Author-X-Name-Last: Zhu Title: Ultra-wideband RCS reduction realized by a coding diffusion metasurface Abstract: In this study, a coding diffusion metasurface (CDMS) based on a circular-polarization (CP)-maintaining metasurface is proposed for radar cross-section (RCS) reduction. The CP-maintaining metasurface can achieve ultra-wideband CP-maintaining reflection, and its main reflection phase under CP incidence can be adjusted at will by the Pancharatnam-Berry phase generated by the rotation of its unit cell, so it can be used to design CDMS. Thus, based on the CP-maintaining metasurface, the 2-bit CDMS is proposed. The simulated and measured results demonstrate that the CDMS can achieve highly effective and ultra-wideband RCS reduction under arbitrarily polarized incidences, compared with a pure metallic plate of the same size, its RCS can be reduced by more than 10 dB under normal incidence in the ultra-wide frequency band of 7.1-33.6 GHz with a relative bandwidth of 130.2%; moreover, when the incident angle is increased to 40°, an ultra-wideband RCS reduction can still be achieved. Journal: Journal of Electromagnetic Waves and Applications Pages: 778-789 Issue: 7 Volume: 38 Year: 2024 Month: 05 X-DOI: 10.1080/09205071.2024.2333989 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2333989 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:7:p:778-789 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2336033_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Daniel H. Gutierrez Author-X-Name-First: Daniel H. Author-X-Name-Last: Gutierrez Author-Name: Ranajoy Bhattacharya Author-X-Name-First: Ranajoy Author-X-Name-Last: Bhattacharya Author-Name: Pranay Doshi Author-X-Name-First: Pranay Author-X-Name-Last: Doshi Author-Name: Dennis Nordlund Author-X-Name-First: Dennis Author-X-Name-Last: Nordlund Author-Name: Ram P. Gandhiraman Author-X-Name-First: Ram P. Author-X-Name-Last: Gandhiraman Title: Plasma jet printing of copper and silver antennas operating at 2.4 GHz Abstract: Printing has emerged as a technically feasible and economically viable approach to fabricate antennas on a wide range of rigid and flexible substrates. Printing offers several advantages such as rapid prototyping, minimal number of processing steps and minimal equipment needs relative to conventional microfabrication and other antenna manufacturing techniques, versatility in the choice of substrates and low cost. Here we use a plasma-based printing approach to print self-sintered copper and silver antennas. The morphology of the printed films is continuous with nanoparticles agglomerated and fused together under the influence of the plasma. The printed antennas exhibit a reflection coefficient of about −20 dB or lower and bandwidth over 10% at a resonant frequency around 2.4 GHz. The results show the feasibility of printing high performance antennas on flexible substrates such as polyimide using plasma printing technology. Journal: Journal of Electromagnetic Waves and Applications Pages: 790-801 Issue: 7 Volume: 38 Year: 2024 Month: 05 X-DOI: 10.1080/09205071.2024.2336033 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2336033 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:7:p:790-801 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2336040_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Junlin Wang Author-X-Name-First: Junlin Author-X-Name-Last: Wang Author-Name: Tao Liu Author-X-Name-First: Tao Author-X-Name-Last: Liu Author-Name: Xin Wang Author-X-Name-First: Xin Author-X-Name-Last: Wang Author-Name: Min Wei Author-X-Name-First: Min Author-X-Name-Last: Wei Author-Name: Yuhang Lu Author-X-Name-First: Yuhang Author-X-Name-Last: Lu Title: Four-port low-profile broadband antenna with fan-leaf slits and shorting pins for 5G mobile applications Abstract: A four-port low-profile broadband patch antenna is designed for fifth-generation (5G) multi-input multi-output (MIMO) mobile applications. The designed antenna loads shorting pins S1 and S2 on a square patch with etched fan-leaf slits, making the parasitic patch work more visible. In addition, loading shorting pin S3 excites a low-frequency resonant mode, which enables the antenna to completely cover frequency ranges of 3.3–5 GHz (5G N77 and N79 bands). The effective height of the designed antenna is only 3.7 mm (0.05λ at 4.15 GHz). The antenna achieves a good balance between impedance bandwidth and profile, realizing wide bandwidth coverage. To confirm the precision of the results, the designed antenna is fabricated and measured. The measured results show that the −6 dB impedance bandwidth covers 3.3–5 GHz. All the isolation between ports are superior to 12 dB. The envelope correlation coefficients (ECCs) is below 0.15 and the overall efficiency is between 50% and 90% in the 3.3–5 GHz. Journal: Journal of Electromagnetic Waves and Applications Pages: 802-812 Issue: 7 Volume: 38 Year: 2024 Month: 05 X-DOI: 10.1080/09205071.2024.2336040 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2336040 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:7:p:802-812 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2350430_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Wang Chungang Author-X-Name-First: Wang Author-X-Name-Last: Chungang Author-Name: Wang Zichen Author-X-Name-First: Wang Author-X-Name-Last: Zichen Title: Composite scattering computation from multiple dielectric targets of one-dimensional fractal sea surface using MOM Abstract: Bistatic scattering coefficient have important application of ocean active microwave remote sensing. In this paper, a general expression of the composite scattering coefficient for multiple dielectric targets of one-dimensional fractal sea surface is derived by MOM method. Secondly, the bistatic scattering coefficient is computed, there are two class missile targets and one class ship target of one-dimensional fractal sea surface, and the influence of the water dielectric constant, fractal dimension, wind speed, the target dielectric constant and spatial position is discussed, and the corresponding conclusions are given. The proposed algorithm is able to solve some composite scattering problems, such as ‘dielectric or conductive object + rough surface’, ‘dielectric or conductive floating object +rough’ and it has certain generalization and reference, and it lays a foundation for solving the composite scattering coefficient of multiple medium targets in two-dimensional fractal sea surface. Journal: Journal of Electromagnetic Waves and Applications Pages: 932-954 Issue: 8 Volume: 38 Year: 2024 Month: 05 X-DOI: 10.1080/09205071.2024.2350430 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2350430 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:8:p:932-954 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2345680_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Yinlong Kuang Author-X-Name-First: Yinlong Author-X-Name-Last: Kuang Author-Name: Lianwens Deng Author-X-Name-First: Lianwens Author-X-Name-Last: Deng Author-Name: Gaoyang Zhu Author-X-Name-First: Gaoyang Author-X-Name-Last: Zhu Author-Name: Hongjian Li Author-X-Name-First: Hongjian Author-X-Name-Last: Li Author-Name: Shengxiang Huang Author-X-Name-First: Shengxiang Author-X-Name-Last: Huang Title: RCS-reduced patch antenna with wide frequency tuning range based on absorbing metasurface Abstract: A frequency-tunable patch antenna with reduced radar cross section (RCS) based on absorbing metamaterial is proposed. By controlling the external voltage of the varactor diodes, the working frequency  of the patch can be adjusted. Through an investigation of the composite structure of the patch and absorbing metamaterial, RCS reduction is achieved over the entire wide tunable frequency range of the antenna. Measured results illustrate that the proposed patch antenna can dynamically operate in the range from 2.28 to 3.6 GHz with a gain variation of 7.1–8.7 dBi. Meanwhile, the RCS can be reduced by at least 7 dB and up to 20 dB in a fractional bandwidth of 44.9% of the antenna under a normal incidence. In comparison to conventional RCS-reduced antennas, the proposed one features a broader frequency tuning range and has potential value in wideband radar systems under complex electromagnetic interference environments. Journal: Journal of Electromagnetic Waves and Applications Pages: 898-912 Issue: 8 Volume: 38 Year: 2024 Month: 05 X-DOI: 10.1080/09205071.2024.2345680 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2345680 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:8:p:898-912 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2343866_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Peidong Yang Author-X-Name-First: Peidong Author-X-Name-Last: Yang Author-Name: Xiaobo Liu Author-X-Name-First: Xiaobo Author-X-Name-Last: Liu Author-Name: Anxue Zhang Author-X-Name-First: Anxue Author-X-Name-Last: Zhang Author-Name: Xiaoming Chen Author-X-Name-First: Xiaoming Author-X-Name-Last: Chen Title: Extension of effective permittivity for metallic elements on the substrates interface Abstract: Previously, the influence of substrate interface on the metallic element is always described by the specific effective permittivity. Here, the metallic element on the substrate interface can be converted into that in a homogenized equivalent substrate with almost arbitrary permittivity. Specifically, according to the definition of the permittivity, the substrate interface with a small thickness can be regarded as a homogenized equivalent substrate. Based on the tangential components of the electrical fields, it can be derived that the equivalent permittivity is strongly related to the thickness of the equivalent substrate. Finally, the simulation results demonstrate that the electromagnetic response of the metallic element placed in the homogenized equivalent substrate keeps unchanged as that on the substrate interface. Thus, the proposed method not only provides a generalized means to describe the electromagnetic influence of the substrate interface on the metallic element, but also greatly simplifies the analytical design of multi-layered metasurface. Journal: Journal of Electromagnetic Waves and Applications Pages: 860-876 Issue: 8 Volume: 38 Year: 2024 Month: 05 X-DOI: 10.1080/09205071.2024.2343866 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2343866 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:8:p:860-876 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2339313_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Lianjie Li Author-X-Name-First: Lianjie Author-X-Name-Last: Li Author-Name: Yaxuan Han Author-X-Name-First: Yaxuan Author-X-Name-Last: Han Author-Name: Baoyu Yang Author-X-Name-First: Baoyu Author-X-Name-Last: Yang Author-Name: Yong Juan Author-X-Name-First: Yong Author-X-Name-Last: Juan Author-Name: Zhao Chen Author-X-Name-First: Zhao Author-X-Name-Last: Chen Author-Name: Junying Zhang Author-X-Name-First: Junying Author-X-Name-Last: Zhang Author-Name: Zhi-Ling Hou Author-X-Name-First: Zhi-Ling Author-X-Name-Last: Hou Title: Vanadium dioxide-based H-shaped terahertz metasurface for beam modulation Abstract: Metasurfaces have become increasingly crucial in applications involving electromagnetic beam modulation. Herein, an H-shaped terahertz (THz) metasurface based on vanadium dioxide (VO2) is proposed to achieve an equal reflectivity amplitude of approximately 0.7 and a phase difference of 180° when VO2 is in the insulating and metallic states, with the deviation less than 0.3%. The distribution of the electromagnetic field indicates that the constant amplitude inversion phenomenon is caused by the mode change from three-quarter wavelength resonance to surface plasmon resonance. The proposed metasurface unit has a minimum size of 26.6 µm, which reduces the cost of fabrication. Additionally, five feasible size-designing schemes are proposed, in which the amplitude varies in a narrow range of 0.675–0.685 with a phase difference of 180°, solving the potential problem of dimensional distortion caused by manufacturing process limitations. This structure provides a new way for the development of high-precision and low-cost intelligent THz metasurfaces. Journal: Journal of Electromagnetic Waves and Applications Pages: 833-841 Issue: 8 Volume: 38 Year: 2024 Month: 05 X-DOI: 10.1080/09205071.2024.2339313 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2339313 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:8:p:833-841 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2343868_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Kai Zhang Author-X-Name-First: Kai Author-X-Name-Last: Zhang Author-Name: Lu Qing Author-X-Name-First: Lu Author-X-Name-Last: Qing Author-Name: Gai Liu Author-X-Name-First: Gai Author-X-Name-Last: Liu Author-Name: Li Quan Author-X-Name-First: Li Author-X-Name-Last: Quan Title: Sensorless fuzzy control algorithm for permanent magnet synchronous motor based on particle swarm optimization parameter identification and harmonic extraction Abstract: In sensorless control of permanent magnet synchronous motor (IPMSM) with sliding mode observer, the problem of parameter robustness and poor stability seriously affects the control effect of sensorless operation. Therefore, a fuzzy sliding mode observer (SMO) phaselocked loop (PLL) combining particle swarm optimization (PSO) parameter identification and recursive least squares adaptive linear (RLS-Adaline) harmonic extractor is proposed. First, the fuzzy controller is used to process the control parameters of the sliding mode observer and the phaselocked loop. Secondly, the RLS-Adaline harmonic extractor is used to effectively filter the higher harmonic component of the back electromotive force (EMF), thus significantly improving the sensorless control effect. Thirdly, the PSO algorithm is used to identify the parameters of the motor, and the effect of parameter identification is judged by the performance index. The experimental results show that the proposed control method can effectively reduce the speed error and rotor position error. Journal: Journal of Electromagnetic Waves and Applications Pages: 877-897 Issue: 8 Volume: 38 Year: 2024 Month: 05 X-DOI: 10.1080/09205071.2024.2343868 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2343868 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:8:p:877-897 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2350426_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Litian Wang Author-X-Name-First: Litian Author-X-Name-Last: Wang Author-Name: Xuan Chen Author-X-Name-First: Xuan Author-X-Name-Last: Chen Author-Name: Weicheng Peng Author-X-Name-First: Weicheng Author-X-Name-Last: Peng Author-Name: Lirong Qian Author-X-Name-First: Lirong Author-X-Name-Last: Qian Author-Name: Cuiping Li Author-X-Name-First: Cuiping Author-X-Name-Last: Li Author-Name: Yahui Tian Author-X-Name-First: Yahui Author-X-Name-Last: Tian Author-Name: Honglang Li Author-X-Name-First: Honglang Author-X-Name-Last: Li Author-Name: Dan Li Author-X-Name-First: Dan Author-X-Name-Last: Li Author-Name: Lin Miao Author-X-Name-First: Lin Author-X-Name-Last: Miao Author-Name: Yang Xiong Author-X-Name-First: Yang Author-X-Name-Last: Xiong Author-Name: Xiaokun Bi Author-X-Name-First: Xiaokun Author-X-Name-Last: Bi Title: Wideband bandpass filter with ultra-wide stopband based on cross-shaped parallel coupled lines Abstract: A broadband out-of-band rejection capability and multiple transmission zeros of wideband bandpass filter are proposed and validated in this article, which employ quadruple anti-parallel coupled-line structures to form a novel cross-shaped resonator planar topology. The centered frequency of the single wideband bandpass filter designed for verification is located at 2.4 GHz (f0) with a fractional bandwidth of 50%. The interaction of crossed multiple anti-coupled lines with a lowpass-loaded fan constitutes the wideband with nine transmission zeros in the 5 f0 frequency range for improved suppression extending to 26.5 GHz (10.7 f0) with a suppression level of 12.5 dB. Moreover, the designed prototype filter is implemented and tested with a measured minimum insertion loss of 0.9 dB. Good agreement between the measured and simulated results is attained to successfully validate the correctness of the proposed design approach. Journal: Journal of Electromagnetic Waves and Applications Pages: 913-927 Issue: 8 Volume: 38 Year: 2024 Month: 05 X-DOI: 10.1080/09205071.2024.2350426 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2350426 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:8:p:913-927 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2340650_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Sourabh Rana Author-X-Name-First: Sourabh Author-X-Name-Last: Rana Author-Name: Priyanka Jain Author-X-Name-First: Priyanka Author-X-Name-Last: Jain Title: Utilizing characteristics mode analysis for designing a miniaturised high-gain metasurface antenna with wideband circular polarization and reduced scattering Abstract: This work presents a novel design of a low-profile broadband circularly polarized (CP) metasurface (MS) antenna based on characteristic mode analysis (CMA) technique for potential use in C-band satellite communications. The proposed antenna is composed of a 4 × 4 array of truncated patch unit cells and incorporates an enhanced slot coupling feeding structure. CMA technique is employed to analyse and modify to improved CP performance. The proposed design exhibits good radiation characteristics including measured − 10 dB impedance bandwidth of 22.72% (4.8–6.05 GHz), a 3 dB axial ratio bandwidth (ARBW) of 16.3% (5.1–5.95 GHz), and a peak gain of 8 dBi within its operational frequency range. Furthermore, the antenna's metasurface design contributes to scattering suppression over a wide frequency span (4–18 GHz), with a notable peak reduction of 9.1 dB at 8 GHz. This characteristic holds potential significance for radar cross-section (RCS) reduction. Journal: Journal of Electromagnetic Waves and Applications Pages: 842-859 Issue: 8 Volume: 38 Year: 2024 Month: 05 X-DOI: 10.1080/09205071.2024.2340650 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2340650 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:8:p:842-859 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2350427_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Akhlesh Lakhtakia Author-X-Name-First: Akhlesh Author-X-Name-Last: Lakhtakia Title: The free-space dyadic Green function is orthogonal to its curl Abstract: The free-space dyadic Green function in electromagnetics is orthogonal to its own curl on any spherical surface whose center is the source point. Journal: Journal of Electromagnetic Waves and Applications Pages: 928-931 Issue: 8 Volume: 38 Year: 2024 Month: 05 X-DOI: 10.1080/09205071.2024.2350427 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2350427 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:8:p:928-931 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2354716_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Rania Hamdy Elabd Author-X-Name-First: Rania Hamdy Author-X-Name-Last: Elabd Author-Name: Ahmed Jamal Abdullah Al-Gburi Author-X-Name-First: Ahmed Jamal Abdullah Author-X-Name-Last: Al-Gburi Title: Ultra-Compact 4-Port MIMO Antenna with Defected Ground Structure and SAR Analysis for 28/38 GHz 5G Mobile Devices Abstract: To tackle the challenge of keeping 5G mobile devices compact while supporting millimeter-wave bands, we've created an ultra-compact 4-port dual-band MIMO antenna with a defected ground structure (DGS). This design minimizes mutual coupling and covers a broad frequency range. Built on a Rogers TMM4 substrate with dimensions of 17.76×17.76 mm2, the antenna includes four planar patch antennas positioned perpendicularly at the corners. Each antenna operates at 28/38 GHz and features a rectangular patch with four rectangular slots and a full ground plane. The patches are separated by 0.5 λo, with the DGS further reducing mutual coupling. Both simulations and measurements indicate a significant reduction in mutual coupling (−39 to −60 dB), improving ECC, TARC, MEG, and DG. Time-domain and SAR analyses confirm the antenna's efficiency and its suitability for 5G devices. Journal: Journal of Electromagnetic Waves and Applications Pages: 1000-1025 Issue: 9 Volume: 38 Year: 2024 Month: 06 X-DOI: 10.1080/09205071.2024.2354716 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2354716 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:9:p:1000-1025 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2354715_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Prodyuti Sarkar Author-X-Name-First: Prodyuti Author-X-Name-Last: Sarkar Author-Name: Rahul Mondal Author-X-Name-First: Rahul Author-X-Name-Last: Mondal Author-Name: P. Soni Reddy Author-X-Name-First: P. Soni Author-X-Name-Last: Reddy Author-Name: Snehasish Saha Author-X-Name-First: Snehasish Author-X-Name-Last: Saha Author-Name: Piyali Basak Author-X-Name-First: Piyali Author-X-Name-Last: Basak Author-Name: Partha Pratim Sarkar Author-X-Name-First: Partha Pratim Author-X-Name-Last: Sarkar Title: Detection of adulterants in rice grains by the characteristics of reflection coefficient of the incident microwave signal Abstract: Detection of food quality by identifying different adulterants in food products is a grave requirement for the food industry. Various methods of food analysis have been evolved to identify the quality and quantity of impurities but those methods are time-consuming, expensive and laborious. Our research aims at reducing the challenges experienced in these existing methods. Our procedure is to detect food adulterants using a microwave signal and observe the change in reflection coefficient and resonant frequency of the reflected microwave signal. The property of modification of reflection coefficient and resonant frequency of reflected microwave signal from pure rice grains in the presence of adulterants like small stones/pebbles and broken rice is exploited. In this work, the detection and proportion of adulterants, such as stones and low-quality broken rice in fresh rice in varying proportions, have been determined. Adulterants as low as 2% weight of rice are highly detectable utilizing microwave. Journal: Journal of Electromagnetic Waves and Applications Pages: 989-999 Issue: 9 Volume: 38 Year: 2024 Month: 06 X-DOI: 10.1080/09205071.2024.2354715 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2354715 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:9:p:989-999 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2354717_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: H. Citak Author-X-Name-First: H. Author-X-Name-Last: Citak Title: High-precision reading of a weak magnetostatic field Abstract: Efforts have recently been put into developing proton precession magnetometers (PPM) in order to measure weak magnetic fields with high precision. Although high-cost commercial PPMs are available today, there are ongoing studies for low power consumption, low cost, high accuracy and resolution. Accordingly, in this study, a new PPM with a measurement range of 20,000 nT-120,000 nT, a production cost of $2000 and an accuracy of 0.13 nT was developed and its performance in determining the earth’s magnetic field was examined. It was determined that the developed PPM has an advantage over its commercial equivalents (G857, WCZ, etc.) in terms of price-performance ratio and can be used to determine small magnetic field values such as the earth’s magnetic field. Journal: Journal of Electromagnetic Waves and Applications Pages: 1026-1040 Issue: 9 Volume: 38 Year: 2024 Month: 06 X-DOI: 10.1080/09205071.2024.2354717 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2354717 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:9:p:1026-1040 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2354724_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Ju-Ik Oh Author-X-Name-First: Ju-Ik Author-X-Name-Last: Oh Author-Name: Jong-Won Yu Author-X-Name-First: Jong-Won Author-X-Name-Last: Yu Author-Name: Young-Dam Kim Author-X-Name-First: Young-Dam Author-X-Name-Last: Kim Title: Far-field pattern accuracy improvement in planar near-field measurement using infinitesimal dipole modeling Abstract: This paper discusses the challenges in accurately measuring the far-field performance of array antennas, which have become more complex and larger due to recent trends in increasing the number of elements and the antenna size. The far-field measurement method, which is a general method for measuring a radiation pattern in a far-field, is difficult to be utilized at a high frequency due to limitations in physical chamber size and difficulty in diagnosing an antenna. In order to improve these problems, a near-field measurement method is used as an alternative. Even though using a near-field measurement, the accuracy of the derived far-field pattern is reduced at low elevation angles due to zero-padding of data outside the measurement area. The integration of the near-field measurement with the source reconstruction is a promising approach to enhance the measurement limits of the far-field pattern analysis. This paper aims to extend the previous work to accurately predict the far-field radiation pattern, especially in the low elevation angles. The verification of the proposed method is performed for a standard gain horn and 4 by 4 patch array antennas, with and without beam steering. Journal: Journal of Electromagnetic Waves and Applications Pages: 1056-1068 Issue: 9 Volume: 38 Year: 2024 Month: 06 X-DOI: 10.1080/09205071.2024.2354724 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2354724 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:9:p:1056-1068 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2350431_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Davood Siyar Author-X-Name-First: Davood Author-X-Name-Last: Siyar Author-Name: Hadi Aliakbarian Author-X-Name-First: Hadi Author-X-Name-Last: Aliakbarian Author-Name: Ping Jack Soh Author-X-Name-First: Ping Jack Author-X-Name-Last: Soh Title: A new method for synthesis and designing transmissive linear-to-circular polarization converters based on branch line circuit model Abstract: This paper proposes a new design method of a linear-to-circular polarization converter based on the branch line circuit model. The series branches are implemented by dielectric spacers and the shunt branches are implemented by anisotropic admittance sheets. The admittance matrix of the anisotropic admittance sheets is derived by even and odd mode analysis. A unit cell consisting of two metal layers and a dielectric spacer is then designed using an iterative algorithm for operation from 15.5 to 23 GHz. Results indicate that the axial ratio and insertion loss of the designed polarizer are better than 3 and 1.5 dB respectively, for incident angles between ±45°. To validate the simulation results, a waveguide-based test setup is designed and fabricated, with measurement results indicating good agreement with simulations. The proposed method can be potentially applied to design other anisotropic structures such as half-plate polarizers and polarization rotators. Journal: Journal of Electromagnetic Waves and Applications Pages: 955-968 Issue: 9 Volume: 38 Year: 2024 Month: 06 X-DOI: 10.1080/09205071.2024.2350431 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2350431 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:9:p:955-968 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2354718_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Deepak Ram Author-X-Name-First: Deepak Author-X-Name-Last: Ram Author-Name: Amit Kumar Singh Author-X-Name-First: Amit Kumar Author-X-Name-Last: Singh Author-Name: Somak Bhattacharyya Author-X-Name-First: Somak Author-X-Name-Last: Bhattacharyya Title: A metasurface-based high gain circularly polarized patch antenna with wide global bandwidth Abstract: This paper introduces a novel metasurface (MS)-based circularly polarized (CP) microstrip patch antenna. Utilizing a square microstrip patch with plus- and diagonal-shaped slots on a 1.6 mm thick FR-4 substrate as the host antenna, the design incorporates a 4 × 4 square array MS on another 1.6 mm thick FR-4 substrate, separated by a 3.4 mm thick Teflon layer. The antenna offers a −10-dB impedance bandwidth from 5.45 to 7.55 GHz and an axial ratio (AR) bandwidth between 6.02 and 6.35 GHz, achieving a maximum realized gain of 6.3 dBic at 6.25 GHz, exhibiting right-handed circular polarization (RHCP). An equivalent circuit model is developed to validate impedance response, and the fabricated antenna closely matches simulated results. With a low profile of $ 0.42\lambda\, {\rm o} \times 0.42\lambda\, {\rm o} \times 0.033\lambda\, {\rm o} $ 0.42λo×0.42λo×0.033λo at 6.25 GHz, this CP antenna is suitable for applications like satellite communication for their uplinks and WLAN application. Journal: Journal of Electromagnetic Waves and Applications Pages: 1041-1055 Issue: 9 Volume: 38 Year: 2024 Month: 06 X-DOI: 10.1080/09205071.2024.2354718 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2354718 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:9:p:1041-1055 Template-Type: ReDIF-Article 1.0 # input file: TEWA_A_2350451_J.xml processed with: repec_from_jats12.xsl darts-xml-transformations-20240209T083504 git hash: db97ba8e3a Author-Name: Ashish Kumar Verma Author-X-Name-First: Ashish Kumar Author-X-Name-Last: Verma Author-Name: Rahul Singhal Author-X-Name-First: Rahul Author-X-Name-Last: Singhal Title: Investigations on relevance of angular stability and polarization independence of frequency selective reflector in planar antenna gain enhancement Abstract: The relevance of angular stability (AS) and polarization independence (PI) is investigated by rotating the frequency selective reflectors (FSRs) kept behind a 10 GHz triangular slot antenna in orthogonal directions. Three distinct frequency selective surfaces (FSSs) based on closely packed rhombic loop (RL), square loop (SL) and merged dual rhombic loops (MDRL) are developed for the analysis under normal and oblique incidences. The gain enhancement of 4.87, 7.17 and 4.85 dB is achieved when the antenna is backed by 5 × 5 arrays of RL, MDRL and SL FSS, respectively. Later, with equal sized substrates, the gain enhancement of 7.25, 7.17 and 8.10 dB is achieved when the antenna is backed by 61 × 61 mm2 RL, MDRL and SL FSSs, respectively. It appears that stringent characteristics of FSSs i.e. AS and PI can be compromised for FSRs while employing antenna gain enhancement techniques. Journal: Journal of Electromagnetic Waves and Applications Pages: 969-988 Issue: 9 Volume: 38 Year: 2024 Month: 06 X-DOI: 10.1080/09205071.2024.2350451 File-URL: http://hdl.handle.net/10.1080/09205071.2024.2350451 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:taf:tewaxx:v:38:y:2024:i:9:p:969-988