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Title: ACES Journal June 2020 Cover
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
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Title: ACES Journal June 2020 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
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Title: ACES Journal June 2020 Full
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
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Title: Parallel Implementation and Branch Optimization of EBE-FEM Based on CUDA Platform
Abstract: The finite element analysis of large complex structures makes higher demand on memory capacity and computation speed, which leads to the inefficiency of traditional serial finite element method (FEM) for such large-scale problems. In this paper, the element-byelement finite element method (EBE-FEM) has been implemented parallelly on CUDA (Compute Unified Device Architecture) platform, and been programmed using C++ language. The thread branches that exist in parallel reduction program have been researched and optimized to improve parallel efficiency. The correctness of algorithms and programs are verified by the analysis of an open slot of motor. The optimized parallel program is applied to analyze the main magnetic field of a singlephase transformer. The results show that the EBE-FEM implemented on CUDA platform is more effective than serial EBE-FEM, and branch optimization can improve the speedup further.
Author(s): Y. Zhang, X. Yan, X. Ren, S. Wang, D. Wu, B. Bai
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
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Title: High-Order Small Perturbation Method of Arbitrary Order for Conducting Rough Surface Scattering under TE Incidence
Abstract: A novel closed-form high-order small perturbation method (HOSPM) for the analysis of scattering from 1-D conducting random rough surfaces under TE incidence is developed. The main theoretical contributions of the HOSPM are as follows: (1) our method yields a general high-order SPM form for scattered fields of arbitrary orders, (2) Faà di Bruno's formula is introduced into computational electromagnetics (CEM) for the first time to expand a tapered incident wave and its partial derivatives in power series form, and (3) the form is simple and easy to program and does not require any mathematical pretreatment. Comparisons are made between the method of moments (MOM) and different-order HOSPMs in terms of several aspects, including accuracy and time efficiency. The order convergence of the HOSPM is discussed, the regions of validity with regard to correlation lengths and root mean square (RMS) heights are demonstrated for the 2nd-order HOSPM, and the robustness of the 2nd-order HOSPM is proven over a broad range of frequencies
Author(s): Q. Wang, C. Lin, Z.-Y. Lei, J.-Q. Hou, L. Li
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
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Title: Electromagnetic Waves Interaction with a Human Head Model for Frequencies up to 100 GHz
Abstract: Specific absorption rate (SAR), penetration depth, and temperature rise in a one-dimensional (1D) dispersive human head model due to electromagnetic fields radiated by wireless communication systems operated up to 100 GHz are evaluated with the use of a Multiphysics model. In this model, the Debye model of human head tissue parameters is integrated into the finite-difference time-domain method with the use of the auxiliary differential equation to obtain solutions at multiple frequencies of interest using a single simulation. Then, the SAR, peneration depth, and temperature rise in the 1D head model are calculated for each frequency of interest. The effects of frequency on the SAR, penetration depth, and temperature rise in the head are investigated.
Author(s): F. Kaburcuk, A. Z. Elsherbeni, R. Lumnitzer, A. Tanner
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
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Title: Acceleration of Dual Reflector Antenna Radiation Analysis using Double Bounce Physical Optics Accelerated using Multipole Method
Abstract: The multipole method is firstly used to accelerate the radiation analysis of the dual reflector antenna with the double-bounce physical optics. The algorithm starts with physical optics to calculate the equivalent electric current on the subreflector. Then the equivalent electric current on the main reflector can be obtained through the current on the subreflector. It should be noted that the modified multilevel fast multipole method (MLFMM) is applied to accelerate the calculation between the main reflector and the subreflector. In this way, the computation complexity is reduced greatly, thus the computational time can be significantly saved. At last, numerical results are given to demonstrate the superior efficiency and accuracy of the proposed method.
Author(s): C. Wu, J. Li
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
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Title: Sparse Representation of Targets with Mixed Scattering Primitives
Abstract: A combination of two scattering primitives – wedge diffraction primitives and isotropic point scatterers – is used to reconstruct far-field monostatic scattering patterns of several target geometries and addresses shortcomings of traditional approaches that only use a single type of primitive (e.g., approximations in analytic solutions, slow convergence). An l1-norm minimization technique is applied to determine a set of weights for the point scatterers. We show that combining these two types of primitives yields better reconstruction performance than when each primitive type is used individually.
Author(s): J. Lee, P. J. Collins, J. A. Jackson
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
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Title: A Novel Omnidirectional Circularly Polarized Pagoda Antenna with Four Shorting Pins for UAV Applications
Abstract: A novel omnidirectional circularly polarized (CP) pagoda antenna with four shorting pins is presented. In this structure, four curved branches are utilized to generate horizontal polarization, while coaxial cable and four shorting pins produce vertical polarization. Omnidirectional CP radiation is achieved by combining the radiation from the branches and the shorting pins. The curved branches loaded with shorting pins reduce the size of the antenna and the antenna is loaded with the lower substrate with two coupling patches to improve the bandwidth. The novel pagoda antenna is fabricated and measured. Its final dimensions are 0.42λ0*0.42λ0*0.33λ0 (λ0 is the free-space wavelength at operating frequency). The impedance bandwidth (S11≤-10dB) is 0.53GHz and the axial ratio (AR) bandwidth (AR≤3dB) is 0.95GHz, which can be used for unmanned aerial vehicles’ diagram transmission in China.
Author(s): Z. Li, Y. Zhu, Y. Shen, X. Liu, G. Peng
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
Download Link:Click here to download PDF     File Size: 1903 KB

Title: Performance of Aeronautical Mobile Airport Communications System in the Case of Aircraft at Final Approaching or Initial Climbing
Abstract: The aeronautical mobile airport communications system (AeroMACS) is proposed to support the communications between the tower and aircrafts or the service vehicles in the range of airport. In this paper, the working environment that the aircraft at final approaching or initial climbing (AFAIC) is researched. By considering the influence of Doppler frequency shift and the channel model in AFAIC case, we propose a transmission scheme which can obtain preferable transmission performance for low order modulation. Simulation results of the signal-to-noise ratio loss, the spectrum efficiency and the bit error rate are given, which indicate that the proposed scheme can meet the demand of AeroMACS and expand the zone of airport communication area.
Author(s): Y. Ji, Y. Wang, Y. Sang
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
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Title: Broadband Circularly Polarized Antenna by Using Polarization Conversion Metasurface
Abstract: A compact and broadband circularly polarized antenna is proposed. A linear-to-circular polarization conversion metasurface is designed to broaden the 3-dB axial ratio bandwidth and the impedance bandwidth of the proposed antenna, with the mechanism of the metasurface investigated. Different with the conventional metasurface antenna designed by using uniform unit cells, this design makes use of two metasurface arrays with different unit cells. Full wave simulations show that the 10-dB impedance bandwidth of the proposed antenna is from 4.32 to 6.5 GHz (40.3%), and the 3-dB AR bandwidth is from 5 to 5.61 GHz (11.5%). Compared with that using the uniform elemental array, this design leads to more than 10% improvement in the 10-dB impedance bandwidth and more than 11.7% improvement in the axial ratio bandwidth. The proposed antenna has been fabricated and the simulated results have been verified with the measurements.
Author(s): Z.-J. Han, W. Song, X.-Q. Sheng
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
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Title: Numerical Analysis of Wideband and High Directive Bowtie THz Photoconductive Antenna
Abstract: This paper presents a novel wideband and high directivity Bowtie photoconductive antenna (PCA) for THz frequency applications. The radiation properties of proposed PCA were analyzed by varying important design parameters, such as substrate thickness, conductor thickness, bowtie antenna width, length and gap. The optimized values of these parameters are then used to design a wideband PCA THz antenna which exhibits impedance bandwidth of 3 THz, 3 dB AR bandwidth of 6 THz, peak directivity of about 18.2 dBi and peak radiation efficiency of 98% within the operating band. To improve the directivity of the proposed antenna, a silicon-based lens is added in the structure and the effect of silicone lens on THz antenna directivity is also studied for enhanced directivity of proposed antenna. The proposed THz antenna can be a prospective candidate for future THz applications such as spectroscopy, imaging, sensing and indoor communication.
Author(s): A. Dhiflaoui, A. Yahyaoui, J. Yousaf, S. Bashir, B. Hakim, T. Aguili, H. Rmili, R. Mittra
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
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Title: Mathematical Modelling on the Effects of Conductive Material and Substrate Thickness for Air Substrate Microstrip Patch Antenna
Abstract: The use of microstrip patch configuration in the 5th generation (5G) wireless network is expected to fulfill the demands of smartphone users by significantly increasing the capacity of the communication technology. The main aim of this paper is to disclose the development of a mathematical model on the effects of conductive material and substrate thicknesses on the centre frequency for the performance evaluation of a low profile, costeffective antenna in 5G devices applications. This mathematical model is proposed for an antenna system operated with air substrate resonating at a bandwidth range of 5 GHz - 38 GHz. The effects of different thickness of conductive material and substrate on the antenna's bandwidth, gain, and efficiency for 5G applications were studied. Antennas were fabricated and tested in this study to evaluate the robustness of the proposed mathematical model at 28 GHz, 24 GHz, and 10 GHz. Gains of 9.55 dBi, 9.53 dBi and 10.1 dBi, impedance bandwidths of 2.12 GHz, 2.14 GHz and 0.41 GHz, with input reflection coefficients of 42.75 dB, 25.33dB and 21.51 dB, and performance efficiencies of 98.91, 87.4 and 83.2% were obtained for the respective resonances. For validation of results, the experimental results and the simulation results from the proposed mathematical model were made into comparison, and excellent correlation between the measured and simulated results was obtained.
Author(s): A. S. B. Mohammed, S. Kamal, M. F. bin Ain, R. Hussin, Z. A. Ahmad, U. Ullah, M. Othman, M. F. Ab Rahman
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
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Title: A Dual-polarized UWB Antenna Fed by a New Balun for Electronic Reconnaissance System Application
Abstract: For a practical engineering application, a printed ultra-wide band (UWB) antenna with dual polarization is presented in this paper. An integrated Balanced-to-unbalanced (Balun) transformer from microstrip line to coplanar stripline (CPS) is designed, which is employed to feed the symmetrically coplanar Vivaldi radiator. Two substrates are used to support the Vivaldi radiators which are orthogonally mounted. The proposed antenna can build two orthogonal UWB channels and receive two polarization components of incident electromagnetic signal. By bending the balanced coplanar striplines, the cross placement of two polarization radiators can be easily realized, which is suitable for the engineering application. A dualpolarized Vivaldi antenna with the frequency range from 2.5GHz to 6GHz was simulated and fabricated. The measured indicated that the average return loss of designed antenna is less than -10dB and the port isolation degree is about 20dB with the operational frequency range, the gains are about larger than 3dB and the average cross polarization levels are about -20dB. The research results verify the feasibility of the proposed antenna scheme. The presented dual-polarized antenna has the advantages of easy design, high port isolation and convenient engineering application, which can be used in the fields such as electronic reconnaissance system.
Author(s): J. Wu, X. Zhu
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
Download Link:Click here to download PDF     File Size: 1874 KB

Title: A Wideband Wide-beam Dual Polarized Dipole Antenna and its Application in Wideband Wide-angle Scanning Array
Abstract: A wideband wide-beam dual polarized dipole antenna is proposed in this paper. The antenna has a compact size (0.48λ0×0.48λ0×0.154λ0) and can operate in a wide frequency range from 1.7GHz to 2.4GHz with a half power beam-width more than 100° in the H-plane for dual polarization. Furthermore, the proposed antenna is employed in two linear arrays. The main beam of the configured arrays can scan from -60° to +60° with a gain fluctuation less than 4dB over the entire band for dual polarization. The antenna is fabricated and measured in an anechoic chamber. The measured results have a good agreement with the simulated results.
Author(s): J. Y. Yin, H. J. Sun, L. Zhang
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
Download Link:Click here to download PDF     File Size: 1622 KB

Title: Metamaterial Based Compact Branch-Line Coupler with Enhanced Bandwidth for Use in 5G Applications
Abstract: A novel compact 5G branch-line coupler (BLC) based on open-circuit coupled-lines and interdigital capacitor structure is presented in this paper. The proposed BLC shows the composite right/left handed (CRLH) metamaterial transmission-line (TL) operation. The proposed BLC is designed and simulated using CST microwave studio. The designed BLC is then fabricated using the FR4 substrate (εr = 4.3 and h = 1.66mm). The proposed 5G BLC with coupled-lines and the interdigital capacitor has achieved the fractional bandwidth of ~ 40.2% and the size reduction of 54% as compared to the conventional BLC. The fabricated BLC operates at 2.74 – 4.15GHz frequency band with a coupling factor of -3 ± 0.2dB and the phase difference of 88o between the output ports. The BLC measurements are performed at the operating frequency of 3.5GHz. The simulated and measured scattering parameters and phase difference results are in good agreement with each other. The proposed design is suitable for use in future butler-matrix based beamforming networks for antenna array systems in 5G wireless applications.
Author(s): A. K. Vallappil, M. K. A. Rahim, B. A. Khawaja, M. Aminu-Baba
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
Download Link:Click here to download PDF     File Size: 1906 KB

Title: Ultra-Low Loss and Flat Dispersion Circular Porous Core Photonic Crystal Fiber for Terahertz Waveguiding
Abstract: A novel design of circular porous core photonic crystal fiber (CCPCF) is proposed and studied for Terahertz propagation with an ultra-low-loss. The effective index, effective mode area, dispersion, material and bending losses of the suggested design are studied using full vectorial finite element method. The CCPCF with high cladding air filling factor and porous core exhibits ultra-low material absorption loss of 0.022 cm-1 at a frequency of 1.0 THz. Further, very low bending losses of 2.2×10-18 cm-1 can be achieved for 1.0 cm bending radius at 1.0 THz with low confinement loss of 1.37×10-5 cm-1. Additionally, an ultra-flat low dispersion of 0.61 ± 0.035 ps/THz/cm can be obtained within the frequency range of 0.8-1.0 THz. Therefore, the reported CCPCF has a strong potential for transmission in the Terahertz regime.
Author(s): A. M. Singer, A. M. Heikal, H. A. El-Mikati, S. S. A. Obayya, M. F. O. Hameed
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
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Title: Fast Rise-Time Electromagnetic Pulse Protection Characteristics of ZnO Varistors
Abstract: In order to study the response of ZnO varistors under the radiation of fast rise-time electromagnetic pulse, an experiment system is built composed of square wave pulse source, coaxial cable, coaxial fixture, attenuator, oscilloscope and insulating gas vessel. Electromagnetic pulse protection characteristics of ZnO varistors are tested and analyzed. Results show that: appearance of negative pulse in the responsive waveform means the completion of field-induced insulatorconductor phase transition for ZnO varistors. Peak value of responsive positive pulse decreases after phase transition, and the residual voltage is generally constant for different pulse strength and widths. The phenomenon of overshoot voltage is observed. Negative pulse is caused by the reflection of electromagnetic wave after the phase transition. The resistance of ZnO after phase transition is less than 50 Ω and decreases linearly along with the increase of incident voltage or field, which leads to a highly nonlinear current-voltage characteristic of ZnO varistors in the radiating electromagnetic environment. Sum of energy of positive and negative pulse keeps constant, which indicates that the weakened positive pulse is converted into negative pulse. So impact of negative pulse needs to be taken into consideration when ZnO varistors are used to protection against strong electromagnetic pulse.
Author(s): W. Zhang, Y. Wang, J. Shen
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
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Title: Magneto-Mechanical Behavior Analysis using an Extended Jiles-Atherton Hysteresis Model for a Sheet Metal Blanking Application
Abstract: Manufacturing processes affect the magnetic properties of the ferromagnetic components of electrical equipment. The optimization of the designed devices depends on two factors: the mechanical state of the material of a blanked part, especially near the cutting edge, and the magneto-mechanical behavior of the material used. In this paper we investigate the magnetic induction degradation of a blanked stator fabricated using fully processed, non-oriented Fe–(3 wt%)Si steel sheet. Owing to the geometric symmetry, we first simulated a half-stator teeth blanking using the Abaqus software. Subsequently, a magneto-mechanical extended Jiles–Atherton hysteresis model was used to determine the magnetic induction distribution on the blanked teeth stator. The numerical results show that the magnetic induction degradation can reach 25% upon applying moderate magnetic field, i.e., 1000 A/m, and 8% upon applying magnetic field close to the magnetic saturation, i.e., 3500 A/m. The depth of the affected region was approximately 1.25 mm before the material regained its initial magnetic state.
Author(s): K. Hergli, H. Marouani, M. Zidi, Y. Fouad
File Type: Journal Paper
Issue:Volume: 35      Number: 6      Year: 2020
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