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Title: ACES Journal January 2018 Cover
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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Title: ACES Journal January 2018 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
Download Link:Click here to download PDF     File Size: 303 KB

Title: ACES Journal January 2018 Full
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
Download Link:Click here to download PDF     File Size: 8813 KB

Title: A Convolutional Perfectly Matched Layer (CPML) for the Fourth-Order One-Step Leapfrog HIE-FDTD Method
Abstract: A new convolutional perfectly matched layer (CPML) for the fourth-order one-step leapfrog hybrid implicit explicit finite-difference time-domain (HIEFDTD) method for the TE case has been proposed in this paper. When the time step size satisfies with the time stability condition, the maximum reflection error of the proposed method is below -72dB, which demonstrates good absorbing performance of the CPML method. To verify the accuracy and efficiency of the proposed method, we compare the results of the traditional FDTD method and the HIE-FDTD method. Numerical examples demonstrate that the proposed method consumes about 60.13% less CPU time than the traditional FDTD method and 41.60% less CPU time than the existing HIE-FDTD method.
Author(s): M. Dong, J. Chen, A. Zhang
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
Download Link:Click here to download PDF     File Size: 1674 KB

Title: FDTD Evaluation of LEMP Considering the Lossy Dispersive Ground
Abstract: An accurate evaluation of lightning electromagnetic pulse (LEMP) using the finite-difference time-domain (FDTD) method in 2-D cylindrical coordinates is studied, which takes the soil dispersion into account. The parameters of engineering soil models are reformed by the vector-fitting (VF) scheme, for an efficient handling in FDTD. The FDTD updating equations for the dispersive soil are developed with the semi-analytical recursive convolution (SARC) algorithm. The cylindrical CPML is also developed for truncating the dispersive soil. The efficiency of the proposed method is validated by comparing the numerical results with the Cooray-Rubinstein (CR) approximation. The proposed method provides an accurate FDTD evaluation of LEMP considering the soil dispersion and can be further incorporated into the simulations of more complicated LEMP problems.
Author(s): Z. Sun, L. Shi, Y. Zhou, B. Yang, W. Jiang
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
Download Link:Click here to download PDF     File Size: 1840 KB

Title: Design of a Jerusalem-Cross Slot Antenna for Wireless Internet Applications
Abstract: This paper provides a fast solution for the design of a Jerusalem-cross slot antenna for arbitrarily specifying any two operating frequencies. From simulation data and measurement results, the dualresonant frequencies of the Jerusalem-cross slot antenna are found at near 5.8 and 24.0 GHz for the impedance matching with better than 15 dB return loss. It is found that the simulated and measured -10 dB bandwidths are 22.1% and 24.4% at 5.8 GHz respectively. The simulated and measured -10 dB bandwidths are 3.41% and 4.58% at 24.0 GHz, respectively. The simulated and measured results of radiation patterns in the E- and H-plane at frequencies of 5.8 and 24.0 GHz are broad and smooth. The antenna gains obtained by measurement and simulation at frequencies of 5.8 and 24.0 GHz are close to 3.0 and 6.0 dBi, respectively. This Jerusalem-cross slot antenna has a compact size with three dimensions of 22.731×7.577×0.87 mm which can be fabricated at a low cost using the standard PCB process. The compact patch antenna is suitable for applications in unlicensed frequency bands of 5.8 and 24 GHz for wireless internet applications including RFID systems, medical devices, and the internet of things (IoT).
Author(s): S.-H. Wen, H.-Y. Chen
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
Download Link:Click here to download PDF     File Size: 2248 KB

Title: Null-Steering Beamformer Using Bat Algorithm
Abstract: This paper proposes an adaptive null-steering beamformer based on Bat Algorithm (BA) for Uniform Linear Array (ULA) antennas to suppress the interference. The beamformer is targeted at steering nulls of ULA pattern in the directions of the interferences. The amplitude-only nulling method has been utilized for adjusting excitation weight of each array element. In order to validate the proposal, several scenarios of ULA array pattern imposed with the prescribed nulls have been investigated and compared with those of accelerated particle optimization (APSO) and genetic algorithm (GA). The proposed beamformer has shown the ability to suppress sidelobes and to place precisely single, multiple, and broad nulls at arbitrary interference directions. Furthermore, the beamformer is much faster and more effective than APSO and GA-based ones.
Author(s): T. V. Luyen, T. V. B. Giang
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
Download Link:Click here to download PDF     File Size: 2070 KB

Title: A Compact Triple-Band Notched MIMO Antenna for UWB Systems
Abstract: A miniaturization ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna with triple-notched band function is presented in the paper. There are two similar monopole radiators in the UWBMIMO system. Based on half-cutting method, the system only occupies 21×27 mm2. Three inverted L-shaped slots are inserted to get three rejected bands for suppressing interference from 3.5 GHz WiMAX, 5.5 GHz WLAN, and 8.1 GHz X-band. With a T-shaped stub extruding from the ground plane, both impedance bandwidth and port isolation are effectively improved. The proposed antenna covers operating frequency band of 3.1-11 GHz except three notched bands, and has a low port isolation of better than -20 dB. Moreover, good radiation patterns, stable gain and low envelope correlation coefficient (ECC) also ensure that the designed antenna is helpful in UWB systems.
Author(s): L. Wu, Y. Xia, X. Cao
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
Download Link:Click here to download PDF     File Size: 1848 KB

Title: Multi-Functional Ultra-Wideband Monopole Antenna with High Frequency Selectivity
Abstract: A multi-functional microstrip-fed ultrawideband (UWB) monopole antenna has been presented. By loading two dual-mode resonators and shunt metallic strips on the reference UWB antenna, two additional operational states are created, including band-notched UWB response (i.e., 3.1~11.5 GHz passband response except the notched band of 5.15~5.8 GHz) and narrow bandpass response (5.5-5.95 GHz) with high frequency selectivity. Moreover, the frequency characteristics of bandpass filtering antenna is also studied when we solder two lumped-chip 0 omega resistors instead of the shunt metallic strips. Four antenna prototypes are designed, fabricated and measured to validate the design concept. Full-wave electromagnetic simulator HFSS is used for the antenna design optimization and performance prediction. The measured results are presented including return losses, gains and radiation patterns, declaring that the proposed antennas have good impedance matching performance and radiation patterns.
Author(s): Y. J. Guo, K. D. Xu, X. H. Tang
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
Download Link:Click here to download PDF     File Size: 2221 KB

Title: Novel Compact Microstrip Dual-Mode Filters with Two Controllable Transmission Zeros
Abstract: Novel compact pentagonal dual-mode filters by short-loaded are presented. The field patterns of this type of resonators are investigated using full-wave electromagnetic simulations. The technique of utilizing capacitive and inductive source-load coupling to improve the performance of filters is fully researched. Advantages of using this type of filter are not only its compact size, but also its transmission zeros that can be independently controlled. Then, two dual-mode bandpass filters are designed, fabricated and tested to validate the design. Good agreement is achieved between the measured results and simulated ones.
Author(s): Z. Zhu, L. Cao, C. Wei
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
Download Link:Click here to download PDF     File Size: 1667 KB

Title: Performance of Multiple-Feed Metasurface Antennas with Different Numbers of Patch Cells and Different Substrate Thicknesses
Abstract: The design and performance of low-profile, multiple-feed metasurface antennas with different numbers of patch cells and different substrate thicknesses at a terahertz frequency are presented in this paper. The utilized antenna designs consist of a periodic array (N × M) metallic square-patch metasurface and a planar feeding structure, which are both patterned on an electrically thin, high-permittivity GaAs substrate. The antenna gain increased in a linear fashion with an increasing number of patch cells, which were directly fed by the slit feedline. A 3-dB gain increment was observed irrespective of the substrate thickness when the number of patch cells was doubled. However, the 3-dB gain bandwidth as well as the radiation efficiency changed significantly with varying substrate thicknesses. The described antenna structure offers useful characteristics by means of a combination of different substrate thicknesses and patch numbers. In addition, the proposed antenna design features a number of benefits, including a low profile, mechanical robustness, easy integration into circuit boards, and excellent suitability for low-cost mass production.
Author(s): N. Hussain, I. Park
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
Download Link:Click here to download PDF     File Size: 1747 KB

Title: Characterization of Spatial Reflection Co-efficient for Ground-to-Aircraft and Satellite-to-Aircraft Communication
Abstract: Because of high sensitivity and long range capability in modern radars, Radar Cross-Section (RCS) is considered to be one of the most important factors in the performance evaluation of stealth technology and for defense applications, especially those that deal with airborne weapon system. In this paper, a concrete relationship is established between RCS and spatial reflection coefficient (SRC) for the two proposed scenarios, i.e., Satellite-to-Aircraft and Ground-to- Aircraft. Geometrical models of the two proposed scenarios are presented for the evaluation of correct incident angles of impinging waves on the surface of aircraft and their corresponding RCS observations. For numerical computation of RCS, a simulation tool POFACET® [1] based upon the methodology of Physical Optics (PO) and a FACET-based aircraft A380 model is used for the designed scenarios. In both the scenarios, the result shows that the aircraft has strong signal reflecting properties which results in the form of RCS to radar receiver or neighboring aircrafts. Further, the RCS results are used to evaluate the spatial reflection coefficients of scattered signal received at any neighboring signal receiving unit. Comparison between RCS and SRC validates that these terms have similar scattering behavior and can be used interchangeably for performance evaluation of communication system models. From the result, it is evident to mention that flying aircrafts are one prominent source of interference which may provide interference to its neighboring aircrafts and as a result degrades their communication performance.
Author(s): M.-Y. Masood Mirza, N. M. Khan, A. Jamal, R. Ramer
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
Download Link:Click here to download PDF     File Size: 2044 KB

Title: Synthetic Asymptote Formulas of Square Coaxial Line
Abstract: This paper derives simple computer-aided design (CAD) formulas of characteristic impedance and open-ended capacitance of square coaxial line by synthetic asymptote and moment method. These formulas can be used for the design of the 3-D frequency selective surface (FSS) with square coaxial line as unit cells. Both of the formulas can give good physical insights and have only one or two arbitrary constants to be matched with numerical results. A good agreement was found between the results by the formulas and numerical method.
Author(s): J. Ge, J. Zhu, Z. Yu, H. Zhang, W. Tang
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
Download Link:Click here to download PDF     File Size: 1905 KB