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Title: ACES Journal January 2018 Cover
Abstract: ACES
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File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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Title: ACES Journal January 2018 Front/Back Matter
Abstract: ACES
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File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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Title: ACES Journal January 2018 Full
Abstract: ACES
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File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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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
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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
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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
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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
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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
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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
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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
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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
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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

Title: Assessment of ALEGRA Computation for Magnetostatic Configurations
Abstract: A closed-form solution is described here for the equilibrium configurations of the magnetic field in a simple heterogeneous domain. This problem and its solution are used for rigorous assessment of the accuracy of the ALEGRA code in the quasistatic limit. By the equilibrium configuration we understand the static condition, or the stationary states without macroscopic current. The analysis includes quite a general class of 2D solutions for which a linear isotropic metallic matrix is placed inside a stationary magnetic field approaching a constant value Hi° at infinity. The process of evolution of the magnetic fields inside and outside the inclusion and the parameters for which the quasi-static approach provides for self-consistent results is also explored. It is demonstrated that under spatial mesh refinement, ALEGRA converges to the analytic solution for the interior of the inclusion at the expected rate, for both body-fitted and regular rectangular meshes.
Author(s): M. Grinfeld, J. Niederhaus, A. Porwitzky
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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Title: Far-Field Synthesis of Sparse Arrays with Cross-polar Pattern Reduction
Abstract: This paper presents a fully deterministic iterative algorithm for the far-field synthesis of antenna arrays with reduction of the cross-polar component. The algorithm synthesizes the excitations as well as the positions of the array elements, providing a sparse geometry. Starting from an initial set of possible positions, the proposed algorithm iteratively solves a sequence of convex optimization problems. At each iteration a suitable objective function is minimized, which allows to reduce the number of radiating elements, among those of the initial set, in presence of constraints on the far-field co-polar and cross-polar patterns. The adopted formulation leads to a second order cone problem (SOCP), which is iteratively solved with CVX, a Matlab-based modeling system developed at the Stanford University and available on the Internet.
Author(s): G. Buttazzoni, R. Vescovo
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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Title: Compact Shaped Antennas for Wide-Band Radiogoniometry
Abstract: In this paper, a wide band monopole antenna with a shaped profile is presented. Shaped profile and end-caps allow for a compact antenna with respect to wavelength. Antenna is designed to be as isotropic as possible and with low phase deviation from spherical wave front to allow accurate detection of the direction of arrival of an unknown signal when used in radiogoniometry applications.
Author(s): A. Manna, G. Pelosi, M. Righini, L. Scorrano, S. Selleri, F. Trotta
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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Title: RCS Results for an Electrically Large Realistic Model Airframe
Abstract: The accuracy with which MLFMM, PO and PO with SBR can calculate the RCS of a realistic electrically large model airframe is investigated. The target has a maximum electrical length of 106 lambda. An accurate 3D numerical model of the target was created using a laser scanner. The numerical results are validated against data measured in a compact range.
Author(s): C. Pienaar, J. W. Odendaal, J. C. Smit, J. Joubert, J. E. Cilliers
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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Title: Measurements of Backscattering from a Dihedral Corner in a Reverberating Chamber
Abstract: In this paper, the backscattering of a dihedral corner is evaluated by measurements accomplished within the reverberating chamber (RC) of the Università degli Studi di Napoli Parthenope, formerly Istituto Universitario Navale (IUN). The obtained results are found in good agreement with those of a previous very accurate model, whose validity was assessed by anechoic chamber measurements.
Author(s): A. Sorrentino, G. Ferrara, M. Migliaccio, S. Cappa
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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Title: Geometrical Scale Modeling of Gain and Echo Area: Simulations, Measurements and Comparisons
Abstract: Geometrical scale modeling is often necessary to perform measurements of parameters and figures-of-merit of antennas and radar targets with large physical dimensions that cannot be accommodated in indoor and controlled experimental facilities. The measured and simulated parameters and figures-of-merit of the scaledmodels can then be translated to represent, if transformed properly, those of the full-scale models. In this paper, the basic theory is summarized which relates the gain and the echo area (RCS) of scaled models to those of their full-scale counterparts. Simulations and measurements are performed on scaled models, for both gain and RCS, and compared with those of full-scale models to verify the geometrical scaling. For the gain, a quarter-wavelength monopole on a scaled helicopter airframe, and for the RCS, a flat plate of complex configuration, are considered for simulations, measurements and comparisons. A very good agreement has been obtained for both gain and RCS between both sets of data.
Author(s): C. A. Balanis, K. Zhang, C. R. Birtcher
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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Title: Review of Recent Advances and Future Challenges in Antenna Measurement
Abstract: This paper reviews the last advances in Antenna Measurement Field that took place during the previous years in order to analyse the challenges for the antenna measurement community, both industrial and academic, for the future years. The paper begins with an introductory review of the antenna measurement methodologies innovations, continuing with measurement systems technical improvements and concluding with the challenges for the antenna measurement community in the close future.
Author(s): M. Sierra-Castañer
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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Title: Specific Absorption Rate for Agri-Food Materials from Multiple Antenna Exposure
Abstract: This paper presents an evaluation of the Specific Absorption Rate (SAR) in agri-food when it is exposed to wireless communication devices with multiple transmitting antennas. In particular, we model a simplified coconut which is exposed to antennas working at the frequency of 2.45 GHz. Two antenna configurations are being considered. One is a single dipole antenna, and the other is two co-polarized dipole antenna array. As a result, we observed that the SAR of the coconut for single antenna case is relatively smaller than that for multiple antenna one.
Author(s): D. T. Le, B. Bisceglia
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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Title: Hybrid Electromagnetic Modeling of Lens-Integrated Antennas for Non-Contact On-Wafer Characterization of THz Devices and Integrated Circuits
Abstract: A hybrid full-wave/quasi-optical electromagnetic model for the design of lens-integrated THz antennas for high frequency non-contact device characterization (30 GHz – 3 THz) is presented. Experimental validation of the antenna properties (input impedance and radiation pattern) is also provided to demonstrate the accuracy of the proposed model.
Author(s): C. Caglayan, G. C. Trichopoulos, K. Sertel
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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Title: An Empirical Modeling of Electromagnetic Pollution on a University Campus
Abstract: In this study, electric field strength (E) levels were measured on Ondokuz May?s University’s Kurupelit Campus and Faculty of Medicine Hospital in Samsun, Turkey between years 2013-2015. 840 short term and two long term measurements were performed using PMM–8053 and SRM–3006 at 60 different locations of which 30 were on both the campus and hospital. The results show that the measured E levels are far below the limits that are determined by ICNIRP. Based on the measurement analysis, a novel empirical model that allows characterizing the total E of medium using three main electromagnetic (EM) sources with 99.7% accuracy was proposed. Then other new models to estimate main distribution of total E were suggested. With the use of these models, E values of main pollution sources can be estimated with 95.2% accuracy and easily lead to prediction of future EM pollution levels.
Author(s): C. Kurnaz
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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Title: A Planar NF–FF Transformation for Quasi-Spherical Antennas using the Innovative Spiral Scanning
Abstract: An effective probe compensated near-field– far-field (NF–FF) transformation with planar spiral scanning, using a minimum number of NF data, has been experimentally validated. It allows a remarkable measurement time saving, due to the continuous movements of the positioning systems and to the reduced number of needed NF data. Such a technique is based on a nonredundant sampling representation of the voltage acquired by the probe, obtained by using the theoretical foundations of the NF–FF transformations with spiral scans for quasi-spherical antennas. Then, the NF data needed by the plane-rectangular NF–FF transformation are efficiently recovered from those acquired along the spiral, via an optimal sampling interpolation formula.
Author(s): F. D’Agostino, F. Ferrara, C. Gennarelli, R. Guerriero, M. Migliozzi
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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Title: Gradient-Based Near-Field Antenna Characterization in Planar Geometry
Abstract: A near field characterization technique, based on the optimization of the Singular Value Behavior, is here accelerated by using the analytical expression of the gradient of the relevant objective functional. This solution allows to conveniently tackle the cases of electrically large antennas.
Author(s): A. Capozzoli, C. Curcio, A. Liseno
File Type: Journal Paper
Issue:Volume: 33      Number: 1      Year: 2018
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