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Title: ACES Journal May 2019 Cover
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: ACES Journal May 2019 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: ACES Journal May 2019 Full
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Miniaturized Cross-Lines Rectangular Ring-Shaped Flexible Multiband Antenna
Abstract: A compact, flexible antenna for wireless applications, i.e., WLAN/WiMAX/Wi-Fi, UMTS2100, C-Band, and DSRC is presented. The quad-band antenna is designed and analyzed in terms of efficiency, gain, radiation pattern, return loss, and VSWR. The optimized design consists of a CPW fed rectangular ring patch with the semi-circular ground. The cross-lines and the semicircular ground is investigated to ascertain the multiband effect. A concept of inset feed mechanism is also interpolated to enhance impedance matching. The framed antenna is examined under the bent condition as well. The reported work is an apt candidate for the proposed applications because of its high efficiency of 95% with a peak gain of 3.22 dBi along with VSWR less than 2. With stable radiation pattern and bandwidth, there is a justified concurrence between simulated and measured results.
Author(s): A. Javed, A. Ejaz, S. Mehak, Y. Amin, J. Loo, H. Tenhunen
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Frequency Adjustable Dual-Band Microstrip Gap-Ring-Slot Antenna Design Using the Cylindrical TLM Method
Abstract: This paper introduces a design of a frequency adjustable dual-band circular patch antenna with a gapring- slot accompanied by a study of a cylindrical TLM method effectiveness and capabilities. The antenna is fabricated on Rogers 4003 substrate and measured results have been used to validate the used approach. Through comparison with corresponding rectangular TLM mesh results, the cylindrical TLM method has been found not only as more efficient requesting much smaller number of cells to be applied but also more capable to accurately describe narrow ring slots and small angular features. The designed antenna resonates at two frequencies, 2.77 GHz and 3.72 GHz, with the possibility of additional frequency tuning. A frequency adjustments study has been carried out and, accordingly, design corrections have been proposed either to independently tune the frequency or to simultaneously adjust both frequencies.
Author(s): T. Z. Dimitrijevic, J. J. Jokovic, N. S. Doncov
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Shaped-Beam Circularly-Polarized Practical Antenna Array for Land Imaging SAR Systems
Abstract: A planar array of M × N circularly polarized microstrip patch antennas is proposed for high resolution land-imaging applications using an airborne side-looking Synthetic Aperture Radar (SAR) systems. The microstrip patch is designed to produce either right-hand or lefthand circular polarization. The planar array is designed to produce a circularly polarized three-dimensional beam of cosecant-squared shape in the range direction and uniform shape in the azimuth direction. The mutual coupling between the adjacent patches in the proposed array is studied for the assessment of the final array design and is shown to have no bad effects on the resulting beam shape or the array performance. A computationally efficient Particle Swarm Optimization (PSO) algorithm is developed and applied to find the amplitude and phase distributions of the feeding voltages over the planar array elements required to produce the desired radiation patterns. This technique is achieved by developing a fast algorithm to extend the amplitudes and phases calculated for M-element and N-element linear arrays to be applied to the elements of a two-dimensional M × N planar array without the need to apply the PSO to calculate the amplitudes and phases for the entire elements of the planar array. A perfect three-dimensional pattern with the desired shapes in both azimuth and range directions is achieved. The input impedance, the axial ratio and the shapes of the radiation patterns produced by the proposed antenna array are investigated and shown to be satisfactory over the frequency band of 3.91 − 4.11 GHz.
Author(s): M. A. El-Hassan, K. F. A. Hussein, A. E. Farahat, K. H. Awadalla
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Wideband Quasi-Yagi Antenna with Broad-Beam Dual-Polarized Radiation for Indoor Access Points
Abstract: This paper presents a wideband, broad beamwidth, dual-polarized antenna for the indoor access points. Its primary radiating elements are two quasi-Yagi antennas, which are arranged orthogonally. The antenna element employs two balanced directors to broaden bandwidth and avoid the structural conflict of the orthogonal installation. A microstrip-slotline transformer is used in the feeding structure for allowing the wideband operation and high port-to-port isolation. The dualpolarized quasi-Yagi antenna is incorporated with a metallic cavity in order to improve the unidirectional radiation in terms of gain, front-to-back ratio, and beamwidth. The final prototype has been fabricated and tested. The antenna yielded a wide impedance bandwidth covering a frequency range from 1.64 to 3.0 GHz (60%) for both ports with port-to-port isolation of a higher than 25 dB. In addition, at both ports, the antenna achieves stable unidirectional radiation with broad beamwidth, high front-to-back ratio, and high radiation efficiency.
Author(s): S. X. Ta, C. D. Bui, T. K. Nguyen
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: A Wide-Beam Antenna Based on Missile Telemetry System
Abstract: This paper presents an antenna system with multiple patches and multiple layer substrates for missile telemetry application. The antenna is comprised by a driven microstrip line, which is printed on the bottom layer dielectric substrate, and two parasitic patch radiators which are printed on the upper dielectric substrate. The microstrip line is excited by a coaxial probe directly, and the two parasitic patches are excited by the coupling energy. In order to broaden the beam width of the microstrip antenna, two parasitic patch radiators with different sizes are printed on the upper dielectric substrate. The width of the microstrip line is linearly varied to obtain a wide impedance-matching bandwidth. This antenna is simulated and optimized by using the full wave electromagnetic simulation technique. The simulated results show that the voltage standing wave ratio (VSWR) is less than 1.9 between 2.15GHz and 2.17GHz. At 2.16GHz, the VSWR of port is 1.29 and the 3dB beam widths of radiation patterns at E planes and H planes were more than 89.2 degrees. The proposed antenna is processed and measured. The measured results show that the proposed antenna achieves the expected radiation performance and validates the effectiveness of the antenna design. The antenna scheme studied in this paper is suitable for missile telemetry system. The research results have laid a technical foundation for its practical engineering application.
Author(s): L. Song, X. Tian
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Ku-Band Phase-Gradient Metasurface for Broadband High-Gain Circularly Polarized Lens Antenna
Abstract: In this paper, a novel broadband high-gain, circularly polarized planar lens antenna is presented. We used the rotation elements to design a transmission-type polarization conversion planar phase-gradient metasurface (PPGM). By adjusting the rotational angles of the metal patch on the element, we obtained the desired transmission phase shift for PPGM. We used a patch antenna as a feed source, which formed a lens antenna system integrated with the PPGM. The simulation results showed that the PPGM can achieve a high-efficiency, cross-polarization conversion for vertical incidence of a right-handed circularly polarized plane wave. Our numerical and experimental results agreed well with each other, indicating that the antenna system had a peak gain of 18.8 dB, a good axial ratio better than 2 dB at 13 GHz, with an aperture efficiency of 50.56% and a focal length/diameter (F/D) ratio of 0.307. In addition, its -10 dB impedance and 3dB axial ratio bandwidth reached up to 940 MHz. The lens antenna performed well and can be applied in many communication systems.
Author(s): J. Su, Z. Li, Z. Li, Q. Guo, Y. L. Yang
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: 24 GHz Graphene Patch Antenna Array
Abstract: The discovery of Graphene has created new applications for the next generation electronics due to its electrical characteristic. A compact patch antenna with graphene as conducting media has been designed for wearable, medical and consumer electronics application at 24 GHz. The patch has a dimension of 5×5 mm and is designed over 0.254 mm thick roger material. The antenna has been combined to make it an array form for increasing its gain while various antenna parameters have been obtained for its comparison with copper conductive patch. The ground patch is made of Perfect Electric Conductor (PEC) in both cases. Various parametric results show that graphene patch similar to copper patch provides a comparable return loss and VSWR although there has been observed some decrease in its gain and efficiency and an increase in its bandwidth. Thus, graphene can be a good alternative to copper conductive patch within higher GHz and THz frequency range.
Author(s): V. Kumar
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: A Microstrip Patch Array Antenna with Metal Mesh Structure for Cross Polarization Suppression
Abstract: A 1×4 microstrip patch array antenna is presented for Ku-band radar systems. A metal mesh structure working as a polarizing filter (twist reflector) is employed to reduce the cross-polarization of the antenna. The metal mesh structure is simple and easy to be printed on a commercial substrate. The proposed antenna has been designed and analyzed by using commercially available software – Computer Simulation Technology Microwave Studio (CST MWS), which is based on the finitedifference- time-domain algorithm. A prototype antenna is built and tested. The return loss has been compared between measured and simulated data under the criterion of VSWR less than 2 throughout the designed 14.9 to 15.1 GHz frequency range. The cross-polarization levels in both E and H planes are better than -21 dB, with fair regular radiation patterns.
Author(s): Q. Zhang
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Ultra-Wideband Six-port Network Constructed by 90° and In-Phase Power Dividers
Abstract: This article proposes a six-port network design with an ultra-wideband operation from 3.1 to 10.6 GHz. The proposed six-port configuration is constructed by two types of power dividers with different phase characteristics of 0° (in-phase) and 90°. The new proposed configuration eliminates one unused port of the conventional six-port. Both components forming the proposed six-port are designed utilizing the microstrip-slot technique to accomplish the designated UWB operating frequency. The six-port is designed via the use of CST Microwave Studio (CST MWS) and realised by applying Rogers TMM4 substrate. Comparable simulated and measured performances are achieved in terms of S-parameters and phase differences between each consecutive port across UWB frequency range.
Author(s): N. Seman, K. H. Yusof, M. H. Jamaluddin, T. A. Rahman
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: VHF-UHF Monocone Antenna for Ground Penetrating Radar Application
Abstract: This paper introduces a VHF-UHF monocone antenna for ground penetrating radar GPR application. The proposed antenna covers different bandwidths through only changing the cone geometry. Same ground plane shape and feeding system are used. Firstly, both conventional and proposed monocone antennas are designed, simulated and their simulated results are compared. One antenna cone is fabricated and measured for verification purpose. Good agreement is obtained between measured and simulated bandwidths. The measured bandwidth extends from 73 MHz to 500 MHz. Secondly, another antenna cone is designed and simulated without altering the upper or the lower cone radii. The second cone antenna bandwidth extends from 130 MHz to 1000 MHz. The receiver antenna of the commercial SIR 2000 impulse GPR is replaced by the proposed VHF-UHF first monocone antenna and the field test results are recorded and discussed.
Author(s): T. G. Abouelnaga, E. A. Abdallah
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Transparent Circular Monopole Antenna for Automotive Communication
Abstract: A novel fractal shaped antenna on transparent material is communicated in this article. The proposed antenna is flexible and conformal on the automotive surface to serve at vehicular communication applications. Polyvinyl chloride substrate material of ɛr=3 and loss tangent 0.02 is used in the antenna design with overall dimension of 55 x 40 x 3 mm. The virtual placement of the antenna on vehicular surface is simulated with the combination of ANSYS HFSS and Savant tools. Far-field radiation and the Electric-field distribution with respect to the antenna placement on vehicular structure is analyzed and presented in this work. The prototyped antenna measurements are in good agreement with the simulation.
Author(s): S. Bandi, D. K. Nayak, B. T. P. Madhav, A. Tirunagari
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Norm Constrained Noise-free Algorithm for Sparse Adaptive Array Beamforming
Abstract: In this paper, a reweighted l1-norm constrained noise-free normalized least mean square (NLMS) (RL1- CNFLMS) algorithm is proposed for dealing with sparse adaptive array beamforming. The proposed RL1-CNFLMS algorithm integrates a reweighted l1-norm penalty into the traditional objective function of constrained least mean square least mean square (LMS) (CLMS) algorithm to drive the weighted coefficient vector to sparsity. Besides, the Lagrange multiplier (LM) method and the gradient descent principle are employed during the derivation procedure for getting the update equation. Additionally, we utilize the l1-l2 optimization method to acquire the noise-free a posteriori error signal in normalizing process to achieve a quicker convergence speed, a better signal to interference plus noise ratio (SINR) performance as well as a higher array sparsity with an acceptable computational complexity. Simulation results turn out that by using the noise-free and norm constraint techniques, a fairly comparable beampattern is achieved by using only 38.4%, 39.4% and 69.4% antenna elements in contrast to the constrained NLMS (CNLMS), reweighted l1-norm constrained LMS (RL1- CLMS) and reweighted l1-norm constrained normalized LMS (RL1-CNLMS) algorithms, respectively.
Author(s): W. Shi, Y. Li, L. Sun, J. Yin, L. Zhao
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Different Array Synthesis Techniques for Planar Antenna Array
Abstract: In this paper, a genetic algorithm (GA) is used to synthesize and optimize the excitation weights of a planar array for satellite communications based on ITU Radio Regulations 2016. The planar array is arranged into symmetric square lattices of subarrays. Each subarray is assumed to be consisting of 4×4 isotropic, uniformspaced, and uniform-weighted elements. The proposed arrays are assumed to be consisting of 4×4 and 16×16 subarrays. A genetic algorithm is used to optimize the weights at the subarrays. Three different cases are studied in the paper. The first case is dealing with an amplitude-only weighting synthesis of the planar array. In this case the ratios of amplitude weights of subarrays are varied continuously from 0 to 1. In the second case, a phase-only synthesis of the planar array is discussed where the phases are varied in a continuous range between -pi/2 and 0° while the amplitudes of all subarrays are the same. In the third case a complex weight synthesis is presented. In this case the ratios of the amplitudes are constrained between 0.7 and 1 whereas the phases are varied continuously from -pi/2 to 0°. Moreover, the amplitude is varied with both continuous and discrete values. A comparison between the three methods is presented to develop the optimum technique for feeding an antenna array for satellite communication systems.
Author(s): T. Sallam, A. M. Attiya
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Using MATLAB’s Parallel Processing Toolbox for Multi-CPU and Multi-GPU Accelerated FDTD Simulations
Abstract: MATLAB is a good testbed for prototyping new FDTD techniques as it provides quick programming, debugging and visualization capabilities compared to lower level languages such as C or FORTRAN. However, the major disadvantage of using MATLAB is its slow execution. For faster simulations, one should use other programming languages like Fortran or C with CUDA when utilizing graphics processing units. Development of simulation codes using these other programming languages is not as easy as when using MATLAB. Thus the main objective of this paper is to investigate ways to increase the throughput of a fully functional finite difference time domain method coded in MATLAB to be able to simulate practical problems with visualization capabilities in reasonable time. We present simple ways to improve the efficiency of MATLAB simulations using the parallel toolbox along with the multi-core central processing units (CPUs) or the multiple graphics processing units (GPUs). Native and simple MATLAB constructs with no external dependencies or libraries and no expensive or complicated hardware acceleration units are used in the present development.
Author(s): A. J. Weiss, A. Z. Elsherbeni, V. Demir, M. F. Hadi
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Transient Analyses of Grounding Electrodes Considering Ionization and Dispersion Aspects of Soils Simultaneously: An Improved Multiconductor Transmission Line Model (Improved MTL)
Abstract: This paper proposes an approximate model in the frequency domain for transient analysis of grounding electrodes buried in ionized and dispersive soils. The proposed method, called multi-conductor transmission line model (MTL), can easily treat the frequency dependence of electrical parameters of soil. It can also incorporate soil ionization by gradually changing the respective electrode radius. Extensive simulation results are presented to confirm the accuracy of the MTL.
Author(s): S. S. Sajjadi, V. Aghajani, S. R. Ostadzadeh
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Robust Adaptive Beamforming Based on Fuzzy Cerebellar Model Articulation Controller Neural Network
Abstract: To solve the problem of degraded adaptive beamforming performance of smart antenna caused by array steering vector mismatch and array manifold errors, a robust beamforming algorithm based on Fuzzy Cerebellar Model Articulation Controller (FCMAC) neural network is proposed. The proposed algorithm is based on explicit modeling of uncertainties in the desired signal array response and a FCMAC neural network. The calculation of the optimal weight vector is viewed as a mapping problem, which can be solved using FCMAC neural network trained with input/output pairs. Our proposed approach provides excellent robustness against some types of mismatches and keeps the mean output array SINR consistently close to the optimal value. Moreover, the FCMAC neural network avoids complex matrix inversion operations and offers fast convergence rate. Simulation results show that the proposed algorithm can significantly enhance the robustness of the beamformer in the presence of array steering vector mismatch and array manifold errors, and the output performance is superior to the current methods.
Author(s): J. Yu, P. Fan, C. Li, X. Lu
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Fast Solution of Low-Frequency Problems Using Efficient Form of MLACA with Loop-Tree Basis Functions
Abstract: In this paper, an efficient scheme of numerical method is proposed to solve the low frequency (LF) problems, which combines the loop-tree basis functions with an efficient form of multilevel adaptive cross approximation (EFMLACA) algorithm. It utilizes the loop-tree basis functions to divide the vector part and scalar part of the impedance matrix. Meanwhile, the scalar part is frequency normalized. Through this operation, it can avoid the low frequency breakdown problem. In order to accelerate the matrix vector multiplication, the EFMLACA algorithm is applied. Meanwhile, the compressed block decomposition (CBD) preconditioner is applied to improve the condition number of poor convergence problems. The numerical results demonstrate that the memory requirement and computation time required for a matrix vector multiplication of EFMLACA algorithm is much less than that of MLACA and ACA-SVD. Moreover, the matrix vector multiplication of EFMLACA algorithm is also much more efficient than that of low-frequency multilevel fast multipole algorithm (LF-MLFMA).
Author(s): Z. Jiang, X. Zhao, Y. Jiang, X. Qiao, Q. Wang
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Analysis of RCS Signatures of Chipless RFID Tags Based on Arabic Alphabet Letters with Punctuation
Abstract: In this paper, we investigate chipless RFID (Radio Frequency Identification) tags based on Arabic Alphabets with points, to be used as RF coding particles. First, the tags were designed by considering an Arial font to generate the metallic letters printed on flexible Kapton substrates. Next, the points were connected to form the main bodies of the letters to improve their Radar Cross Section (RCS) signatures when illuminated with incident electromagnetic waves within the frequency band of 2-8 GHz, for both horizontal and vertical polarizations. Good agreement between simulated and measured results has been obtained. We have found that among all of the similar letters studied, those stripline connections provided us the best way to take into account of the presence of the points and then conveniently distinguish the RCS signals characterizing each letter with a unique RF response. Finally, a lookup table for the identification of the 18 letters with punctuation that have been studied has been carried out.
Author(s): O. Boularess, L. Ladhar, A. Affandi, S. Tedjini
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Realization of Dielectric Sheets for Gain Improvement of Ultra-Wideband Horn Antennas Using 3D Printer Technology
Abstract: In this work, 3D printing technology had been used to prototyped 10 dielectric sheets with relative dielectric constant of 2.5 for gain improvement of a TEM horn antenna. By loading the 3D printed dielectric sheets to the aperture of the horn antenna it is achieved to improve the radiation performance of the antenna over an ultra-wide operation band of 2-13 GHz. Here the Periodic dielectric sheets are designed to function similarly to a dielectric lens for focusing the incoming electromagnetic waves to increase directivity properties, while keeping their mismatching characteristics with less size and low manufacturing cost compared to its counterpart lens designs. The dielectric sheets had been prototyped via the use of 3D printing technology for experimental measurements. The measured performance of the proposed 3D printed dielectric loaded TEM horn antenna is compared with its counterpart ultra-wide band gain improvement methods for horn antennas in literature. From the measured results of the prototyped module, not only the proposed 3D printed dielectric sheets are smaller and have lower cost compared to their counterpart designs but also achieves to improve the gain characteristics of the antenna design over an ultra-wide band operation band without a distortion on antenna’s S11 characteristics.
Author(s): M. A. Belen, P. Mahouti
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Design of Ultra-wideband and Transparent Absorber based on Resistive Films
Abstract: Researching and developing of ultra-wideband capability and high light transmittance have been hot issues in the field of new artificial electromagnetic stealth material. In this paper, a novel transparent metamaterial absorber, made of resistive films and glass, has been presented. The simulation results show that, under the incidence of plane wave, the absorber realizes high absorption during frequency range from 3.5 GHz to 18.5 GHz while keeping insensitive to polarization. A prototype has been fabricated and tested, and the measurement results are in good consistent with simulation. Along with its high transmittance and superior absorption, we expect that the absorber has great potential applications in RCS (Radar Cross Section) reduction and electromagnetic shielding.
Author(s): X. Lu, J. Chen, Y. Huang, Z. Wu, A. Zhang
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Modeling of Via Interconnect through Pad in Printed Circuit Board
Abstract: In this paper the methods of finding inductance L of a cylindrical via and capacitance C due to via pad in printed circuit board (PCB) are described. Initially a thin cylindrical via of diameter d without pad is connected between a 50 ohm copper trace on the top of a dielectric substrate and a ground plane at the bottom. The line is terminated with matched load. The geometrical structure is simulated using Ansoft HFSS software tools to find the input reflection coefficient S11. The value of inductance of the via is determined in terms of S11 using transmission line formulation. The theoretical and experimental results for L as a function of d, h, and d/h are compared with those obtained from empirical formulae developed by the other authors. The results are found in good agreement. Secondly a square via pad is added in the trace in absence of via. The equivalent capacitance C of the pad is calculated in the same way from S11 as it is done for L. Finally, the PCB model is configured with a cylindrical via connected between the pad in the trace and the ground plane. The complex load impedance values are obtained from the electrical equivalent circuit of the L-C combination. This impedance is also determined from the S11 parameter using HFSS.
Author(s): A. Ghosh, S. K. Das, A. Das
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Small Size and Wide-Band Band Pass Filter with DGS/CRLH Structures
Abstract: A small size and wide-band band pass filter with high performance for WiMAX applications is introduced. The filter is designed by utilizing one composite right left handed transmission line (CRLHTL) metamaterial cell and two gap lumped capacitors. The filter has a center frequency of 5.3 GHz and a 3dB bandwidth from 4.2 GHz to 6.4 GHz. A lower than 0.5 dB insertion loss within pass-band is achieved. A single transmission zero at 6.52 GHz is achieved to increase the selectivity of the proposed filter. The rejection band is extended to be up to 10 GHz. A comparison between circuit simulation, EM simulation and measured results is introduced with good consistency between them. The filter has a small size (26.8 × 16.5 mm2) which is smaller than recently reported wide band filters.
Author(s): A. A. Ibrahim, M. A. Abdalla, W. A. E. Ali
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: An Equivalent Modeling Method for the Radiated Electromagnetic Interference of PCB Based on Near-field Scanning
Abstract: Since the structure complexity of a PCB makes its EMI modeling be very difficult or impossible, an equivalent modeling method to predict the electromagnetic radiation of a PCB is presented by means of a dipole array based on near-field scanning. Firstly, the equivalent modeling method is theoretically derived and its accuracy is validated by a commercial full-wave tool. Then, the equivalent model is applied to predict the electromagnetic coupling of different parts on a PCB and the electromagnetic leakage of a PCB in an enclosure with numerous small apertures. The results show that the proposed method has high efficiency and acceptable accuracy.
Author(s): Y.-S. Xiao, D. Ren, P. Xiao, P.-A. Du
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Plane Wave Scattering by a Dielectric Circular Cylinder in the Vicinity of a Conducting Strip (TM Case)
Abstract: Scattering of plane electromagnetic waves by a dielectric circular cylinder in the vicinity of a conducting strip is presented. Two methods of solution are introduced. The first is an exact solution in which the scattered field from conducting strip is expressed in terms of Fourier series of radial and angular Mathieu function of unknown coefficient. Meanwhile the scattered field from the circular cylinder is expressed in terms of Fourier series of Bessel functions of unknown coefficient. The unknown coefficient can be obtained by enforcing the boundary conditions. The application of the boundary condition requires the use of the addition theorem of Mathieu to Bessel functions and vice versa. The second method is based in an asymptotic technique introduced by Karp and Russek for solving scattering by wide slit. The technique assumes the total scattered field from the strip and the dielectric cylinder as the sum of the scattered fields from the individual element due to a plane incident wave plus scattered fields from factious line sources of unknown intensity located at the center of every element. The line sources account for the multiple scattering effect. By enforcing the boundary conditions, the intensity of the line sources can be calculated. Numerical examples are calculated using both methods showing excellent agreement in all cases.
Author(s): H. A. Ragheb
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Metamaterial Sensor for Transformer Oil, and Microfluidics
Abstract: Metamaterial sensor which is composed of split square rings to operate in X band for liquid and microfluidics has been proposed in this study. For measurement and simulation, we have designed and manufactured a sample holder for easy injection and measurement of fluids. Dielectric properties of the fluid samples have been changed according to the usage time, humidity etc. Proposed structure reacts to the dielectric constants of the transformer oil or the other microfluidics by resonance frequency which is also validated by simulation and testing. While 70MHz bandwidth change in the resonance frequency for transformer oil has been observed, it dramatically increases to 210MHz and decreases to 40MHz for methanol and olive oil adulteration. Reflection coefficient measurements for clear (unused) transformer oil, methanol and olive oil along with corn oil have been performed. Tested results are generally compatible with the simulated ones. Proposed structure, can be effectively used for liquids whose dielectric constant varying from 2 to 24. Simulation study shows us that the proposed structure gives 560MHz bandwidth when clear transformer oil is replaced with acetone. Implementation of transformer oil as well as microfluidics with high quality factor is the novel side of proposed sensor study.
Author(s): M. Bakir, M. Karaaslan, F. Karadag, S. Dalgac, E. Unal, O. Akgol
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: A Novel Zigzag Line-based EBG Structure for the Simultaneous Switching Noise Suppression
Abstract: Simultaneous switching noise (SSN) generated between the power supply and the ground plane of a high-speed digital circuit is considered to be one of the most important factors affecting the signal integrity of a circuit system. In order to suppress the simultaneous switching noise, a new coplanar electromagnetic band-gap structure is proposed in this paper. Based on the zigzag line and square patch bridge, the inductance between the neighboring units can be enhanced. The results showed that the bandwidth of the band-gap is 0.1 ~ 12.6GHz when the depth of the new electromagnetic band-gap (EBG) structure is -30 db. Compared to the same parameter of the L-bridge structure, the relative bandwidth is about 48.7% and the cut-off frequency of the stop-band lower limit is reduced by 600MHz. The simultaneous switching noise on the power supply plane can be suppressed in all directions, and the signal integrity is less affected when the signal is transmitted by the differential line.
Author(s): Q. Xue, Z. Wang, Y. Tian, P. Wang
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Modified Combined Tangential Formulation for Stable and Accurate Analysis of Plasmonic Structures
Abstract: We consider a modified combined tangential formulation (MCTF) for stable and accurate analysis of plasmonic problems involving metallic objects modeled as penetrable bodies. For a wide range of negative real permittivity values, corresponding to varying characteristics of metals at THz, infrared, and visible frequencies, MCTF provides accurate solutions in comparison to the conventional formulations for penetrable objects. We further show that, for structures with subwavelength dimensions, penetrable models formulated with MCTF can be essential for accurate analysis, rather than the perfectly conducting formulations, even at the lower THz frequencies.
Author(s): B. Karaosmanoglu, O. Ergul
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
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Title: Genetic Algorithm Optimization of a Dual Polarized Concentric Ring Array
Abstract: We use a genetic algorithm to minimize the relative sidelobe level (RSLL) of a dual polarized concentric ring array. The optimization variables are the placement of uniformly weight spiral antennas in an aperture with a small area. We optimized a cost function with isotropic sources instated of spiral elements to make the cost function reasonable to evaluate. We developed approaches to calculate a faster cost function and reduce the number of function calls in the optimization. We then calculated the array with an approximation of the element pattern to evaluate its performances.
Author(s): P. Mendes Ruiz, I. D. Hinostroza Sáenz, R. Guinvarc'h, R. Haupt
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
Download Link:Click here to download PDF     File Size: 1551 KB

Title: Design of Double Layers Miniaturized Trimmed Semi-Rectangular Monopole with Partial Ground Plane for Short Ranges Wireless Systems
Abstract: This paper presents a new miniaturized design of antenna with extremely wide bandwidth. The design consists of trimmed half rectangular patch printed on a 10x13 mm2 substrate of Rogers Duroid RT5880Lz with relative permittivity of ɛr=1.96 and loss tangent of 0.0009. The monopole has a partial modified ground plane structure to enhance the impedance matching and to provide wider bandwidth from 2.6 GHz to 15.7 GHz with reflection coefficient less than -10 dB. The proposed design has been tested, optimized, and experimentally measured for verifications; simulated and measured results have achieved high concord. The presented monopole is suitable for short range wireless systems as well as lower 5G bands applications.
Author(s): H. Alsaif
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
Download Link:Click here to download PDF     File Size: 1369 KB

Title: Gain Enhancement of Microstrip Patch Antenna Using Metamaterial Superstrate
Abstract: In this work, a gain enhancement of conventional microstrip patch antenna has been treated for WLAN applications. About 1.3dB gain enhancement, compared to a conventional patch, has been achieved by loading the microstrip patch with a metamaterial superstrate composed of 2x3 array of Square Split Ring Resonator. Simulations have been carried out using Ansys HFSS. Measured results have been taken to validate the simulation result.
Author(s): H. R. Vani, M. A. Goutham, Paramesha
File Type: Journal Paper
Issue:Volume: 34      Number: 5      Year: 2019
Download Link:Click here to download PDF     File Size: 1328 KB