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Title: ACES Journal October 2012
File Type: Journal Paper
Issue:Volume: 27      Number: 10      Year: 2012
Download Link:Click here to download PDF     File Size: 12948 KB

Title: ACES Journal October 2012 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 27      Number: 10      Year: 2012
Download Link:Click here to download PDF     File Size: 642 KB

Title: High-Directive Patch and Dipole Antennas using Biased Grounded Ferrite
Abstract: In this paper, a new perfect magnetic conductor (PMC) substrate for improving the directivity of patch and dipole antennas is introduced. We used biased grounded ferrite to construct this new substrate. The most important difference between this substrate and the other artificial magnetic conductor (AMC) structures is the homogeneity. A conventional electromagnetic AMC has a periodic nature and as a result it is not homogenous but this novel substrate is homogenous. The results show that the directivity of both the patch and the dipole antennas is improved surprisingly in the presence of this novel homogenous PMC substrate. The physical reasons for the improvements are also given. Moreover, at the last section, we have calculated the magnetic loss of this magnetic anisotropic substrate.
Author(s): A. H. Gangaraj, M. Tayarani, A. Abdolali
File Type: Journal Paper
Issue:Volume: 27      Number: 10      Year: 2012
Download Link:Click here to download PDF     File Size: 2143 KB

Title: Integration of An Optimized E-Shaped Patch Antenna into Laptop Structure for Bluetooth and Notched-UWB Standards using Optimization Techniques
Abstract: In this article, an optimized E-shaped patch antenna for Bluetooth (2.4 - 2.484 GHz) and UWB (3.1- 10.6 GHz) applications with WLAN (5.15 - 5.825 GHz) band-notched characteristics is proposed. The dimensions of the E-shaped structure in addition to the position of the slotted C-shape in the ground plane are optimized using recent optimization techniques such as modified particle swarm optimization (MPSO), bacterial swarm optimization (BSO), and central force optimization (CFO). The optimization algorithms were implemented using MATLAB-software and linked to the CST Microwave Studio Suite® version 2011 to simulate the antenna. Next, the effects of the laptop structure on the antenna radiation characteristics are considered. To validate the results, the antenna structures are simulated by the finite difference time domain method (FDTD).
Author(s): A. M. Montaser, K. R. Mahmoud, H. A. Elmikati
File Type: Journal Paper
Issue:Volume: 27      Number: 10      Year: 2012
Download Link:Click here to download PDF     File Size: 4076 KB

Title: Compact Ultra-Wideband (UWB) Bandpass Filter with Dual Notched Bands
Abstract: A compact ultra-wideband (UWB) bandpass filter with two controllable highly selective notched bands is presented. The modified stepped impedance resonator (SIR) and two interdigital feed-lines realize the UWB passband. The loaded stubs at each side of the modified SIR and the U-shaped slot on the ground plane produce two notched bands at desired frequencies without increasing the total size of the filter. High performance achieved by the proposed UWB filter is validated by both simulations and measurements.
Author(s): S. Gao, S. Xiao, J. L. Li
File Type: Journal Paper
Issue:Volume: 27      Number: 10      Year: 2012
Download Link:Click here to download PDF     File Size: 1550 KB

Title: Compact Microstrip-fed Monopole Antenna with Modified Slot Ground Plane for UWB Applications
Abstract: A novel UWB microstrip-fed monopole antenna with modified structure has been designed and analyzed. The main body of the antenna under consideration consists of a quasi square radiating patch with tapered steps and a modified slotted ground plane. Due to the repeatedly cutting of three notches on the radiating patch and also inserting a rectangular slot and three tapered steps on the ground plane, a new resonance is excited and a wide bandwidth is obtained. By applying two sleeves with proper sizes to the antenna structure, an even wider impedance bandwidth is achieved. The antenna has a compact size of 18×12×1.6mm3 and operates over the frequency range of 2.34 – 21.43 GHz (9.15:1; 160%). The impedance bandwidth improvement process of the proposed antenna is presented and discussed in detail.
Author(s): M. Majidzadeh, C. Ghobadi
File Type: Journal Paper
Issue:Volume: 27      Number: 10      Year: 2012
Download Link:Click here to download PDF     File Size: 2147 KB

Title: Compact Microstrip Low-Pass Filter Design with Ultra-Wide Reject Band using a Novel Quarter-Circle DGS Shape
Abstract: A novel quarter-circle defected ground structure shape is introduced in this paper to design and implement an ultra-wide reject band low-pass filter (LPF). Moreover, an equivalent circuit model (ECM) is presented. The proposed LPF has small size and, a low insertion loss and a return loss less than -20 dB. Also, a round -20 dB suppression level ranging from 4 GHz to more than 20 GHz is achieved. The simulated results obtained by ECM and full-wave EM show good agreement with the measured ones.
Author(s): M. Challal, A. Boutejdar, M. Dehmas, A. Azrar, A. Omar
File Type: Journal Paper
Issue:Volume: 27      Number: 10      Year: 2012
Download Link:Click here to download PDF     File Size: 1421 KB

Title: Band-Notch Slot Antenna with Enhanced Bandwidth by using ?-Shaped Strips Protruded inside Rectangular Slots for UWB Applications
Abstract: A novel method for designing a new slot antenna with band-notch characteristic for UWB applications has been presented, in this paper. The proposed antenna consists of a slotted ground plane with an extra rectangular slot on its top, in which a ?-shaped strip is protruded, and a square-ring radiating stub in which a ?-shaped strip is protruded. By inserting the rectangular slot with a ?-shaped strip which is protruded inside this slot, in the ground plane, additional resonance is excited and hence much wider impedance bandwidth can be produced, especially at the higher band, which consequently results in a wide usable fractional bandwidth of more than 125% (3.07-14.03 GHz). In order to generate a bandnotch characteristic, we use a square-ring radiating stub with a ?-shaped strip which is protruded inside this radiating stub. The measured results reveal that the presented slot antenna offers a wide bandwidth with a band-notch operation which notches the WLAN band (5.02-5.97 GHz). The designed antenna has a small size of 20×20 mm2. Good VSWR and radiation pattern characteristics are obtained in the frequency band of interest.
Author(s): A. Valizade, Ch. Ghobadi, J. Nourinia, N. Ojaroudi, M. Ojaroudi
File Type: Journal Paper
Issue:Volume: 27      Number: 10      Year: 2012
Download Link:Click here to download PDF     File Size: 1347 KB

Title: Broadband and Compact Zeroth-Order Resonant Antennas with Truncated Grounds
Abstract: This paper presents the analysis and design of broadband and compact zeroth-order resonant (ZOR) antennas based on truncated grounds. A ZOR unit cell, whose physical size is independent of the operating frequency due to the fundamental infinite wavelength, can be implemented with a composite right/left-handed (CRLH) or inductor-loaded transmission line (TL). The two types of ZOR antennas with extended bandwidth and more compact size are achieved by introducing the truncated grounds. It is also shown that the supported infinite wavelength can be used to generate a monopole-like radiation pattern. The characteristics of the broadband and compact size of the proposed antennas are verified by the simulated and measured results.
Author(s): J. C. Liu, W. Shao
File Type: Journal Paper
Issue:Volume: 27      Number: 10      Year: 2012
Download Link:Click here to download PDF     File Size: 934 KB

Title: Efficient PEEC-Based Simulations using Reluctance Method for Power Electronic Applications
Abstract: This paper presents a partial element equivalent circuit (PEEC)-based solver that has been accelerated to exploit the massively parallel structure of graphics processing unit (GPU) technology, in order to employ a reluctance-based method in an efficient way. A grouping algorithm is also presented which makes reluctance calculation efficient, suitable for GPUs, and feasible even for very large problems. It has been shown that by using the reluctance method, the coefficient matrix in the system equation can be safely sparsified whilst the required accuracy is maintained. Because the calculation of the reluctance matrix includes matrix inversion, which is a task with high computational complexity, GPUs as cooperative units are utilized to reduce computational costs by taking advantage of parallelism. Two test models have been simulated and analyzed to benchmark the solver, and the results have been compared with the previously developed solver. Furthermore, analyzing the results reveals that the reluctance method makes it possible to use a considerably sparser system and thereby solve large problems by decreasing the memory demands and the solution time. It is also proven that the solution is reliable and accurate, whereas the problem has become noticeably smaller.
Author(s): D. Daroui, J. Ekman
File Type: Journal Paper
Issue:Volume: 27      Number: 10      Year: 2012
Download Link:Click here to download PDF     File Size: 928 KB

Title: Method of Moments (MoM) Modeling for Resonating Structures: Propagation inside a Parallel Plate Waveguide
Abstract: Method of Moments (MoM) modeling inside resonating structures is discussed and a novel approach called Multi-MoM (Mi-MoM) is proposed. Propagation inside a two-dimensional (2D) non-penetrable parallel plate waveguide is taken into account. The Mi-MoM results are compared with the analytical reference solution. Practical ways of different source representations (untilted/tilted Gaussian beams) are also presented. Finally, surface irregularities inside the waveguide and their effects on the propagation are modeled with both Mi-MoM and the Split-Step Parabolic Equation (SSPE) method.
Author(s): G. Apaydin, L. Sevgi
File Type: Journal Paper
Issue:Volume: 27      Number: 10      Year: 2012
Download Link:Click here to download PDF     File Size: 2721 KB

Title: Comparison of Dynamic Differential Evolution and Asynchronous Particle Swarm Optimization for Inverse Scattering of a Two-Dimensional Perfectly Conducting Cylinder
Abstract: The application of optimization techniques for shape reconstruction of a perfectly conducting two-dimensional cylinder buried in a slab medium is reported in this paper, for which comparative study of four population-based optimization algorithms are conducted. The method of finite difference time domain (FDTD) is employed for the analysis of the forward scattering part, while the inverse scattering problem is transformed into an optimization one. Four algorithms including particle swarm optimization (PSO), asynchronous particle swarm optimization (APSO), differential evolution (DE) and dynamic differential evolution (DDE) are applied to reconstruct the location and shape of a 2-D perfectly conducting cylinder. The performance of these optimization techniques is tested through the use of simulated fields to mimic the experimental measurements contaminated with additive white Gaussian noise. The reconstructed results show that DDE and APSO algorithms outperform the algorithms DE and PSO in terms of convergence speed. And DDE is concluded as the best algorithm in this study.
Author(s): C. L. Li, C. H. Huang, C. C. Chiu, C. H. Sun
File Type: Journal Paper
Issue:Volume: 27      Number: 10      Year: 2012
Download Link:Click here to download PDF     File Size: 775 KB