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Title: ACES Journal June 2012
File Type: Journal Paper
Issue:Volume: 27      Number: 6      Year: 2012
Download Link:Click here to download PDF     File Size: 4859 KB

Title: ACES Journal June 2012 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 27      Number: 6      Year: 2012
Download Link:Click here to download PDF     File Size: 639 KB

Title: Dual-Band Loop-Loaded Printed Dipole Antenna with a Wideband Microstrip Balun Structure
Abstract: A novel loop-loaded printed dipole (LLPD) with a wideband balun structure is presented for aiming a dual-band antenna operation at 3.0/5.5 GHz bands. The proposed balun structure alone demonstrates VSWR<1.5 performance over a 3:1 bandwidth. As the loop elements placed on the antenna aperture provides dual-band operation with at least 15% impedance bandwidths, the wideband balun/feed allows for matched and balanced excitation for the dipole over the bands of interest. An equivalent circuit modeling of the LLPD antenna is presented along with the corresponding simulations and measurements.
Author(s): M. H. B. Ucar, A. Sondas, Y. E. Erdemli
File Type: Journal Paper
Issue:Volume: 27      Number: 6      Year: 2012
Download Link:Click here to download PDF     File Size: 511 KB

Title: An Efficient Meshless Approach to Multi-scale Modeling in the Time-domain
Abstract: An efficient multi-scale approach to meshless modeling of three-dimensional guided wave problems is realized by hybridization of the radial point interpolation method (RPIM) and the unconditionally stable leapfrog alternatingdirection implicit (ADI-) RPIM scheme. In it, the solution domain is regionalized; the leapfrog ADIRPIM is applied to regions with coarse nodal distributions while the original RPIM is applied to the rest of the dense nodal solution domain. With application of the leapfrog ADI scheme, a uniform time-step can now be applied to the entire solution domain without temporal and spatial interpolation between different computational regions. Furthermore, in the proposed scheme, implicit updating of field variables is confined only within the regions of densely-distributed nodes, yielding a significant saving in memory overhead and a further reduction in CPU time in comparison with leapfrog ADI-RPIM and original RPIM, respectively.
Author(s): Y. Yu, F. Jolani, Z. Chen
File Type: Journal Paper
Issue:Volume: 27      Number: 6      Year: 2012
Download Link:Click here to download PDF     File Size: 536 KB

Title: Efficient Marching-on-in-Degree Solver of Time Domain Integral Equation with Adaptive Cross Approximation Algorithm-Singular Value Decomposition
Abstract: Adaptive cross approximation algorithm with singular value decomposition postcompression (ACA-SVD) is introduced into the marching-on-in-degree solver of time domain integral equation for the analysis of transient electromagnetic scattering from perfect electric conductor (PEC). The computational domain is divided into multilevel groups based on octree. ACA-SVD algorithm is utilized to compute the impedance matrices associated with the wellseparated groups at each level. Whereas, the impedance matrices formed by self and neighboring groups are calculated entirely in the traditional manner. Numerical results demonstrate that the proposed method can greatly reduce the memory requirement and matrix-vector product (MVP) time per iteration.
Author(s): H. H. Zhang, Q. Q. Wang, Y. F. Shi, R. S. Chen
File Type: Journal Paper
Issue:Volume: 27      Number: 6      Year: 2012
Download Link:Click here to download PDF     File Size: 388 KB

Title: Optimization of Reception Antenna Composed with Unbalanced Fed Inverted L Element for Digital Terrestrial Television
Abstract: The structure of the array antenna for the reception antenna of the digital terrestrial television broadcasting in Japan is optimized by PSO algorithm. The unbalanced fed ultra low profile inverted L antenna is used as the driven element and two wires are located at the forward and backward directions of the driven element. In the case of antenna size of 170 mm by 325 mm by 29 mm, the return loss bandwidth less than -10 dB is satisfied at the whole broadcasting frequency band (240 MHz) and the directivity of 5.44 dBi to 7.19 dBi is obtained. In the numerical analysis, the electromagnetic simulator WIPL-D based on the method of moment is used.
Author(s): D. Yagyu, M. Taguchi
File Type: Journal Paper
Issue:Volume: 27      Number: 6      Year: 2012
Download Link:Click here to download PDF     File Size: 711 KB

Title: A Hybrid Finite Element-Boundary Integral-Characteristic Basis Function Method for Scattering by Multiple 3-D Cavities
Abstract: An efficient hybrid finite elementboundary integral-characteristic basis function method (FE-BI-CBFM) is proposed to solve the problem of electromagnetic scattering by multiple three-dimensional (3-D) cavities embedded in a conducting plane. Specifically, the finite element method is used to obtain the solution of the vector wave equation inside each cavity and the boundary integral equation is applied on the apertures of all the cavities as a global boundary condition. The resultant coupling system of equations is solved by using an excitation independent characteristic basis function method. Some numerical results are included to illustrate the validity and capability of the proposed method.
Author(s): Z. Cui, Y. Han
File Type: Journal Paper
Issue:Volume: 27      Number: 6      Year: 2012
Download Link:Click here to download PDF     File Size: 458 KB

Title: Investigation of Frequency Effects on the Performance of Single-Sided Linear Induction Motor
Abstract: Single-sided linear induction motors (SLIMs) have been widely used in industry, especially in high-speed transportation systems. The performance of the SLIMs is considerably affected by the characteristics of its secondary back-iron. The conductivity of the iron used as well as its magnetic permeability influence the performance of the machine, while the magnetic permeability itself is affected by the input frequency of the SLIM. In this paper, using Dancan equivalent circuit model and considering all phenomena involved in the single-sided linear induction motor, the outputs of the motor such as efficiency, power factor, normal force and output thrust are analytically derived. Then, the effects of the input frequency on depth of the field penetration and saturation level of the secondary backiron as well as the SLIM outputs are analyzed. To confirm the analytical results, 2D time-stepping finite element method is employed. The results are in good agreement with each other confirming the analytical analysis.
Author(s): A. Shiri, A. Shoulaie
File Type: Journal Paper
Issue:Volume: 27      Number: 6      Year: 2012
Download Link:Click here to download PDF     File Size: 356 KB

Title: Simulation and Analysis of HEMP Coupling Effect on a Wire Inside an Apertured Cylindrical Shielding Cavity
Abstract: High altitude nuclear electromagnetic pulse (HEMP) can damage electronic equipments of radar and communication systems. Back door coupling is one of the main ways of HEMP attacks on the electronic devices. In this paper, the three-dimensional (3D) electromagnetic (EM) simulation software MicroStripes7.5, which is based on the transmission line matrix (TLM) method, are employed to investigate the HEMP coupling effect on a wire located inside a cylindrical shielding cavity having one or few apertures. The EM models of the wire and the apertured shielding cavity are constructed, and the induced wire currents through the aperture of cavity are simulated. By comparing the simulation results of the wire with and without shield of the cavity, the shielding effectiveness (SE) is calculated. Further, the effects on induced wire in various cases are compared and analyzed, including single-aperture and multiple-aperture, different incident angles, polarization angles, and wire locations. Also, the cylindrical cavity is compared with the rectangular cavity.
Author(s): S. T. Song, H. Jiang, Y. L. Huang
File Type: Journal Paper
Issue:Volume: 27      Number: 6      Year: 2012
Download Link:Click here to download PDF     File Size: 905 KB

Title: Planar Circular Monopole Antenna with Perforated Dielectric Resonator for Notched Ultra-Wide Band Applications
Abstract: In this paper, a planar circular patch antenna is presented for UWB operating characteristics. The bandwidth of the proposed antenna is increased by inserting a perforated dielectric resonator (DR) material with the planar monopole. The design combines the advantages of a small size dielectric resonator (DR) and thin planar monopole antennas. Two antenna designs A and B are proposed. In design A, two layers of the same dielectric material are presented with the same radius and different thicknesses. While in antenna design B, only one dielectric material layer perforated by 11 holes drilled with the same radius is considered. The effects with respect to the geometric parameters of the proposed antennas on impedance bandwidth and radiation pattern are discussed. In addition, the two proposed antennas are designed to have a rejection frequency band from 5 to 6 GHz by inserting two U-shaped slots in the ground plane, where the WLAN service is allocated. The proposed antennas are completely designed and analyzed using the finite element method (FEM), and then the finite integral transform (FIT) technique is used to check the validity of the numerical results.
Author(s): S. H. Zainud-Deen, A. Shaker, K. R. Mahmoud
File Type: Journal Paper
Issue:Volume: 27      Number: 6      Year: 2012
Download Link:Click here to download PDF     File Size: 1008 KB

Title: Reducing the Numerical Calculation in the Wave Iterative Method by Image Processing Techniques
Abstract: The wave iterative method is a numerical method used to model electromagnetic circuits. It is based on the concept of waves in the place of electromagnetic fields. To study the electronic circuits having complex structures, this method requires much time. We propose in this article to improve this method by using techniques of image processing. Thatís why the structure of the studied circuit is considered as an image. The objective is to reduce computing time by reducing dimensions of the calculation matrices. The reduced matrices are built containing only the important part of the information. Our goal is to prove that the most important zones in the structure are located in the contour with small steps in the vicinity of the contour.
Author(s): H. Hrizi, N. Sboui
File Type: Journal Paper
Issue:Volume: 27      Number: 6      Year: 2012
Download Link:Click here to download PDF     File Size: 308 KB

Title: Characterization of Packet-Level Measurements for Vehicular Wireless Networks
Abstract: A comprehensive understanding of the fading effect on vehicular communications is essential for reliable intelligent transportation system (ITS). Dozens of experiments were performed in the real urban area to collect various types of vehicular wireless data measurements. Then a simulation model of radio link between double mobile nodes was proposed. Based on the real measured data, the proposed model, and the existing model are all applied to the simulator for comparison. It is shown that by evaluating the packet level performance for double mobile vehicles in an urban area, the proposed model performed better. Significant realism can be added to existing systems with clear implications on the design of upper layer protocols by modeling the fading characters for vehicular communications.
Author(s): Y. Wang, X. Xing, Y. Zhang
File Type: Journal Paper
Issue:Volume: 27      Number: 6      Year: 2012
Download Link:Click here to download PDF     File Size: 755 KB