ACES Publication Search
There are 12 search results for:
| Title: | ACES March 2011 Full Journal |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 3 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 9842 KB |
| Title: | ACES March 2011 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 3 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 995 KB |
| Title: | Homogenization of Thin Dielectric Composite Slabs: Techniques and Limitations |
| Abstract: | This paper compares different methods for retrieving the transverse effective permittivity of periodic composite slabs whose longitudinal thickness is only a few unit cells. Two computational methods are considered, one based on simulated scattering parameters (S-parameters) and the other one based on fiel averaging by integration. The effect of frequency dispersion is studied by comparing the results with electrostatic estimates given by analytical mixing formulas. Furthermore, the influenc of the slab thickness is studied. We also discuss the boundary effects on the interfaces of the slabs. |
| Author(s): | H. Kettunen, J. Qi, H. Wallén, A. Sihvola |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 3 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 741 KB |
| Title: | Hardware Accelerated Design of Millimeter Wave Antireflective Surfaces: A Comparison of Field-Programmable Gate Array (FPGA) and Graphics Processing Unit (GPU) Implementations |
| Abstract: | Engineered materials that demonstrate a specific response to electromagnetic energy incident on them in antenna and radio frequency component design applications are in high demand due to both military and commercial needs. The design of such engineered materials typically requires numerically intensive computations to simulate their behavior as they may have electrically small features on a large area or often the overall system performance is required, which means modeling the entire integrated system. Furthermore, to achieve an optimal performance these simulations need to be run many times until a desired solution is achieved, presenting a major hindrance in arriving at a feasible solution in a reasonable amount of time. One example of such applications is the design of antireflective (AR) surfaces at millimeter wave frequencies, which often involves sub-wavelength gratings in an electrically large multilayer structure. This paper investigates the use of field-programmable gate arrays (FPGAs) and graphics processing units (GPUs) as coprocessors to the CPU in order to expedite the computation time. Preliminary results show that the hardware implementation (100 MHz) on Xilinx Virtex4LX200 FPGA is able to outperform a single-thread software implementation on Intel Itanium 2 processor (1.66 GHz) by 20 folds. However, the performance of the FPGA implementation lags behind the single-thread implementation on a modern Xeon (2.26 GHz) by 3.6. On the other hand, modern GPUs demonstrate an evident advantage over both CPU and FPGA by achieving 20 speedup than the Xeon processor. |
| Author(s): | O. Kilic, M. Huang, C. conner, M. S. Mirotznik |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 3 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 1061 KB |
| Title: | Diffraction of Obliquely Incident Plane Waves by an Impedance Wedge with Surface Impedances Being Equal to the Intrinsic Impedance of the Medium |
| Abstract: | Diffraction of plane waves by an impedance wedge with surface impedances equal to the intrinsic impedance of surrounding medium is investigated for oblique incidence case. In the oblique incidence case, the scattering problem cannot be solved explicitly because of the resultant coupled system of functional equations unless the system is decoupled. Therefore under the assumed condition on wedge impedance, these functional equations are decoupled and the expression for the diffraction coefficient is derived as well as the diffracted fields. |
| Author(s): | T. Ikiz, M. K. Zatero?lu |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 3 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 1415 KB |
| Title: | Equivalent Electromagnetic Currents on Infinite Stratified Homogeneous Bi-anisotropic Media Backed by A PEC Layer |
| Abstract: | In this work, the equivalent electromagnetic (EM) currents on the surface of stratified homogeneous bi-anisotropic media backed by a perfect electric conductor (PEC) layer are derived and investigated. By using the representation of Maxwell's equations with a first-order state-vector differential equation, the tangential field components and the corresponding equivalent EM currents at the interface between the outmost bi-anisotropic media layer and the free space is derived analytically and can be easily degenerated into the single anisotropic and isotropic cases. This work is considered as a further step in the study of the EM characteristics of stratified complex media and the obtained results may provide a way for approximately fast calculation of the EM scattering from PEC targets coated by stratified homogeneous bi-anisotropic media. Simulation results are given to validate our analysis and conclusions. |
| Author(s): | S. Tian, Z. Li, C. Q. Gu, D. P. Ding |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 3 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 688 KB |
| Title: | FEKO-Based Method for Electromagnetic Simulation of Carcass Wires Embedded in Vehicle Tires |
| Abstract: | In a tire pressure monitoring system in which a pressure censor and a transmit antenna are contained in a tire, electromagnetic simulations of radiations from carcass embedded tires are requested. However, it is difficult to accurately determine these shielding effects. In this study, methods for performing accurate electromagnetic simulation by adopting the MoM scheme are determined. In the study of the electric fields inside a tire, calculated results are compared with the theoretical distributions in a coaxial cylindrical resonator. In the case of a dense carcass arrangement, simulation results are in good agreement with theoretical results. In the study of electric fields penetrating carcass wires, the results of the MoM scheme are compared with those obtained using the finite element method (FEM). The adequate mesh size of the tire rubber in the MoM scheme for which the accuracy of the simulation results is guaranteed is established. Finally, electromagnetic simulations of an actual carcass tire model are performed. |
| Author(s): | N. Q. Dinh, T. Teranishi, N. Michishita, Y. Yamada, K. Nakatani |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 3 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 4937 KB |
| Title: | A Redundant Loop Basis for Closed Structures with Application to MR Basis |
| Abstract: | A redundant loop basis is proposed and applied as the solenoidal part of the recently developed multiresolution (MR) basis for closed surfaces at low frequencies. By keeping all loop basis functions, the “symmetry” of the MR solenoidal basis can be maintained for closed surfaces. As a consequence, the convergence of iterative solvers for the expanded MR basis can be effectively improved by using the redundant loop basis without disturbing the accuracy of results. Since the expanded MR basis functions are linear combinations of standard Rao-Wilton-Glisson (RWG) functions, it can be applied to the existing MoM codes easily. The positive behavior of redundant loop basis on MR basis for closed surfaces is analyzed and discussed in detail in this paper. Numerical results demonstrate that the expanded MR basis performs better than the original MR basis and has significant advantages over the traditional loop-tree basis for 3D electromagnetic scattering of closed structures in the low frequency range. |
| Author(s): | J. J. Ding, R. S. Chen, J. Zhu, Z. H. Fan, D. Z Ding |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 3 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 1198 KB |
| Title: | An Effective Technique for Enhancing Anti-Interference Performance of Adaptive Virtual Antenna Array |
| Abstract: | In this paper, we proposed an effective technique to enhance the anti-interference performance of the adaptive antenna arrays. The null depth in the direction of interferers determines the anti-interference performance of an adaptive antenna array. However, the null depth generated by the conventional virtual array transformation (VAT) algorithm is usually not sufficient. By introducing the interference direction information into the transformation matrix, we can effectively improve the level of null depth; in turn, the anti-interference performance of the adaptive antenna arrays is significantly enhanced. The numerical experiments are employed to validate the proposed approach. |
| Author(s): | W. Li, Y. Li, L. Guo, W. Yu |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 3 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 773 KB |
| Title: | A High Performance Parallel FDTD Based on Winsock and Multi-Threading on a PC-Cluster |
| Abstract: | Parallel technology is a powerful tool to provide the necessary computing power and memory resources for the FDTD method to simulate electrically-large and complex structures. In this paper, a high performance parallel FDTD is developed for multi-core cluster systems. It employs Winsock to achieve efficient inter-process communication as well as multi-threading to make full use of the hardware resources of multi-core processors on a PC-cluster. Key steps for parallel FDTD such as synchronization, data exchange, load balancing, etc., are investigated. An experiment simulating the scattering of an incident electromagnetic wave form of a computer case is presented which shows that the proposed parallel FDTD achieved speedup of 25.1 and parallel efficiency of 83.7% when 10 processors with 30 cores are utilized, and outperforms traditional parallel FDTD based on MPI or MPI-OpenMP, which gained speedup of 22.9, 24.9 and parallel efficiency of 76.3%, 83.1% respectively under the same circumstances. |
| Author(s): | X. Duan, X. Chen, K. Huang, H. Zhou |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 3 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 1027 KB |
| Title: | Negative Index of Reflection in Planar Metamaterial Composed of Single Split-Ring Resonators |
| Abstract: | This paper reports the negative index of refraction in planar metamaterial consisted of only a traditional single split-ring resonator (SRR), which is proved to exhibit simultaneously negative permittivity and negative permeability without the use of assistant metallic structures by retrieving the effective electromagnetic parameters. With the aid of current distributions investigation, it is demonstrated that within the left-handed band the negative permittivity is generated in a way analogous to the case of dual parallel cut-wire metamaterial, and negative permeability arises from the asymmetric second-order magnetic resonant mode. |
| Author(s): | M. Tang, S. Xiao, D. Wang, J. Xiong, K. Chen, B. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 3 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 1537 KB |
| Title: | Deformation Effect on Transmission Properties of the One Dimensional Photonic Crystal |
| Abstract: | We considered the influence of multilayer structure parameters which are the index contrast, the period’s number and the reference wavelength on the transmission spectrum of a deformed structure. Deformation was introduced by applying the power law y = xk +1.We revealed that the higher optical index contrast enhance the deformation effect on transmission properties of the structure at normal incidence. This work is a detailed study of the effect of the deformation introduced in the multilayer stack according to the mentioned law. |
| Author(s): | A. Mouldi, M. Kanzari |
| File Type: | Journal Paper |
| Issue: | Volume: 26 Number: 3 Year: 2011 |
| Download Link: | Click here to download PDF File Size: 628 KB |