ACES Publication Search
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| Title: | ACES December 2010 Full Journal |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 5722 KB |
| Title: | ACES December 2010 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 395 KB |
| Title: | Twenty Three Years: The Acceptance of Maxwell’s Equations |
| Abstract: | Maxwell first published what came to be called “Maxwell’s equations” in 1865. However, it was not until 1888, and Heinrich Hertz’s experimental validation, that Maxwell’s equations were widely accepted as correct. The story of the intervening 23 years is little known. Maxwell, who died in 1879, was exceptionally modest and did not promote his own results at any time. The survival of Maxwell’s equations was up to the only three researchers in the entire world who paid serious attention to Maxwell’s paper in 1865, and his seminal Treatise in 1873: Oliver Heaviside, Oliver Lodge, and George Francis FitzGerald. Later, Hertz joined the group forming “The Four Maxwellians”. In this paper, we describe the torturous 23 year path Maxwell’s equations took from their creation to their initial acceptance. |
| Author(s): | J. C. Rautio |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 1079 KB |
| Title: | Material Realizations of Perfect Electric Conductor Objects |
| Abstract: | This article discusses the distinction between interfaces and boundaries in electromagnetics. Boundary conditions can be used to narrow down the computation domain of complex problems. However, terminating the space by a boundary condition is an approximation in real-world situations where fields penetrate across interfaces. To make this approximation accurate, the material parameters need to have a very strong contrast between the materials on the adjacent sides of the interface. In this article, the question is addressed how extreme the permittivity and permeability have to be in order to reasonably model a surface as a perfect electric conductor (PEC) boundary. It is argued that in addition to the large value of the permittivity, also a very small magnitude of the permeability is necessary in order to speed up the convergence of a material response towards the ideal PEC case. |
| Author(s): | A. Sihvola, I. V. Lindell, H. Wallén, P. Ylä-Oijala |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 517 KB |
| Title: | Domain Decomposition Methods Combining Surface Equivalence Principle and Macro Basis Functions |
| Abstract: | The basics of two domain decomposition methods based on the surface equivalence principle and the method of moments, namely, the surface tangential equivalence principle (TEPA) and the linear embedding via Green’s operators (LEGO), are outlined to solve electromagnetic scattering problems. In order to efficiently solve large problems, the methods are combined with the characteristic basis function method and the eigencurrent expansion method. Numerical examples demonstrate that the developed hybrid techniques lead to a significant reduction on the number of degrees of freedom and the size of the matrix equation to be solved. |
| Author(s): | P. Ylä-Oijala, V. Lancellotti, B. P. de Hon, S. Järvenpää |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 414 KB |
| Title: | Validation, Verification and Calibration in Applied Computational Electromagnetics |
| Abstract: | Model validation, data verification, and code calibration (VV&C) in applied computational electromagnetics is discussed. The step by step VV&C procedure is given systematically through canonical scenarios and examples. Propagation over flat-Earth with linearly decreasing vertical refractivity profile, having an analytical exact solution, is taken into account as the real-life problem. The parabolic wave equation (PWE) is considered as the mathematical model. MatLab-based numerical simulators for both the split step Fourier and finite element implementations of the PWE are developed. The simulators are calibrated against analytical exact and high frequency asymptotic solutions. Problems related to the generation of reference data during accurate numerical computations are presented. |
| Author(s): | G. Apaydin, L. Sevgi |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 1225 KB |
| Title: | Quasi-Dynamic Homogenization of Geometrically Simple Dielectric Composites |
| Abstract: | The frequency dependence of the effective permittivities of simple dielectric composites is evaluated by different quasidynamic homogenization methods. Three retrieval approaches based on the scattering parameters are proposed for dielectric materials. A compensation method for the conventional Nicolson-Ross-Weir (NRW) retrieval is applied to eliminate the Fabry- Pérot (FP) resonances and their distortions of the retrieval results. All these quasi-dynamic homogenization methods are then evaluated by comparing the corresponding retrieval results against one another. Finally, by comparing these retrieval results with the static Lord Rayleigh prediction, the limitation of the quasi-static approximation for such composites is considered. |
| Author(s): | J. Qi, H. Kettunen, H. Wallén, A. Sihvola |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 541 KB |
| Title: | Multi-Frequency Higher-Order ADI-FDTD Solvers for Signal Integrity Predictions and Interference Modeling in General EMC Applications |
| Abstract: | The precise and wideband modeling of electromagnetic interferences and their effect on the signal integrity of microwave structures is presented in this paper, via an efficient 3-D dispersionoptimized method. Introducing a novel frequencydependent alternating-direction implicit finitedifference time-domain algorithm in general curvilinear coordinates, the technique establishes a consistent multi-frequency higher-order stencil management formulation. Moreover, for arbitrary geometric discontinuities and abrupt curvatures, a field projection scheme is devised. Thus, the detrimental dispersion errors of existing approaches are drastically minimized and time-steps can now greatly exceed the stability condition at any frequency range. The proposed method leads to affordable simulations and very accurate results, as proven by a variety of electromagnetic compatibility problems. |
| Author(s): | N. V. Kantartzis |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 613 KB |
| Title: | Improved Performance of FDTD Computation Using a Thread Block Constructed as a Two-Dimensional Array with CUDA |
| Abstract: | In a previous study, the authors proposed an finite-difference time-domain (FDTD) implementation for a compute unified device architecture (CUDA) compatible graphics processing unit (GPU) using a thread block constructed as a two-dimensional (2-D) array. However, it was found that the larger the computational domain of the 2-D FDTD simulation using the GPU, the slower the computational speed. In the present paper, the authors investigated the computational performance with respect to the size of a thread block constructed as a 2-D array, and improved the performance of the implementation. Finally, regardless of the size of computational domain, the computational speed using a single GPU (NVIDIA GeForce GTX 280) achieved approximately 30.0 Gflops, which was approximately 20 times faster than that of a single core of a central processing unit (Intel 3.0-GHz Core 2 Duo). The improved performance was approximately 65% of the theoretical peak performance (47.23 Gflops) obtained by the theoretical memory bandwidth (141.7 GB/s). |
| Author(s): | N. Takada, T. Shimobaba, N. Masuda, T. Ito |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 407 KB |
| Title: | A Single-Field FDTD Formulation for Electromagnetic Simulations |
| Abstract: | A set of general purpose single-field finite-difference time-domain (FDTD) updating equations for solving electromagnetic problems is derived. The formulation uses a single-field expression for full-wave solution. This formulation can provide numerical results similar to those obtained using the traditional Yee algorithm with less computer resources. The traditional FDTD updating equations are based on Maxwell's curl equations whereas the single-field FDTD updating equations, used here, are based on the vector wave equation. Performance analyses of the single–field formulation in terms of CPU time, memory requirement, stability, dispersion, and accuracy are presented. It was observed that the single-field method is significantly efficient relative to the traditional one in terms of speed and memory requirements. |
| Author(s): | G. Aydin, A. Z. Elsherbeni, E. Arvas |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 345 KB |
| Title: | Bandwidth Control of Optimized FDTD Schemes |
| Abstract: | We investigate the potential of controlling the wideband behavior of finite-difference time-domain (FDTD) methods, which adopt extended spatial operators while maintaining the standard temporal updating procedure. Specifically, single-frequency optimization is performed first, while wider bands are then treated with the aid of the least-squares technique. The proposed methodology is applied to various discretization schemes with different stencil sizes and shapes, thus verifying its versatile character. Theoretical as well as numerical results are presented, which demonstrate that the optimization process has a beneficial impact on the efficiency of FDTD algorithms, and yields attractive alternatives for reliable multi-frequency simulations. |
| Author(s): | T. T. Zygiridis |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 413 KB |
| Title: | A Small Dual Purpose UHF RFID Antenna Design |
| Abstract: | In this paper, designs and development of a small dual purpose UHF RFID planar antenna and an RFID tag antenna for small wireless application devices are presented. The planar antenna resonates at both the European and US RFID bands. It has a reasonable gain on both RFID bands with an omni-directional radiation pattern. The RFID tag antenna is designed for the European UHF RFID band. Experimental results for radiation pattern, input impedance reflection coefficient, and tag antenna realized gain confirmed the validity of the designs based on numerical simulations. |
| Author(s): | A. A. Babar, L. Ukkonen, A. Z. Elsherbeni, L. Sydanheimo |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 937 KB |
| Title: | Evaluation of EM Absorption in Human Head with Metamaterial Attachment |
| Abstract: | The reduction of electromagnetic (EM) absorption with metamaterial is performed by the finite-difference time-domain method with lossy- Drude model by CST Microwave Studio in this paper. The metamaterials can be achieved by arranging split ring resonators (SRRS) periodically. The SAR value has been observed by varying the distances between head model to phone model, different distance, different thickness, and different size of metamaterial design. Metamaterial has achieved 53.94% reduction of the initial SAR value for SAR 10 gm. |
| Author(s): | M. R. I. Faruque, M. T. Islam, N. Misran |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 360 KB |
| Title: | CAD Technique for Microwave Chemistry Reactors with Energy Efficiency Optimized for Different Reactants |
| Abstract: | Upgrading successful processes of microwave-assisted organic synthesis to the level of industrial technology is currently slowed by difficulties in experimental development of largescale and highly-productive reactors. This paper proposes to address this issue by developing microwave chemistry reactors as microwave systems, rather than as black-box-type units for chemical reactions. We suggest an approach based on the application of a neural network optimization technique to a microwave system in order to improve its coupling (and thus energy efficiency). The RBF network optimization with CORS sampling introduced in our earlier work and capable of exceptionally quick convergence to the optima due to a dramatically reduced number of underlying 3D FDTD analyses, is upgraded here to account for an additional practically important condition requiring optimal design of the reactor for different reactants. Viability of the approach is illustrated by three examples of finding the geometry of a conventional 99% energy efficient microwave reactor for 3/3/6 different materials; with 1/5/1 liter reactants, seven-parameter optimization yields the best configurations taking only 16/38/115 hours of CPU time of a regular PC. |
| Author(s): | E. K. Murphy, V. V. Yakovlev |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 440 KB |
| Title: | Dynamic Simulation of Electromagnetic Actuators Based on the Co-Energy Map |
| Abstract: | The development of new and efficient control methodologies demands the availability of mathematical models for the electromagnetic device under control. These models must be solved with great accuracy and speed. The finite element method (FEM) gives truthful results but computational demanding increases with device geometrical complexity. This paper proposes a new method for dynamic behavior simulation that uses FEM software at its early stage, to obtain the co-energy map for devices concerning static positions for different excitation currents. Inductance and force maps are derived from the co-energy map. A numerical model of a case study is built with Matlab© to obtain device dynamic response. The software implementation procedure is described in detail. The achieved results are compared with the ones obtained from the FEM tool analysis. The small computation effort required by the proposed analysis method makes possible that complex control methodologies can be developed and tested based on the proposed model. |
| Author(s): | A. E. Santo, M. R A. Calado, C. M. P. Cabrita |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 781 KB |
| Title: | Mutual Coupling Reduction in Dielectric Resonator Antenna Arrays Embedded in a Circular Cylindrical Ground Plane |
| Abstract: | In this paper, the radiation characteristics and the mutual coupling between two identical cylindrical dielectric resonator antennas embedded in a cylindrical structure in different configurations are calculated. To reduce the mutual coupling between the two antennas, the surface of the cylinder ground plane is defected by cutting slots, or inserting quarter wavelength grooves between the two antennas. The finite element method and the method based on the finite integration technique are used to calculate the radiation characteristics of the antenna. |
| Author(s): | S. H. Zainud-Deen, H. A. Malhat, K. H. Awadalla |
| File Type: | Journal Paper |
| Issue: | Volume: 25 Number: 12 Year: 2010 |
| Download Link: | Click here to download PDF File Size: 383 KB |