378 research outputs found

    An efficient asymptotic extraction approach for the green's functions of conformal antennas in multilayered cylindrical media

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    Asymptotic expressions are derived for the dyadic Green's functions of antennas radiating in the presence of a multilayered cylinder, where analytic representation of the asymptotic expansion coefficients eliminates the computational cost of numerical evaluation. As a result, the asymptotic extraction technique has been applied only once for a large summation order nn. In addition, the Hankel function singularity encountered for source and evaluation points at the same radius has been eliminated using analytical integration

    An Improved Iterative Technique for the Quasi-Tem Analysis of Generalized Planar Lines

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    The Generalized Bioconjugate Gradient Method (GBGM) and FFT algorithms are used for the quasi-TEM analysis of generalized multistrip lines embedded in multilayered lossless/lossy, iso/anisotropic dielectric and/or magnetic media. Important computational improvement is achieved by including asymptotic extraction techniques in the determination of the spatial Green’s function matrix. Comparisons with other iterative procedures are presented. Several practical structures are analyzed and numerical results are compared with previously published data

    High-Performance Computing for the Electromagnetic Modeling and Simulation of Interconnects

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    The electromagnetic modeling of packages and interconnects plays a very important role in the design of high-speed digital circuits, and is most efficiently performed by using computer-aided design algorithms. In recent years, packaging has become a critical area in the design of high-speed communication systems and fast computers, and the importance of the software support for their development has increased accordingly. Throughout this project, our efforts have focused on the development of modeling and simulation techniques and algorithms that permit the fast computation of the electrical parameters of interconnects and the efficient simulation of their electrical performance

    Use of ground planes within the spatial images technique: Application to the analysis of rectangular multilayered shielded enclosures

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    The use of ground planes is proposed inside the spatial images technique in order to calculate the multilayered shielded Green's functions for rectangular enclosures. The positions of the ground planes are dynamically located, covering two walls of the cavity, as a function of the source position. Spatial mirror images, related to the ground planes, are used to perfectly impose the boundary conditions along these cavity walls. This completely removes the problems associated to the singular behavior of the source when it is placed close to a wall or a corner, improving numerical stability. In addition, the method leads to a very efficient computation (about 15 times faster than the original approach), due to the reduced number of non-mirror images that must be effectively computed. A multi-band filter in hybrid waveguide-microstrip technology is analyzed with the new method, showing excellent agreement with measured data.Ministerio de Educación y Ciencia, Ref. TEC2007-67630-C03-02. Fundación Séneca, Ref. 08833/PI/08

    Fast and accurate MoM analysis of periodic arrays of multilayered stacked rectangular patches with application to the design of reflectarray antennas

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    The scattering of plane waves by periodic arrays of stacked rectangular patches in multilayered substrates is a problem that has to be solved many times when designing reflectarray antennas made of those patches under the local periodicity assumption. The solution to the periodic multilayered problem has been traditionally carried out by means of the Galerkin?s version of the method of moments (MoM) in the spectral domain. This approach involves the computation of double infinite summations, and whereas some of these summations converge very fast, some other converge very slowly. In this paper, the slowly convergent summations are computed by making use of an enhanced mixed potential integral equation (MPIE) formulation of the MoM in the spatial domain. This enhanced formulation is based on the interpolation of the multilayered periodic Green?s functions, and on the efficient computation of the four-dimensional (4-D) integrals leading to the MoM matrix entries. Both the novel hybrid spectral?spatial MoM code and the standard spectral domain MoM code have been used for the design of a contoured beam reflectarray antenna. It has been verified that the spectral?spatial MoM code requires CPU times that are typically 30 times smaller than those required by the pure spectral domain MoM code

    Electromagnetic Wave Theory and Applications

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    Contains table of contents for Section 3, reports on six research projects and a list of publications and conference papers.Joint Services Electronics Program Contract DAAL03-89-C-0001National Science Foundation Grant ECS 86-20029Schlumberger- Doll ResearchU.S. Army Research Office Contract DAAL03 88-K-0057U.S. Navy - Office of Naval Research Contract N00014-90-J-1002National Aeronautics and Space Administration Grant NAGW-1617U.S. Navy - Office of Naval Research Grant N00014-89-J-1107National Aeronautics and Space Administration Grant NAGW-1272National Aeronautics and Space Administration Agreement 958461U.S. Army - Corps of Engineers Contract DACA39-87-K-0022U.S. Air Force - Electronic Systems Division Contract F19628-88-K-0013U.S. Navy - Office of Naval Research Grant N00014-89-J-1019Digital Equipment CorporationIBM CorporationU.S. Department of Transportation Contract DTRS-57-88-C-00078Defence Advanced Research Projects Agency Contract MDA972-90-C-002

    Improvements in the MoM analysis of 2-D planar multilayered periodic structures

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    In this paper the authors apply the Method of Moments (MoM) to the analysis of the scattering of a multilayered periodic strip grating by a plane wave with oblique incidence and arbitrary polarization. It is shown that the use of an improved MoM spatial domain approach is one order of magnitude faster than the use of the classical MoM spectral domain approach when basis functions that account for edge singularities are used in the modeling of the current density on the metallizations

    Electromagnetic Wave Theory and Applications

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    Contains reports on twelve research projects.Joint Services Electronics Program (Contract DAALO3-86-K-0002)National Science Foundation (Grant ECS 85-04381)National Aeronautics and Space Administration/Goddard Space Flight Center (Contract NAG5-270)National Aeronautics and Space Administration/Goddard Space Flight Center (Contract NAG5-725)U.S. Navy - Office of Naval Research (Contract N00014-83-K-0258)U.S. Navy - Office of Naval Research (Contract N00014-86-K-0533)U.S. Army - Research Office Durham (Contract DAAG29-85-K-0079)International Business Machines, Inc.National Aeronautics and Space Administration/Goddard Space Flight Center (Contract NAG5-269)Simulation TechnologiesSchlumberger-Doll Researc
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