Download or read book Electromagnetic Scattering from Finite Arrays of Dielectrically covered Circular Cavities in a Ground Plane written by Frank Javier Villegas and published by . This book was released on 2002 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electromagnetic Scattering Analysis of a Three dimensional cavity backed Aperture in an Infinite Ground Plane Using a Combined Finite Element Method method of Moments Approach written by and published by . This book was released on 1995 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electromagnetic Scattering from a Rectangular Cavity Recessed in a 3 D Conducting Surface written by M. D. Deshpande and published by . This book was released on 1995 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Three dimensional Electromagnetic Scattering from a Circular Tube of Finite Length written by Cheng C. Kao and published by . This book was released on 1970 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electromagnetic Scattering Analysis of a Three Dimensional Cavity Backed Aperture in an Infinite Ground Plane Using a Combined Finite Element Method Method of Moments Approach written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-20 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: A combined finite element method/method of moments (FEM/MoM) approach is used to analyze the electromagnetic scattering properties of a three-dimensional-cavity-backed aperture in an infinite ground plane. The FEM is used to formulate the fields inside the cavity, and the MoM (with subdomain bases) in both spectral and spatial domains is used to formulate the fields above the ground plane. Fields in the aperture and the cavity are solved using a system of equations resulting from the combination of the FEM and the MoM. By virtue of the FEM, this combined approach is applicable to all arbitrarily shaped cavities with inhomogeneous material fillings, and because of the subdomain bases used in the MoM, the apertures can be of any arbitrary shape. This approach leads to a partly sparse and partly full symmetric matrix, which is efficiently solved using a biconjugate gradient algorithm. Numerical results are presented to validate the analysis. Reddy, C. J. and Deshpande, Manohar D. and Cockrell, C. R. and Beck, F. B. Langley Research Center RTOP 505-64-70-01...
Download or read book Analysis of Three dimensional cavity backed Aperture Antennas Using a Combined Finite Element Method Method of Moments Geometrical Theory of Diffraction Technique written by C. J. Reddy and published by . This book was released on 1995 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electromagnetic Scattering from Arbitrarily Shaped Aperture Backed by Rectangular Cavity Recessed in Infinite Ground Plane written by C. R. Cockrell and published by . This book was released on 1997 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electromagnetic Scattering Analysis of a Three dimensional cavity backed Aperture in an Infinite Ground Plane Using a Combined Finite Element Method written by C.J. Reddy and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electromagnetic Scattering from Arbitrarily Shaped Aperture Backed by Rectangular Cavity Recessed in Infinite Ground Plane written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-02 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: The electromagnetic scattering from an arbitrarily shaped aperture backed by a rectangular cavity recessed in an infinite ground plane is analyzed by the integral equation approach. In this approach, the problem is split into two parts: exterior and interior. The electromagnetic fields in the exterior part are obtained from an equivalent magnetic surface current density assumed to be flowing over the aperture and backed by an infinite ground plane. The electromagnetic fields in the interior part are obtained in terms of rectangular cavity modal expansion functions. The modal amplitudes of cavity modes are determined by enforcing the continuity of the electric field across the aperture. The integral equation with the aperture magnetic current density as an unknown is obtained by enforcing the continuity of magnetic fields across the aperture. The integral equation is then solved for the magnetic current density by the method of moments. The electromagnetic scattering properties of an aperture backed by a rectangular cavity are determined from the magnetic current density. Numerical results on the backscatter radar cross-section (RCS) patterns of rectangular apertures backed by rectangular cavities are compared with earlier published results. Also numerical results on the backscatter RCS patterns of a circular aperture backed by a rectangular cavity are presented. Cockrell, C. R. and Beck, Fred B. Langley Research Center RTOP 505-64-52-04...
Download or read book Electromagnetic Scattering from a Cavity in a Ground Plane written by William D. Wood and published by . This book was released on 1997-03-01 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: The electromagnetic scattering from an arbitrarily shaped open cavity embedded in a perfectly conducting, infinite ground plane is examined. The cavity is filled with a linear, isotropic, homogeneous material. The fields in the cavity interior and above the ground plane are expressed in terms of the tangential fields on the cavity surface and aperture. A coupled set of three integral equations is developed governing the tangential fields on the aperture and cavity surface. The support of the unknown tangential fields is finite. A moment-method based algorithm to approximate the solution to the integral equations for axisymmetric geometries is developed. The unknown tangential fields are expanded using piecewise-linear functions in the elevation plane and complex exponentials in the azimuth plane. Orthogonality is exploited to reduce the size of the matrix. The algorithm yields a well-conditioned numerical solution. The solution obeys the edge condition at the aperture rim. The integral equations are uniquely solvable at frequencies where other integral equation-based techniques admit spurious solutions. Radar cross section calculations are compared to experimental measurements of full-scale physical models. Results show that an open cavity can serve as an effective radar cross section enhancement device.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2002 with total page 858 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electromagnetic Scattering written by P. L. E. Uslenghi and published by . This book was released on 1978 with total page 824 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electromagnetic Scattering is a collection of studies that aims to discuss methods, state of the art, applications, and future research in electromagnetic scattering. The book covers topics related to the subject, which includes low-frequency electromagnetic scattering; the uniform asymptomatic theory of electromagnetic edge diffraction; analyses of problems involving high frequency diffraction and imperfect half planes; and multiple scattering of waves by periodic and random distribution. Also covered in this book are topics such as theories of scattering from wire grid and mesh structures; t ...
Download or read book Electromagnetic Scattering from Semi Infinite Planar Arrays written by Peter J. Collins and published by . This book was released on 1996-09-01 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: A hybrid method of moments(MM) based numerical model for the electromagnetic scattering from large finite by infinite planar slot arrays is developed. The method incorporates the novel concept of a physical basis function (PBF) to dramatically reduce the number of required unknowns. The model can represent a finite number of slot columns with slots oriented along the infinite axis, surrounded by an arbitrary number of coplanar dielectric slabs. Each slot column can be loaded with a complex impedance, allowing one to tailor the edge currents to provide a desired echo width pattern. The surface equivalence theorem is used to convert the original slotted ground plane geometry to an equivalent unbroken ground plane with magnetic surface currents. An integral equation based on these magnetic scattering currents is solved via the MM. The magnetic currents are approximated by a set of basis functions composed of periodic basis functions representing the edge slot columns and a single PBF representing the interior slot columns. In particular, the PBF captures the behavior of the central portion of the array where the perturbations from the edges have become negligible. Based on Floquet's theorem, the PBF is able to represent an arbitrarily large number of slot columns with just one unknown. The array scanning method (ASM) provides the contributions from the individual edge columns. Finally, a newly developed one sided Poisson sum formulation provides an efficient means to account for the stratified dielectric media via a spectral domain conversion. The hybrid method is validated using both MM reference codes and measured data. The results clearly demonstrate the method's accuracy as well as its ability to handle array problems too large for traditional MM solutions.
Download or read book Electromagnetic Scattering of a Smooth Finite size Ground Plane written by David Alan Buchanan and published by . This book was released on 1987 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fractal Apertures in Waveguides Conducting Screens and Cavities written by Basudeb Ghosh and published by Springer. This book was released on 2014-06-12 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the design and analysis of fractal apertures in waveguides, conducting screens and cavities using numerical electromagnetics and field-solvers. The aim is to obtain design solutions with improved accuracy for a wide range of applications. To achieve this goal, a few diverse problems are considered. The book is organized with adequate space dedicated for the design and analysis of fractal apertures in waveguides, conducting screens and cavities, microwave/millimeter wave applications followed by detailed case-study problems to infuse better insight and understanding of the subject. Finally, summaries and suggestions are given for future work. Fractal geometries were widely used in electromagnetics, specifically for antennas and frequency selective surfaces (FSS). The self-similarity of fractal geometry gives rise to a multiband response, whereas the space-filling nature of the fractal geometries makes it an efficient element in antenna and FSS unit cell miniaturization. Until now, no efforts were made to study the behavior of these fractal geometries for aperture coupling problems. The aperture coupling problem is an important boundary value problem in electromagnetics and used in waveguide filters and power dividers, slotted ground planes, frequency selective surfaces and metamaterials. The present book is intended to initiate a study of the characteristics of fractal apertures in waveguides, conducting screens and cavities. To perform a unified analysis of these entirely dissimilar problems, the “generalized network formulation of the aperture problems” by Mautz and Harrington was extended to multiple-aperture geometry. The authors consider the problem of coupling between two arbitrary regions coupled together via multiple apertures of arbitrary shape. MATLAB codes were developed for the problems and validated with the results available in the literature as well as through simulations on ANSOFT's HFSS.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1998 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 804 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
