Download or read book An Efficient and Robust Solution to Time Domain Integral Equations of Electromagnetics and Their Implementation for Homogeneous and Inhomogeneous Dielectric Scatterers written by Greeshma Pisharody and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent developments in the areas of high-resolution radar technology, electromagnetics pulse (EMP) simulation studies, target identification techniques, and singularity expansion method (SEM) related problems where the transient response plays a vital role have increased the need for a reliable and robust time domain integral equation (TDIE) solver. Numerical methods based on TDIEs are needed for their geometrical flexibility, lack of numerical dispersion, efficiency for broadband, time-varying, and nonlinear problems, and intrinsic incorporation of radiation condition. Despite these advantages and the multiplying need for a TDIE solver, the issues of instability and inaccuracy encountered in their execution still continue to haunt them and hamper their widespread implementation. This work aims at developing a stable and accurate TDIE technique based on the marching-on-in-time (MOT) method using special temporal basis functions and bandlimited extrapolation. The work developed here uses a method called AMBLE: A ccurate M arching by B and- L imited E xtrapolation. AMBLE was initially implemented for PECs using bandlimited interpolatory functions (BLIFs) and higher-order vector basis functions to effect the temporal and spatial discretization of the surface integral equations, respectively. Since the basis functions used for the temporal representation are noncausal, an extrapolation scheme was employed to recover the ability to solve the problem by marching on in time. Early results of AMBLE showed that it rendered stable and accurate results for closed scatterers but went unstable for open scatterers. The instability witnessed was a slow growing, low frequency type that occurred due to the existence of solenoidal currents. The work presented here overcomes this low frequency instability using two novel stabilization techniques. The first method augments the commonly used tangential field integral equations with additional integral equations that impose conditions on the temporal derivative of the normal magnetic field. The next method developed here is based on the same idea, but with an entirely different implementation. Specifically, it uses a loop-tree decomposition of the space of spatial basis functions and treats the equations tested with solenoidal testing functions differently than the other equations. Numerical results show that the modified methods are stable and accurate retaining the superlinear and exponential convergence with regard to spatial and temporal discretizations respectively, observed in early AMBLE implementations. (Abstract shortened by UMI.).

Download or read book Integral Equations and Iteration Methods in Electromagnetic Scattering written by A. B. Samokhin and published by Walter de Gruyter. This book was released on 2013-03-12 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Integral Equation Methods for Electromagnetic and Elastic Waves written by Weng Chew and published by Springer Nature. This book was released on 2022-05-31 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integral Equation Methods for Electromagnetic and Elastic Waves is an outgrowth of several years of work. There have been no recent books on integral equation methods. There are books written on integral equations, but either they have been around for a while, or they were written by mathematicians. Much of the knowledge in integral equation methods still resides in journal papers. With this book, important relevant knowledge for integral equations are consolidated in one place and researchers need only read the pertinent chapters in this book to gain important knowledge needed for integral equation research. Also, learning the fundamentals of linear elastic wave theory does not require a quantum leap for electromagnetic practitioners. Integral equation methods have been around for several decades, and their introduction to electromagnetics has been due to the seminal works of Richmond and Harrington in the 1960s. There was a surge in the interest in this topic in the 1980s (notably the work of Wilton and his coworkers) due to increased computing power. The interest in this area was on the wane when it was demonstrated that differential equation methods, with their sparse matrices, can solve many problems more efficiently than integral equation methods. Recently, due to the advent of fast algorithms, there has been a revival in integral equation methods in electromagnetics. Much of our work in recent years has been in fast algorithms for integral equations, which prompted our interest in integral equation methods. While previously, only tens of thousands of unknowns could be solved by integral equation methods, now, tens of millions of unknowns can be solved with fast algorithms. This has prompted new enthusiasm in integral equation methods. Table of Contents: Introduction to Computational Electromagnetics / Linear Vector Space, Reciprocity, and Energy Conservation / Introduction to Integral Equations / Integral Equations for Penetrable Objects / Low-Frequency Problems in Integral Equations / Dyadic Green's Function for Layered Media and Integral Equations / Fast Inhomogeneous Plane Wave Algorithm for Layered Media / Electromagnetic Wave versus Elastic Wave / Glossary of Acronyms

Download or read book Parallel Solution of Integral Equation Based EM Problems in the Frequency Domain written by Y. Zhang and published by John Wiley & Sons. This book was released on 2009-06-29 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: A step-by-step guide to parallelizing cem codes The future of computational electromagnetics is changing drastically as the new generation of computer chips evolves from single-core to multi-core. The burden now falls on software programmers to revamp existing codes and add new functionality to enable computational codes to run efficiently on this new generation of multi-core CPUs. In this book, you'll learn everything you need to know to deal with multi-core advances in chip design by employing highly efficient parallel electromagnetic code. Focusing only on the Method of Moments (MoM), the book covers: In-Core and Out-of-Core LU Factorization for Solving a Matrix Equation A Parallel MoM Code Using RWG Basis Functions and ScaLAPACK-Based In-Core and Out-of-Core Solvers A Parallel MoM Code Using Higher-Order Basis Functions and ScaLAPACK-Based In-Core and Out-of-Core Solvers Turning the Performance of a Parallel Integral Equation Solver Refinement of the Solution Using the Conjugate Gradient Method A Parallel MoM Code Using Higher-Order Basis Functions and Plapack-Based In-Core and Out-of-Core Solvers Applications of the Parallel Frequency Domain Integral Equation Solver Appendices are provided with detailed information on the various computer platforms used for computation; a demo shows you how to compile ScaLAPACK and PLAPACK on the Windows® operating system; and a demo parallel source code is available to solve the 2D electromagnetic scattering problems. Parallel Solution of Integral Equation-Based EM Problems in the Frequency Domain is indispensable reading for computational code designers, computational electromagnetics researchers, graduate students, and anyone working with CEM software.

Download or read book Time Domain Integral Equation based Methods for Analyzing Electromagnetic Scattering from Objects Residing in Lossy Media written by Peilin Jiang and published by ProQuest. This book was released on 2007 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation is concerned with the development of efficient time domain integral equation (TDIE)-based marching-on-in-time (MOT) schemes pertinent to transient analysis of electromagnetic scattering from objects residing in lossy media. Classical MOT schemes have a computational complexity scaling as O( N2sN2t ) and a memory requirement as O( N2sNt ), respectively. To alleviate the demands of computational resources, two techniques are proposed in this dissertation, viz., the Prony series-based recursive convolution scheme and the multilevel plane wave time domain (PWTD) algorithm. The former reduces the computational cost to O( N2sNt log Nt). The latter is the extension of the PWTD scheme for free space and is able to speed up the evaluation of fields radiated by band-limited and time-limited sources far enough away. When these two techniques are hybridized in the MOT scheme, i.e., the recursive convolution scheme evaluates the near-field interaction, and the multilevel PWTD algorithm evaluates the far-field interactions, the enhanced scheme has a computational complexity of O(NsNt log Ns(log Ns + log 2 Nt)) and a memory requirement of O(NsNt). As applications of the developed solver, the electromagnetic scattering from perfect electric conductors residing in lossy media and the light scattering from homogeneous and inhomogeneous biological cells are analyzed. The corresponding TDIEs are also formulated considering the particularities of application scenarios. Numerous numerical examples are presented to demonstrate the fast solver's efficacy and ability to solve realistic problems.

Download or read book A Robust Stabilization Methodology for Time Domain Integral Equations in Electromagnetics written by Andrew J. Pray and published by . This book was released on 2014 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Time Domain Boundary Integral Equations Analysis written by Amir Geranmayeh and published by Sudwestdeutscher Verlag Fur Hochschulschriften AG. This book was released on 2011-01 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present research study mainly involves a survey of diverse time-domain boundary element methods that can be used to numerically solve the retarded potential integral equations. The aim is to address the late-time stability, accuracy, and computational complexity concerns in time-domain surface integral equation approaches. The study generally targets the transient electromagnetic scattering of three- dimensional perfectly conducting bodies. Efficient algorithms are developed to numerically solve the electric, magnetic, and combined field integral equations for the unknown induced surface current. The algorithms are mainly categorized into three major discretization schemes, namely the marching-on- in-time, the marching-on-in-order, and the convolution quadrature methods or finite difference delay modeling. Possible choices of space-time integration are examined and the results are compared with the finite integration technique's solution. The outcome is applied to the non- dispersive modeling of the field propagation in particle accelerator structures, when travelling bunches of charged particles passes through the beam line elements.

Download or read book Application of Geometric Algebra to Electromagnetic Scattering written by Andrew Seagar and published by Springer. This book was released on 2015-11-12 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents the Clifford-Cauchy-Dirac (CCD) technique for solving problems involving the scattering of electromagnetic radiation from materials of all kinds. It allows anyone who is interested to master techniques that lead to simpler and more efficient solutions to problems of electromagnetic scattering than are currently in use. The technique is formulated in terms of the Cauchy kernel, single integrals, Clifford algebra and a whole-field approach. This is in contrast to many conventional techniques that are formulated in terms of Green's functions, double integrals, vector calculus and the combined field integral equation (CFIE). Whereas these conventional techniques lead to an implementation using the method of moments (MoM), the CCD technique is implemented as alternating projections onto convex sets in a Banach space. The ultimate outcome is an integral formulation that lends itself to a more direct and efficient solution than conventionally is the case, and applies without exception to all types of materials. On any particular machine, it results in either a faster solution for a given problem or the ability to solve problems of greater complexity. The Clifford-Cauchy-Dirac technique offers very real and significant advantages in uniformity, complexity, speed, storage, stability, consistency and accuracy.

Download or read book Integral Equations for Real Life Multiscale Electromagnetic Problems written by Francesca Vipiana and published by IET. This book was released on 2024-01-09 with total page 397 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compiled by two editors with substantial experience in developing algorithms to numerically solve integral equations in the case of discretized real-life structures, this book explains the main available approaches for the numerical solution of surface integral equations for analysing real-world multi-scale electromagnetic problems.

Download or read book Integral Equation Techniques in Transient Electromagnetics written by Dragan Poljak and published by Computational Mechanics. This book was released on 2003 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transient electromagnetic phenomena can be treated in two ways, either using direct time domain modeling or frequency domain analysis applying the inverse Fourier transform. Both approaches are important since each has distinct advantages depending on the situation or the application.

Download or read book Integral Accuracy and the Stability of Time Domain Integral Equations for Electromagnetic Scattering written by Jielin Li and published by . This book was released on 2019 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stability of time domain integral equation approaches to the computation of electromagnetic scattering is profoundly affected by the accuracy of the underlying numerical integration methods used for computation of the kernel elements. In most publications, numerical integrals are assumed exact and higher integral orders are assumed to deliver higher accuracy. The lack of attention to this detail has led to inaccurate conclusions about the stability of different solution methods. In this work, we examine the complicated relationship between the actual accuracy of integral computation and the resulting stability of integral equations. Numerical results show that numerical integrals are not as exact as expected, and that stability may be improved for a higher integral accuracy. Moreover, while integral accuracy is not always improved by higher order integration rules, more careful integration (as delivered by adaptive integration methods) is often helpful. Numerical results for a range of problems demonstrate these contentions.

Download or read book Alternative Field Representations and Integral Equations for Modeling Inhomogeneous Dielectrics written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-10 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: New volume and volume-surface integral equations are presented for modeling inhomogeneous dielectric regions. The presented integral equations result in more efficient numerical implementations and should, therefore, be useful in a variety of electromagnetic applications. Volakis, John L. Unspecified Center NASA-CR-189953, NAS 1.26:189953, UMICH-025921-25-T NAG2-541...

Download or read book The Finite Difference Time Domain Method for Electromagnetics written by Karl S. Kunz and published by CRC Press. This book was released on 1993-05-03 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Finite-Difference Time-domain (FDTD) method allows you to compute electromagnetic interaction for complex problem geometries with ease. The simplicity of the approach coupled with its far-reaching usefulness, create the powerful, popular method presented in The Finite Difference Time Domain Method for Electromagnetics. This volume offers timeless applications and formulations you can use to treat virtually any material type and geometry. The Finite Difference Time Domain Method for Electromagnetics explores the mathematical foundations of FDTD, including stability, outer radiation boundary conditions, and different coordinate systems. It covers derivations of FDTD for use with PEC, metal, lossy dielectrics, gyrotropic materials, and anisotropic materials. A number of applications are completely worked out with numerous figures to illustrate the results. It also includes a printed FORTRAN 77 version of the code that implements the technique in three dimensions for lossy dielectric materials. There are many methods for analyzing electromagnetic interactions for problem geometries. With The Finite Difference Time Domain Method for Electromagnetics, you will learn the simplest, most useful of these methods, from the basics through to the practical applications.

Download or read book Forward and Inverse Scattering Algorithms Based on Contrast Source Integral Equations written by Peter M. van den Berg and published by John Wiley & Sons. This book was released on 2021-02-15 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: A guide to wave-field computational methods based on contrast source type of integral equations Forward and Inverse Scattering Algorithms Based on Contrast Source Integral Equations presents a text that examines wave-field computational methods based on contrast source type of integral equations and the computational implementation in wave-field based imaging methods. Written by a noted expert on the topic, the book provides a guide to efficient methods for calculating wave fields in a known inhomogeneous medium. The author provides a link between the fundamental scattering theory and its discrete counterpart and discusses the forward scattering problem based on the contrast-source integral equations. The book fully describes the calculation of wave fields inside and outside a scattering object with general shape and material property and reviews the inverse scattering problem, in which material properties are resolved from wave-field measurements outside the scattering object. The theoretical approach is the inverse of the forward scattering problem that determines how radiation is scattered, based on the scattering object. This important book: Provides a guide to the effects of scalar waves, acoustic waves and electromagnetic waves Describes computer modeling in 1D, 2D and 3D models Includes an online site for computer codes with adjustable configurations Written for students, researchers, and professionals, Forward and Inverse Scattering Algorithms Based on Contrast Source Integral Equations offers a guide to wave-field computational methods based on contrast source type of integral equations and the computational implementation in wave-field based imaging methods.

Download or read book Numerical Solutions of Electromagnetic Problems by Integral Equation Methods and Finite difference Time domain Method written by Xiaoyi Min and published by . This book was released on 1989 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis and Numerical Solution of an Integral Equation Method for Electromagnetic Scattering from a Cavity in a Ground Plane written by Eric T. Howe and published by . This book was released on 2001-09-01 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this research the electromagnetic scattering of a plane wave from a two-dimensional cavity embedded in an infinite, perfectly conducting ground plane is investigated. The plane wave is assumed to be under transverse electric (TE) polarization with respect to the x-axis. The cavity may be empty or filled with an arbitrary homogeneous, lossy material. A coupled set of scalar integral equations that govern the electromagnetic scattering is implemented. An approximate solution to the scalar integral equations is found via a Method of Moments (MoM) algorithm. The algorithm is implemented in a computer code, and approximations to the total magnetic field on the cavity surface and aperture as well as the normal derivative of the total magnetic field on the cavity aperture are obtained. These fields are then used to calculate the two-dimensional monostatic RCS signatures of various test cavities. The numerical results from the algorithm are shown to agree well with the RCS signatures calculated by other well-known methods and published results. In addition to being accurate, the algorithm is very computationally efficient. The process results in simply solving a relatively small, well-conditioned matrix system for each incident angle to produce the unknown fields.

Download or read book Multiresolution Time Domain Scheme for Electromagnetic Engineering written by Yinchao Chen and published by Wiley-Interscience. This book was released on 2005-01-28 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rapid development of computer techniques and information technologies in recent decades has fueled the need for efficient tools for electromagnetic modeling of millimeter-wave integrated circuits, high-speed and high-density VLSI circuits, including computer chips and wireless computer applications.