An Iterative Truncation Method For Unbounded Electromagnetic Problems Using Varying Order Finite Elements

Abstract: It is important to use appropriate mesh truncation schemes and accurate absorbing boundary conditions (ABC) on the truncation surfaces to achieve reliable computational results while solving electromagnetic radiation and scattering problems in unbounded regions with the finite element method (FEM). In this study, a new set of higher order absorbing boundary conditions is derived and a novel method for their true synunetric implementation is proposed. The performance of the ABCs is validated through several numerical experiments conducted.

A new edition of the leading textbook on the finite element method, incorporating major advancements and further applications in the field of electromagnetics The finite element method (FEM) is a powerful simulation technique used to solve boundary-value problems in a variety of engineering circumstances. It has been widely used for analysis of electromagnetic fields in antennas, radar scattering, RF and microwave engineering, high-speed/high-frequency circuits, wireless communication, electromagnetic compatibility, photonics, remote sensing, biomedical engineering, and space exploration. The Finite Element Method in Electromagnetics, Third Edition explains the method’s processes and techniques in careful, meticulous prose and covers not only essential finite element method theory, but also its latest developments and applications—giving engineers a methodical way to quickly master this very powerful numerical technique for solving practical, often complicated, electromagnetic problems. Featuring over thirty percent new material, the third edition of this essential and comprehensive text now includes: A wider range of applications, including antennas, phased arrays, electric machines, high-frequency circuits, and crystal photonics The finite element analysis of wave propagation, scattering, and radiation in periodic structures The time-domain finite element method for analysis of wideband antennas and transient electromagnetic phenomena Novel domain decomposition techniques for parallel computation and efficient simulation of large-scale problems, such as phased-array antennas and photonic crystals Along with a great many examples, The Finite Element Method in Electromagnetics is an ideal book for engineering students as well as for professionals in the field.

A novel computational procedure called the scaled boundary finite-element method is described which combines the advantages of the finite-element and boundary-element methods : Of the finite-element method that no fundamental solution is required and thus expanding the scope of application, for instance to anisotropic material without an increase in complexity and that singular integrals are avoided and that symmetry of the results is automatically satisfied. Of the boundary-element method that the spatial dimension is reduced by one as only the boundary is discretized with surface finite elements, reducing the data preparation and computational efforts, that the boundary conditions at infinity are satisfied exactly and that no approximation other than that of the surface finite elements on the boundary is introduced. In addition, the scaled boundary finite-element method presents appealing features of its own : an analytical solution inside the domain is achieved, permitting for instance accurate stress intensity factors to be determined directly and no spatial discretization of certain free and fixed boundaries and interfaces between different materials is required. In addition, the scaled boundary finite-element method combines the advantages of the analytical and numerical approaches. In the directions parallel to the boundary, where the behaviour is, in general, smooth, the weighted-residual approximation of finite elements applies, leading to convergence in the finite-element sense. In the third (radial) direction, the procedure is analytical, permitting e.g. stress-intensity factors to be determined directly based on their definition or the boundary conditions at infinity to be satisfied exactly. In a nutshell, the scaled boundary finite-element method is a semi-analytical fundamental-solution-less boundary-element method based on finite elements. The best of both worlds is achieved in two ways: with respect to the analytical and numerical methods and with respect to the finite-element and boundary-element methods within the numerical procedures. The book serves two goals: Part I is an elementary text, without any prerequisites, a primer, but which using a simple model problem still covers all aspects of the method and Part II presents a detailed derivation of the general case of statics, elastodynamics and diffusion.

Novel Technologies for Microwave and Millimeter-Wave Applications provides an overview of current research status in selected field, to facilitate a learning process from concepts to practices, from component design to system architecture, and from small scale to large scale. Each chapter focuses on a topic and is organized to be self-sufficient. Contents in each chapter include concise description of relevant background information, major issues, current trend and future challenges. Useful references are also listed for further reading. Novel Technologies for Microwave and Millimeter-Wave Applications is suitable as a textbook for senior or graduate courses in microwave engineering.

This book contains papers presented at the International Symposium on Elect- magnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF’07 which was held in Prague, the Czech Republic, from September 13 to 15, 2007. ISEF conferences have been organized since 1985 and from the very beginning it was a common initiative of Polish and other European researchers who have dealt with electromagnetic ?eld in electrical engineering. The conference travels through Europe and is organized in various academic centres. Relatively often, it was held in some Polish city as the initiative was on the part of Polish scientists. Now ISEF is much more international and successive events take place in different European academic centres renowned for electromagnetic research. This time it was Prague, famous for its beauty and historical background, as it is the place where many c- tures mingle. The venue of the conference was the historical building of Charles University, placed just in the centre of Prague. The Technical University of Prague, in turn, constituted the logistic centre of the conference. It is the tradition of the ISEF meetings that they try to tackle quite a vast area of computational and applied electromagnetics. Moreover, the ISEF symposia aim at combining theory and practice; therefore the majority of papers are deeply rooted in engineering problems, being simultaneously of a high theoretical level.

A new method of modeling electromagnetic waves by the finite element method is presented. The method is based on a numerical formulation in which different orders of polynomials are used to approximate the three different components of either the electric or the magnetic field vectors. It provides a reliable procedure for the finite element solution of three-dimensional electromagnetic field problems. Heretofore, such solutions were plagued by the presence of spurious modes. The new method is applied to the analysis of fields in resonant electromagnetic cavities. Keywords: Bistatic scattering; Finite element analysis; Cloning; Measurements.

This book is a self-contained, programming-oriented and learner-centered book on finite element method (FEM), with special emphasis given to developing MATLAB® programs for numerical modeling of electromagnetic boundary value problems. It provides a deep understanding and intuition of FEM programming by means of step-by-step MATLAB® programs with detailed descriptions, and eventually enabling the readers to modify, adapt and apply the provided programs and formulations to develop FEM codes for similar problems through various exercises. It starts with simple one-dimensional static and time-harmonic problems and extends the developed theory to more complex two- or three-dimensional problems. It supplies sufficient theoretical background on the topic, and it thoroughly covers all phases (pre-processing, main body and post-processing) in FEM. FEM formulations are obtained for boundary value problems governed by a partial differential equation that is expressed in terms of a generic unknown function, and then, these formulations are specialized to various electromagnetic applications together with a post-processing phase. Since the method is mostly described in a general context, readers from other disciplines can also use this book and easily adapt the provided codes to their engineering problems. After forming a solid background on the fundamentals of FEM by means of canonical problems, readers are guided to more advanced applications of FEM in electromagnetics through a survey chapter at the end of the book. Offers a self-contained and easy-to-understand introduction to the theory and programming of finite element method. Covers various applications in the field of static and time-harmonic electromagnetics. Includes one-, two- and three-dimensional finite element codes in MATLAB®. Enables readers to develop finite element programming skills through various MATLAB® codes and exercises. Promotes self-directed learning skills and provides an effective instruction tool.