Download Free High Order On Surface Radiation Boundary Conditions In Electromagnetics Book in PDF and EPUB Free Download. You can read online High Order On Surface Radiation Boundary Conditions In Electromagnetics and write the review.

This dissertation presents procedures for implementing high order boundary conditions in time and frequency domains for solving exterior problems governed by the Helmholtz equation and the wave equation exterior to a perfectly conducting scatterer. Solving problems governed by two and three-dimensional wave equations in exterior domains is a complex task. There are techniques to reduce the computational complexities; one technique is On-Surface Radiation Boundary Conditions (OSRBC). There has been a recent interest in revisiting this technique for two and three-dimensional problems. In this research, we explore the implementation of a new high order OSRBC based on the high order local boundary conditions introduced in for two and three dimensions to solve the wave equation in exterior domains. As will be seen later, the OSRBC implementations require normal derivatives of the scattered field on the surface of the scatterer. For the two-dimensional case, we develop a Fourier spectral method based on discrete Fourier transform to find the normal derivative of the electromagnetic field on the surface of the scatterer. The method involves transforming the high order time dependent local boundary conditions to frequency-domain and implementing it on the surface of the scatterer. The normal derivative of the scattered field is needed for applications such as the calculation of the radar cross-section and the surface current. We consider the two-dimensional problem for a perfectly conducting scatterer with arbitrary cross section. The numerical implementations and their performances for a wide range of frequencies are demonstrated and compared to the frequency-domain integral equation for the scattered field. The advantage of the new method is that the On-Surface Radiation Boundary Conditions (OSRBCs) is applicable to a wide range of frequencies. A series of numerical tests demonstrate the accuracy and efficiency of these conditions to a wide range of frequencies. Both the exact solutions, as well as the high order local boundary conditions solutions, are compared. For the two and three-dimensional time dependent wave equations cases, we simulate exact solutions in a large exterior domain because explicit solutions are not available. The implementation involves a new novel approach based on bilinear transformation, which simplified the implementation process and lead to higher accuracy compared to the different types of finite difference schemes used to approximate the first and second order partial derivative in the new high order OSRBC and the auxiliary functions that define the high order boundary conditions. A series of numerical tests demonstrate the accuracy and efficiency of the new high order OSRBC for two and three-dimensional problems. Both the long domain solutions, as well as the OSRBC solutions, are compared.
The work presented in this thesis deals with the behavior of the scattered electromagnetic field on the surface of the scatterer. Namely, our goal is to find the normal derivative of the field numerically for applications such as the calculation of the radar cross-section or surface current. The phenomenon is addressed through the resolution of a wave problem with boundary conditions specified using a sequence of local operators. We consider the two dimensional problem with an arbitrary-shaped scatterer made in a material assumed perfectly conducting. At first, we introduce the main theoretical ideas and concepts that will serve our work and that have inspired it; this prceeds from the mathematical formulation of the solutions, to the solving procedures and through the expression of the boundary conditions. In a second part, a method to find exact solutions will be presented for comparison purpose. The solutions thus found will be later compared to the results obtained from our numerical procedures. These procedures are presented in detail in the third and fourth chapters, they include a brute-force method and a Laplace-transform based method. Finally, the results are presented, discussed and a statement of the method performance will be set. Figures are included to illustrate our views.
This book comprehensively describes a variety of methods for the approximate simulation of material surfaces.
Electromagnetic scattering from complex objects has been an area of in-depth research for many years. A variety of solution methodologies have been developed and utilised for the solution of ever increasingly complex problems. Among these methodologies, the subject of impedance boundary conditions has interested the authors for some time. In short, impedance boundary conditions allow one to replace a complex structure with an appropriate impedance relationship between the electric and magnetic fields on the surface of the object. This simplifies the solution of the problem considerably, allowing one to ignore the complexity of the internal structure beneath the surface. This book examines impedance boundary conditions in electromagnetics. The introductory chapter provides a presentation of the role of the impedance boundary conditions in solving practical electromagnetic problems and some historical background. One of the main objectives of this book is to present a unified and thorough discussion of this important subject. A method based on a spectral domain approach is presented to derive the Higher Order Impedance Boundary Conditions (HOIBC). The method includes all of the existing approximate boundary conditions, such as the Standard Impedence Boundary Condition, the Tensor Impedence Boundary Condition and the Generalised Impedance Boundary Conditions, as special cases. The special domain approach is applicable to complex coatings and surface treatments as well as simple dielectric coatings. The spectral domain approach is employed to determine the appropriate boundary conditions for planar dielectric coatings, chiral coatings and corregated conductors. The accuracy of the proposal boundary conditions is discussed. The approach is then extended to include the effects of curvature and is applied to curved dielectric and chiral coatings. Numerical data is presented to critically assess the accuracy of the results obtained using various forms of the impedence boundary conditions. A number of appendices that provide more detail on some of the topics addressed in the main body of the book and a selective list of references directly related to the topics addressed in this book are also included.
This is nothing less than an essential text in what is a new and growing discipline. Electromagnetic modeling and computations is expanding as a result of the steadily increasing demand for designing electrical devices, modeling electromagnetic materials, and simulating electromagnetic fields in nanoscale structures. The aim of this volume is to bring together prominent worldwide experts to review state-of-the-art developments and future trends of modeling and computations in electromagnetics.
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.
The first book of its kind to cover a wide range of computational methods for electromagnetic phenomena, from atomistic to continuum scales, this integrated and balanced treatment of mathematical formulations, algorithms and the underlying physics enables us to engage in innovative and advanced interdisciplinary computational research.
Electromagnetic Radiation, Scattering, and Diffraction Discover a graduate-level text for students specializing in electromagnetic wave radiation, scattering, and diffraction for engineering applications In Electromagnetic Radiation, Scattering and Diffraction, distinguished authors Drs. Prabhakar H. Pathak and Robert J. Burkholder deliver a thorough exploration of the behavior of electromagnetic fields in radiation, scattering, and guided wave environments. The book tackles its subject from first principles and includes coverage of low and high frequencies. It stresses physical interpretations of the electromagnetic wave phenomena along with their underlying mathematics. The authors emphasize fundamental principles and provide numerous examples to illustrate the concepts contained within. Students with a limited undergraduate electromagnetic background will rapidly and systematically advance their understanding of electromagnetic wave theory until they can complete useful and important graduate-level work on electromagnetic wave problems. Electromagnetic Radiation, Scattering and Diffraction also serves as a practical companion for students trying to simulate problems with commercial EM software and trying to better interpret their results. Readers will also benefit from the breadth and depth of topics, such as: Basic equations governing all electromagnetic (EM) phenomena at macroscopic scales are presented systematically. Stationary and relativistic moving boundary conditions are developed. Waves in planar multilayered isotropic and anisotropic media are analyzed. EM theorems are introduced and applied to a variety of useful antenna problems. Modal techniques are presented for analyzing guided wave and periodic structures. Potential theory and Green's function methods are developed to treat interior and exterior EM problems. Asymptotic High Frequency methods are developed for evaluating radiation Integrals to extract ray fields. Edge and surface diffracted ray fields, as well as surface, leaky and lateral wave fields are obtained. A collective ray analysis for finite conformal antenna phased arrays is developed. EM beams are introduced and provide useful basis functions. Integral equations and their numerical solutions via the method of moments are developed. The fast multipole method is presented. Low frequency breakdown is studied. Characteristic modes are discussed. Perfect for graduate students studying electromagnetic theory, Electromagnetic Radiation, Scattering, and Diffraction is an invaluable resource for professional electromagnetic engineers and researchers working in this area.
This book focuses on computational methods to determine the dynamics of large-scale electromagnetic, acoustic, and mechanical systems, including those with many substructures and characterized by an extended range of scales. Examples include large naval and maritime vessels, aerospace vehicles, and densely packed microelectronic and optical integrated circuits (VLSI). The interplay of time and frequency-domain computational and experimental procedures was addressed, emphasizing their relationship and synergy, and indicating mathematics research opportunities.