Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722235819
Category :
Languages : en
Pages : 30
Get Book Here
Book Description
Surface impedance boundary conditions are employed to reduce the solution volume during the analysis of scattering from lossy dielectric objects. In the finite difference solution, they also can be utilized to avoid using small cells, made necessary by shorter wavelengths in conducting media throughout the solution volume. The standard approach is to approximate the surface impedance over a very small bandwidth by its value at the center frequency, and then use that result in the boundary condition. Here, two implementations of the surface impedance boundary condition are presented. One implementation is a constant surface impedance boundary condition and the other is a dispersive surface impedance boundary condition that is applicable over a very large frequency bandwidth and over a large range of conductivities. Frequency domain results are presented in one dimension for two conductivity values and are compared with exact results. Scattering width results from an infinite square cylinder are presented as a two dimensional demonstration. Extensions to three dimensions should be straightforward. Beggs, John H. and Luebbers, Raymond J. and Yee, Kane S. and Kunz, Karl S. Unspecified Center NAG1-1350; NAG1-1332; NAG1-1221...
Author: Sunitha Chandra
Publisher:
ISBN:
Category : Boundary value problems
Languages : en
Pages : 60
Get Book Here
Book Description
"This thesis consists of two sections. In Section 1, an efficient implementation of a surface impedance boundary condition in the Finite Difference Time Domain method is introduced. This algorithm is implemented in FDTD to include skin effect loss due to the finite conductivity of good conductors. Two test cases are simulated to show the effect of skin effect loss in good conductors. In Section 2, a full-wave FDTD model for the estimation of EMI due to the gaps in the ground plane is compared with a SPICE model. It is also shown that circuit signal quantities fairly accurately"--Abstract, leaf iii.
Author: Sergey V. Yuferev
Publisher: CRC Press
ISBN: 1420044907
Category : Technology & Engineering
Languages : en
Pages : 412
Get Book Here
Book Description
Surface Impedance Boundary Conditions is perhaps the first effort to formalize the concept of SIBC or to extend it to higher orders by providing a comprehensive, consistent, and thorough approach to the subject. The product of nearly 12 years of research on surface impedance, this book takes the mystery out of the largely overlooked SIBC. It provides an understanding that will help practitioners select, use, and develop these efficient modeling tools for their own applications. Use of SIBC has often been viewed as an esoteric issue, and they have been applied in a very limited way, incorporated in computation as an ad hoc means of simplifying the treatment for specific problems. Apply a Surface Impedance "Toolbox" to Develop SIBCs for Any Application The book not only outlines the need for SIBC but also offers a simple, systematic method for constructing SIBC of any order based on a perturbation approach. The formulation of the SIBC within common numerical techniques—such as the boundary integral equations method, the finite element method, and the finite difference method—is discussed in detail and elucidated with specific examples. Since SIBC are often shunned because their implementation usually requires extensive modification of existing software, the authors have mitigated this problem by developing SIBCs, which can be incorporated within existing software without system modification. The authors also present: Conditions of applicability, and errors to be expected from SIBC inclusion Analysis of theoretical arguments and mathematical relationships Well-known numerical techniques and formulations of SIBC A practical set of guidelines for evaluating SIBC feasibility and maximum errors their use will produce A careful mix of theory and practical aspects, this is an excellent tool to help anyone acquire a solid grasp of SIBC and maximize their implementation potential.
Author: Stephen Gedney
Publisher: Springer Nature
ISBN: 3031017129
Category : Technology & Engineering
Languages : en
Pages : 242
Get Book Here
Book Description
Introduction to the Finite-Difference Time-Domain (FDTD) Method for Electromagnetics provides a comprehensive tutorial of the most widely used method for solving Maxwell's equations -- the Finite Difference Time-Domain Method. This book is an essential guide for students, researchers, and professional engineers who want to gain a fundamental knowledge of the FDTD method. It can accompany an undergraduate or entry-level graduate course or be used for self-study. The book provides all the background required to either research or apply the FDTD method for the solution of Maxwell's equations to practical problems in engineering and science. Introduction to the Finite-Difference Time-Domain (FDTD) Method for Electromagnetics guides the reader through the foundational theory of the FDTD method starting with the one-dimensional transmission-line problem and then progressing to the solution of Maxwell's equations in three dimensions. It also provides step by step guides to modeling physical sources, lumped-circuit components, absorbing boundary conditions, perfectly matched layer absorbers, and sub-cell structures. Post processing methods such as network parameter extraction and far-field transformations are also detailed. Efficient implementations of the FDTD method in a high level language are also provided. Table of Contents: Introduction / 1D FDTD Modeling of the Transmission Line Equations / Yee Algorithm for Maxwell's Equations / Source Excitations / Absorbing Boundary Conditions / The Perfectly Matched Layer (PML) Absorbing Medium / Subcell Modeling / Post Processing
Author: Karl S. Kunz
Publisher: Routledge
ISBN: 1351410474
Category : Science
Languages : en
Pages : 466
Get Book Here
Book Description
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.
Author: Jiayuan Fang
Publisher:
ISBN:
Category :
Languages : en
Pages : 372
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1572
Get Book Here
Book Description
Author: Saad Bashir
Publisher: BoD – Books on Demand
ISBN: 9535122053
Category : Technology & Engineering
Languages : en
Pages : 280
Get Book Here
Book Description
This book endeavors to give the reader a strong base in the advanced theory of electromagnetic waves and its applications, while keeping pace with research in various other disciplines that apply electrostatics/electrodynamics theory. The treatment is highly mathematical, which tends to obscure the principles involved.
Author: Yang Hao
Publisher: Artech House
ISBN: 1596931604
Category : Technology & Engineering
Languages : en
Pages : 395
Get Book Here
Book Description
Master powerful new modeling tools that let you quantify and represent metamaterial properties with never-before accuracy. This first-of-its-kind book brings you up to speed on breakthrough finite-difference time-domain techniques for modeling metamaterial characteristics and behaviors in electromagnetic systems. This practical resource comes complete with sample FDTD scripts to help you pave the way to new metamaterial applications and advances in antenna, microwave, and optics engineering. You get in-depth coverage of state-of-the-art FDTD modeling techniques and applications for electromagnetic bandgap (EBG) structures, left-handed metamaterials (LHMs), wire medium, metamaterials for optics, and other practical metamaterials. You find steps for computing dispersion diagrams, dealing with material dispersion properties, and verifying the left-handedness. Moreover, this comprehensive volume offers guidance for handling the unique properties possessed by metamaterials, including how to define material parameters, characterize the interface of metamaterial slabs, and quantify their spatial as well as frequency dispersion characteristics. The book also presents conformal and dispersive FDTD modeling of electromagnetic cloaks, perfect lens, and plasmonic waveguides, as well as other novel antenna, microwave, and optical applications. Over 190 illustrations support key topics throughout the book.
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages :
Get Book Here
Book Description
