Chapter 7 - Transmission Line Modeling Method

Abstract

The relationship between electromagnetic field quantities and voltage and current on transmission lines is well-known. This relationship has been used in solving the electromagnetic (EM) problems. These principles are used along with the theory of pulse propagation on transmission lines to develop a numerical technique compatible with computational techniques for the solution of two-dimensional electromagnetic problems. This method was called the transmission line matrix method and is now called the transmission line modeling (TLM) method. This method is used for many applications such as the analysis of various waveguides, calculation of induced surface currents on objects due to an incident electromagnetic pulse, and radar cross-sections due to plane wave incidence. The TLM method provides a reliable numerical procedure to analyze a wide variety of electromagnetic problems. The TLM method allows one to model arbitrary geometries that may be composed of anisotropic inhomogeneous materials. This method is not limited by the frequency of interest, but only by the available computer resources. The chapter discusses the TLM starting at a basic level to outline the fundamental TLM concepts. This is followed by more advanced topics and listing of numerous references for readers desiring more in-depth details. The chapter aims to enable the reader with a basic understanding of field theory and transmission line concepts to be able to not only understand the TLM method, but also to develop a working TLM algorithm and work on physical problems.