Introduction of Reflection and Transmission Coefficients for Nonuniform Radiating Transmission Lines

In the framework of a high-frequency transmission-line theory for nonuniform lines (TLST), new reflection and transmission coefficients are derived using generalized definitions of equivalent quantities from the classical transmission-line theory. This leads to local and frequency-dependent reflection and transmission coefficients expressed in terms of matrizant elements. These quantities are needed to describe networks of nonuniform radiating transmission lines. A comparison between the currents calculated in the approach of TLST and those calculated with the aid of the new transmission and reflection coefficients shows an excellent agreement.

I. Introduction

Conductors play an important role in electrical engineering. They constitute one of the main parts in every electrical and electronic system. Wanted signals are transmitted between devices and electronic components via conductors, and in many cases, they are also integrators for interfering (unwanted) signals. Therefore, from the EMC point of view, it is essential to understand electromagnetic coupling processes to multiconductor transmission lines (TLs). This analysis is needed for the purpose of assessing and protecting an electrical system against inadvertent and intentional coupling. At a fist glance, one may argue that the tools to handle this problem already exist: the classical transmission-line theory (cTLT) (see[1], [2], and references given therein).