New propagation models for electromagnetic waves along uniform and nonuniform cables

This paper discusses the mathematical modeling of the propagation of electromagnetic energy along nonuniform transmission lines. This electromagnetic energy can either be transmitted signals or disturbances caused by electromagnetic interference. Emphasis is laid on the basic ideas behind the transmission-line super theory and the solution of the corresponding telegrapher equations. We show how to establish these telegrapher equations for nonuniform transmission lines and how to calculate the per-unit-length parameters. Afterwards we discuss several solution methods, like numerical integration techniques and semi-analytical approaches. With selected examples we demonstrate the application of our new tools.