Electromagnetic effects on transmission lines

by David A. Larrabee

East Stroudsburg University

Abstract

Electromagnetic fields can generate interference on intersystem wiring and cabling. Often this interconnection is in the form of cables and other forms of transmission lines. The simplest model for the system interconnections is a two wire transmission line. Even such a simple case is complex when the wavelength approaches the spacing between the conductors. In such a case one needs to use the full set of Maxwell's equations. Such calculations are computationally expensive.

The general solution to this problem provides more information than is needed. A simpler approach is to compute the resonant frequency amplitudes using a modified transmission line model which includes a radiation resistance term. We compare such an approach with solutions obtained from a Maxwell equation solver and discuss the implications for the design engineer.