Consideration of power in a lossless transmission line

Abstract

One of the topics in an undergraduate electrical engineering curriculum in a electromagnetics or power systems course is the transmission line. When the line is modeled with the distributed parameters, the power P, delivered to the load at the end of a lossless line is usually of interest and is given by: P=1/2|V/sup +/|/R/sub 0/(1-|K/sub L/|/sup 2/) where V/sup +/ is the peak value of incident voltage, K/sub L/ is the voltage reflection coefficient at the load, and R/sub 0/ is the characteristic resistance of the line. This paper points out that the above equation is a special case of a more general equation for the power delivered to the load for a low loss line. The power delivered to a load by a low loss line is obtained from time domain and frequency domain considerations. Numerical examples are given.