Equivalency Between Circuit and Field Theories for Describing Pulse Propagation in a Coaxial Cable

A detailed analysis is conducted to describe the propagation of a step pulse along a coaxial cable of circular cross section. The geometry is chosen for two reasons: its obvious practical importance, and the fact that it can be analyzed in a simple and exact manner. The propagation of electromagnetic energy along a transmission line (of which the coaxial cable is a particular example) has led to controversy which has its roots in a misunderstanding of the physical phenomenon, namely in the confusion between the velocity of propagation of a signal and the speed of conduction electrons along the line, resulting in the absurd statement that electric charges cannot exist. This erroneous conclusion has been debunked by several researchers, see e.g. [1], [2]. Nevertheless, it is instructive to revisit the issue utilizing the simple geometry considered herein, which is done in the first part of this work by examining in detain the physical phenomenon of propagation of a step pulse along the cable.