Calculating Coaxial Transmission-Line Step Capacitance (Correspondence)

As a frequent user of the curves given by J. R. Whinnery, H. W. Jamieson and T. E. Robbins, I found it useful to arrive at a simple polynomial in powers of /spl alpha/ and /spl tau/, which makes it possible to incorporate the step-capacitance calculation in a subroutine in a computer program dealing with transmission line calculations in coaxial lines.