My question is to what extent are the below quantities still used by present-day microwave engineers? The reflection and transmission coefficients are fundamental, and VSWR and return loss are commonly cited as figures of merit. Some of them are easy to understand, others I had decipher from scans of Smith's 1944 paper. (Note: using MathJax, make sure your browser is compatible) I was curious about the 'radially scaled parameters' part of printed Smith charts that have several scales printed in nomographic form.