Most of you have probably heard of the Smith chart. The intimidating graph, developed by Philip Smith in 1939, is just about as bad as it looks. How he came up with this is an untold story, but he provided a solution to the complex calculations on transmission lines. And as you will find out, it’s useful for working out transmission-line problems and in designing impedance-matching circuits. If you have avoided the Smith chart in the past, here’s a primer on how to take advantage of it.