See, for instance, the input impedance equation for a load attached to a transmission line of length L and characteristic impedance Z0. Smith Charts were originally developed around 1940 by Phillip Smith as a useful tool for making the equations involved in transmission lines easier to manipulate. The Smith Chart is used to display a real antenna's impedance when measured on a Vector Network Analyzer (VNA). Smith Charts are also extremely helpful for impedance matching, as we will see. Smith Charts can be used to increase understanding of transmission lines and how they behave from an impedance viewpoint.
The Smith Chart is a fantastic tool for visualizing the impedance of a transmission line and antenna system as a function of frequency. SMITH CHART, SOLUTIONS OF PROBLEMS USING SMITH CHART
