Leonard M. Schwab

This paper discusses the Smith Chart, used by RF, antenna, and broadcast engineers between roughly 1940 and 1980 for the design of matching circuits. Use of the chart was time-consuming and error-prone, however, and numerical methods such as the Real Frequency Technique were widely used as alternatives when computers became more readily available. Nonetheless, the Smith Chart never lost popularity as a design tool in many European and Asian countries, and in the 1990s, several new graphics-based Smith Chart software design tools emerged on the market.

The paper provides historical background and information about related design aids and software solutions available today.