TechXchange Topics - Markets - Automotive - Technologies - Test & Measurement Components Cellular / 5G / 6G EDA. The Smith chart can be used to simultaneously display multiple parameters including impedances, admittances, reflection coefficients, S n n ) is fixed. Impedance Matching Basics: Smith Charts Microwaves & RF. While Smith had originally called it a ' transmission line chart' and other authors first used names like ' reflection chart', ' circle diagram of impedance', ' immittance chart' or ' Z-plane chart', early adopters at MIT's Radiation Laboratory started to refer to it simply as ' Smith chart' in the 1940s, a name generally accepted in the Western world by 1950. McRae, who were familiar with conformal mappings, was reworked into the final form in early 1937, which was eventually published in January 1939. Starting with a rectangular diagram, Smith had developed a special polar coordinate chart by 1936, which, with the input of his colleagues Enoch B. It was independently proposed by Tōsaku Mizuhashi ( 水橋東作) in 1937, and by Amiel R. The Smith chart (sometimes also called Smith diagram, Mizuhashi chart ( 水橋チャート), Mizuhashi–Smith chart ( 水橋スミスチャート), Volpert–Smith chart ( Диаграмма Вольперта-Смита) or Mizuhashi–Volpert–Smith chart), is a graphical calculator or nomogram designed for electrical and electronics engineers specializing in radio frequency (RF) engineering to assist in solving problems with transmission lines and matching circuits. For the similar term Volpert graph, see Volpert graph (disambiguation).