However, the remainder is still mathematically relevant, being used, for example, in oscillator design and stability analysis. : 93–103 The Smith chart is most frequently used at or within the unity radius region. The Smith chart can be used to simultaneously display multiple parameters including impedances, admittances, reflection coefficients, S n n scattering parameters, noise figure circles, constant gain contours and regions for unconditional stability. 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. Electrical engineers graphical calculator
