The 3D Smith Chart: From Theory to Experimental Reality

The Smith chart was primarily developed, extended, and refined by Phillip Hagar Smith [1] in a series of works published [2]-[4] between 1939 and 1969. Smith was born in Lexington, Massachusetts, in 1905. He majored in electrical communications at Tufts University and joined the Radio Research Department of Bell Telephone Laboratories (now Bell Labs) in 1928. While there, in around 1930, Smith started work on the diagram that was to become the Smith chart. He submitted the initial version to Electronics Magazine in 1937; the magazine finally published his diagram in 1939 [2]. The MIT Radiation Laboratory started using the chart. In 1940, and in 1944 Smith published a second article that incorporated further improvements, including the use of the chart with either impedance or admittance coordinates. In 1952, Smith was elevated to IEEE Fellow for his contributions to the development of antennas and the graphical analysis of transmission-line characteristics. The first issue of Microwave Journal (1958) published a biography of Smith to acknowledge the importance of his contributions. In 1969, he wrote the book Electronic Applications of the Smith Chart in Waveguide, Circuit and Component Analysis; he retired from Bell Labs in 1970. In 1975, he received the IEEE Microwave Theory and Techniques Society?s Special Recognition in Microwave Applications award for the Smith chart, and in 1994 he was elected to the New Jersey Inventors Hall of Fame.