Phillip Hagar Smith (April 29, 1905–August 29, 1987) was an electrical engineer, who became famous for his invention of the Smith chart.
Smith graduated from Tufts College in 1928. While working for RCA, he invented his eponymous Smith chart. He retired from Bell Labs in 1970.
Phillip Smith invented the Smith Chart in 1939 while he was working for The Bell Telephone Laboratories. - When asked why he invented this chart, Smith explained: - :"From the time I could operate a slide rule, I've been interested in graphical representations of mathematical relationships."
In 1969 he published the book Electronic Applications of the Smith Chart: In Waveguide, Circuit, and Component Analysis, a comprehensive work on the subject.