Philip Smith


Philip Smith
Lexington, MA, USA
Death date
Associated organizations
Bell Labs
Fields of study


Philip Smith, radar developer and inventor of the Smith Chart, was born in Lexington, Massachusetts on 29 April 1905. He grew up on a farm in Lexington and was educated in the town’s public schools. As a teenager, Smith put together an amateur radio station with many homemade parts and even contributed a number of short articles to the radio section of the Boston Traveler. This intense interest in radio left little doubt in Smith’s mind that he wanted an electrical engineering career. Unfortunately, his other subjects, such as History and French suffered, and Smith had to spend an extra year studying to pass his college entrance exams.

The studying paid off and Smith attended Tufts College (now Tufts University), where he was an active amateur radio operator. He graduated in 1928 with a degree in electrical engineering. That same year he joined the technical staff of the Radio Research Department of Bell Telephone Laboratories in New Jersey where he would work for over 40 years.

During his tenure at Bell Labs, Smith was involved in many different types of research. These included the design and installation of directional antenna equipment for commercial AM radio broadcasting, early microwave radar antenna developments for submarine use, FM broadcasting antenna design, and military weapon radar systems. He also supervised groups responsible for the electrical design of the Distant Early Warning (DEW) Line, the Nike-Zeus missile, and an anti-ballistic-missile program for the U. S government that became known as Safeguard. However, Smith remains most well known for developing the Smith Chart, a kind of engineers’ play chart for microwaves.

After a long, illustrious career, Smith retired from Bell Labs in 1970 and formed his own company, Analog Instruments, which merchandised navigational instruments for light aircraft and later supplied Smith Charts and chart-related items. By 1975 Smith had sold about 9 million copies of his chart to microwave engineers all over the world. Even though computers are now the dominant design tool, the Smith Chart remains vital to the field of microwaves. Its usefulness continues to this day as a method of displaying measured and calculated data produced by computer software and modern measurement instruments.

Smith joined the IRE in 1930, and was elevated to fellow of the IRE in 1952 for his "contributions to the development of antennas and graphical analysis of transmission line characteristics." and a special award from the IEEE Microwave Theory and Techniques Society for the development of the Smith Chart.

Smith passed away on 29 August 1987.

Further Reading

Philip H. Smith Oral History