In one line: A Bell Labs radio engineer who spent most of a decade refining a better way to calculate transmission lines. He kept going through slow acceptance, until his chart became one of the most enduring tools in electrical engineering.
Core idea
Phillip Hagar Smith (1905–1987) grew up in Lexington, Massachusetts, was an active radio amateur in college, and graduated from Tufts in electrical engineering in 1928. He went straight to Bell Telephone Laboratories [1], [2].
His early work was practical and physical: matching long transmission lines to large shortwave antenna arrays for transatlantic radiotelephone service. Measuring the standing waves on those lines was laborious. One account describes a sensing coil carried along the line on a long pole while a colleague read the meter through a telescope [2]. Smith wanted a faster way to turn the measurements into answers.
How it works: the chart’s long road
- Late 1920s–early 1930s: a rectangular chart. His first graphical aid for the transmission-line equations worked, but it couldn’t cover the full range of impedances.
- 1936: a polar form. A new layout held every possible impedance, but its grid lines weren’t true circles, so it was hard to draw accurately.
- 1937: the modern chart. Suspecting that a grid of orthogonal circles would be more practical, Smith brought in two colleagues who knew conformal mapping, E. B. Ferrell and J. W. McRae. Together they arrived at essentially the chart used today.
- 1937–1939: slow acceptance. There were few technical journals and none in microwaves. The article finally appeared in Electronics in January 1939, about two years later.
- 1940s: adoption. Waveguide researchers at Bell Labs, and then the MIT Radiation Laboratory, formed in 1940, put the chart into everyday use for wartime radar work. Smith later called the Radiation Laboratory’s engineers his first customers. A 1944 article added the admittance form.
- Recognition. The first issue of Microwave Journal, in 1958, opened with a biography of Smith and a series on his chart [1]. He was named an IRE Fellow, held about twenty patents, retired from Bell Labs in 1970, and saw his charts sold by the millions.
Smith did much more than the chart:
- antennas for one of the first production radars
- a basic patent on the adjustable matching stub
- broadcast antennas
- years of committee work on technical standards
In practice: a leadership lens
- Persistence on a real problem. A colleague’s tribute, quoted in Smith’s book, put it this way: “it was to his everlasting credit that he did not allow his idea to die on the vine, but nourished it until he had brought it to a high degree of perfection” [2].
- Knowing what you don’t know. The decisive step came from asking colleagues with different mathematical expertise for help.
- Building tools for others. The chart’s value was that it let other engineers solve problems faster. Its lasting influence is the influence of a good tool, not of a position.
- Selling the idea. Even an excellent idea took years and persistent advocacy to publish and adopt.
Questions to ask yourself
- Which recurring problem in my field could a better tool or method simplify for everyone?
- Whose expertise would get me past the step I’m stuck on?
- How long am I willing to keep improving an idea that others haven’t yet recognized?
Connections
- His invention: Smith Chart. How to study a leader like him: Studying a Leader.
- Another engineer-leader profile: Bernard M. Gordon. Refinement through practice: Perfect Practice. Collaboration: Teaming.
- Capabilities exercised: Initiative, Resourcefulness, Communicating and Advocacy, Connecting Across Disciplines.
Sources
- Smith (1969) Electronic Applications of the Smith Chart [2], including the biography in the 1995 reprint
- Microwave Journal (1958-1959) Early Issues [1]