Phillip H. Smith

Phillip H. Smith (April 29, 1905 – August 29, 1987) was an American electrical engineer who made significant contributions to the field of RF engineering. He is primarily known for his work on transmission line theory and impedance matching. Smith's research in the 1930s while working at Bell Labs led to the development of the Smith Chart, which is a graphical representation of complex impedance values.

The Smith Chart is a polar plot that helps engineers analyze and design RF circuits, such as impedance matching networks and transmission lines. It provides a visual representation of impedance and reflection coefficient values, allowing engineers to easily determine the impedance characteristics of a system and make necessary adjustments to optimize performance.

The Smith Chart has become an essential tool in RF engineering, and it is widely used in various applications, including antenna design, RF filter design, and microwave circuit design. It simplifies calculations and provides a intuitive way to understand and manipulate complex impedance values.

Here is "The Oral History: Phillip H. Smith," and interview by Engineering and Technology History Wiki. This January 1939 issue of Electronics magazine might be the first appearance of the most recognized version of the Smith Chart.