Ronold Wyeth Percival King (September 19, 1905 – April 10, 2006) was an American applied physicist, known for his contributions to the theory and application of microwave antennas. He published twelve books and over three hundred articles in his area, as well as mentored one hundred doctoral dissertations.
Born in Williamstown, Massachusetts, he moved to Rochester, New York, where his father worked as a professor of German. He earned an A.B. (1927) and S.M. (1929) degree in physics from the University of Rochester. He was an exchange student at the University of Munich (1928-29) and attended Cornell University (1929-30), before completing his graduate studies at University of Wisconsin–Madison (1932) where he obtained a Ph.D. on the thesis Characteristics of Vacuum Tube Circuits Having Distributed Constants at Ultra-Radio Frequencies advised by Edward Bennett and subsequently was a research assistant (1932-34).
King was an instructor and assistant professor in physics at Lafayette College (1934-37), and a Guggenheim Fellow overseas (1937, 1958). He joined Harvard University as an instructor (1938), as assistant professor (1939), associate (1942), and as Gordon McKay Professor of Applied Physics (1946-72, taken over by his former student Tai Tsun Wu), and professor emeritus (1972). He resided at Winchester, Massachusetts, and wrote the autobiography A Man of the 20th Century.
His research group at Harvard spent the 1940s and 1950s developing the theory of antenna (radio), using the cylindrical antenna as a boundary value problem subject to Maxwell's equations. Also, scattering and diffraction of electromagnetic waves from spheres, cylinders, strips, and disks, conducted within earth, under water or in tissue. King is responsible for the inverted-F antenna, the most widely used antenna in mobile phones. However, he did not develop this antenna for that purpose. Rather the intended use was missile telemetry.