In 1948, electrical engineers and brothers Russell H. and Sigurd F. Varian founded Varian Associates in San Carlos, California, with physicists William Webster Hansen and Edward Ginzton. The founders had worked together at the Sperry Gyroscope Company, in a group that conducted research on vacuum tubes and electronic circuitry. Varian Associates’ first product was the klystron, an electronic tube capable of generating electromagnetic waves at microwave frequencies. The Varian brothers had invented the device and created the first working prototype in 1937. In 1953, the company relocated to Palo Alto to become the first tenant of the new Stanford Research Park.