Study of microwave frequency radiated from a vircator

Summary form only given. Microwave frequency radiated from a virtual cathode oscillator (vircator) is studied experimentally. The vircator diode consists of an annular cathode of diameter of 2.0-3.5 cm and 1 mm in thickness and an aluminum foil of 15 /spl mu/m in thickness. The emitted microwaves were extracted axially through a circular waveguide with a diameter of 4.5 cm and a length of 1 m, and radiated outward through a circular horn attached to the waveguide. The radiated microwave signals were picked up by an open-end rectangular waveguide antenna (WRJ-10) at the position of 1 m from the circular horn. The microwave frequency was then determined from the propagation time of the signals in a line of 105-m waveguide.