A single control electrostatic focus back-ward wave oscillator for X-band operation

This paper describes an X-band backward wave oscillator using the electrostatic focus principle applied to an interdigital line as described by Hergenrother and Bowers last year. The tube operates over the frequency range of 8.5 to 9.6 kmc with a minimum power output of 20 milliwatts and can be voltage tuned by altering a single electrode voltage. The tube is of metal and ceramic construction and has a waveguide output projecting from its side which may be used for supporting the tube. The use of electrostatic focus has permitted a weight reduction of 75% over a corresponding magnetic focus tube resulting in a net weight of lbs. The design of the interdigital line will be described and performance data curves for the tube will be presented.