Experimental study on quasi-TE mode radiation from a high power backward wave oscillator

The dispersion relation of quasi-TEls modes in sinusoidally corrugated meta l wall slow wave structure with an annular electron beam is derived and ana lyzed numerically. Results of the numerical analysis for quasi-TE11 mode an d conventional TM01 mode are compared with experimental results. TE11 mode in addition to TM01 mode microwave oscillation is observed near 2 pi mode r egion of operation. It is confirmed that oscillation property of both modes agree fairly well with numerically predicted values. The study of quasi-TE mode oscillation is required for an optimum design of a high power backwar d wave oscillator that works in a single frequency over a wide range of ope rating conditions.