摘要
We design and fabricate a novel electron gun and conduct an experiment using a tapered structure for the reflective gyrotron backward-wave oscillator (gyro-BWO). The electron gun and the interaction structure provide an ideal beam-wave coupling which enhances the interaction efficiency over a broad bandwidth. The cutoff section and mild tapers in the cavity region help to generate the 203 GHz waves operating at TE 02 mode with the peak power efficiency of 30% and a wide bandwidth of 8.5 GHz. Preliminary experimental results will be reported.