Design of a Coherent Smith-Purcell Superradiation Source at W-band

When the surface wave interacts with the electron beam, the group gathers to form the periodic electron beam group, and radiates the frequency doubling signal of the surface wave, namely the so-called “coherent”. In this paper, a coherent Smith-Purcell superradiation (SPR) source at W-band is proposed. By using cylindrical periodic metal gratings with period of 1.03 mm and groove depth of 0.857mm, and a hollow pulsed electron beam with voltage of 18.4kV, repetition frequency of 47GHz, the radiation power reaches 2W at 93.784GHz. The result shows that the triple-mirror quasi-optical cavity plays a very important role in the resonance and energy feedback of coherent SPR. The system provides a new way for the development of tunable terahertz radiation sources.