A Rectangular Corrugated KU-Band BWO With Dual Resonator

A Ku-band backward wave oscillator (BWO) with a sheet- beam source and dual prebunch resonating cavity is presented in this paper. The design presented in this paper couples a rectangular grated dual-sided slow wave structure (SWS) with two pairs of resonating cavities to improve the efficiency of the device. The rectangular grated SWS offers the benefit of a high coupling impedance to provide high beam-wave interaction efficiency. A sheet beam electron source of large aspect ratio is used, with the dimensions of 24.5mm width and 1mm thickness. With the properly sized reflector resonators, the BWO is shown to have an output of 340MW, with a peak efficiency of up to 34.55% at the operating frequency of 14.21GHz. The output mode is TE
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, with mode efficiency of 93.7%. The input current is 4.1 kA and the input beam energy is 240kV.