R-band Backward Wave Oscillator based on Metamaterial Structure and Multi-electron Beams

R-band backward wave oscillator (BWO) based on metamaterial (MTMs) and Multi-electron Beams is presented as a novel high-power terahertz radiation source. We analyzed and retrieved the effective permittivity and permeability of the slow wave structure (SWS) by HFSS. And the Particle-in-cell (PIC) is performed to obtain the beam-wave interaction. Finally, the results show the radiation source can generate 65W output power with the interaction efficiency of 6% at the frequency of 230GHz on the condition of the beam voltage of 35kV and total current of 30mA.