Investigation of Circular Comb Slow-Wave Structure of THz Backward-Wave Oscillators
THz返波管圆波导梳状慢波结构的研究

3-D electromagnetic simulation software is used to calculate the dispersion and interaction impedance of circular comb Slow-Wave Structure (SWS) which works for Terahertz (THz) Backward-wave Oscillators (BWO). The results show that the inner radius of SWS is 0.175mm in the band of 430-570GHz, and the inner radius of SWS is 0.1mm in the band of 760-940GHz. The large radius of SWS is a great help for improving beam transmission. The interaction impedance of fundamental backward wave of the SWS is smaller than 1 is a good explain to the truth that the electronic efficiency of THz BWO is smaller than 0.01%.