Flatted Grating Folded Waveguide Slow Wave Structure for 0.2 THz Traveling Wave Tube
Jingrui Duan, Zhigang Lu, Peng Gao, Zhenting Zheng, Zechuan Wang, Yuan Zheng, Zhanliang Wang, Shaomeng Wang, Huarong Gong, Yubin Gong
Abstract
A novel slow wave structure (SWS), flatted grating folded waveguide (FGFW), has been proposed for terahertz (THz) traveling wave tubes (TWTs). Compared to a conventional folded waveguide (FW), FGFW provides a wider operating bandwidth, lower ohmic loss, and a stronger longitudinal electric field, resulting in a higher interaction impedance. Further, the beam-wave interaction results verified that driven by a sheet beam with a voltage of 18 600 V and a current of 0.08 A, FGFW-TWT can be achieved with a gain of up to 26.0 dB at 190 GHz, as well as the maximum output power of 126.7 W at 203 GHz. Moreover, the bandwidth, saturated power, gain, and electron efficiency of FGFW-TWT have been significantly improved over those of FW-TWT. Meanwhile, the good transmission characteristics for FGFW-SWS have been experimentally evidenced.