Research on Folded Double-Groove Waveguide With Two Sheet Beams Operating on High-Order TE20 Mode for High-Power Terahertz TWT

In this article, a folded waveguide with two coupling grooves is proposed for high-power and high-frequency traveling wave tubes (TWTs). The structure allows a modified TE20 high-order mode interact with two sheet electron beams. The transmission characteristics of this novel structure were simulated and measured. A good
${S}_{{21}}$
of −10 dB and
${S}_{{11}}$
of less than −15 dB were achieved in the 218–230-GHz range. Moreover, simulations of the beam–wave interaction in this structure predicted an output power of 930 W at 220 GHz, with a small signal gain of 58 dB and a 3-dB bandwidth of 1.3 GHz.