A Novel Low Loss Sawtooth Slow Wave Structure for 0.66-THz Traveling Wave Tubes

A novel low loss sawtooth (ST) slow wave structure (SWS) is proposed as a solution to the challenges presented by terahertz (THz) traveling wave tubes (TWTs), known for their machining difficulty and insertion loss. Compared with folded waveguide (FWG) SWS, the ST SWS is easier to machine and takes a 44.96% lower insertion loss. Driven by a pencil beam (PB) gun of 19.0 kV, 15.0 mA, and an input power of 1 mW, the comparative output performance of the ST circuit and FWG circuit is evaluated using the particle-in-cell (PIC) method. The ST circuit shows enhancement in both the maximum output power and 3-dB bandwidth, which improved by 13.21% and 42.86%, respectively.