Two-Stage 0.34 THz Sine Waveguide Slow Wave Structure

Considering the feasibility of manufacturing 0.34THz traveling wave tube (TWT), this paper proposes a new two-seg-ment sine waveguide slow-wave structure (SWS). Unlike the con-ventional sine wave waveguide, a round beam tunnel is used in this modified structure. In order to increase the output power while reducing the impact of reflected signal, this structure adopts the two-stage structure and the phase velocity jump technology. Attenuators are considered here to absorb the reflected signal in the new SWS. The simulation results show that the new structure has the advantages of machinability, wide bandwidth and high gain. Through PIC simulation, for a 54 mm long slow-wave circuit, with an input power of 8 mw, the gain of the new structure is greater than 31 dB and the output power is above 10W in the 0.325-0.355 GHz frequency range.