Particle-In-Cell Simulation of 0.108THz Folded Waveguide Traveling Wave Tubes

Folded Waveguide (FW) Traveling Wave Tubes (TWT) is a kind of high frequency, high power, and moderate bandwidth slow-wave structures. In many applications, FWTWT is a seductive choice. Such as radars, communication systems and electron counter measure. In this paper, a two-section folded waveguide at 0.108THz is designed to get 50W of average power. The structural parameters and dispersion characteristics of this folded waveguide are optimized through a detailed analysis. Influence of simulation parameters, angle dispersion, energy dispersion and roughness on output power are investigated using particle-in-cell (PIC) simulation. Analysis the phase velocity on the output power, and the results indicate that the output power can be increased by reducing the phase velocity. The simulation results shows that the maximum output power and gain are about 50W and 30dB at 0.108THz, and the bandwidth of this folded waveguide is about 10GHz, which is driven by an electron beam with operation voltage 13.2KV and current 0.08A.