Design of a two-beam folded waveguide traveling-wave tube with Phase Shift section

A two-beam folded waveguide traveling wave tube, working at 94GHz, operating at fundamental mode (TE₁₀) is designed and optimized. High frequency characteristics are analyzed. The saturated output power of two-beam FWTWT is about 2.5 times of single-beam FWTWT under the same operating voltage and current simulated by MAGIC3D software. That is the interaction efficiency is increased by 1.25 times. The saturated circuit length is reduced from 55periods to 49 periods which is reduced about 6 periods. A method of adding Phase Shift section is proposed to increase output power. The saturated output power is increased by 28.6% from 150W to 193W through adding Phase Shift section.