Simulation study of D-band extended interaction klystron amplifier

A D-band extended interaction klystron amplifier is investigated. A traveling wave structure is adopted as the input and output structure to improve the bandwidth. When the operating voltage is 22 kV, and current is 0.3 A. The simulation results show that a maximum output power of 450 W is obtained with the input power of 31.25 mW, the corresponding gain is 41.5 dB, efficiency is 6.8%, and a 3-dB bandwidth of about 600 MHz can be achieved. Our work provides a feasible method to the improvement of bandwidth for the extended interaction klystron amplifier.