Design and Experiment of a Dielectric-Loaded Gyro-TWT With a Single Depressed Collector

A Ka -band gyrotron traveling wave tube (gyro-TWT) with a single depressed collector (SDC) has been designed, and the SDC has been experimentally verified for the first time in the tube with a dielectric-loaded circuit. The effect of reflection electrons on the output power and the movement of electrons in gyro-TWT with an SDC are also analyzed in this article. The simulation results indicate that gyro-TWT driven by a 60-kV, 10-A electron beam can achieve about 230-kW maximum peak power and 150 kW recycled power with a 15-kV depressed collector. The overall efficiency of gyro-TWT increases from 38.3% to 51.1%. The hot experiment results show that the measured maximum peak power is 155.3 kW at 31 GHz, corresponding to an average power of 15.53 kW with a 10% duty factor and 140 kW pulsed recycle power with a 14-kV depressed collector. The overall efficiency is improved from 27.1% to 33.8% and increased by 24.7%. The saturated bandwidth is 4 GHz from 27.7 to 31.7 GHz.