Design of Large Orbit Gyro-TWT RF Window at Ka-Band

In this article, in order to improve the transmission capacity and power capacity of the gyrotron traveling-wave tube (gyro-TWT) RF window, the RF window for a large orbit gyro-TWT in TE21-mode at Ka-band is studied by two aspects from structure design and thermal analysis. The double disk window working for TE21-mode at Ka-band is designed by transmission cascade matrix through the method of field matching theory. The results of theory analysis, simulation, and experiment are consistent, achieving a frequency bandwidth of VSWR below 1.3 of 4 GHz for this window. Thermal analysis result shows that when the average power of gyro-TWT is 10 kW, the maximum central temperature of the window is 54.186 degree celsius and the critical temperature difference is 29.581 degree celsius, and combined with the maximum of the critical temperature difference of sapphire concludes that the power capacity is 50 kW.