Microwave System for Input-Output Radiation of the Two-Cascade Gyro-TWT at 3-mm Wavelength

The paper presents the results of calculations of the output microwave systems of broadband gyro-TWTs of the 3 mm wavelength range united in the common cascade. To achieve a high output power (300 kW), it is proposed to use a cascade of two gyro-TWTs, the first of which has a relatively high gain (40-60 dB), and the second has a high output power with a moderate gain (15-20 dB). The radiation output of the first stage is performed along the axis of the tube through the waveguide depressed collector. The microwave system of the second stage has a transverse radiation input-output through a single barrier window with the signal separation by their polarizations. The transformation of wave fields is carried out by waveguide converters and a system of external quasi-optical mirrors. The calculated efficiency of the output system in the frequency range 90-100 GHz exceeds 95%. The paper compares the methods and approaches used to model the microwave systems.