Design of a W-band gyro-TWT

The design of a W-band gyrotron-travelling-wave tube (gyro-TWT) operating in the circular TE₀₁ mode at fundamental cyclotron harmonic are presented. A dielectric-loaded structure is adopted in the interaction circuit of the gyro-TWT to suppress spurious modes TE₁₁ and TE₂₁. A saturated peak power of 180 kW is simulated with saturated gain of 62 dB, efficiency of 28.5% in operating voltage 70kV, electron beam current 9A and bandwidth of 5 GHz (~7%).