Analysis and Suppression of the Higher Order Competition Modes in Ku-Band Magnetically Insulated Transmission Line Oscillator

A Ku-band magnetically insulated transmission line oscillator is proposed and investigated numerically and experimentally. In the initial experiments, we found that the higher order competition modes in the device limited the microwave power, and the competition modes were identified to be HEM11 and TM02 modes by analyzing the dispersion relationships, the simulation results, and the experiment phenomena. The factors, such as the concentricity, the cathode emission uniformity, and the diode voltage, play important roles in the suppression of these competition modes. In the subsequent experiments, the higher order competition modes are effectively suppressed, and the designed TM01 mode microwave is generated with the frequency of 12.33 GHz, the power of 600 MW, and the pulsewidth of 35 ns.