Final version - Improvements on Distortion of Frequency Spectrum for a Type of X Band Magnetron via PIC Simulation

Basing onthe curve of anode voltage via anode currents, cold and hot test data, structure parameters of the resonance system, 3D-models of a particular type of X-band magnetron were established for studying distortion of frequency spectrum in the tube. The amplitudes and frequencies of all modes were acquired via PIC simulation in CST Microwave Studio while altering the cathode's height and diameter, emission current from the cathode, static magnetic field, and anode voltage. When comparing these simulations with experiment results, it was determined that the main cause of spectrum distortion was the splitting of the operating mode and the disturbance of competitive modes, which was brought on by an imbalance between the structure of the interaction gap, the size of the cathode, the electric current from the cathode emitter, and operating magnetic strength. By adjusting the operating and other structure settings, properly increasing the cathode axial height and diameter, reducing the axial magnetic field on the cathode surface, selecting appropriate electric currents from the cathode emitter, this problem has finally been resolved.