Particle-in-cell simulation of saturation process of multipactor in parallel-plate transmission lines

The multipactor saturation process in parallel-plate transmission lines is simulated using particle-in-cell (PIC) method. By changing the weight value of macro-particle, a time-saving simulation approach has been found firstly. Then the break of focus effect is observed in the simulation of saturation process, and the critical frequency of saturation is obtained and compared with theoretical prediction. The power loss and noise producing of the saturation current is also analyzed with the PIC simulations. It is found that the power attenuation factor increases with the input power and apparent multi-harmonic frequency noise is produced.