Investigation of multipactor effect on return loss degradation

Multipactor effect on a dual-mode second-order waveguide filter response is presented. First, a dual-mode second-order waveguide filter using elliptical waveguide irises as input and output coupling is designed and simulated. Then multipactor current density is calculated with respect to the multipactor RF breakdown threshold in the elliptical waveguide irises. The magnetic filed corresponding to the multipactor current is then calculated and its equivalent surface impedance is applied to the solution space. Afterwards, the electromagnetic field distribution inside the filter is simulated using a finite-element simulator. The simulation results clearly show the effect of multipactor on the frequency response of the filter.