Simulations of multipactor thresholds in shielded microstrip lines

Abstract

A particular software ‘MuSLi’ has been developed and applied for simulations of the multipactor effect in shielded microstrip lines with cross-sections that are partially filled with dielectric material. The software combines an electromagnetic field solver, determining the electric field structure in the microstrip line, and a Monte Carlo algorithm, calculating the corresponding electron trajectories taking into account a spread of the electron initial velocity and different secondary emission properties of the metal and dielectric surfaces. The simulations were carried out for a number of structures of interest for communication systems, currently being discussed for application in coming space missions. The microstrip line system is shown to be strongly resistant to multipactor growth and the main reason for this is identified as the ponderomotive (or Miller) force, which governs the average electron motion in non-uniform rf fields and which tends to push the electrons out of regions with strong rf fields.