Theoretical and Experimental Results for Multipactor Effect in Groove Gap Waveguide Bandpass Filters with Inductive Coupling Irises

This article presents the theoretical study and experimental validation of the multipactor (MP) effect in bandpass filters implemented in groove gap waveguide (GGW) technology. Such filters are based on rectangular cavities and inductive coupling irises, whose optimized dimensions (widths and lengths) are fixed between rows of metal pins. For the effective design of the considered GGW filter, an equivalent counterpart in standard rectangular waveguide (RW) technology will be first studied, using very efficient tools for computing its electrical response and MP discharge breakdown levels. Two prototypes of the GGW and RW bandpass filters, designed to operate at 17.5 GHz (for Ka-band satellite downlink applications), are manufactured for validation and comparison purposes. Both of them are made of aluminium material, whose properties (in terms of secondary electron emission) have also been measured, as well as considered in the prediction of MP threshold levels using available software tools. Proceeding in this way, an outstanding matching between all simulated and experimental results of the MP effect has been achieved.