Study of the Multipactor Effect in Groove Gap Waveguide Technology

Abstract

This paper presents a theoretical and experimental comparative study of the different multipactor threshold values obtained in rectangular waveguide (RW) and groove gap waveguide (GGW). To this end, the multipactor effect has been first analysed in a RW with a recently developed theoretical model. Then, the multipactor breakdown power levels in the equivalent GGW have been predicted with an accurate electron tracking code, showing a significant increment compared with the RW case. In order to validate these results, two E-plane WR-90 rectangular waveguide transformers have been designed with a full-wave electromagnetic simulation tool. The central sections of these transformers have been implemented in RW and GGW, respectively, and their multipactor breakdown power levels have also been predicted. The two designed transformers have been fabricated in aluminium, and then measured in terms of electrical response (scattering parameters) and RF multipactor effect (power threshold values). All the experimental results agree well with the set of simulated data, thus fully validating the performed study.