Carbon Coating to Mitigate Multipactor Effect in Microwave Filters

This paper focuses on the experimental demonstration of multipactor mitigation in functional devices operating in L-Band via coating ultrathin layers of carbon. A 2nd order filter, based on silvered half-wavelength short-circuited coaxial SIRs, allowing to localize the avalanche of electrons, between two removable cylinders has been specifically designed. As predicted by the simulation studies and subsequently verified experimentally, a significant improvement in multipactor threshold was achieved by coating the surfaces prone to multipactor with a thin layer of high sp2 hybridized carbon.