Multipactor RF Breakdown in Coaxial Transmission Lines With Digitally Modulated Signals

Abstract

The aim of this paper is the study of the RF multipactor breakdown in coaxial transmission lines excited by a single carrier with a digitally modulated signal. Employing an in-house developed code, numerical simulations are performed to determine the RF multipactor voltage threshold for several digitally modulated signals under different modulations schemes: quadrature phase-shift keying, 16-quadrature amplitude modulation, 16-amplitude and phase-shift keying, and 32-amplitude and phase-shift keying. Moreover, a coarse method based on the envelope integration to determine the RF multipactor voltage threshold when involving arbitrary digital modulations is also presented. These results are also compared with the 20-gap-crossing rule used in the space standard document ECSS-E20-1A. In order to validate the theoretical results, a test campaign was performed for realistic modulated signals, finding good agreement between theoretical predictions and experimental data.