Adaptive onboard compensation of non-linear HPAs and imperfect butler matrices in multiport amplifiers for high throughput satellites

摘要

Multiport amplifier (MPA) is a key technology for future high throughput satellites (HTS) which aim at delivering extremely high data rates with flexible payloads. MPAs offer more flexible and efficient use of power onboard the satellite. This paper outlines two major issues which degrade the optimal MPA performance, i.e. the non-linear effects of high power amplifiers (HPAs) and the hardware imperfections in implementing input/output-hybrid Butler matrices (INET/ONET). Furthermore, a novel two-step technique to improve MPA performance is presented. The proposed technique compensates the imperfect INET/ONET in the first step and predistorts the non-linear amplifiers in the second step. Simulation results presented indicate that by implementing the proposed adaptive solution, we gain in the bit error ratio (BER) performance and the system robustness to hardware imperfections.