Power, Efficiency, and Linearity Trade-Off in Designing GaN Solid-State Power Amplifiers (SSPAs) for SATCOM Applications

Satellite communications (SATCOM) play a key role in enabling global connectivity, ensuring that people, businesses, and communities can stay connected regardless of their geographic location. As the ground network continues to advance with 5G and beyond, SATCOM will continue to evolve, offering even faster data rates, higher capacity, and expanded capabilities. To this purpose, constellations of very-high-throughput satellites (vHTSs) are under development, envisaging the adoption of many technology breakthroughs such as signals with large peak-to-average power ratio (PAPR), active antenna array and power flexibility concepts. These are relatively new requirements for space applications, which have to be added to the typical ones such as high reliability, good thermal management, small size, and weight. Accounting for such a scenario, this contribution discusses power, efficiency, and linearity trade-off in Solid-State Power Amplifiers (SSPAs) for SATCOM, by presenting the design, realization, and experimental characterization of a GaN SSPA conceived for Ka-band downlink (17.3-20.2GHz) applications with 125W power and 30% peak efficiency. Moreover, the SSPA achieves 100W average output power and an NPR better than 18dB when driven with a white-noise-like signal having 10dB PAPR and an instantaneous bandwidth of 2.9GHz.