W band solid-state power amplifier for aerospace usage

Concentrating on the high frequency aerospace demand of solid-state power amplifier (SSPA), this paper presents the methodology and key technique of a W-band 3-W SSPA that achieves high efficiency while maintaining excellent reliability capability. An improved Magic-T power combiner is utilized to achieve high output power, and eliminate the influence of the parallel end-stage gallium-nitride high-electron-mobility-transistor (GaN HEMT) PAs by its good isolation performance. The SSPA's millimetre-wave circuit is implemented by three stages of amplifier, to realized more than 30-dB power gain. The power-supply circuit based on the two-transistor forward topology is proposed for voltage converting and output serious sequence controlling. The SSPA is fabricated and measured, achieving 33-dBm to 34.1-dBm output power within the frequency range of 92-96 GHz, with the power gain of 31-32 dB, and peak efficiency of 7.1%, respectively. The proposed SSPA shows competitive performance for space application.