Design of 400-W Multi-Stage Power Amplifier Block for S-Band Primary Surveillance Radar

This paper presents the design philosophy, realization technique, and test results of a phase and gain-controlled 400-W solid-state power amplifier (SSPA) with 56 dB gain for use in a 2.7-2.9 GHz S-Band primary surveillance radar (PSR) system. The SSPA consists of a two-stage GaN power amplifier, a three-stage GaAs preamplifier, a voltage-controlled phase shifter, and a voltage-controlled attenuator. Pulsed measurement results demonstrate a minimum of 400W (56 dBm) output power, 56 dB gain over the 2.7-2.9 GHz bandwidth, and a measured power added efficiency (PAE) between 64%-68%. To the author's knowledge, this study represents a significant advancement in terms of efficiency, gain, size, weight, and power within the existing literature.