Development of ultra wideband, high efficiency, distributed power amplifiers using discrete GaN HEMTs

This study describes the design and performance of a discrete ultra wideband GaN HEMT distributed power amplifier (DPA) with over 5 W (37 dBm) output power and a PAE exceeding 27% in the 0.02–3 GHz frequency range. The implemented DPA design is comprised of three discrete GaN HEMT devices. Its performance was enhanced using tapered drain lines and non-uniform gate capacitive coupling. The design methodology is based on both small and large signal analysis using harmonic balance technique, and their associated predicted and experimental results are discussed here in detail.