Ultra wideband high gain GaN power amplifier

A three-stage power amplifier will be described which was designed for 5 W or better power over many octaves. A mixed topology was chosen to obtain the best bandwidth and power. First two stages are single-ended feedback designs for best gain and linear drive for the output. The last stage is a distributed PA, which is optimized to achieve high output power and high drain efficiency. The PA is designed and fabricated using discrete 2W GaN transistor die in all stages in a mixed hybrid and softboard medium. The design was fully simulated. Both measurement results and the theoretical predictions will be presented. This GaN PA has over 43 dB linear gain with good port match and it provides greater than 37 dBm of saturated power and over 20% PAE in the 0.02 to 3 GHz frequency range.