GaN MMIC Doherty power amplifier solutions for backhaul microwave links

In this paper, two 5W power amplifier solutions for microwave backhaul at 7GHz are presented. They are based on 0.25μm GaN on SiC MMIC technology, and rely on advanced Doherty schemes. The first solution maximizes the back-off efficiency at center frequency, reaching a value around 50% at 7dB OBO. The second MMIC is optimized for a wideband behavior, with efficiency exceeding 40% on a 15% relative bandwidth. Characterization results and system level behavior of the two proposed MMICs are compared and discussed