GaN-MMIC Doherty power amplifier with integrated reconfigurable input network for microwave backhaul applications

A 7 GHz GaN MMIC Doherty power amplifier with reconfigurable input network for backhaul applications, is presented. The reconfigurable solution is conceived to be simply implemented in MMIC technologies. To demonstrate the effectiveness of the strategy, a second Doherty with fixed input network, has been designed for comparison. Both prototypes have been realized adopting a commercial GaN HEMT process and characterized in large signal conditions. The experimental results prove the capability of the proposed solution to overcome the issues related to the inaccuracy of the active device nonlinear models especially for the Class-C bias condition required by the Peak amplifier. At 7 GHz both MMICs exhibit an output power of 40 dBm. However, at 6 dB of output power backoff, the reconfigurable Doherty efficiency is 43%, 10% higher than the one of the DPA with fixed input network.