Design of a Back-off Range Reconfigurable Sequential Power Amplifier with Doherty Type Load Modulation

A novel design of back-off range reconfigurable Sequential power amplifier with Doherty type load modulation (SPA-D) is proposed in this paper. A PIN diode is added to the reconfigurable load modulation network (Re-LMN) of SPA-D. By controlling the state of switch, the theoretical back-off range can be reconfigured between 6dB and 9dB. For verification, a reconfigurable SPA-D was designed and fabricated from 3.1 to 3.5GHz. The measurement results show that the designed reconfigurable SPA-D can achieve 43.2-45.7dBm output power with 9dB back-off drain efficiency higher than 40% and 43.3-45.7 dBm output power with 6dB back-off drain efficiency higher than 44%.