A High-Efficiency Symmetrical Doherty Power Amplifier With Back-Off Reconfigurability

Abstract

This letter presents the design of a symmetrical Doherty power amplifier (DPA) with output power back-off (OBO) range reconfigurability by using a new and explicit circuit model. The theoretical analysis reveals that OBO range (>9 dB) can be extended and controlled without changing the circuit structure, taking advantage of the phase shift of DPA matching subnetworks and adjusting the drain bias. To verify the proposed theory, a DPA is designed across 2–2.4 GHz with a 9-dB OBO range. Also, 11 dB can be further implemented by drain bias adjusting. The experimental results show drain efficiencies of 47%–52% at 9-dB OBO levels and 45%–49% at 11-dB OBO levels across 2–2.4 GHz, respectively.