Design of Irregular Structure DPA with Large back-off Power Range Based on Impedance and Phase Hybrid Optimization

In order to achieve the efficient operation of Doherty power amplifier under large back-off power range, an irregular structure Doherty power amplifier with large back-off power range is designed. By using the impedance phase hybrid objective function, the output matching network is optimized by determining the load impedance and phase of the required frequency point and combining with the grid discrete structure, which reduces the efficiency inconsistency caused by the phase dispersion in the broadband of the existing Doherty power amplifier with large back-off power range. To verify the proposed method, a 2.2-2.5 GHz Doherty power amplifier with large back off power range is designed and implemented. Measurement results show that the efficiency of 9 dB power back-off is in the range of 51%-56% in the working frequency band. It meets the demand for peak-to-average ratio signals of future mobile communication systems.