Design of Broadband High-Efficiency Doherty Power Amplifier Using Post-Matching Network

This paper presents a broadband Doherty power amplifier(DPA) with 500 MHz bandwidth. Same drain voltages on the carrier and auxiliary device are employed to run the symmetric Doherty operation. At the same time, the post-match network instead of λ/4 transformer is used to expand the bandwidth. The DPA which shows high-efficiency at 6-8 dB output power back-off(OBO) is designed and implemented by using commercial GaN HEMTs. The amplifier achieves drain efficiencies of 44.6%-58% under a 6-8 dB OBO. Saturated output power 43.4-44.2 dBm with efficiencies of 54.8%-67.3% are measured from 2.1 to 2.6 GHz.