A High-Efficiency Doherty Power Amplifier with Filtering Matching and Harmonic Suppression

This letter introduces a Doherty Power Amplifier (DPA) with filter matching and harmonic suppression architecture. The integrated design of the filtering networks and the DPA exhibits advantages of improved integration level, lower losses, and higher out-of-band attenuation. The suppression of the second and the third harmonics also improves the efficiency of the DPA. The filtering DPA designed in this letter uses GaN HEMT and can work over the range of 3.2-3.6 GHz. The measured results indicate that the maximum output power of DPA is 43.6-45.1 dBm, with saturated drain efficiency (DE) of 60.1%-65%, and 36.1%-45.9% at the 6 dB power back-off. The measured adjacent channel leakage power ratio (ACLR) is -33.7/-53.14 dB with and without the digital pre-distortion with the 20 MHz long-term-evolution (LTE) signals.