A 4 GHz High-Efficiency High-Linearity GaN Doherty Power Amplifier with Dual DC-Power Supplies

Abstract

This paper elaborates the basic operation principle of the Doherty power amplifier (DPA) and analyzes the method of improving the linearity of the DPA. A novel DPA with dual DC power supplies and a high linearity is designed and implemented at the operating frequency of 4 GHz. EM (Electro Magnetic)/Circuit Co-Simulation shows that under one tone test, the DPA can obtain the high performance of the 40.4 dBm saturated output power, about 63% maximum power added efficiency (PAE) and about 50% PAE at 6 dB output power back-off (OBO). Under two tones test, the third order inter-modulation distortion (IMD3) is less than-30 dBc when the input power is less than 27dBm. Moreover the DPA delivers the maximum PAE of 61% with the corresponding input power of 26.5 dBm and output power of 38.5 dBm respectively.