High efficiency broadband GaN HEMT power amplifier based on three-frequency point matching method

To cover the working frequency bands of the three mobile carriers of China Mobile, China Telecom, and China Unicom, power amplifiers (PAs) are required to own broadband. A PA with bandwidth 1.3–2.7 GHz is designed (fully covers the operating bands of the three mobile carriers). Measured results show that greater than 68% efficiency is attained over a 75% bandwidth from 1.3 to 2.7 GHz. The output power is larger than 40.2 dBm with gain varying from 10 to 13 dB across the band. In this article, three-frequency point matching method is applied in order for broadband matching. High-efficiency is achieved by a specially designed impedance matching topology which realizes short-circuits of the second harmonics and open-circuits of the third harmonics at different frequencies. The designed broadband high-efficiency GaN PA provides a new approach and method for the development of PAs in 4G base stations.