2019 Volume 16 Issue 18 Pages 20190480
This paper proposes a simple method for designing a broadband Doherty power amplifier. The two-port network is used to represent the output matching networks and load modulation networks. Then, the relationships between the parameters of the two-port network and the output impedances of the transistors and the impedances of the power amplifier branches at the combiner are derived. The output matching network and the load modulation network are designed based on the parameters of the two-port network. A broadband Doherty power amplifier is designed and fabricated to verify the effectiveness of the proposed method. The measured results show that the saturated output power is 43.5–45 dBm and the saturated drain efficiency is 65–75% in 2.1–2.7 GHz. And the drain efficiency is greater than 40% at the 6 dB power back-off in the same frequency band. And the gain is above 12 dB.
