A broadband Doherty power amplifier based on the two-port networks method

Abstract

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 backoff in the same frequency band. And the gain is above 12 dB.

Design of a 12dB back-off asymmetric Doherty power amplifier using reactive output impedance

“…The techniques that can improve the efficiency at OPBO are important issues in the research [10,11,12,13,14]. So, several Doherty power amplifiers (DPAs) have been investigated and developed [15,16,17,18,19]. However, the conventional DPA can only maintain high efficiency within 6 dB OPBO range [20,21,22], which can hardly fulfill the requirements of future modulated signals with higher PAPR.…”