A power amplifier by using asymmetrical branch-line coupler

Abstract

In this paper, a novel power amplifier (PA) is proposed. An asymmetrical branch-line coupler is exploited as the output matching circuits of the proposed PA. Meanwhile, by setting the impedance conditions with trade-off in desired pass-band appropriately, impedance matching and output power combination can be realized in a single circuit. A brief analysis of the asymmetrical branch-line coupler is presented. Compared with the traditional high-power PAs design method, this design method can meet the requirement of the miniaturization. To prove the validity of the proposed method, a PA works at 2 GHz is designed, fabricated and measured by using a 10-W gallium nitride (GaN) transistor (CGH40010F). The measured results show that a saturated output power of 42.8-45.2 dBm with a poweradded efficiency of 52.0-62.6% is achieved and a saturated power gain between 7.9 and 10.1dB.

A high‐efficiency power amplifier by using harmonics control

“…It effectively solves the complexity of traditional PA design. In 2022, an asymmetrical branch-line coupler (ABLC) is exploited to design a high-power PA. 10 With this method, impedance matching and power combination can be realized at the same time. But the efficiency needs to be improved, as the ABLC cannot control harmonics effectively.…”