Highly efficient broadband class-J power amplifier using modified multisection quarter-wave lines and short-circuited stubs

摘要

This study presents a broadband and high-efficiency Class-J power amplifier (PA)-based on a modified multisection quarter-wave lines and short-circuited stubs matching network (MN). It is noted that the modified structure, with good design convenience and great frequency selectivity, especially in the roll-off region between the highest frequency of the desired band (f(H)) and second harmonic of the lowest frequency of the band (2f(L)), is for the first time employed to design PAs with more optimal performance and greater bandwidths (BWs). A step-by-step design procedure of the proposed structure is presented. Experimental results show that using a 10-W Wolfspeed GaN HEMT device, a highly efficient broadband Class-J PA is realised from 1.4 to 2.4 GHz (fractional BW = 52.6%) with measured drain efficiency of 63.0-68.9% and output power of 39.8-40.3 dBm.