Linear power amplifier based on 3-way Doherty amplifier with predistorter

This paper presents a 3-way Doherty amplifier with predistorter (PD) for a repeater application. It is implemented using three 60 Watts PEP silicon LDMOSFETs and tested using two-tone and one- and two-carrier down-link WCDMA signals. For the two-carrier downlink WCDMA signal, the amplifier provides -49.1 dBc adjacent-channel-leakage-ratio (ACLR) and 10.3% power-added efficiency (PAE) at an output power 40 dBm which is an improvement of 8.5 dBc in linearity and 2% in efficiency compared to a similar class-AB amplifier.