Enhanced class-A/AB mobile terminal power amplifier efficiency by input envelope injection and ‘self’ envelope tracking

Summary form only given, as follows. A baseband modulation technique is proposed to improve the efficiency and linearity of Class-A/AB RF power amplifiers (PAs). The baseband load impedance is optimized, and the input envelope along with the RF signal is fed to the PA input. The resulting baseband modulation at the drain increases saturated RF output power for a given dc power consumption. A 2 GHz HFET PA exhibited significant improvement in peak PAE from 40% to 54% for a two-tone input and from 23% to 27% for a 5 MHz BW 64-QAM signal.