A high-efficiency HBT-based class-E power amplifier for 2 GHz

A Class-E power amplifier (PA) based on a GaAs heterojunction bipolar transistor (HBT) is presented. The single-ended single-stage PA delivers 24 dBm of output power at 2 GHz, achieves a peak power added efficiency (PAE) of 68% and exhibits an excellent transducer power gain higher than 16 dB. The PAE remains high over a wide output power range. The circuit contains the standard 50-ohm input and output match and is capable of high-efficiency power amplification of constant-envelope signals, which has been demonstrated with the GMSK signal. Both lumped- and distributed-components concepts for the practical implementation of the load network are presented and discussed.