57 efficiency, wide dynamic range linearized heterojunctionFET-based power amplifier for wide-band CDMA handsets

摘要

A high efficiency, wide dynamic range linearized power amplifierhas been developed for 1.95 GHz wide-band CDMA (W-CDMA) handsets. Theamplifier is based on a developed heterojunction FET, and its linearityand efficiency are further improved by incorporating a MMICpredistorter. The output power (P_out) and power addedefficiency (PAE) of the amplifier improve significantly from 25.5 dBmand 54.4% to 26.2 dBm and 57.4% respectively after the use of thepredistorter, measured at an adjacent channel leakage power ratio (ACPR)of -40 dBc. With bias control, the linearized amplifier also shows anexcellent low P_out (13 dBm) performance, achieving a PAE of47.7% at the same ACPR criteria. This performance is believed to be thehighest PAE reported for W-CDMA handset amplifiers