A linearized power amplifier MMIC for 3.5V battery operated wide-band CDMAhandsets

A linearized power amplifier (PA) MMIC has been developed for 1.95GHz wide- band CDMA handsets. The PA is based on a developed heterojunction FET desig ned for 3.5V battery operation. Predistortion linearization was employed to compensate the nonlinearities of the PA for linearity and efficiency enhan cement. To maintain a compact design, the predistorter was integrated with the PA onto a single MMIC chip. After linearization, the output power (P-ou t) and power added efficiency (PAE) of the PA MMIC are improved significant ly from 28.0dBm and 40.0%, to 28.8dBm and 44.5%, respectively, measured at -38dBc adjacent channel leakage power ratio (ACPR) with a 3.84Mcps hybrid p hase shift keying signal. By combining with bias control, the linearized PA MMIC also demonstrates an excellent low P-out (13dBm) performance, achievi ng a PAE of 24.0% at the same ACPR criteria.