EFFICIENCY EHANCEMENT OF WCDMA BASE-STATION ENVELOPE TRACKING POWER AMPLIFIERS VIA LOAD MODULATION

摘要

Load impedance modulation and gate bias control were investigated to improve the performance of W-CDMA base-station envelope tracking amplifiers by means of simulations based on the measured data of a 10-W GaAs FET power amplifier. It is shown that adapting the load impedance along with the drain bias voltage can effectively improve the average efficiency of envelope tracking amplifier. The improvement becomes more apparent in the operating regime of power back-off.