Fully-automated adaptive analog predistortion power amplifier in WCDMA applications

This paper represents a fully-automated adaptive analog predistortion power amplifier for repeater systems with digital signal processor (DSP) control of a spectrum monitor, which detects the output spectrum of the RF power amplifier and improves the linearity automatically by controlling the gate bias voltage of the main power amplifier and the vector modulator of the analog predistorter. We implement a 30 W class AB power amplifier that adopts a general 3^rd-order predistorter with the spectrum monitor in the wideband code division multiple access (WCDMA) band. In this system, all operations for the linearization are achieved fully automatically under various power levels and temperatures.