Abstract
An adaptive bias strategy is proposed to harden fully integrated CMOS RF power amplifiers against time-dependent parametric degradation due to hot carrier injection. PA transistor DC current is compared to a reference using an operational transconductance amplifier that provides an adaptive gate DC voltage to the PA transistor as its threshold voltage increases due to stress. Based on degradation modelling obtained from experimental accelerated aging of a transistor and a RF PA implemented on a 130 nm technology, time dependent simulation results of the adaptive bias show that the proposed circuit effectively compensates for the threshold voltage increase of the main transistor.