Linearization Techniques for Wideband Envelope Tracking Systems for Handsets
This talk will focus on the necessary digital baseband signal processing (signal generation, mismatch control and linearization) to guarantee linearity levels in high efficiency amplification topologies based on dynamic supply strategies. Envelope shaping and both I-Q digital predistortion (DPD) and envelope linearization methods will be presented. Envelope linearization methods are used to compensate for the unwanted RF leakage that appears at the output of envelope tracking modulators when operating envelope tracking power amplifiers with wideband signals. Experimental results obtained with a system-on-chip ET PA board designed by Hisilicon for mobile applications, operated with NR-5G signals of bandwidths ranging from 20 to 200MHz, will be shown and discussed.