Sensitivity of AM/AM linearizer to AM/PM distortion in devices

Baseband injection is a technique that can provide a cost-effective linearizing solution that can be combined with supply modulation techniques such as envelope tracking (ET), to minimize AM/AM distortion and potentially simplify the DSP linearization requirement and associated cost. Recently [8], a new approach for computing the baseband injection stimulus, formulated in the envelope domain, was introduced. The concept was originally demonstrated using a 10W Cree GaN-on-SiC HFET device. In this work its robustness with respect to alternative device technology is investigated using 25W Nitronex NPTB00025 GaN-on-SiC HEMT depletion-mode and a 10W, high-voltage LD-MOS, enhancement-mode devices. Its effectiveness in dealing with AM/AM distortion is confirmed.