Integrated Bandwidth Reduction and Shaping Technique for Wideband Millimeter Wave Envelope Tracking Power Amplifier with Digital Predistortion

A novel integrated bandwidth reduction and shaping technique with digital predistortion is proposed to significantly reduce the bandwidth of the drain supply voltage and realize the shaping operation simultaneously for millimeter-wave envelope tracking power amplifiers (ET PAs). By adopting this method, the bandwidth of envelope signal can be reduced to only 1.2x the signal modulated bandwidth and the corresponding digital predistortion is employed to compensate the nonlinearity caused by the proposed technique. Experiments have been carried out on a ET PA that is operated with the center frequency of 41 GHz and excited by a 10-MHz 16-QAM signal, which have shown that the efficiency of ET PA can be effectively maintained compared with the one with ideal de-trough envelope and satisfactory linearization performance can be achieved.