New supply modulation optimization methodology for concurrent dual band envelope tracking power amplifier

In this paper, the design, implementation, and measurement results of a concurrent dual-band envelope tracking (ET) system is presented. A GaN power amplifier (PA) is designed for concurrent dual-band operation. The iso-gain shaping functions for envelope tracking are then extracted from the characterization of the PA in each band. To investigate the envelope tracking performance under concurrent dual-band operation and establish the optimal dual-band shaping function, a new supply modulation scheme is proposed. An experimental test bench is also presented. The performances of the new schemes are evaluated with a dual-band signal based on a LTE signal with PAR of 10dB centered at 1892.8MHz and a WCDMA signal with PAR of 5dB centered at 2200MHz. Experimental results show 57 % average drain efficiency for peak output power of 36.6 dBm and 36.5 dBm.