Bi-dimensional shaping function in concurrent dual band GaAs envelope tracking power amplifier

This work reports for the first time the characterization and the bi-dimensional shaping function for a dual-band 10W ET-PA operating in concurrent mode at 870 and 1950 MHz. The characterization involved WCDMA 6.5 PAR excitation, and a detailed analysis of the signals statistic resulting from the ET mode is reported as well. The measured data reported an average DE for the concurrent modes of 49.2 %, while we observed a significant variation of the PAR, with respect to single band operation. We demonstrate that this PAR variation is due to the specific gain versus power level shape, which is established during the concurrent ET-PA operation.