Characterization of memory effects in concurrent dual-band PAs

In this paper the nonlinearity of concurrent dual-band power amplifier (PA) is investigated by using modulated signals and digital multi-tone signals. The difference between ordinary inter-modulation distortion in single band power amplifier and the distortion from cross-modulation between dual bands in a concurrent dual-band PA has been verified and studied. According to AM-AM and AM-PM performances in different modes, the concurrent dual-band mode has more scattered behavior. To evaluate and quantify the memory due to the cross-modulation, and identification method is used to extract the amplitudes and phases of different inter-modulation products, which is useful for power amplifier behavior modeling and linearization.