Identification of Multitone X-Parameters Under Variable Random Phase Wideband Excitations

We investigate the concept of multitone X-parameters for characterizing the behavior of an off-the-shelf power amplifier under wideband excitation similar to real-life telecommunication signals. To achieve this, we created a set of random phase multitone excitations and identified large- and small-signal terms for each wideband signal. For simplification, we ignored terms describing mixing and harmonic-related products. We show how the terms identified are affected by input signal conditions by presenting and discussing results for two exemplary multitone realizations. For this investigation, we kept the power amplifier's load conditions constant.