Applying memory polynomial model to linearize wideband multi-bit delta-sigma based transmitters

摘要: Abstract This paper presents a new predistortion linearization technique based on the memory polynomial model of power amplifier (PA) and multi-bit delta-sigma modulator (DSM), in order to avoid reverse modeling associated instability problems. In this topology, DSM is utilized as digital predistorter by locating forward PA its feedback path. The has two main advantages. First, it applies instead PA, which leads less implementation complexity and, therefore, greater robustness against instability. Second, using dynamic static makes more applicable for wideband signals, due compensation effects. To justify advantages, linearizers both models have been designed tested. For 4 MHz WiMAX signal, measurement results show an improvement 17.2 dB signal-to-noise distortion ratio (SNDR) model, compared 13 dB model.