Digital predistorter architecture with small signal gain control for highly nonlinear RF power amplifiers

In this paper, a digital predistorter (DPD) architecture is proposed for the linearization of highly nonlinear RF power amplifiers. This digital predistorter architecture uses a complexity reduced and a computationally efficient procedure to synthesis the predistortion function. Unlike conventional digital predistortion architectures that require more than one characterization to get a perfect match between the PA´s nonlinearity and that of the DPD, the proposed architecture uses a single characterization and iteratively optimizes the predistortion function performance by controlling the predistorter´s small signal gain. Experimental validation carried on a highly nonlinear RF power amplifier demonstrates the ability of the predistorter´s small signal gain control to improve the linearity performance.