Simplified power adaptive digital predistorter for RF power amplifiers in dynamic power transmission

A simplified power adaptive digital predistorter (DPD) is proposed in this paper to compensate the nonlinear distortion of the power amplifier (PA) within a wide range of input power variation. Compared to the original power adaptive method which requires doubling the number of the coefficients in model extraction, the proposed model can significantly reduce the coefficients number, which further decreases the system cost and complexity. A high power Doherty PA was employed to validate the proposed DPD. Measurement results show that the nonlinear distortion of the PA at multiple power levels can be effectively removed.