An Augmented Time-Domain Poly-Harmonic Distortion Model for Digital Predistortion of Power Amplifiers With Severe Load Mismatch

Compensating for the nonlinear distortion of power amplifiers (PAs) with load mismatch is a tricky task, especially when the voltage standing wave ratio (VSWR) is higher than 3. This letter proposes an augmented time-domain poly-harmonic distortion (A-TD-PHD) model for the linearization of PAs with severe load mismatch. Based on the high-order extension of the classic poly-harmonic distortion (PHD) model, the proposed A-TD-PHD model can compensate for the nonlinear distortion induced by severe load mismatch accurately. Experimental validations are carried out using a 100-MHz orthogonal frequency division multiplexing (OFDM) signal. The proposed A-TD-PHD model shows excellent linearization performance for PAs with severe load mismatch (VSWR >= 3), which has a great application value for the digital predistortion (DPD) technique in 5G handsets.