RF solid state power amplifier linearization using unbalanced parallel predistortion structure

Presents an improved adaptive RF predistortion method used for linearization of solid state power amplifier (SSPA). This proposed technique is based on a predistortion circuit, whose AM/AM and AM/PM response are separately implemented as polynomial approximations of the respective responses of the ideal linearizer. Unlike other RF predistorters, the polynomial complexity of two branches is unbalanced based on difference of amplitude and phase nonlinearity. Adaptation is accomplished by iterative adjustment of predistorter parameters to minimize the adjacent channel interference (ACI) power and a simple secant optimization way is used. The simulation result shows this scheme attains similar performance compared with other well-known RF predistortion method but reduces the implementation complexity.