Parallel adaptive predistortion for RF power amplifier linearization

This paper presents a parallel adaptive predistorter design technique for RF power amplifier linearization, based on the indirect learning architecture. The predistortion is accomplished by inverse modeling of the AM/AM response and modeling of the AM/PM response of a high power amplifier. In order to implement the predistortion adaptively, the coefficient vectors for the amplitude inverse and for the phase modeling are updated in parallel, from the amplitude response and phase response of the amplifier output, respectively. The performance of the proposed parallel adaptive predistortion linearizer (PAP-LZR) is illustrated by linearizing traveling wave tube (TWT) nonlinear amplitude and phase characteristics, suppression of intermodulation products, and adapting to a change in TWT parameters.