Effects of even-order nonlinear terms on power amplifier modeling and predistortion linearization

Power amplifier (PA) is an essential component in communication systems and is nonlinear in nature. Digital baseband predistortion is an emerging cost effective approach to linearize a PA. To study PA nonlinear characteristics and to construct a predistorter, accurate nonlinear models are often necessary. Polynomials have been used extensively for modeling the behavior of the PA or the predistorter. For bandpass communication signals, attention has been paid mainly to odd-order nonlinear terms. In this paper, we reveal the benefit of including even-order nonlinear terms in baseband modeling of the PA and in enhancing predistortion performance.