Rf Power Amplifier Linearization Technology Research

Linearity of transmits channel is endued with new requirements in the third generation communication system. And RF power amplifier is the leading factor of the nonlinearity of transmits channel. This paper mainly discusses the linaearization of RF power amplifier.At first, the nonlinear characteristic of the RF power amplification is discussed in this paper. Several typical mathematic model of the RF power amplifier is presented in this paper. Second, we analyzed the principle of the baseband adaptive predistorter and some typical preditorter architectures; introduced several adaptive algorithms and compared the Mean Square Error(MSE) algorithm with Recursive Least Square(RLS) algorithm. Finally, this paper presents an adaptive polynomial type predistorter lineariser in which the RLS algorithm is employed for the optimization process. Through simulation, it is proved that the linearization technique can improve the linearity of the Power Amplifier. Also, a modified version of a polynomial predistorter lineariser is presented which has a faster rate of convergence by an order of magnitude. Adaptability of the proposed lineariser with change in the power amplifier, demodulator, modulator are tested. Results show that the lineariser can adapt to these changes.