Nowadays, with rapid growth of wireless communication systems, demand for integration of wireless transceivers on a single chip called system on chip (SoC), has been increased. Therefore CMOS technology is widely used to implement SOCs because of its low cost and high capability of integration. RF power amplifier is one of the most important components in a communication system. Nowadays most of new digital communication standards such as WiMAX rely on modulations like OFDM because of their high spectral efficiency. The main disadvantage of OFDM is its high peak-to-average power ratio which makes it very sensitive to nonlinearity of power amplifier. The nonlinearity of a power amplifier gives rise to spectral regrowth, magnitude and phase distortion in the transmitted signal. Most high efficiency power amplifiers are intensively nonlinear and therefore cannot be used for OFDM signal amplification. On the other hand, to have a high efficiency power amplifier in any portable communication system is very important in the power consumption point of view. One method to amplify signals like OFDM by nonlinear power amplifier is to apply some linearization techniques on power amplifier to improve its nonlinear behavior. Among different linearization techniques, predistortion is one of the most popular techniques that can be realized by using proper digital structures. Among different ways for implementing predistorter (look-up table or implementation by modeling power amplifier), implementation of predistorter by modeling power amplifier is more proper way of implementation because, in look- up table implementation we need a large amount of memory for saving correction coefficients and convergence speed for updating of these coefficients is very slow. Also this approach is not appropriate for applications that deal with wideband modulation. This is because in such applications power amplifier memory effect due to frequency dependence of impedances, cannot be disregarded. In this thesis adaptive memory polynomial based predistorter is used to linearize the power amplifier. Memory polynomial is an accurate and simple model for modeling nonlinear systems with memory. The coefficients of predistorter are extracted using indirect learning structure based on an adaptive algorithm like LMS or RLS. The main advantage of this approach is that it can work with any nonlinear characteristics of power amplifier in an adaptive manner. The aim of this thesis is to evaluate the performance of this technique for linearizing CMOS power amplifiers. We use this technique to linearize a CMOS power amplifier with a paralleled left; MARGIN: 6pt 0cm 0pt; unicode-bidi: embed; DIRECTION: ltr" align=left Key Words: RF power amplifier, Power added efficiency (PAE), OFDM, Adaptive memory Polynomial based predistorter, Memory effect.