Linearization of Power Amplifiers using Predistortion Method

A power amplifier (PA) is a fundamental component in the transmitters. When the signal bandwidth is increased, memory effects are appeared and are not negligible. These distortions and interferences reduce extremely the performance of the transmitter system. In order to transmit the high-quality signal and have a system with high efficiency, the solution is compensating the nonlinearity of the power amplifier by the linearization methods. There are several linearization techniques to improve the efficiency power amplifier. Some of these methods include feedback, feedforward, and predistortion. One of the advantages of pre-distortion linearization method compared to other methods can be noted to the low cost and implementation complexity reduction. Generating the nonlinearity distortion prior to the power amplifier is called the predistortion (PD) such that the generated nonlinearity can remove the inherent nonlinearity of the power amplifier. The predistortion can be utilized in the baseband domain and then be implemented by digital signal processing (DSP) methods.