PA Linearization for Modern Communication Systems

In third generation (3G) mobile communication systems, ultra linear amplification is required for complex modulation formats. Nonlinear amplification yields inter-modulation distortion (IMD) products and results in unacceptable spectral regrowth in the adjacent channels. To achieve ultra linear amplification, special linearization techniques are usually employed. Various techniques have been developed to reduce IMD products in high power amplifiers and generally, three main linearization methods are used. They are the predistortion method, the feedback method and the feedforward method.