KEYNOTE: Understanding Linearization and its Recent Developments

Linearization has become of enormous importance because of the need to efficiently send greater and greater amounts of information over a limited spectrum. It is of special value at frequencies below 1 GHz because of the limited bandwidth available at these lower frequencies and that information rate/Hz is dependent on the level of distortion. This talk will review the basics of linearization; a systematic procedure for reducing an amplifier’s distortion [1], [2]. It will discuss the linearization of high power amplifiers (HPAs), particularly those at HF through UHF and the considerations/trades associated with its application. The links between linearity and efficiency will be considered. Of the three most common forms of linearization; feedback, feedforward and predistortion, predistortion linearization (PDL) is by far the most popular form used at RF and microwave frequencies. PDL techniques will be the focus of this presentation.