Implementation of a linearized power amplifier using the predistorter and direct conversion technique

Abstract

A linearization system with a digital adaptive predistorter is implemented in order to restrict the spectral spreading and adjacent channel interference in mobile radio systems. Using the output of amplifiers which is directly down-converted to a baseband predistorter and the quantized power of transmitted baseband signal, the look-up table is completed by an adaptive algorithm. An experiment shows that the peak to sidelobe ratio is 15 dB higher than that of a nonlinear amplifier.<>