IMPROVED PREDISTORTION COMPENSATION FOR A POWER AMPLIFIER

摘要

The invention relates to an amplifier arrangement (10) for amplifying an inp ut using a distorting main power amplifier (14) such as one operating as a class AB amplifier. The method and apparatus add to the input signal to the main amplifier (14) a predistortion signal intended to compensate for the distortion added by th e main power amplfier (14). In accordance with the invention, the input to the predistortion circuit (12) is modified by measuring peak-to-peak signal values of the distortion in the output of the main power amplifier (14). The peak-to-peak values are measure d in a signal derived by comparing an output derived from the main amplifier (14) with an output derived from the input signal. A digitally controlled processor (16) iteratively modifies various phase and gain controls to adjust the output of the amplifier.