A first vector modulator is inserted in the input route of an amplifier to vary the input signal of the amplifier. A second vector amplifier is inserted in the second signal route to vary the input signal of the second signal route. A controller controls the first vector modulator to minimize the distortion...http://www.google.de/patents/US6232838?utm_source=gb-gplus-sharePatent US6232838 - Feed-forward amplifier and method of compensating non-linear distortion in the same
