A method of reducing distortion in the output of an amplifier is provided.
The method comprises subtractively combining baseband error signals with
the appropriate phase shift with baseband input signals, the baseband
error signals generated by subtractively combining delayed fed-forward
portions of the baseband input signals with baseband converted portions
of a fed-back amplified output signal, the amplified output signal being
a distorted replica of combined up-converted baseband input signals. The
baseband error signals being filtered prior to the combining function,
and also providing inputs to a controller which adjusts active elements
of the amplification and fed-back paths in order to minimize the
distortion within the output of the amplifier.