Patent ID: 6600369
Filing Date: 2003-07-29
Classification: H03F

Abstract:
A system for linear amplification of an input signal to produce an amplified output signal, the system comprising:an envelope detector that determines an envelope detector signal based on the input signal; an amplifier bias controller operably coupled to the envelope detector that produces a plurality of control signals based on the envelope detector signal; a predistortion signal loop operably coupled to the amplifier bias controller, the predistortion signal loop having a companion amplifier stage and operative, in response to a first control signal of the plurality of control signals, to modify the input signal using the companion amplifier stage to produce a predistorted input signal comprising a distortion component introduced by the companion amplifier stage; and a main amplifier stage operably coupled to the amplifier bias controller and further operably coupled to the to the predistortion signal loop, wherein the main amplifier stage receives a second control signal of the plurality of control signals from the amplifier bias controller and, based on the second control signal, amplifies the predistorted input signal to produce the amplified output signal, and wherein the distortion component of the predistorted input signal at least partially cancels a distortion component introduced to the amplified output signal by the main amplifier stage.