Patent ID: 6756844
Filing Date: 2004-06-29
Classification: H03F

Abstract:
A feed forward type distortion compensation amplification apparatus, comprising:a distortion detection loop having a first phase shifter, a first amplitude adjuster and a main amplifier; a distortion compensation loop having a second phase shifter, a second amplitude adjuster and an error amplifier; means for canceling a first distortion element generated from the distortion detection loop by a second distortion element generated from the distortion compensation loop and generating an output signal; and a bias controller for controlling bias levels of the main amplifier and the error amplifier based on a power level of the cutout signal, wherein the bias controller includes: a control unit for storing the bias levels of the main amplifier and the error amplifier and retrieving a main amp bias level for the main amplifier and an error amp bias level for the error amplifier in response to the power level of the output signal; a first bias control unit for controlling a bias of the main amplifier based on the retrieved main amp bias level; and a second bias control unit for controlling a bias of the error amplifier based on the retrieved error amp bias level.