Patent ID: 6809588
Filing Date: 2004-10-26
Classification: H03F

Abstract:
A distortion compensation circuit for reducing an unbalance between a higher 3rd order distortion and a lower 3rd order distortion generated by an amplifier which amplifies an input signal having at least two frequency components, the distortion compensation circuit comprising:amplitude modulation means for performing an amplitude modulation on the input signal by using a control signal having a frequency corresponding to a difference between the frequency components, wherein the distortion compensation circuit cancels the unbalance by using sideband signals generated as a result of the amplitude modulation performed by the amplitude modulation means and the amplitude modulation means includes control signal generating means for generating the control signal based on an envelope of the input signal; amplitude adjusting means for adjusting an amplitude of the control signal; phase adjusting means for adjusting a phase of the control signal; and amplitude modulation performing means for performing an amplitude modulation on the input signal based on the control signal to thereby generate the sideband signals.