Patent ID: 7142615

Claim:
A distortion compensator for compensating for distortion produced in an amplifier that amplifies multiple frequency band signals, the distortion compensator comprising: a signal level detection means for detecting an overall level of a signal to be amplified as combined multiple frequency band signals; a distortion compensation means for conducting different distortion compensation based on the detection result separately for each frequency band signal in the signal to be amplified; and a frequency band combining means for combining multiple frequency band signals compensated by the distortion compensation means and outputting the combination result to the amplifier, wherein the distortion compensation means includes a plurality of predistortion means for generating distortion for each frequency band signal and predistortion control means for controlling generation of distortion by the plurality of predistortion means based on the detection result of the signal level detection means, and wherein the frequency band combining means includes signal frequency band converting means for converting each of the distortion-compensated frequency band signals compensated by the distortion compensation means to a different frequency band signal, combining the multiple different frequency band signals obtained by the conversion and outputting the combination result to the amplifier.