Patent ID: 6771708
Filing Date: 2004-08-03
Classification: H03F

Abstract:
A nonlinear compensator for compensating for the nonlinear characteristic of a compensated electronic device that deals with a transfer signal, said nonlinear compensator comprising:a signal processing section which takes in an input signal and an output signal of said compensated electronic device, demodulates the signals suitably in such a manner that they have the same signal form, detects the time difference and phase difference between the two signals by correlating the two signals with each other, and not only synchronizes the two signals with each other but also causes the phase of one signal to coincide with that of the other on the basis of the detected time difference and phase difference; a distortion detecting section for detecting, as distortion components, an amplitude error and phase error in the input signal and output signal of said compensated electronic device that have been synchronized with each other and made in phase with one another by the signal processing section; and a distortion correcting section for producing the amount of nonlinear distortion compensation for said compensated electronic device on the basis of the distortion components detected by the distortion detecting section and compensating for the input signal to said compensated electronic device on the basis of the amount of distortion compensation; wherein said signal processing section includes an input demodulation section for generating an input-side base band signal by demodulating the transfer signal to said compensated electronic device and an output demodulation section for generating an output-side base band signal by demodulating the transfer signal outputted from said compensated electronic device, detects the time difference and phase difference between the input-side and output-side base band signals obtained at said input demodulation section and output demodulation section, and not only synchronizes the two signals with each other but also causes the phase of one signal to coincide with that of the other on the basis of the detected time difference and phase difference, and further includes an output converting section for converting the output of said distortion correcting section into the format of the original transfer signal.