Patent ID: 8358682
Filing Date: 2013-01-22
Classification: G01R

Abstract:
1. A signal processing apparatus comprising a digitizer that converts an input analog signal into a digital signal and a distortion identifying section that identifies non-linear distortion in a reference digital signal generated by the digitizer when the digitizer is supplied with a reference analog signal, wherein the distortion identifying section includes: a reference spectrum calculating section that calculates a spectrum of the reference digital signal; a reference data converting section that rearranges each of a plurality of frequency components in the spectrum such that (i) a fundamental wave component and harmonic wave components of the reference digital signal are within a first Nyquist region of the spectrum of the reference digital signal and (ii) image components of the fundamental wave component and the harmonic wave components are within a second Nyquist region of the spectrum; and a distortion detecting section that detects the non-linear distortion of the reference digital signal caused by each harmonic wave component, based on each harmonic wave component having a prescribed order number in the spectrum in which each frequency component has been rearranged by the reference data converting section.