Analysis of second-order harmonic distortion of ADC using bispectrum

This paper presents a new frequency-domain approach to test the second-order harmonic distortion of an analog-to-digital converter (ADC). It uses triple correlation and its Fourier transform, bispectrum, to suppress quantization noise and improve the testing accuracy of weak second-order harmonics. Our approach is independent of the triggering delay that is a known weakness of the spectral averaging method. The new method is also less sensitive to the quantization noise than the power spectrum averaging method. Both theoretical analyses and illustrative computer simulations are provided