A Wiener model based post-calibration of ADC nonlinear distortion

Abstract

A post-compensation method based on decoupled Wiener model to eliminate the nonlinearity of Analog-to-Digital Converters is proposed in this paper. The compensator of memoryless nonlinearity is composed of a nonlinear subsystem without memory and a dynamic linear subsystem. The model parameters of Wiener model are measured by using harmonic distortion information in ADC output by sinusoidal signal stimulation. The results of experiment indicate that the spurious free dynamic range (SFDR) of this technique achieves about 20-dB improvement. Frequency sweeping results show that the parameters of nonlinear compensator can be acquired by a training signal excitation. With the help of narrowband-dithering technique, the Wiener model based compensator results in extra 10-dB improvement in SFDR by tiny cost of signal-to-noise ratio.