Joint estimation of filter nonidealities in continuous-time sigma-delta modulators by using an unscented Kalman filter

In this work, a method for the estimation of filter nonidealities in continuous-time sigma-delta modulators is presented. Nonidealities in the filter of a sigma-delta modulator are having a detrimental effect on the performance of the overall analog-to-digital conversion. Once these imperfections are known, they can be reduced or even eliminated by analog or digital correction techniques. Although there have been many publications concerning estimation and correction, most of them are considering only one or few of all possible nonidealities jointly. The presented approach of using an unscented Kalman filter is capable of tracking several errors simultaneously.