Pattern noise in the frequency Delta Sigma modulator

In this paper, we show that the first-order frequency delta-sigma modulator is equivalent to a traditional delta-sigma modulator with respect to patte rn noise. We further propose two techniques for reducing the effect of patt ern noise. The first technique is based on time-domain dithering which is i mplemented by adding white phase noise to the FM signal. The second techniq ue is based on locating the narrow dynamic range that may be in this kind o f modulators, in a pattern noise valley. This technique can utilize pattern noise to make the modulator provide significantly higher digital resolutio n than the white quantization noise model predicts. Finally, the theory is verified by measurements.