In this paper we present a method for stability analysis of high order Sigma-Delta modulators. The method is based on a parallel decomposition of the modulator. Using this presentation the general N-th order modulator could be considered as made up of N first order modulators, which interact only through the quantizer function. The decomposition helps us to extract the stability conditions of t...

An important factor affecting the performance of modulators is their tone behavior. A recent approach to alleviate the tone problem consists of moving the open-loop poles outside the unit circle. In this paper, we determine the frequency location of two dominant tones as a function of pole-location, and discuss the effect of pole location on the relative amplitude of low-frequency tones. Audio ...

Extending an existing architecture for delta-sigma conversion of vector inputs, we suggest spectrally shaping quantization noise jointly in temporal and spatial frequency domains with delta-sigma modulation, and we examine the application of the idea to wideband antenna or acoustic arrays and to halftoning of video imagery.

Sigma delta modulation is a popular technique for high-resolution analog-to-digital conversion and digital-to-analog conversion. We investigate chaotic phenomena in multibit first-order sigma-delta modulators. Particular attention is placed on the occurrence of periodic orbits or limit cycles. These may result in idle tones audible to the listener when sigma-delta modulation is used for audio s...

........................................................................................................... i Acknowledgement ............................................................................................ iii List of Publications .......................................................................................... v

................................................................................................................................................ ii Acknowledgments ............................................................................................................................ iii Table of