Galton This research is evaluating the viability of and will further develop a novel technique for simultaneously performing the previously separate operations of phase-tracking and A/D conversion. The technique gives rise to a family of systems referred to as Sigma-Delta Frequency-to-Digital Converters (SDFDCs), and offers the potential of significant reductions in analog circuit requirements for a variety of applications. Each system uses coarse analog phase measurements, quantization noise shaping, and decimation filtering to perform instantaneous frequency-to-digital conversion. Because they operate on instantaneous frequency in the manner that SD modulators operate on amplitude, they share many of the benefits enjoyed by SD modulator-based A/D converters such as reduced analog circuit requirements and amenability to VLSI implementation. The research is developing rigorous theoretical results supported by simulations with the goal of characterizing SDFDC performance. A VLSI prototype targeted to a specific application will also be developed.
