The Circuits and Systems Group specializes in the modeling, simulation, analysis and design of nonlinear mixed-signal circuits and systems for applications in communications and signal processing. The group has particular expertise in techniques such as nonlinear dynamical system theory and mixed-signal simulation; it targets applications including oscillators, digital delta-sigma modulators (DDSM) and fractional-N frequency synthesizers. The theoretical and solution-focused research bridges the traditionally separate fields of Circuits and Systems and Solid-State Circuits. We publish primarily at the International Symposium on Circuits and Systems and in the IEEE Transactions on Circuits and Systems, as well as the European Solid-State Circuits Conference and in the Journal of Solid-State Circuits. We have also published monographs on DDSMs and All-Digital Phase-Locked Loops. Our recent theoretical innovations include injection-locked frequency dividers, error masking, and bus-splitting, which have enabled high-speed and reduced-complexity DDSMs. Our patented DDSM technology underpins the best-in-class performance of a commercial family of monolithic fractional-N frequency synthesizers.
Current research is focused on minimizing nonlinearity-induced spurs and noise in high-performance frequency synthesizers for wireless and wireline applications. In addition, we are investigating novel synthesizer architectures for low-energy edge-of-network nodes in the Internet of Everything.