Wandering spur suppression in a 4.9-GHz fractional-N frequency synthesizer
Loading...
Files
Date
2022-04-15
Authors
Mai, Dawei
Donnelly, Yann
Kennedy, Michael Peter
Tulisi, Stefano
Breslin, James
Griffin, Patrick
Connor, Michael
Brookes, Stephen
Shelly, Brian
Keaveney, Mike
Journal Title
Journal ISSN
Volume Title
Publisher
Institute of Electrical and Electronics Engineers (IEEE)
Published Version
Abstract
Fractional-N frequency synthesizers that use a digital Δ-Σ modulator (DDSM) to control the feedback divider can exhibit spurious tones that move about in the frequency domain; these are known colloquially as ``walking'' or wandering spurs. Building upon a theoretical explanation of the origin of wandering spurs, this article presents two methods to suppress them. It describes a 4.9-GHz 180-nm SiGe BiCMOS charge-pump phase-locked loop (CP-PLL) fractional-N frequency synthesizer platform with a divider controller that can function as: 1) a standard MASH 1-1-1; 2) a MASH 1-1-1 with high-amplitude dither; and 3) a MASH 1-1-1 with a modified third stage. Measurements confirm the effectiveness of the wandering spur suppression strategies.
Description
Keywords
Divider controller , Fractional-N frequency synthesizers , Phase noise , Phase-locked loops (PLLs) , Quantization noise , Spurious tones , MASH digital Δ-Σ modulator (DDSM)
Citation
Mai, D., Donnelly, Y., Kennedy, M. P., Tulisi, S., Breslin, J., Griffin, P., Connor, M., Brookes, S., Shelly, B. and Keaveney, M. (2022) 'Wandering spur suppression in a 4.9-GHz fractional-N frequency synthesizer', IEEE Journal of Solid-State Circuits. doi: 10.1109/JSSC.2022.3163080