Spurs in Fractional-N Frequency Synthesizers

The performance of a fractional-N frequency synthesizer is degraded due to the presence of unwanted spurious tones (spurs) in the output spectrum. The Digital Delta-Sigma Modulator can be directly responsible for the generation of spurs because of its inherent nonlinearity and periodicity. In this booklet we have predicted that specific nonlinearities in a fractional-N frequency synthesizer produce spurs at well-defined frequencies even if the output of the DDSM is spur free. Different spur free DDSM architectures have been investigated for the analysis of spurious tones in the output spectrum of fractional-N frequency synthesizers.

Autorentext

Born in Mansehra (Khawari), Pakistan in 1985. He received B.S. degree in Computer Engineering from Comsats University in 2007 and M.S. degree in Electrical Engineering (Communication Electronics) from Linköping University, Sweden in 2012. He worked as visiting researcher in Circuits and Systems Group at Tyndall National Institute, Cork, Ireland.