Comparison of the simulated performance of two divider controllers in a fractional-N frequency synthesizer with a piecewise-linear charge-pump nonlinearity
Abstract
Reducing and ultimately eliminating nonlinearity-induced spurious tones (spurs) is a key motivation for the design of novel divider controllers for fractional-N frequency synthesizers. Two types of nonlinearities have historically been considered in this context: polynomial and piecewise-linear (PWL). Successive requantizers (SQs) have been designed for spur immunity in the presence of polynomial nonlinearities but it has been shown that SQs produce spurious tones in the phase noise spectrum in the presence of a PWL nonlinearity. Recently a new type of modified second order SQ has been introduced which tries also to minimize spurious tone production in the PWL case. In this paper, the simulated performance of a fractional-N frequency synthesizer incorporating the new divider controller is compared with that of one which uses a novel dithered MASH 1-1 structure. Our novel divider controller matches the performance of the modified higher-order SQ, but with less hardware.
Publication Title
2016 27th Irish Signals and Systems Conference, ISSC 2016
Recommended Citation
Mai, D., Mo, H., & Kennedy, M. (2016). Comparison of the simulated performance of two divider controllers in a fractional-N frequency synthesizer with a piecewise-linear charge-pump nonlinearity. 2016 27th Irish Signals and Systems Conference, ISSC 2016 https://doi.org/10.1109/ISSC.2016.7528444
