Reduced-noise frequency divider system
View Patent ↗Embodiments of a reduced noise reduction system (“RNFDS”) include a frequency divider and a resampler in signal communication with the frequency divider. The frequency divider receives an input signal and, in response, produces a divided signal. The input signal has a first frequency and the divided signal has a second frequency, different from the first frequency. The resampler receives the input signal and the divided signal, and resamples the divided signal using the input signal as a sampling clock signal to produce a resampled output signal. The frequency divider imposes edge jitter on the divided signal. Resampling the divided signal produces the resampled output signal with an edge jitter comparable with that of the input signal.
1. A reduced-noise frequency divider system (“RNFDS”), comprising:
a frequency divider configured to receive an input signal and, in response, to produce a divided signal; and
a resampler connected to receive the input signal and the divided signal, and operable in response to the input signal to resample the divided signal to produce a resampled output signal; wherein:
the RNFDS additionally comprises a delay module connected to receive the divided signal and operable to produce a delayed divided signal; and
the resampler comprises:
a first resampler connected to receive the divided signal and an antiphase component of the input signal and operable in response to the antiphase component of the input signal to resample the divided signal to produce a first resampled signal component,
a second resampler connected to receive the delayed divided signal and an in-phase component of the input signal and operable in response to the in-phase component of the input signal to resample the delayed divided signal to produce a second resampled signal component, and
a summing node at which the resampled signal components are summed to produce the resampled output signal.
2. The RNFDS of claim 1 , additionally comprising a filter connected to receive the resampled output signal and operable to filter the resampled output signal to produce a filtered resampled output signal.
3. The RNFDS of claim 1 , additionally comprising a filter connected to receive the resampled output signal and operable to filter the resampled output signal to produce a filtered resampled output signal.
4. The RNFDS of claim 3 , in which the filter is a low-pass filter.
5. The RNFDS of claim 1 , additionally comprising an inverter connected to receive the input signal and operable to invert the input signal to produce the antiphase component of the input signal.
6. The RNFDS of claim 1 , in which the input signal is a differential signal.
7. The RNFDS of claim 1 , in which the frequency divider is a divide-by-N frequency divider, where N is the modulus of the frequency divider.
8. A reduced-noise frequency dividing method, comprising:
receiving an input signal;
dividing the input signal in frequency to produce a divided signal; and
resampling the divided signal using the input signal as a sampling clock signal to produce a resampled output signal; wherein:
the method additionally comprises delaying the divided signal to produce a delayed divided signal, and
the resampling comprises:
resampling the divided signal using an antiphase component of the input signal as a sampling clock signal component to produce a first resampled signal component,
resampling the delayed divided signal using an in-phase component of the input signal as a sampling clock signal component to produce a second resampled signal component, and
summing the resampled signal components to produce the resampled output signal.
9. The method of claim 8 , additionally comprising filtering the resampled output signal to produce a filtered resampled output signal.
10. The method of claim 8 , additionally comprising filtering the resampled output signal to produce a filtered resampled output signal.
11. The method of claim 10 , in which the filtering comprises low-pass filtering.
12. The method of claim 8 , in which the receiving comprises inverting the input signal to produce the antiphase component of the input signal.
13. A reduced-noise frequency divider system (“RNFDS”), comprising:
means for dividing an input signal in frequency to produce a divided signal; and
means for resampling the divided signal in response to the input signal to produce a resampled output signal; wherein
the RNFDS additionally comprises means for delaying the divided signal to produce a delayed divided signal; and
the means for resampling comprises:
means for resampling the divided signal using an antiphase component of the input signal as a sampling clock signal component to produce a first resampled signal component,
means for resampling the delayed divided signal using an in-phase component of the input signal as a sampling clock signal component to produce a second resampled signal component, and
means for summing the resampled signal components to produce the resampled output signal.
14. The RNFDS of claim 13 , additionally comprising means for filtering the resampled output signal to produce a filtered output signal.
15. The RNFDS of claim 13 , additionally comprising means for filtering the resampled output signal to produce a filtered resampled output signal.
16. The RNFDS of claim 13 , additionally comprising means for inverting the input signal to produce the antiphase component of the input signal.
17. The RNFDS of claim 13 , in which the means for frequency dividing comprises a divide-by-N frequency divider, where N is the modulus of the frequency divider.