Fractional-N phase locked loop

Details Fractional-N phase locked loop Fractional-N phase locked loop

2007-05-25

2009-10-20

Mis, David (Department: 2817)

Oscillators

Automatic frequency stabilization using a phase or frequency...

Tuning compensation

C331S00100A, C331S025000

Reexamination Certificate

active

07605665

ABSTRACT:
An apparatus and method is disclosed to substantially reduce phase noise introduced in fractional-N phase-locked loop (PLL) through feedback modulation. A fractional frequency divider is introduced in the feedback path of the PLL to generate a true fractional division factor with finite fractional steps to increase the resolution of the PLL by a factor equal to the inverse of the finite step size in the fractional frequency divider. Increasing the resolution of the PLL reduces phase noise. The fractional frequency divider uses the true fractional division factor to divide the frequency of a single output of a multi-phased voltage controlled oscillator (VCO) by the fractional division factor to match the frequency of the divided feedback signal to frequency a reference signal. The fractional frequency divider incrementally selects among all the outputs of the multi-phased VCO according to either a forward phase shifting operation or a backward phase shifting operation to generate a true fractional division factor.

REFERENCES:
patent: 5970110 (1999-10-01), Li
patent: 6714056 (2004-03-01), Fallahi et al.
patent: 7042258 (2006-05-01), Booth et al.
patent: 7356111 (2008-04-01), Dean
patent: 2003/0198311 (2003-10-01), Song et al.
patent: 2003/0231069 (2003-12-01), Chiang et al.
patent: 2005/0197073 (2005-09-01), Klemmer
patent: 2006/0245531 (2006-11-01), Leonowich et al.
patent: 2007/0285176 (2007-12-01), North
Meninger, S.,Sigma-Delta Fractional-N Frequency Synthesis, Massachusetts Institute of Technology, Jun. 7, 2004, downloaded from http://www-mtl.mit.edu/˜coyote/rfic6.pdf.

Affiliated with

Also associated with

Rating

Fractional-N phase locked loop does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Fractional-N phase locked loop, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fractional-N phase locked loop will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-4076598