Miscellaneous active electrical nonlinear devices – circuits – and – Signal converting – shaping – or generating – Synchronizing
Reexamination Certificate
2005-10-04
2005-10-04
Lam, Tuan T. (Department: 2816)
Miscellaneous active electrical nonlinear devices, circuits, and
Signal converting, shaping, or generating
Synchronizing
C377S048000, C331S025000
Reexamination Certificate
active
06952125
ABSTRACT:
A system and method for improving the signal-to-noise ratio of a frequency generator suppresses phase noise and noise generated from mismatches in the internal generator circuits. This is accomplished using a modulation scheme which shifts spurious noise signals outside the loop bandwidth of the generator. When shifted in this manner, the noise signals maybe removed entirely or to any desired degree using, for example, a filter located along the signal path of the generator. In one embodiment, a Sigma-Delta modulator controls the value of a pulse-swallow frequency divider situated along a feedback path of a phase-locked loop to achieve a desired level of noise suppression. In another embodiment, a reference signal input into a phase-locked loop is modulated to effect noise suppression. In another embodiment, the foregoing forms of modulation are combined to accomplish the desired frequency shift. Through these modulation techniques, the signal-to-noise ratio of the frequency generator may be substantially improved while simultaneously achieving faster lock times.
REFERENCES:
patent: 5038117 (1991-08-01), Miller
patent: 5070310 (1991-12-01), Hietala et al.
patent: 5777521 (1998-07-01), Gillig et al.
patent: 6566964 (2003-05-01), Hirano
patent: 6603360 (2003-08-01), Kim et al.
patent: 6642800 (2003-11-01), Drapkin et al.
patent: 2002/0030546 (2002-03-01), Keating
patent: 2002/0033738 (2002-03-01), Saeki et al.
patent: 2003/0062959 (2003-04-01), Tsuda et al.
Behzad Razavi, RF MICROELECTRONICS, Chapter 8.
Ahn Young-ho
Koo Yi-do
Lee Jeong-Woo
Lee Kyeongho
Park Joonbae
Fleshner & Kim LLP
GCT Semiconductor Inc.
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