The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 25, 2006
Filed:
Aug. 05, 2005
Bardo Müller, Dreieich, DE;
Jörg Hüster, Langen, DE;
Thomas Musch, Mühlheim/Ruhr, DE;
Fujitsu Limited, Kawasaki, JP;
Abstract
A variable frequency synthesizer comprising a sigma-delta modulator is provided. Such synthesizers provide an exact average frequency whereas the instantaneous frequencies varies. The sigma-delta modulator comprises a plurality of accumulator stages being connected in cascade. At least one input value of an accumulator () being part of the sigma-delta modulator has a second component which is equal to an overflow signal (of, of, of, of) multiplied by a factor. This feedback reduces the-maximum fluctuation of the instantaneous frequencies. Phase jitter generated by non-linearities of the phase detector, the charge pump and the VCO is therefore reduced.