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:
Aug. 31, 2010
Filed:
May. 30, 2008
Manuel P. Gabato, Jr., Elmhurst, IL (US);
John J. Bozeki, Elgin, IL (US);
Joseph A. Charaska, Melrose Park, IL (US);
Paul H. Gailus, Prospect Heights, IL (US);
Manuel P. Gabato, Jr., Elmhurst, IL (US);
John J. Bozeki, Elgin, IL (US);
Joseph A. Charaska, Melrose Park, IL (US);
Paul H. Gailus, Prospect Heights, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A method and apparatus for reducing in-band spurs in a fractional-N synthesizer () includes generating a compensated current signal by a charge pump () coupled to a phase detector (). The compensated current signal includes in-band spurs having frequencies within a frequency bandwidth associated with a loop filter (). The method then includes selectively dithering the compensated current signal with a sufficient dither level to spread the frequencies of in-band spurs beyond the frequency bandwidth associated with the loop filter (). The dithered compensated current signal is then passed through the loop filter () for filtering the in-band spurs having frequencies beyond the frequency bandwidth. The method then includes generating a voltage controlled oscillator (VCO) signal with reduced in-band spurs proportional to the filtered compensated current signal.