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:
Oct. 02, 2012
Filed:
Dec. 29, 2009
Stephen Mark Beccue, Thousand Oaks, CA (US);
Stephen Mark Beccue, Thousand Oaks, CA (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
A frequency synthesis circuit is disclosed. The circuit includes a phase-locked loop and multi-phase oscillator such as a rotary traveling wave oscillator (RTWO). The oscillator provides a plurality of phases that are applied to a selection circuit. The selection circuit, in response to the output of a delta-sigma modulator, selects one of the phases of the multi-phase oscillator to minimize phase shift noise when the divider ratio in the loop changes, thereby eliminating a source of noise that contaminates the synthesized frequency. This permits the use of the frequency synthesis in applications requiring a high degree of spectral purity.