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. 01, 2003
Filed:
Jun. 27, 2000
Ken Gentile, Bahama, NC (US);
John Kornblum, Greensboro, NC (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
Direct digital synthesis (DDS) methods and structures are provided that increase DDS output frequencies f without requiring a corresponding increase in the rate f at which DDS structures must operate. An exemplary method generates a periodic stream of digital words at a clock frequency f wherein the words represent respective amplitudes of a predetermined periodic waveform, the periodic stream has a period P and the digital words are spaced by a phase step &phgr; . This method comprises the steps of a) with a count capacity C, counting modulo n&phgr; at a reduced clock frequency (1/n)f to thereby generate a primary substream of digital words, b) phase offsetting the primary substream to form n−1 secondary substreams of digital words wherein the primary and secondary substreams are phase spaced by the phase step &phgr; , c) converting the digital words of each of the primary, and secondary substreams to converted digital words that represent respective amplitudes of the predetermined waveform, and d) interleaving the primary and secondary substreams to thereby form the periodic stream of digital words that occur at the clock frequency f .