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. 21, 1990
Filed:
Apr. 22, 1988
Applicant:
Inventor:
Kenneth A Essenwanger, Walnut, CA (US);
Assignee:
Hughes Aircraft Company, Los Angeles, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03K / ;
U.S. Cl.
CPC ...
364721 ; 328 14 ;
Abstract
A direct digital synthesizer (DDS) accumulator circuit is disclosed wherein a selected few of the low order accumulator bits are dithered by a pseudorandom number generator in order to introduce flat frequency deviation density to suppress spurious signals including those close-in to the output or fundamental frequency. The accumulator circuit may advantageously be sectioned into a lower order accumulator and higher order accumulator in a pipelined combination with a sine approximation output circuit in order to construct a DDS circuit wherein such spur suppression is achieved without decreasing system throughput.