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. 07, 2009
Filed:
Mar. 10, 2008
Christopher H. Dick, San Jose, CA (US);
Frederic J. Harris, Lemon Grove, CA (US);
Christopher H. Dick, San Jose, CA (US);
Frederic J. Harris, Lemon Grove, CA (US);
XILINX, Inc., San Jose, CA (US);
Abstract
Method and apparatus for digital frequency synthesis are described. A frequency synthesizer has an accumulator, an adder, and a predictive filter. The adder is configured to subtract a predicted error from a phase profile signal. A quantized version of the phase profile signal is separated from an error portion thereof. The predictive filter, set for a fraction of a sample frequency bandwidth, is coupled to receive the error portion for generation of a next predicted error. A storage device has digital representations of sinusoidal signals accessible responsive to the quantized version of the phase profile signal. A digital-to-analog converter is coupled to receive a digital representation of a sinusoidal signal obtained from the storage device to provide an analog sinusoidal signal. An anti-imaging filter is coupled to receive the analog sinusoidal signal and configured to filter out noise.