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. 14, 2015
Filed:
Mar. 11, 2013
Raytheon Company, Waltham, MA (US);
Jack W. Lee, Sudbury, MA (US);
David M. Upton, Sudbury, MA (US);
Michael E. Yeomans, Sudbury, MA (US);
Marc S. Wald, Sudbury, MA (US);
James P. Dumais, Sudbury, MA (US);
Raytheon Company, Waltham, MA (US);
Abstract
A high spectral purity swept local oscillator including a tracking filter. The output of a swept DDS oscillator may be improved by filtering it with a band-pass filter having an adjustable center frequency, which is adjusted in real time to track the instantaneous frequency of the DDS oscillator. The tracking may be accomplished by comparing, using a phase comparator, the phase at the output of the band-pass filter to the phase at its input, and feeding back to the frequency control input of the band-pass filter a signal corresponding to the phase difference measured by the phase comparator.