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:
Mar. 22, 2011
Filed:
Sep. 28, 2006
Kan Tan, Beaverton, OR (US);
John C. Calvin, Portland, OR (US);
Kalev Sepp, Portland, OR (US);
Tektronix, Inc., Beaverton, OR (US);
Abstract
A method of measuring transport delay and jitter with a realtime oscilloscope using cross-correlation acquires waveforms from two test points in a system under test. Clock recovery is run on both waveforms to obtain respective rates and offsets. A time offset between the two waveforms is computed. The jitter from the two test points is filtered and a mean-removed cross-correlation coefficient is computed from the filtered jitters. A fractional delay is computed using interpolation based on LMS error, and the respective computational components are summed to compute a transport delay between the two test points. The transport delay may be used to adjust clock edges from one waveform for comparison with data transition edges of the other waveform to measure jitter.