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:
Dec. 15, 2015
Filed:
Mar. 22, 2013
Symbol Technologies, Inc., Schaumburg, IL (US);
Timothy B. Austin, Stony Brook, NY (US);
Symbol Technologies, LLC, Holtsville, NY (US);
Abstract
Determining movement of a Radio Frequency Identification (RFID) tag first establishes a phase difference/frequency model comprising a set of phase-wrapped local rates-of-change and an intercept point. RFID tag readings are then made to measure phase differences between the interrogation signal and the tag response at different frequencies. A correlation is determined between the measured phase differences versus frequency and the phase-wrapped local phase rates-of-change of the phase difference/frequency model. If the correlation is better than or equal to a predetermined limit, the tag is stationary, or if the correlation is worse than the predetermined limit, the tag is moving.