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:
Jan. 08, 2013
Filed:
Feb. 28, 2012
Kurt E. Sundstrom, Woodinville, WA (US);
Scott A. Cooper, Seattle, WA (US);
Amir Sarajedini, Aliso Viejo, CA (US);
Aanand Esterberg, Seattle, WA (US);
Todd E. Humes, Shoreline, WA (US);
Christopher J. Diorio, Shoreline, WA (US);
Kurt E. Sundstrom, Woodinville, WA (US);
Scott A. Cooper, Seattle, WA (US);
Amir Sarajedini, Aliso Viejo, CA (US);
Aanand Esterberg, Seattle, WA (US);
Todd E. Humes, Shoreline, WA (US);
Christopher J. Diorio, Shoreline, WA (US);
Impinj, Inc., Seattle, WA (US);
Abstract
RFID tags are commanded to generate a pilot tone in their backscatter. When the backscattered pilot tone is received in the reader, the pilot tone is used to estimate the tag period/frequency. Then, the estimate is used to seed and lock a symbol timing recovery loop, which provides a detected signal to one or more correlators for detecting the tag preamble. A delayed version of the received tag signal is compared against a baseline signal threshold established from the received signal to detect the pilot tone.