System and method of estimating true bearings of radio frequency identification (RFID) tags associated with items located directly underneath an overhead antenna array in a controlled area
US9361494B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 9, 2014 |
| Grant date | Jun 7, 2016 |
| Priority date | — |
| Expiry date | Dec 19, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S3/16
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An RFID tag reading system and method estimate true bearings of RFID tags associated with items located in a scan zone directly underneath an overhead array of antenna elements. A controller energizes a plurality of diametrically opposite antenna elements to yield electric fields having polarizations, and switches each antenna element between mutually orthogonal polarizations. A primary transmit beam and a primary receive beam are steered at a primary steering angle over the scan zone, and a plurality of secondary receive beams are steered over the scan zone at different secondary steering angles that are offset from the primary steering angle by receiving secondary receive signals from each tag, and by processing the secondary receive signals to estimate a true bearing for each tag.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.