Item finding using RF signalling
US7142120B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2004 |
| Grant date | Nov 28, 2006 |
| Priority date | — |
| Expiry date | Feb 9, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/751
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Methods and apparatus are provided for locating one among many items equipped with RFID tags. The apparatus comprises a portable system interrogating the RFID tags and receiving responses therefrom that depend at least on their bearing angle. A comparator selects responses from the one item and ignores others. An annunciator indicates the presence of the one item in the interrogator field of view and, desirably but not essentially, its relative proximity. A directional antenna whose beam pattern is limited in azimuth and/or elevation provides bearing angle information. Its field of view becomes progressively smaller as the antenna approaches the one item so that a user can substantially pinpoint its location without needing any of the usual RFID infrastructure. Tag response hit rate and/or signal strength provides range related information to the interrogator. Optionally, the presence of each new tag is announced until all new tags have been identified.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.