Locating RFID tags
US8289129B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 2008 |
| Grant date | Oct 16, 2012 |
| Priority date | — |
| Expiry date | Apr 18, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S11/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and RFID tag for locating RFID tags. A passive RFID tag A receives a polling command transmitted from a RFID reader and addressed to another passive RFID tag B. The RFID tag A determines that the polling command is not addressed to the RFID tag A and consequent1y, at time t1, switches the RFID tag A to a catching mode for catching echos from other tags. The RFID tag A receives at time t3>t1 an echo of a message sent by the RFID tag B to the RFID reader. The RFID tag A determines a distance (D.t2t) between the RFID tag A and the RFID tag B based on t3 minus t1. The distance D.t2t does not exceed a specified radius limit and the identification of the RFID tag B and the distance D.t2t are stored in a database within the RFID tag A.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.