Object location system and method using RFID
US7119738B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 1, 2004 |
| Grant date | Oct 10, 2006 |
| Priority date | — |
| Expiry date | Sep 30, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S2013/466
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and method is provided for locating objects using RFID tags. The system and method uses an RFID reader and a distance calculator to efficiently and accurately determine the location of objects that include an RFID tag. The RFID reader transmits a plurality of signals to the RFID tag, with the plurality of signals having different fundamental frequencies. In response, the RFID tag backscatter modulates the plurality of transmitted signals to create a plurality of backscatter modulated signals. The RFID reader receives and demodulates the plurality of backscatter modulated signals. The distance calculator determines the phase of the plurality of backscatter modulated signals and determines a rate of change of the phase in the backscatter modulated signals with respect to the rate of change in the fundamental frequency of the transmitted signals and uses this information to calculate the distance to the RFID tag.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.