RFID system with barriers and key antennas
US8933788B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 2012 |
| Grant date | Jan 13, 2015 |
| Priority date | — |
| Expiry date | Jul 14, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/10287
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An RFID system includes a reader with antenna, a first barrier, a tag with a link antenna, a second barrier, and two key antennas connected to the tag, mechanically arranged in that order. The first barrier has two or more apertures in it to produce an interference pattern of a security signal from the reader. The security signal interference pattern passes at least partly through the second barrier. One of the key antennas is at a peak of the pattern after passing through the second barrier, and one is not. The tag includes a controller responsive to a downlink signal from the reader to transmit an uplink signal using the link antenna, but only if the downlink signal is preceded by the security signal and the security signal is received more strongly by the key antenna at the peak than by the other key antenna.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.