RFID tag and antenna
US7612676B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 2007 |
| Grant date | Nov 3, 2009 |
| Priority date | — |
| Expiry date | Jul 3, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q15/008
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The present invention relates to an RFID Tag and Antenna for use with an RFID tag and a method of radio frequency identification (RFID). The RFID Tag comprises a RFID chip 5 for storing data, an antenna 6 and an electromagnetic band gap substrate 12. The RFID chip 5 and the antenna 6 are mounted above the electromagnetic band gap substrate 12. The electromagnetic band gap substrate has a reflection phase which is different from 180° at the operation frequency of the antenna. The electromagnetic band gap substrate enables the RFID to operate even if it is mounted on a conductive object, as the reflection phase is not 180° so it does not destructively interfere with the radiation from the antenna at the operating frequency. Preferably the reflection phase is between 340° and 115° or −95° and 145°. The preferred embodiment uses a band gap substrate having two mushroom-like conductive layers 3, 7 with a dielectric in between.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.