The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 03, 2009
Filed:
Sep. 21, 2007
Matthew Ming Fai Yuen, Hong Kong, CN;
BO Gao, Hong Kong, CN;
Ross David Murch, Hong Kong, CN;
Chi Ho Cheng, Hong Kong, CN;
Matthew Ming Fai Yuen, Hong Kong, CN;
Bo Gao, Hong Kong, CN;
Ross David Murch, Hong Kong, CN;
Chi Ho Cheng, Hong Kong, CN;
The Hong Kong University of Science and Technology, Kowloon, HK;
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 chipfor storing data, an antennaand an electromagnetic band gap substrate. The RFID chipand the antennaare mounted above the electromagnetic band gap substrate. 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 layerswith a dielectric in between.