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:
May. 20, 2008
Filed:
Oct. 29, 2005
Shengbo Zhu, San Jose, CA (US);
Su Shiong Huang, Bellevue, WA (US);
Shengbo Zhu, San Jose, CA (US);
Su Shiong Huang, Bellevue, WA (US);
Magnex Corporation, San Jose, CA (US);
Abstract
An RFID tag having an rfid integrated circuit and an antenna is combined with a first passive antenna circuit to provide an extended operating range. The first passive antenna circuit has a first coil and a first capacitor to tune the passive antenna circuit to a resonant frequency the same as the operating frequency of the RFID tag. The first coil has a central opening larger than the size of the antenna. The passive antenna circuit is arranged with the antenna located in the central opening of the coil, preferably in a co-planar manner, to promote inductive interaction therebetween. A second passive antenna circuit essentially identical to the first, but having larger dimensions, is positioned with the coil of the second passive antenna circuit surrounding the first coil to extend the operating range even further.