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. 08, 2005
Filed:
May. 30, 2001
Applicant:
Gakuji Uozumi, Omiya, JP;
Inventor:
Gakuji Uozumi, Omiya, JP;
Assignee:
Mitsubishi Materials Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B001/00 ;
U.S. Cl.
CPC ...
Abstract
An antenna device of an interrogator which constitutes an automatic identification system by exchanging information with an IC tag attached to an object to be identified by electromagnetic coupling is disclosed. The antenna device comprises an antenna element, and a capacitor connected in series to the antenna element and having a variable capacitance to maintain a predetermined resonance frequency. The predetermined resonance frequency is maintained by switching taps on an antenna coil. Alternatively, the predetermined resonance frequency is maintained by switching taps on a tapped inductor or by a variable inductor.