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:
Feb. 01, 2005
Filed:
Oct. 04, 2001
Philippe Held, Corseaux, CH;
Egon Konopitzky, Chatel-St-Denis, CH;
Martin Miehling, Granges, CH;
Reinhard Jurisch, Erfurt, DE;
Peter Peitsch, Erfurt, DE;
Philippe Held, Corseaux, CH;
Egon Konopitzky, Chatel-St-Denis, CH;
Martin Miehling, Granges, CH;
Reinhard Jurisch, Erfurt, DE;
Peter Peitsch, Erfurt, DE;
Sokymat S.A., Granges, CH;
Abstract
A transponder unit which can be integrated in a transport unit or a card or the like. The transponder unit includes, in addition to an encapsulated transponder of an integrated circuit, an aerial winding having a resistance Rand a capacitor parallel thereto and having a capacitance C. A closed coupling circuit of secondary winding is coupled with the aerial winding by a mutual inductance Mand a substantially larger primary winding in series with the secondary winding and having fewer turns, for example only one turn. To achieve almost optimum energy transfer between a reading device and the transponder and to increase the permissible reading distance, the mutual inductance Mis adjusted to comply with the relationship M=√{square root over ( )}[R/ω) (L+L+2M)], where ω=1/(LC) is true for the receiving frequency ω of the transponder and Land Lare the inductances of the primary winding and of the secondary winding and Mis their mutual inductance.