Title: Device for contactless transmission of data
Application Number: 99808617 Application Date: 1999.05.11
Publication Number: 1309793 Publication Date: 2001.08.22
Approval Pub. Date: 2006.05.10 Granted Pub. Date: 2006.05.10
International Classifi-cation: G06K7/00;G06K19/07
Applicant(s) Name: Infineon Tech. AG. Address:
Inventor(s) Name: L. Gaul;M. Heling
Attorney & Agent: ma tieliang
Abstract:
    The aim of the invention is to reduce the power required to produce a magnetic alternating field of a data transmission/receiving device for operating at least one portable data support. To this end, the impedance of the antenna of the data transmission/receiving device is deliberately mismatched. A reactance is introduced into the antenna in order to tune the antenna outside of the resonance. In the event that the antenna impedance has to be adapted to the characteristic impedance of a line of unknown length, the loss resistance of the antenna is deliberately increased.
Time: 12