Shield element for mounting on an object
First Claim
1. A shield element for attachment to an object, the object containing a transponder chip and a transmission antenna connected to the transponder chip, the shield element comprising:
- a carrier made of electrically nonconductive material;
a closed or closable conductor track on said carrier, said conductor track, when the shield element is mounted to the object, shielding against electromagnetic fields generated by an external read device and oriented onto the transmission antenna of the transponder chip of the object, said conductor track forming an antenna; and
a resonant oscillating circuit including at least one capacitor and said antenna;
said resonant oscillating circuit including at least one switch arranged so that, upon actuation of said switch, an element of said oscillating circuit is short-circuited or deactivated, or a further element of the oscillating circuit selected from the group consisting of a further capacitor, a resistor, and a further coil is switched into said oscillating circuit, so that a resonant frequency thereof changes by at least 10%.
1 Assignment
0 Petitions
Accused Products
Abstract
A shield element for mounting on an object, in particular a flat object, such as a chip card. The object has a base body, an RFID or NFC transponder, a transponder chip and a coil-shaped transmission antenna connected to the RFID or NFC transponder chip. The shield element has a carrier made of non-conductive material. The carrier has a closed or closable conducting path which, upon mounting the shield element on the object, shields the object from the electromagnetic fields generated by an external reading device and directed at the transmission antenna of the RFID or NFC transponder chip.
32 Citations
19 Claims
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1. A shield element for attachment to an object, the object containing a transponder chip and a transmission antenna connected to the transponder chip, the shield element comprising:
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a carrier made of electrically nonconductive material; a closed or closable conductor track on said carrier, said conductor track, when the shield element is mounted to the object, shielding against electromagnetic fields generated by an external read device and oriented onto the transmission antenna of the transponder chip of the object, said conductor track forming an antenna; and a resonant oscillating circuit including at least one capacitor and said antenna; said resonant oscillating circuit including at least one switch arranged so that, upon actuation of said switch, an element of said oscillating circuit is short-circuited or deactivated, or a further element of the oscillating circuit selected from the group consisting of a further capacitor, a resistor, and a further coil is switched into said oscillating circuit, so that a resonant frequency thereof changes by at least 10%. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification