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US 8,798,535 B2Granted
NFC card sensitive to eddy currents
AssigneeInside Secure
InventorsBruno Charrat, Nicolas Cordier
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Abstract
An NFC card includes an antenna circuit including an antenna coil having at least one magnetic axis, and at least one integrated circuit linked to the antenna circuit. The magnetic axis of the antenna coil is substantially parallel to the plane of the card, and is at an angle of 45°±25° with respect to a longitudinal axis LX of the card. Embodiments of the invention are applicable in particular to SIM-NFC card and SD-NFC cards.
Claims14
An NFC card comprising:
- an antenna circuit comprising at least one antenna coil having one magnetic axis, and
- at least one integrated circuit linked to the antenna circuit,
- wherein the magnetic axis of the antenna coil is substantially parallel to the plane of the card, and the magnetic axis of the antenna coil is at an angle between 20° and 70° with respect to a longitudinal axis of the card.
A method for performing a contactless communication between an NFC card and an NFC external device, the method comprising:
- providing an NFC card comprising:
- an antenna circuit including at least one antenna coil having one magnetic axis, and
- at least one integrated circuit linked to the antenna circuit,
- wherein the magnetic axis of the antenna coil is substantially parallel to the plane of the card, and the magnetic axis of the antenna coil is at an angle between 20° and 70° of with respect to a longitudinal axis of the card, and
- wherein the card further comprises at least one electrically conductive screen extending near the antenna coil, which does not cross the magnetic axis, and the card does not include any magnetically permeable material between the at least one conductive screen and the antenna coil,
- setting a tuning frequency of the antenna circuit of the card in the presence of the at least one electrically conductive screen,
- emitting a first oscillating magnetic field with the external device,
- placing the card near the edges of a printed circuit board, and
- sensing, with the antenna coil of the NFC card, a counter magnetic field generated by eddy currents in the printed circuit board, to increase the maximum communication distance between the card and the external device.
6 more elements
Dependencies are inferred from the claim text.