INDUCTIVE EVALUATION OF THE COUPLING FACTOR OF AN ELECTROMAGNETIC TRANSPONDER
First Claim
1. A method for evaluating the current coupling factor between an electromagnetic transponder and a terminal, wherein a ratio between data representative of a voltage across an oscillating circuit of the transponder and obtained for two pairs of inductive and capacitive values of this oscillating circuit, is compared with one or several thresholds, the two pairs of values preserving a tuning of the oscillating circuit to a same frequency.
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Accused Products
Abstract
A method for evaluating the current coupling factor between an electromagnetic transponder and a terminal, wherein a ratio between data representative of a voltage across an oscillating circuit of the transponder and obtained for two pairs of inductive and capacitive values of this oscillating circuit is compared with one or several thresholds, the two pairs of values preserving a tuning of the oscillating circuit to a same frequency.
26 Citations
11 Claims
- 1. A method for evaluating the current coupling factor between an electromagnetic transponder and a terminal, wherein a ratio between data representative of a voltage across an oscillating circuit of the transponder and obtained for two pairs of inductive and capacitive values of this oscillating circuit, is compared with one or several thresholds, the two pairs of values preserving a tuning of the oscillating circuit to a same frequency.
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7. An electromagnetic transponder comprising:
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an oscillating circuit upstream of a rectifying circuit capable of providing a D.C. voltage when the transponder is in the magnetic field of a terminal; and at least one switchable inductive element and at least one switchable capacitive element capable of being functionally connected in parallel with the oscillating circuit. - View Dependent Claims (8, 9, 10)
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Specification