Validation of the presence of an electromagnetic transponder in the field of a phase demodulation reader
First Claim
1. A terminal for generating an electromagnetic field adapted to communicating with at least one transponder entering this field, including:
- an oscillating circuit adapted to being excited by a high-frequency remote supply signal of the transponder;
a phase demodulator for detecting possible data transmitted by the transponder by modulating, at a rate of a sub-carrier, a load that it forms on the terminal'"'"'s oscillating circuit;
and including;
means for regulating a signal phase in the terminal'"'"'s oscillating circuit in response to a reference value having a long response time as compared to said sub-carrier;
means for measuring variables linked to a current in the oscillating circuit and to the voltage thereacross;
means for comparing present values of these variables with predetermined values; and
means for deactivating said phase regulation means.
1 Assignment
0 Petitions
Accused Products
Abstract
A terminal for generating an electromagnetic field adapted to communicating with at least one transponder, and a method for controlling such a terminal including: an oscillating circuit adapted to being excited by a remote supply signal of the transponder; a phase demodulator for detecting possible data transmitted by the transponder; circuitry for regulating the signal phase in the terminal'"'"'s oscillating circuit on a reference value; circuitry for measuring variables linked to the current in the oscillating circuit and to the voltage thereacross; and circuitry for comparing current values of these variables with predetermined values, to determine the presence of a transponder.
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Citations
14 Claims
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1. A terminal for generating an electromagnetic field adapted to communicating with at least one transponder entering this field, including:
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an oscillating circuit adapted to being excited by a high-frequency remote supply signal of the transponder; a phase demodulator for detecting possible data transmitted by the transponder by modulating, at a rate of a sub-carrier, a load that it forms on the terminal'"'"'s oscillating circuit; and including; means for regulating a signal phase in the terminal'"'"'s oscillating circuit in response to a reference value having a long response time as compared to said sub-carrier; means for measuring variables linked to a current in the oscillating circuit and to the voltage thereacross; means for comparing present values of these variables with predetermined values; and means for deactivating said phase regulation means. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for controlling a terminal for generating an electromagnetic field adapted to communicating with at least one transponder entering this field, the terminal including an oscillating circuit adapted to being excited by a high-frequency remote supply signal of the transponder, a phase demodulator for detecting possible data transmitted by the transponder by modulating, at a rate of a sub-carrier, a load that it forms on the terminal'"'"'s oscillating circuit;
- means for regulating a signal phase in the terminal'"'"'s oscillating circuit in response to a reference value having a long response time as compared to said sub-carrier, means for measuring variables linked to a current in the oscillating circuit and to the voltage thereacross, and means for comparing present values of these variables with predetermined values, the method including;
exploiting the results of the comparison means to detect the presence of a transponder in the terminal'"'"'s field; and deactivating the phase regulation means. - View Dependent Claims (9, 10, 11, 12, 13, 14)
- means for regulating a signal phase in the terminal'"'"'s oscillating circuit in response to a reference value having a long response time as compared to said sub-carrier, means for measuring variables linked to a current in the oscillating circuit and to the voltage thereacross, and means for comparing present values of these variables with predetermined values, the method including;
Specification