Detection of change in generated magnetic field due to tag-loading
First Claim
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1. A Near Field Communication method comprising:
- generating, by an antenna of a transmitter, a magnetic field;
receiving, by an antenna of a tag, power from the generated magnetic field which causes a drop in the magnetic field;
estimating the drop in the magnetic field, wherein estimating the drop in the magnetic field further comprises;
sensing a voltage swing across the transmitter antenna; and
separating a first signal representative of a drop in the magnetic field from a second signal representative of information transmitted by the tag through modulation of the magnetic field; and
compensating at least partly for the drop in the magnetic field based on the first signal.
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Abstract
The invention concerns a Near Field Communication method comprising a step (1) of generating, by an antenna of a transmitter, a magnetic field (H), a step (2) of receiving, by an antenna of a tag, power from the generated magnetic field (H), then causing a drop in the generated magnetic field (H), wherein the method further comprises a step (3) of estimating the drop by sensing a voltage swing across said transmitter antenna.
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Citations
13 Claims
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1. A Near Field Communication method comprising:
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generating, by an antenna of a transmitter, a magnetic field; receiving, by an antenna of a tag, power from the generated magnetic field which causes a drop in the magnetic field; estimating the drop in the magnetic field, wherein estimating the drop in the magnetic field further comprises; sensing a voltage swing across the transmitter antenna; and separating a first signal representative of a drop in the magnetic field from a second signal representative of information transmitted by the tag through modulation of the magnetic field; and compensating at least partly for the drop in the magnetic field based on the first signal. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A Near Field Communication transmitter comprising;
- a transmitter antenna configured to generate a magnetic field;
a sensor configured to sense a voltage swing across the transmitter antenna caused by a drop in the magnetic field caused by a tag antenna configured to receive power from the magnetic field; the transmitter configured to estimate the drop in the magnetic field, wherein estimating the drop in the magnetic field includes sensing a voltage swing across the transmitter antenna and separating a first signal representative of a drop caused by the tag antenna entering the magnetic field from a second signal representative of information transmitted by the tag through modulation of the magnetic field; and
the transmitter configured to compensate at least in part for the drop in the magnetic field based on the first signal. - View Dependent Claims (8, 9, 10, 11, 12, 13)
- a transmitter antenna configured to generate a magnetic field;
Specification