DETECTION OF A CONTACTLESS DATA STORAGE DEVICE
First Claim
1. A detection circuit for detecting, within a communication range of an antenna for emitting an electromagnetic field, a contactless data storage device which is configured for inductive coupling with the electromagnetic field, the detection circuit comprising:
- a connector for connecting to the antenna and for detecting a return signal at the antenna during emission of an electromagnetic field pulse,wherein the detection circuit is further configured to generate, during amplitude build-up of carrier oscillation at the beginning of the electromagnetic field pulse, an evaluation signal based on the return signal, andto detect the data storage device within the communication range based on the evaluation signal generated during the amplitude build-up and a threshold value.
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Accused Products
Abstract
For detecting within a communication range of an antenna a contactless data storage device which is configured for inductive coupling with an electromagnetic field emitted by the antenna, a return signal is detected (S1) at the antenna during emission of an electromagnetic field pulse. During amplitude build-up of carrier oscillation at the beginning of the electromagnetic field pulse, an evaluation signal is generated (S2) based on the return signal, and the data storage device is detected (S3) based on the evaluation signal. By detecting the presence of the data storage device based on an evaluation signal generated during amplitude build-up, the detection of the data storage device can be initiated before carrier oscillation of the electromagnetic field pulse is stable. Consequently, the width of the electromagnetic field pulse can be shortened and, therefore, energy consumption for detecting the presence of the data storage device can be reduced.
17 Citations
18 Claims
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1. A detection circuit for detecting, within a communication range of an antenna for emitting an electromagnetic field, a contactless data storage device which is configured for inductive coupling with the electromagnetic field, the detection circuit comprising:
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a connector for connecting to the antenna and for detecting a return signal at the antenna during emission of an electromagnetic field pulse, wherein the detection circuit is further configured to generate, during amplitude build-up of carrier oscillation at the beginning of the electromagnetic field pulse, an evaluation signal based on the return signal, and to detect the data storage device within the communication range based on the evaluation signal generated during the amplitude build-up and a threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 15, 16)
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10. A method of detecting, within a communication range of an antenna for emitting an electromagnetic field, a contactless data storage device which is configured for inductive coupling with the electromagnetic field, the method comprising:
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detecting, at the antenna, a return signal during emission of an electromagnetic field pulse, generating, during amplitude build-up of carrier oscillation at the beginning of the electromagnetic field pulse, an evaluation signal based on the return signal, and detecting the data storage device within the communication range based on the evaluation signal generated during the amplitude build-up and a threshold value. - View Dependent Claims (11, 12, 13, 14, 17, 18)
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Specification