Method for detection of a contactless receiver
First Claim
1. A method for detecting a contactless receiver in a field of an antenna of a contactless reader, said method comprising during a first ramp interval, exciting said antenna by applying a potential difference comprising a ramp between first and second values of said potential difference, and during a first plateau interval following said first ramp interval, maintaining said potential difference at said second value of said potential difference, while maintaining said potential difference at said plateau, measuring a response of said antenna, comparing said measured response and a reference response, and determining presence of a contactless receiver in said field of said antenna based at least in part on a result of said comparison.
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Accused Products
Abstract
A method for detecting a contactless receiver in a field of an antenna of a contactless reader includes during a first ramp interval, exciting the antenna by applying a potential difference comprising a ramp between first and second values of the potential difference, and during a first plateau interval following the first ramp interval, maintaining the potential difference at the second value of the potential difference, while maintaining the potential difference at the plateau, measuring a response of the antenna, comparing the measured response and a reference response, and determining presence of a contactless receiver in the field of the antenna based at least in part on a result of the comparison.
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Citations
21 Claims
- 1. A method for detecting a contactless receiver in a field of an antenna of a contactless reader, said method comprising during a first ramp interval, exciting said antenna by applying a potential difference comprising a ramp between first and second values of said potential difference, and during a first plateau interval following said first ramp interval, maintaining said potential difference at said second value of said potential difference, while maintaining said potential difference at said plateau, measuring a response of said antenna, comparing said measured response and a reference response, and determining presence of a contactless receiver in said field of said antenna based at least in part on a result of said comparison.
- 18. An apparatus for contactless reading, said apparatus comprising an antenna, and a circuit configured for, during a phase of communication with a contactless receiver, selectively exciting said antenna with a frequency substantially equal to a resonant frequency thereof by, during a first ramp interval, applying a potential difference comprising a ramp between first and second values of said potential difference, and during a first plateau interval following said first ramp interval, maintaining said potential difference at said second value of said potential difference, while maintaining said potential difference during said first plateau interval, measuring a response of said antenna, comparing said measured response and a reference response, and determining presence of a contactless receiver in said field of said antenna based at least in part on a result of said comparison.
Specification