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US 6,608,995 B1Granted
Detection circuit for proximity IC card device
AssigneeFujitsu Limited
InventorsYusuke Kawasaki, Yoshiyasu Sugimura, Shigeru Hashimoto
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AssigneeFujitsu Limited
InventorsYusuke Kawasaki, Yoshiyasu Sugimura, Shigeru Hashimoto
Estimating the term…
The present invention relates to a proximity IC card (PICC). More particularly, the present invention relates to and provides a detection circuit of a simple structure, which is easy to set up in a PICC and a proximity coupling device (PCD) for transmitting data to and receiving data from the PICC. This detection circuit is operative to detect a subcarrier signal sent from a PICC and superposed onto a carrier signal received through an antenna. Further, this detection circuit comprises a bias circuit for applying predetermined DC potential to a signal received from the antenna, a rectifier circuit for extracting a subcarrier signal superposed onto the carrier signal by rectifying a signal received from the antenna at a bias point, and an amplifier circuit for amplifying the subcarrier signal extracted at the bias point.
A detection circuit for detecting a subcarrier signal sent from a proximity IC card and superposed onto a carrier signal received through an antenna, said detection circuit comprising:
A detection circuit comprising:
A detection circuit for detecting a data signal sent from a proximity IC card and superposed onto a carrier signal received through an antenna, said detection circuit comprising:
Dependencies are inferred from the claim text.