Detection circuit for proximity IC card device
US6608995B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 2000 |
| Grant date | Aug 19, 2003 |
| Priority date | — |
| Expiry date | Feb 14, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/0008
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.