Capacitive modulation in an electromagnetic transponder
US6356198B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 1999 |
| Grant date | Mar 12, 2002 |
| Priority date | — |
| Expiry date | Dec 20, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K19/0723
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An electromagnetic transponder is provided that includes an oscillating circuit, an electronic circuit, a rectifying circuit, and a capacitive modulation circuit. The oscillating circuit includes an inductive clement and the electronic circuit includes a transmission circuit for transmitting digitally-coded information. The rectifying circuit is coupled to the oscillating circuit to provide a DC supply voltage to the electronic circuit, and the capacitive modulation circuit is coupled to both end terminals of the inductive element and to the reference potential of the electronic circuit. In a preferred embodiment, the capacitive modulation circuit includes two capacitors, with capacitor being coupled between one end terminal of the inductive clement and the reference potential and the other capacitor being coupled between the other end terminal of the inductive element and the reference potential. Also provided is a system of electromagnetic transmission that includes at least one transponder and a terminal that generates an electromagnetic field for communicating with the transponder when the transponder is in the electromagnetic field.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.