Detection, by an electromagnetic transponder reader, of the distance separating it from a transponder
US6650226B1 · kind B1 · utility
36Cited by
73References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 6, 2000 |
| Grant date | Nov 18, 2003 |
| Priority date | — |
| Expiry date | Apr 6, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/0008
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A terminal for generating an electromagnetic field adapted to cooperate with at least one transponder when the transponder enters the electromagnetic field, the terminal including circuitry for determining the distance separating the at least one transponder from the terminal without requiring any transmission from the transponder to the terminal. In one example, the terminal also includes a phase regulation loop that regulates the phase of a signal in an oscillating circuit of the terminal with respect to a reference value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.