Battery-free circuit device for RF identifying tag
US6211786A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 18, 1999 |
| Grant date | Apr 3, 2001 |
| Priority date | — |
| Expiry date | Oct 18, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K19/0723
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
This invention relates to a battery-free circuit device for RF identifying tag. It is advantageous that the electric potential across the antenna coil induced by the change of the alternating magnetic field of the radio wave signals is independent of the modulational switching of the RF identifying tag during the positive half cycles when the antenna is receiving the radio wave signals from the card reader, and that the efficiency of the voltage-charging rectifier circuit remains constant when the data are delivered into the card reader. Furthermore, in this invention, the modulational amplitude of the signals is larger than that in the prior art, thus the propagating distance is longer and it shows better accuracy and reliability in data reading.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.