Identification apparatus and methods
US5302954A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 1992 |
| Grant date | Apr 12, 1994 |
| Priority date | — |
| Expiry date | Nov 18, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B5/45
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An identification system comprising a transponder having receiver means adapted to extract powering energy from a surrounding electromagnet field, transponder transmitter means adapted to transmit at least one unique signal from the transponder, frequency generating means for generating a plurality of pre-determined frequencies, each frequency adapted to carry the signal from the transmitter means to an interrogator receiver means adapted to receive said signals to achieve identification of said transponder, said transponder transmitting signals successively or repetitively using at each successive or repetitive transmission a newly selected frequency or set of newly selected frequencies.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.