Identification system
US5166676A · kind A · utility
198Cited by
12References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 16, 1990 |
| Grant date | Nov 24, 1992 |
| Priority date | — |
| Expiry date | Feb 16, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/046
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A passive integrated transponder (PIT) is attached to or embedded in an item to be identified. It is excited via an inductive coupling from an interrogator. The PIT responds to the interrogator via the inductive coupling with a signal constituting a stream of data unique to the identified item. The signal is in the form of two different frequencies, a shift from one frequency to the second during a bit cell representing a data "one", and a shift from the second frequency to the first frequency representing a data "zero". The responsive signal is then detected and processed for utilization in a data storage or display device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.