Unidirectional field antenna for identification system
US5940043A · kind A · utility
12Cited by
6References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 21, 1997 |
| Grant date | Aug 17, 1999 |
| Priority date | — |
| Expiry date | Feb 21, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q11/14
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An antenna system for use in detecting an information tag in an interrogation zone comprising a first coil for generating a first field in an interrogation zone, a second coil that is larger than said first coil and positioned proximate the first coil for generating a second field that opposes the first field, and a nonferrous conductive plate positioned proximate the first and second coils and being shaped so that its periphery is approximately at least as large as the periphery of the second coil.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.