Passive transponder
US4890111A · kind A · utility
54Cited by
5References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 20, 1987 |
| Grant date | Dec 26, 1989 |
| Priority date | — |
| Expiry date | Oct 20, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q9/26
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The antenna elements of the transponder of this invention are pierced with openings and thus have a general form of loops surrounding spaces devoid of any metallic elements. This arrangement diminishes the capacitance of the stray capacitor formed by the antenna elements and the body of the person carrying the transponder, thus improving the gain thereof. The invention is particularly applicable in the search for avalanche victims.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.