Device for controlling extension and retraction of an antenna
US5689821A · kind A · utility
19Cited by
6References
26Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 28, 1994 |
| Grant date | Nov 18, 1997 |
| Priority date | — |
| Expiry date | Dec 28, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q9/14
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In an IC memory card radio modem including an antenna, intensity of electric field received by the antenna is measured by an electric field intensity detector. An antenna driver is controlled such that, when the electric field intensity exceeds a predetermined value, the antenna is retracted or is not risen. The antenna is extended when the electric field intensity is equal to or lower than the predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.