Dual frequency antenna device
US6201500A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 28, 1999 |
| Grant date | Mar 13, 2001 |
| Priority date | — |
| Expiry date | Jan 28, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q9/14
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
First and second helical antenna elements are connected in series with a radio signal. The first helical antenna element resonates at a first frequency as a 1/4-wavelength antenna. The series combination of the first and second helical antenna elements resonates as a 3/4 wavelength antenna at a second frequency respectively. The two frequencies differ by less than a factor of three. A retractable rod antenna shorts out one of the antenna elements in an extended position at which it is connected to the radio, and is disconnected from the radio in its retracted position. The rod antenna resonates as a 1/4-wavelength antenna at the first frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.