FM-AM windshield antenna
US3972048A · kind A · utility
Inventor
Key dates
| Filing date | Nov 29, 1974 |
| Grant date | Jul 27, 1976 |
| Priority date | — |
| Expiry date | Nov 29, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q5/48
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A conductive body having an opening therein, the edge of opening having a length which is less than a resonant length at AM broadcast band frequencies and greater than a resonant length at FM broadcast band frequencies, is caused to operate as an effective antenna over the FM band or over both the FM and AM bands by electrically shortening the length of the edge of such opening at FM frequencies without physically shortening the perimeter of such opening or electrically shortening the edge of such opening at AM frequencies, a common cable or cables being utilized to couple both AM and FM signals to external circuits, switching at the conductive edge thus being eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.