Independently fed AM/FM heated window antenna
US5781160A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 31, 1996 |
| Grant date | Jul 14, 1998 |
| Priority date | — |
| Expiry date | May 31, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q1/1278
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A radio antenna formed in a vehicle window is coupled with a radio apparatus using an RF transformer having a primary winding connected between the antenna/heating element and the vehicle body and a secondary winding connected between the vehicle body and the radio apparatus. Preferably, the transformer also has a third winding which connects to a second antenna/heating element terminal for completing the electrical supply current circuit through the heating element. The primary winding and third winding are wound with identical turns and connected so the electrical heating current flowing through each winding generates a flux equal in magnitude and opposite in direction to the other to cancel the flux resulting from the heating current and thus prevent saturation of the transformer. Shunting capacitors cause RF currents through the primary winding and third winding to be equal in magnitude and in phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.