Device for the reception of GPS position signals

• US 20020041257A1
• Filed: 10/05/2001
• Published: 04/11/2002
• Est. Priority Date: 10/10/2000
• Status: Active Grant

• Current Assignee: Fiat Auto S.p.A.
• Original Assignee: Fiat Auto S.p.A.
• Inventors: Ugge, Alessandro
• Granted Patent: US 6,525,693 B2
• Time in Patent Office: Days
• US Class Current: 343/713
• CPC Class Codes: H01Q 1/3266 using the mirror of the vehicle
• CPC Class Codes: H01Q 11/08 Helical antennas

Abstract

The device comprises an antenna mounted within an external rear view mirror of the motor vehicle. This antenna is a helical antenna preferably a four-wire helical antenna.

Claims

1. A device for the reception of position signals from the GPS system, on board a motor vehicle, comprising an antenna mounted within an external rear view mirror of the motor vehicle.

2. A device according to claim 1, wherein the antenna is a helical antenna.

3. A device according to claim 2, wherein the antenna is a four-wire helical antenna.

4. A device according to claim 3, wherein the antenna comprises two half turn helical loops disposed at 90°

to one another about the same longitudinal axis.

5. A device according to claim 4, wherein both the said helical loops are formed by simple electrical conductors.

6. A device according to claim 4, wherein a first helical loop is formed by a simple electrical conductor, and the other helical loop is formed half by a simple electrical conductor and half by a section of a transmission line comprising a pair of parallel conductors.

7. A device according to claim 6, wherein the ends of the said first helical loop are each connected to a respective conductor of the said transmission line at one end of this transmission line.

8. A device according to claim 6, in which the simple conductor which forms one half of the said other loop has an end connected to the end of a conductor of the said transmission line, and the other end connected to the opposite end of the other conductor of the said transmission line.

9. A device according to claim 6, wherein the said section of transmission line is a length of co-axial cable.

10. A device according to claim 4, wherein the said antenna comprises a support structure including a cylindrical tubular element of dielectric material the wall of which carries the helical sides of the said loops.

11. A device according to claim 10, in which helical grooves are formed in the inner and outer cylindrical surfaces of the said tubular element, in which grooves lie the helical sides of the said loops.

12. A device according to claim 11, in which the said cylindrical tubular element has an end closed by a bottom wall such that it has an essentially cup-shape form;

the said bottom wall having on its two inner and outer faces respective grooves in which lie rectilinear sides or branches of the said loops.

13. A device according to claim 10, in which the said loops are in part constituted by metal tracks applied to the outer and inner cylindrical surfaces of the said tubular element.

14. A device according to claim 13, in which the said tubular element has an end closed by a bottom wall such that it has an essentially cup-shape form and the said loops are in part constituted by metal tracks applied to the inner and outer faces of the said bottom wall.

15. A device according to claim 6 and claim 13, in which the said section of transmission line comprise two parallel conductive tracks applied to the inner cylindrical surface and outer cylindrical surface respectively of the said tubular support element.

16. A device according to claims 13 and 15, in which the said section of transmission line further includes two parallel conductive tracks applied to the inner and outer faces respectively of the said bottom wall.

17. A device according to claim 14, in which the other end of the tubular element is closed by a disc of dielectric material and the said loops are in part constituted by metal tracks applied to the said disc.

18. A device according to claim 16, in which the said section of transmission line further includes two parallel conductive tracks applied to the inner and outer faces respectively of the said disc.

19. A device according to claim 6 and claim 13, in which the said section of the transmission line is a length of co-axial cable which lies partly in a helical groove of the tubular support element.

20. A device according to claim 4, in which the said antenna comprises a support structure including a cylindrical tubular element of dielectric material the wall of which carries the helical sides of one loop, and a cylinder also of dielectric material, which is disposed within the said tubular element and which carries the helical sides of the other loop.

21. A device according to claim 20, in which in the outer cylindrical surface of the tubular element and of the cylinder respectively are formed respective helical grooves in which lie the helical sides of the said first and said second loop respectively.

22. A device according to claim 20, in which the said loops are in part constituted by conductive tracks applied to the outer cylindrical surface of the tubular element and of the inner cylinder respectively.

23. A device according to claim 10, in which the said cylindrical tubular element is moulded over the helical sides of the said loops.

24. A device according to claim 20, in which the said cylindrical tubular element and the associated cylinder are moulded over the helical sides of the first and second loops respectively.