Microwave antenna for use in a vehicle

• US 6,396,446 B1
• Filed: 03/28/2000
• Issued: 05/28/2002
• Est. Priority Date: 02/16/1999
• Status: Expired due to Term

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Walstra, Eric J., Turnbull, Robert R.
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): NGUYEN, HOANG V
• Application Number:
  US09/535,999
• Time in Patent Office: 791 Days
• Field of Search: 343/713,711,700 MS
• US Class Current: 343/713
• CPC Class Codes: B60C 23/061 by monitoring wheel speed measuring distance traversed on the ground by vehicles G01C22/00
• CPC Class Codes: B60Q 1/1423 Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic
• CPC Class Codes: B60Q 2300/112 Vehicle speed
• CPC Class Codes: B60Q 2300/314 Ambient light
• CPC Class Codes: B60Q 2300/3321 Detection of streetlights
• CPC Class Codes: B60R 1/04 mounted inside vehicle B60R1/025, B60R1/08 take precedence
• CPC Class Codes: B60R 1/088 using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors
• CPC Class Codes: B60R 1/12 Mirror assemblies combined with other articles, e.g. clocks
• CPC Class Codes: B60R 2001/1215 with information displays
• CPC Class Codes: B60R 2001/1246 with clocks
• CPC Class Codes: B60R 2001/1261 with antennae
• CPC Class Codes: B60R 2001/1284 with communication systems other than radio-receivers, e.g. keyless entry systems, navigation systems; with anti-collision systems
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network
• CPC Class Codes: G01S 19/36 relating to the receiver frond end
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: H01Q 1/1271 for mounting on windscreens
• CPC Class Codes: H01Q 1/3266 using the mirror of the vehicle
• CPC Class Codes: H01Q 1/3291 mounted in or on other locations inside the vehicle or vehicle body
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40

Abstract

A microwave antenna for mounting in a vehicle where the antenna includes a dielectric substrate, a conductive resonant patch mounted on one side of the dielectric substrate for receiving signals from a satellite, and a conductive ground plane mounted to an opposite side of the dielectric substrate. The ground plane has an area sufficiently large to shield the resonant patch from any satellite signals that are reflected from a conductive component of the vehicle. The resonant component need not be a patch antenna, but may have another structure such as a helical antenna. The antenna is preferably mounted in a rearview mirror assembly, and the ground plane is configured to shield the resonant component from satellite signals reflected from the mirror.

Claims

1. A rearview mirror assembly for a vehicle comprising:

a mirror mounting structure adapted to be mounted to the vehicle, said mirror mounting structure including a mirror housing;

a mirror mounted in said mirror housing; and

a microwave antenna mounted to said mirror mounting structure, said microwave antenna including a conductive ground plane and a resonant component for receiving signals from a satellite, said ground plane having an area sufficiently large to substantially block satellite signals that are reflected from said mirror towards said resonant component.

2. The rearview mirror assembly of claim 1, wherein said microwave antenna further includes a dielectric substrate, said resonant component is a conductive resonant patch mounted on one side of said dielectric substrate, and said ground plane is mounted to an opposite side of said dielectric substrate.

3. The rearview mirror assembly of claim 1, wherein said mirror mounting structure further includes a mounting bracket adapted to be mounted inside the vehicle in a location proximate to or on the front windshield of the vehicle, said mirror housing is coupled to said mounting bracket, wherein said microwave antenna is mounted to said mounting bracket proximate the windshield.

4. The rearview mirror assembly of claim 3 and further including a microwave receiver circuit at least a portion of which is mounted to said mounting bracket, said microwave receiver circuit being electrically coupled to said microwave antenna.

5. The rearview mirror assembly of claim 1, wherein said mirror mounting structure is configured for mounting to the interior of the vehicle.

6. The rearview mirror assembly of claim 1, wherein said mirror mounting structure is configured for mounting to the exterior of the vehicle.

7. The rearview mirror assembly of claim 1 and further including a microwave receiver circuit electrically coupled to said microwave antenna and mounted in said mirror housing.

8. The rearview mirror assembly of claim 1, wherein said mirror is an electrochromic mirror.

9. The rearview mirror assembly of claim 1, wherein said conductive ground plane is positioned between said resonant component and said mirror.

10. A mirror mounting bracket for mounting an inside rearview mirror assembly to a vehicle, said mirror mounting bracket comprising:

a mounting foot including a mounting portion for mounting said rearview mirror assembly to an inside surface of the front windshield of a vehicle, and an antenna housing portion abutting the inside surface of the front windshield and having an aperture opening towards the inside surface of the front windshield;

a stem extending between said mounting portion and a mirror housing of the rearview mirror assembly; and

a microwave antenna mounted in said aperture of said antenna housing of said mounting foot, said microwave antenna including a conductive ground plane and a resonant component for receiving signals from a satellite, said ground plane is positioned in said antenna housing to shield said resonant patch from any satellite signals that are reflected from a conductive component of the vehicle.

11. The mirror bracket of claim 10 and further including a microwave receiver circuit electrically coupled to said microwave antenna and mounted in said aperture in said antenna housing portion behind said microwave antenna.

12. The mirror bracket of claim 10, wherein said microwave antenna is tuned to receive transmissions from satellites of a position identification system constellation.

13. The mirror bracket of claim 10, wherein said microwave antenna is tuned to receive CD radio transmissions from a satellite.

14. The mirror bracket of claim 10, wherein said microwave antenna further includes a dielectric substrate, said resonant component is a conductive resonant patch mounted on one side of said dielectric substrate, and said ground plane is mounted to an opposite side of said dielectric substrate.

15. The mirror bracket of claim 10, wherein said ground plane has an area large enough to block any satellite signals that are reflected from an interior rearview mirror of the vehicle towards said resonant patch.

16. A microwave antenna for mounting in a vehicle comprising:

a dielectric substrate;

a conductive resonant patch mounted on one side of said dielectric substrate for receiving signals from a satellite; and

a conductive ground plane mounted to an opposite side of said dielectric substrate, said ground plane has an area sufficiently large to shield said resonant patch from any satellite signals that are reflected from a conductive component of the vehicle that would otherwise cause destructive interference with a signal received directly from a satellite, wherein said conductive ground plane is positioned between said resonant patch and said conductive component,

said resonant patch having a generally rectangular shape with the length of a first pair of opposing sides edges selected to tune the antenna to a first resonant frequency for receiving microwave transmissions from a first set of satellites, and the length of a second pair of opposing side edges selected to tune the antenna to a second resonant frequency for receiving microwave transmissions from at least one satellite of a second set of satellites,

wherein said antenna is mounted in a rearview mirror assembly of a vehicle.

17. The microwave antenna of claim 16, wherein the first set of satellites are satellites of a position identification system constellation.

18. The microwave antenna of claim 17, wherein the microwave transmissions from satellites of a position identification system constellation are GPS signals.

19. The microwave antenna of claim 17, wherein the microwave transmissions from satellites of a position identification system constellation are GLONASS signals.

20. The microwave antenna of claim 17, wherein the second set of satellites are satellites of a communication system through which human voice signals are transmitted.

21. The microwave antenna of claim 20, wherein the microwave transmissions from said at least one satellite of the second set of satellites are CD radio signals.

22. The microwave antenna of claim 16, wherein the second set of satellites are satellites of a communication system through which human voice signals are transmitted.

23. The microwave antenna of claim 22, wherein the microwave transmissions from said at least one satellite of the second set of satellites are CD radio signals.

24. The microwave antenna of claim 16, wherein both the first and the second set of satellites are satellites of position identification system constellations, with the first set belonging to a different position identification system than the second set.

25. The microwave antenna of claim 24, wherein the microwave transmissions from the first set of satellites are GPS signals.

26. The microwave antenna of claim 25, wherein the microwave transmissions from the second set of satellites are GLONASS signals.