Antenna diversity system

• US 8,294,625 B2
• Filed: 02/04/2010
• Issued: 10/23/2012
• Est. Priority Date: 02/04/2010
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Kittinger, Gregg R., Hibbard, Donald B. Jr., Trzcinski, David J.
• Primary Examiner(s): LE, HOANGANH T
• Application Number:
  US12/700,515
• Publication Number:
  US 20110187613A1
• Time in Patent Office: 992 Days
• Field of Search: 343/711, 343/712, 343/713, 343/715, 343/900
• US Class Current: 343/713
• CPC Class Codes: H01Q 1/32 Adaptation for use in or on road or rail vehicles
• CPC Class Codes: H01Q 1/3275 mounted on a horizontal surface of the vehicle, e.g. on roof, hood, trunk
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 5/00 Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements combinations of separate active antenna units operating in different wavebands and connected to a common feeder system H01Q21/30
• CPC Class Codes: H01Q 9/30 with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence

Abstract

An antenna of the present invention includes an electrical half wave monopole antenna element fixedly attached to a surface, where the antenna element includes an electrical center. A first electrical feed point is located on a first side of the antenna element. A second electrical feed point is located on a second side of the antenna element. The second side generally opposes the first side of the antenna element. The first and second electrical feed points are about one-twentieth a wavelength from the electrical center. A first signal corresponds with the first electrical feed point and a second signal corresponds with the second electrical feed point. The first signal is out of phase when compared to the second signal.

Claims

1. An antenna configured to mount to a surface, comprising:

a electrical half wave monopole antenna element fixedly attached to the surface, wherein the antenna element includes an electrical center;

a first electrical feed point located on a first side of the antenna element; and

a second electrical feed point located on a second side of the antenna element, wherein the second side generally opposes the first side of the antenna element, and wherein the first and second electrical feed points are located about one-twentieth a wavelength from the electrical center, and

wherein a first signal corresponds with the first electrical feed point and a second signal corresponds with the second electrical feed point, and the first signal is out of phase when compared to the second signal.

2. The antenna of claim 1 wherein the phase difference between the first signal and the second signal is about ninety degrees.

3. The antenna of claim 1 wherein the antenna element includes a third electrical feed point that is located at about the electrical center of the antenna element.

4. The antenna of claim 2 wherein the first electrical feed point and the second electrical feed point are FM feed ports and the third electrical feed point is an AM feed point.

5. The antenna of claim 1 wherein the antenna element is configured to be affixed to one of a rear spoiler, a cowl lip, and a fascia of a vehicle.

6. The antenna of claim 1 wherein the electrical center of the antenna element is located at about a midpoint of the antenna element, and the electrical center is also a mechanical center of the antenna element.

7. A diversity antenna system, comprising:

an electrical half wave monopole antenna element fixedly attached to a surface, the antenna element comprising;

an electrical center;

a first electrical feed point located on a first side of the antenna element; and

a second electrical feed point located on a second side of the antenna element, wherein the second side generally opposes the first side of the antenna element, and wherein the first and second electrical feed points are located about one-twentieth a wavelength from the electrical center,

wherein a first signal corresponds with the first electrical feed point and a second signal corresponds with the second electrical feed point, and the first signal is out of phase when compared to the second signal; and

a diversity combiner in communication with both of the first signal and the second signal, wherein the diversity combiner combines the first signal and the second signal together to create a single antenna signal.

8. The diversity antenna system of claim 7 wherein the single antenna signal is created by selecting a maximum gain value between the first signal and the second signal, wherein the single antenna signal includes the maximum gain value.

9. The diversity antenna system of claim 7 wherein the phase difference between the first signal and the second signal is about ninety degrees.

10. The diversity antenna system of claim 7 wherein the antenna element includes a third electrical feed point that is located at about the electrical center of the antenna element.

11. The diversity antenna system of claim 9 wherein the first electrical feed point and the second electrical feed point are FM feed ports that correspond with an FM signal, and the third electrical feed point is an AM feed point that corresponds with an AM signal.

12. The diversity antenna system of claim 11 wherein the diversity combiner is in communication with an antenna amplifier that selects one of the AM signal and the FM signal.

13. The diversity antenna system of claim 12 wherein the antenna amplifier is in communication with an AM/FM receiver.

14. The diversity antenna system of claim 7 wherein the diversity combiner is integrated with an AM/FM receiver.

15. The diversity antenna system of claim 7 wherein the AM/FM receiver includes an antenna selection circuit.

16. A diversity antenna system, comprising:

an electrical half wave monopole antenna element fixedly attached to a surface, the antenna element comprising;

an electrical center;

a first FM feed point located on a first side of the antenna element; and

a second FM feed point located on a second side of the antenna element, wherein the second side generally opposes the first side of the antenna element, and wherein the first and second FM feed points are located about one-twentieth a wavelength from the electrical center,

wherein a first signal corresponds with the first FM feed point and a second signal corresponds with the second FM feed point, and the first signal is out of phase by ninety degrees when compared to the second signal; and

a diversity combiner in communication with both of the first signal and the second signal, wherein the diversity combiner combines the first signal and the second signal together to create a single antenna signal.

17. The diversity antenna system of claim 16 wherein the single antenna signal is created by selecting a maximum gain value between the first signal and the second signal, wherein the single antenna signal includes the maximum gain value.

18. The diversity antenna system of claim 16 wherein the antenna element includes a third electrical feed point that is located at about the electrical center of the antenna element.

19. The diversity antenna system of claim 17 wherein the third electrical feed point is an AM feed point that corresponds with an AM signal.

20. The diversity antenna system of claim 19 wherein the diversity combiner is in communication with a switching amplifier that selects one of the AM signal and the FM signal.