Multiple antenna array with high isolation

• US 20080062058A1
• Filed: 09/11/2006
• Published: 03/13/2008
• Est. Priority Date: 09/11/2006
• Status: Active Grant

• Current Assignee: TE Connectivity Solutions GmbH (TE Connectivity Ltd. (United Kingdom))
• Original Assignee: Tyco Electronics Corporation (TE Connectivity Ltd. (United Kingdom))
• Inventors: Bishop, Bruce Foster
• Granted Patent: US 7,385,563 B2
• Time in Patent Office: Days
• US Class Current: 343/835
• CPC Class Codes: H01Q 1/52 Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure absorbing means H01Q17/00
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence
• CPC Class Codes: H01Q 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence

Abstract

A high-isolation multiple in, multiple out (MIMO) antenna array includes, in one configuration, a ground plane, and a plurality of antenna transmitting/receiving elements arranged near the periphery of the ground plane, wherein each of the antenna transmitting/receiving elements is resonant at a frequency f. Also, the array includes an isolation antenna element located on the ground plane, between the plurality of antenna transmitting/receiving elements. The isolation antenna element is also resonant at the same frequency f. The plurality of antenna transmitting/receiving elements and the resonant isolation antenna element are arranged on the ground plane arranged so as to achieve substantially greater than 15 dB isolation of the antenna transmitting/receiving elements. In some configurations, at least about 30 dB of isolation of the antenna transmitting/receiving elements can be achieved.

Claims

1. A high-isolation multiple in, multiple out (MIMO) antenna array, said array comprising:

a ground plane;

a plurality of antenna transmitting/receiving elements arranged near the periphery of the ground plane, each said antenna transmitting/receiving element resonant at a frequency f; and

an isolation antenna element located on the ground plane, between said plurality of antenna transmitting/receiving elements and resonant at the same frequency f;

said plurality of antenna transmitting/receiving elements, and said resonant isolation antenna element arranged on said ground plane arranged so as to achieve substantially greater than 15 dB isolation of the antenna transmitting/receiving elements, wherein the antenna transmitting/receiving elements are dual band antenna elements that are resonant at a second frequency f₁ different from f, and wherein the isolation antenna element is a dual band antenna element resonant at the second frequency f_1.

2. An array in accordance with claim 1 wherein said plurality of antenna transmitting/receiving elements, and said resonant isolation antenna element arranged on said ground plane arranged so as to achieve at least about 30 dB isolation of the antenna transmitting/receiving elements.

3. An array in accordance with claim 1 wherein said frequency f is within the 2.4 or 5 GHz WIFI bands.

4. An array in accordance with claim 1 wherein the ground plane is a metal plate.

6. An antenna array in accordance with claim 1 comprising three antenna transmitting/receiving elements equidistant from one another and each said antenna transmitting/receiving element λ

/4 distant from the isolation antenna element, where

$\mathrm{\lambda <br><br>}=\frac{c}{2<br><br>\mathrm{\pi <br><br>}<br><br><br><br>f}.$

7. An array in accordance with claim 1 having a plurality of isolation antenna elements arranged to provide isolation at a plurality of different frequency bands.

8. An array in accordance with claim 1 wherein said isolation antenna element is a monopole antenna.

9. An array in accordance with claim 8 wherein said monopole antenna is ¼

wavelength at frequency f.

5. (canceled)

10. (canceled)

11. (canceled)

12. (canceled)

13. (canceled)

14. (canceled)

15. (canceled)

16. (canceled)

17. (canceled)

18. (canceled)

19. (canceled)

20. (canceled)

21. A high-isolation multiple in, multiple out (MIMO) antenna array, said array comprising:

a ground plane;

a plurality of antenna transmitting/receiving elements arranged near the periphery of the ground plane, each said antenna transmitting/receiving element resonant at a frequency f; and

an isolation antenna element located on the ground plane, between said plurality of antenna transmitting/receiving elements and resonant at the same frequency f;

said plurality of antenna transmitting/receiving elements, and said resonant isolation antenna element arranged on said ground plane arranged so as to achieve substantially greater than 15dB isolation of the antenna transmitting/receiving elements, and wherein said plurality of antenna transmitting/receiving elements comprise three antenna transmitting/receiving elements equidistant from one another and each said antenna transmitting/receiving element is λ

/4 distant from the isolation antenna element, where

$\mathrm{\lambda <br><br>}=\frac{c}{2<br><br>\mathrm{\pi <br><br>}<br><br><br><br>f}.$

22. An array in accordance with claim 21 wherein said plurality of antenna transmitting/receiving elements, and said resonant isolation antenna element arranged on said ground plane arranged so as to achieve at least about 30dB isolation of the antenna transmitting/receiving elements.

23. An array in accordance with claim 21 wherein said frequency f is within the 2.4 or 5 GHz WIFI bands.

24. An array in accordance with claim 21 wherein the ground plane is a metal plate.

25. An array in accordance with claim 21 having a plurality of isolation antenna elements arranged to provide isolation at a plurality of different frequency bands.

26. An array in accordance with claim 21 wherein said isolation antenna element is a monopole antenna.

27. An array in accordance with claim 26 wherein said monopole antenna is 1/4wavelength at frequency f.

28. An array in accordance with claim 26 wherein said monopole is 1/8wavelength at frequency f and is top loaded.

29. An array in accordance with claim 21 wherein said antenna transmitting/receiving elements comprise planar inverted F antennas (PIFAs).

30. A high-isolation multiple in, multiple out (MIMO) antenna array, said array comprising:

a ground plane;

a plurality of antenna transmitting/receiving elements arranged near the periphery of the ground plane, each said antenna transmitting/receiving element resonant at a frequency f; and

an isolation antenna element located on the ground plane, between said plurality of antenna transmitting/receiving elements and resonant at the same frequency f;

said plurality of antenna transmitting/receiving elements, and said resonant isolation antenna element arranged on said ground plane arranged so as to achieve substantially greater than 15dB isolation of the antenna transmitting/receiving elements, and wherein said isolation antenna element is a monopole antenna that is 1/8wavelength at frequency f and is top loaded.

31. A high-isolation multiple in, multiple out (MIMO) antenna array, said array comprising:

a ground plane;

a plurality of antenna transmitting/receiving elements arranged near the periphery of the ground plane, each said antenna transmitting/receiving element resonant at a frequency f; and

an isolation antenna element located on the ground plane, between said plurality of antenna transmitting/receiving elements and resonant at the same frequency f;

said plurality of antenna transmitting/receiving elements, and said resonant isolation antenna element arranged on said ground plane arranged so as to achieve substantially greater than 15dB isolation of the antenna transmitting/receiving elements, and wherein said antenna transmitting/receiving elements comprise planar inverted F antennas (PIFAs).