Wideband, High Isolation Two Port Antenna Array for Multiple Input, Multiple Output Handheld Devices

• US 20120068905A1
• Filed: 11/21/2011
• Published: 03/22/2012
• Est. Priority Date: 03/17/2009
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Ayatollahi, Mina, Rao, Qinjiang, Wang, Dong
• Granted Patent: US 8,933,842 B2
• Time in Patent Office: Days
• US Class Current: 343/841
• CPC Class Codes: H01Q 1/243 with built-in antennas
• 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 1/48 Earthing means; Earth screens; Counterpoises
• CPC Class Codes: H01Q 1/521 reducing the coupling between adjacent antennas
• CPC Class Codes: H01Q 13/106 Microstrip slot antennas patch antenna elements H01Q9/0407
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

A multiple input-multiple output antenna assembly with high isolation between the antennas is disclosed. The antenna assembly includes a substrate with a ground layer at its surface. Two antennas are disposed opposing each other on the substrate. An isolation element in a form of a patterned slot is interposed between the first and second antennas on the ground plane. A first signal port is provided for applying a first signal to excite the first antenna and a second signal port is provided for applying a second signal to excite the second antenna. The isolation element provides isolation that inhibits electromagnetic propagation between the two antennas.

Claims

1-16. -16. (canceled)

17. An antenna assembly for a wireless communication device comprising:

a ground plane;

a first radiating element disposed in the ground plane;

a second radiating element disposed in the ground plane and spaced apart from the first radiating element by at least one-tenth of a wavelength of a resonant frequency of the second radiating element;

an isolating element interposed on the ground plane between the first radiating element and the second radiating element;

wherein the isolating element comprising;

a meandering slot through the ground plane between the first and the second radiating elements, wherein the meandering slot has a first leg that extends orthogonally inward from a location between the first and second radiating elements that is on a common edge of the ground plane, wherein the first leg has an inner end and the meandering slot further comprises a second leg extending from the inner end parallel to the common edge and toward the first radiating element terminating at a first remote end, a third leg projecting from the remote end and away from the common edge until terminating at a second remote end, and a fourth leg extending from the second remote end parallel to the common edge and toward the second radiating element.

18. The antenna assembly as recited in claim 17 wherein the first and the second radiating elements have substantially identical shapes and oppose each other across a width of the ground plane.

19. The antenna assembly as recited in claim 17 wherein at least one of the first and the second radiating elements comprises an inverted F antenna of an electrically conductive material.

20. The antenna assembly of claim 17 wherein the ground plane comprises a layer of electrically conductive material disposed on a surface of a substrate.

21. The antenna assembly of claim 20 wherein the first radiating element and the second radiating element each comprise a slot in a form of an elongated opening in the layer of electrically conductive material, each slot extending inward from an opposing edge of the ground plane and longitudinally parallel to the common edge of the ground plane.

22. The antenna assembly of claim 21 wherein the isolating element is disposed at equal distances from the first and the second radiating elements.

23. The antenna assembly of claim 20 wherein at least one of the first and the second radiating elements comprises an L-shaped slot, extending from an edge of the ground plane.

24. The antenna assembly of claim 17 wherein the meandering slot further comprises a fifth leg projecting from an end of the fourth leg and away from the common edge until terminating at a third remote end, a sixth leg extending from the third remote end parallel to the common edge and toward the first radiating element.

25. The antenna assembly of claim 17 wherein the isolating element is disposed at equal distances from the first and the second radiating elements.

26. The antenna assembly of claim 17 further comprising a substrate of non-conductive material;

and wherein;

the ground plane is formed by a layer of electrically conductive material on the substrate wherein the layer of electrically conductive material has a thickness;

the first radiating element is formed by a first radiation slot in the layer of electrically conductive material; and

the second radiating element is formed by a second radiation slot in the layer of electrically conductive material and spaced from the first radiation slot by at least one-tenth wavelength of a resonant frequency of the second slot antenna.

27. The antenna assembly of claim 26 further comprising:

a first signal port coupled to the first radiating element; and

a second signal port coupled to the second radiating element,

wherein the first radiation slot, the second radiation slot and the meandering slot all pass through the thickness of the layer of electrically conductive material.

28. The antenna assembly of claim 27 wherein the first radiation slot is linear;

and the second radiation slot is linear and aligned parallel to the first radiation slot.

29. The antenna assembly of claim 27 wherein the first radiation slot and the second radiation slot both have an L-shape.

30. The antenna assembly of claim 17 wherein the meandering slot has a serpentine shape.