User terminal antenna arrangement for multiple-input multiple-output communications

• US 7,106,252 B2
• Filed: 02/24/2003
• Issued: 09/12/2006
• Est. Priority Date: 02/26/2002
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Amos, Sonya, Perrott, Roger, Smith, Martin, Power, Dawn
• Primary Examiner(s): Ho, Tan
• Application Number:
  US10/506,060
• Publication Number:
  US 20050104777A1
• Time in Patent Office: 1,296 Days
• Field of Search: 343/702, 343/700.MS, 343/725, 343/846, 343/848
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 1/084 Pivotable antennas
• 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 13/10 Resonant slot antennas
• CPC Class Codes: H01Q 13/106 Microstrip slot antennas patch antenna elements H01Q9/0407
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 25/001 Crossed polarisation dual antennas orthomode horns H01Q13/0258; cross-polarised rear feeds H01Q19/136; orthomode transducers H01P1/161
• CPC Class Codes: H01Q 9/44 with a plurality of divergent straight elements, e.g. V-dipole, X-antenna; with a plurality of elements having mutually inclined substantially straight portions combinations of two or more active elements H01Q21/00; turnstile antennas H01Q21/26
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity

Abstract

Multiple input multiple output (MIMO) systems are able to provide wireless communications at increased data rates. These systems involve using a plurality of antennas on both the transmitter and receiver and the problem of how to accommodate such structures in user terminals, which are often required to be hand held then arises. An antenna arrangement which is suitable for MIMO communications and which can be incorporated into a user terminal such as a personal digital assistant (PDA) is described. A pair of co-polarised umbrella monopoles and a slot antenna are incorporated into a flap which extends at approximately 90° to the body of the PDA. A fourth monopole is mounted and protrudes from the PDA itself.

Claims

1. An antenna arrangement suitable for use in a user terminal in order to provide wireless multiple-input-multiple-output (MIMO) communications, said antenna arrangement comprising:

(i) at least a first and a second ground plane, the first ground plane arranged to be provided in a body of the user terminal and the second ground plane arranged to be provided external to the body of the user terminal; and

(ii) three or more antennas each associated with one of the ground planes, at least one of the antennas being associated with the first ground plane and at least two others of the antennas being associated with the second ground plane;

wherein said ground planes are positionable with respect to one another, in use, such that polarisation diversity is provided between antennas associated with different ones of the ground planes; and

wherein at least two of the antennas associated with the second ground plane are of different polarisations.

2. An antenna arrangement as claimed in claim 1 wherein said antennas are arranged and positioned in order that angular coverage provided by the antennas in use is maximised in at least one plane.

3. An antenna arrangement as claimed in claim 1 wherein at least some of said antennas are arranged to provide spatial diversity.

4. An antenna arrangement as claimed in claim 1 wherein said user terminal is arranged to be hand held.

5. An antenna arrangement as claimed in claim 1 wherein said user terminal comprises a display and wherein one of said ground planes is arranged to be substantially parallel with the display.

6. An antenna arrangement as claimed in claim 5 wherein another of said ground planes is arranged to be provided in a flap moveably connected to the user terminal.

7. An antenna arrangement as claimed in claim 1 which is arranged to operate at least one wavelength and wherein the length of the user terminal is about 0.5 to 1 of that wavelength.

8. An antenna arrangement as claimed in claim 1 wherein each antenna is substantially co-planar with its associated ground plane.

9. An antenna arrangement as claimed in claim 1 wherein each of said antennas is directional in that it has a directive gain in one of at least two different directions.

10. A communications device comprising an antenna arrangement as claimed in claim 1 and which further comprises fewer receive chains than there are antennas.

11. An antenna arrangement suitable for use in a user terminal in order to provide wireless multiple-input-multiple-output (MIMO) communications, said antenna arrangement comprising:

(i) at least a first and a second ground plane, the first ground plane arranged to be provided in a body of the user terminal and the second ground plane arranged to be provided external to the body of the user terminal; and

(ii) a first pair of antennas and a second pair of antennas, each of the antennas being associated with one of the ground planes, at least one of the antennas being associated with the first ground plane and at least another of the antennas being associated with the second ground plane, and said first pair of antennas being polarisation diverse with respect to the second pair of antennas.

12. An antenna arrangement as claimed in claim 11 wherein the first pair of antennas is fed from the second ground plane and only one of the second pair of antennas is also fed from the second ground plane.

13. An antenna arrangement as claimed in claim 12 wherein said one of the second pair of antennas is a slot.

14. An antenna arrangement as claimed in claim 12 wherein the other of the second pair of antennas is a monopole.

15. An antenna arrangement as claimed in claim 12 wherein said other of the second pair of antennas is arranged to protrude from the user terminal in use.

16. An antenna arrangement as claimed in claim 11 wherein the first pair of antennas are spaced as far apart from one another as possible whilst still being suitable for accommodation in the user terminal.

17. An antenna arrangement as claimed in claim 11 wherein said first pair of antennas are selected from monopoles and umbrella monopoles.

18. A user terminal comprising an antenna arrangement suitable for providing wireless multiple-input-multiple-output (MIMO) communications, said antenna arrangement comprising:

(i) at least a first and a second ground plane, the first ground plane being provided in a body of the user terminal and the second ground plane being provided external to the body of the user terminal; and

(ii) three or more antennas each associated with one of the ground planes, at least one of the antennas being associated with the first ground plane and at least two others of the antennas being associated with the second ground plane;

wherein said ground planes are positionable with respect to one another, in use, such that polarisation diversity is provided between antennas associated with different ones of the ground planes; and

wherein at least two of the antennas associated with the second ground plane are of different polarisations.

19. A multiple-input-multiple-output communications system comprising a user terminal as claimed in claim 18 and a signal processor arranged to implement a space time coding communications transmission or reception method.

20. A method of transmitting or receiving space time coding communications using a user terminal comprising the steps of:

(i) providing at least a first and a second ground plane, the first ground plane being provided in a body of the user terminal and the second ground plane being provided external to the body of the user terminal; and

(ii) providing two three or more antennas each associated with one of the ground planes, at least one of the antennas being associated with the first ground plane and at least two others of the antennas being associated with the second ground plane;

wherein said ground planes are positionable with respect to one another, in use, such that polarisation diversity is provided between antennas associated with different ones of the around planes; and

wherein at least two of the antennas associated with the second ground plane are of different polarisations.