Communications antenna structure

• US 6,693,603 B1
• Filed: 12/29/1998
• Issued: 02/17/2004
• Est. Priority Date: 12/29/1998
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Smith, Martin Stevens, Bush, Anton Keith
• Primary Examiner(s): Wimer, Michael C.
• Application Number:
  US09/222,555
• Time in Patent Office: 1,876 Days
• Field of Search: H01/Q.138, H01/Q.136, H01/Q.148, 343/797, 343/826, 343/825, 343/828-830, 343/700.MS, 343/702, 343/846, 343/872
• US Class Current: 343/846
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• 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 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence

Abstract

The present invention relates to a communications antenna structure. The communications antenna structure comprises first and second antennas each having an axis about which a mode of electrical field vector polarisation can be generated. In a first orientation, with an axis associated with the structure vertical, the first antenna operates in a horizontal mode of electrical field vector polarisation and the second antenna operates in a vertical mode of electrical field vector polarisation; and, in a second orientation, with said structure axis horizontal, the first antenna operates in a vertical mode of electrical field vector polarisation and the second antenna operates in a horizontal mode of electrical field vector polarisation.

Claims

1. An antenna arrangement comprising:

a mounting surface;

a first ground plane parallel to said mounting surface bearing a first antenna having a polarisation perpendicular to said first ground plane; and

a second ground plane arranged substantially perpendicular to said mounting surface and bearing a second antenna having a polarisation perpendicular to said second ground plane;

wherein the first and second antennas are not co-planar with respect to one another; and

in use each antenna produces a substantially omnidirectional antenna pattern in an azimuth plane; and

wherein said antenna arrangement is capable of being mounted in two orthogonal orientations wherein;

in a first orientation said mounting surface is horizontal, said first antenna has a first polarization and said second antenna has a second polarization and

in a second orientation said mounting surface is vertical, said first antenna has said second polarization and said second antenna has said first polarization.

2. An antenna arrangement as claimed in claim 1 wherein said antennas each comprise a second radiating section which is provided by a bent section extending substantially parallel to the adjacent ground plane.

3. An antenna arrangement as claimed in claim 1 wherein said antennas are planar inverted F antennas.

4. An antenna arrangement as claimed in claim 1 wherein said second ground plane and said first antenna are not co-planar.

5. An antenna arrangement as claimed in claim 1 wherein the ground planes form part of a box structure.

6. An antenna arrangement as claimed in claim 5 wherein the box structure encloses electrical control circuitry associated with the receiver and transmitters for the antennas and the outside surface has heat sink fins.

7. An antenna arrangement as claimed in claim 1 wherein the antennas are located adjacent a corner of their respective ground planes.

8. An antenna arrangement as claimed in claim 7 wherein the antennas are located within less than a wavelength of the frequency of operation of said corners.

9. A method of operating an antenna arrangement comprising:

a mounting surface;

a first ground plane parallel to said mounting surface bearing a first antenna having a polarisation perpendicular to said first ground plane; and

a second ground plane arranged substantially perpendicular to said mounting surface and bearing a second antenna having a polarisation perpendicular to said second around plane;

wherein the first and second antennas are not co-planar with respect to one another and in use each antenna produces a substantially omnidirectional antenna pattern in an azimuth plane; and

said antenna arrangement is capable of being mounted in two orthogonal orientations wherein;

in a first orientation said mounting surface is horizontal, said first antenna has a first polarization and said second antenna has a second polarization and

in a second orientation said mounting surface is vertical, said first antenna has said second polarization and said second antenna has said first polarization,

the method comprising;

operating said first antenna in a predetermined polarization.

10. A method as claimed in claim 9 wherein said predetermined polarization is vertical or horizontal polarization.

11. A method as claimed in claim 10 wherein said antennas are planar inverted F antennas.

12. A method as claimed in claim 9 wherein the antenna arrangement is operated by receiving or transmitting on both antennas to provide receive or transmit diversity.

13. A method as claimed in claim 9 which further comprises:

in a transmit mode, transmitting a signal from the antenna structure by combining the outputs of the first and second antennas; and

in a receive mode, operating the first and second antennas as a diversity pair.