Array of patch antennas

1. An apparatus comprising:

a ground plane;

an array of antennas, wherein the array comprises antennas arranged in parallel rows and parallel columns, wherein each of the antennas in the array of antennas comprises a radiator and feeds for a first polarization and a second polarization orthogonal to the first polarization;

wherein for one or more columns of the antennas in the array, there is an aligned arrangement of coupling elements comprising coupling elements between the antennas in the respective column,

wherein the coupling elements are separate from the antennas and are electrically floating,

wherein the coupling elements are closer to adjacent antennas in a column of the array, in a column direction, for a column towards a center of the array of antennas than for a column towards a periphery of the array of antennas, such that a length of the coupling elements decreases with distance in a first direction from a center of the array of antennas, and a size of a gap in a second direction orthogonal to the first direction increases with distance in the first direction from the center of the array of antennas.

2. An apparatus as claimed in claim 1 , wherein the coupling elements increase cross-polarization discrimination for the array of antennas, at boresight, being a direction orthogonal to a flat plane of the array of antennas.

3. An apparatus as claimed in claim 1 , wherein the coupling elements are elongate having a length greater than a width, and wherein the aligned arrangement of coupling elements in the respective columns are aligned lengthwise.

4. An apparatus as claimed in claim 1 , wherein the aligned arrangement of coupling elements in a respective column are arranged along a virtual line that bi-sects the antennas of the respective column.

5. An apparatus as claimed in claim 1 , wherein the coupling elements are flat conductive elements.

6. An apparatus as claimed in claim 1 , wherein a printed wiring board comprises the coupling elements and comprises the antennas.

7. An apparatus as claimed in claim 1 , wherein a respective column of the aligned arrangement of coupling elements comprises coupling elements of the same size and shape between the antennas of the respective column.

8. An apparatus as claimed in claim 1 , wherein the coupling elements do not vary their characteristics in a column direction.

9. An apparatus as claimed in claim 1 , wherein the coupling elements vary their characteristics in a row direction.

10. An apparatus as claimed in claim 1 , configured to perform controlling at least phase between feeds.

11. An apparatus as claimed in claim 1 , configured to perform providing a relative phase adjustment to groups of antennas in the array of antennas, wherein the same relative phase adjustment is applied to antennas within a group and different relative phase adjustment is applied to antennas in different groups to effect beam-steering.

12. An apparatus as claimed in claim 1 , further comprising grounded isolation towers positioned at corners of antennas in the array of antennas.

13. An apparatus as claimed in claim 1 , wherein the apparatus is a base station, a base station system, or a part of a base station system.

14. An apparatus as claimed in claim 13 , wherein the apparatus is configured for multiple input multiple output operation.

15. An apparatus as claimed in claim 1 , wherein the apparatus is a portable electronic device.

16. An apparatus as claimed in claim 15 , wherein the apparatus is configured for multiple input multiple output operation.