SMALL CELL ANTENNAS SUITABLE FOR MIMO OPERATION

1 . A base station antenna, comprising:

a first linear array of first frequency band radiating elements that are mounted to extend outwardly from a first backplane;

a second linear array of first frequency band radiating elements that are mounted to extend outwardly from a second backplane;

a third linear array of first frequency band radiating elements that are mounted to extend outwardly from a third backplane;

a fourth linear array of first frequency band radiating elements that are mounted to extend outwardly from a fourth backplane;

a fifth linear array of second frequency band radiating elements that are mounted to extend outwardly from the first backplane; and

a sixth linear array of second frequency band radiating elements that are mounted to extend outwardly from the third backplane,

wherein the first linear array of first frequency band radiating elements is positioned opposite the third linear array of first frequency band radiating elements, and the second linear array of first frequency band radiating elements is positioned opposite the fourth linear array of first frequency band radiating elements, and

wherein the fifth and sixth linear arrays of second frequency band radiating elements are the only second frequency band radiating elements included in the base station antenna.

2 . The base station antenna of claim 1 , wherein the fifth linear array of second frequency band radiating elements is fed out-of-phase with respect to the sixth linear array of second frequency band radiating elements.

3 . The base station antenna of claim 1 , further comprising:

a first radio frequency (“RF”) port;

a first feed network that couples the first RF port to the first and third linear arrays of first frequency band radiating elements;

a second RF port; and

a second feed network that couples the second RF port to the second and fourth linear arrays of first frequency band radiating elements.

4 . The base station antenna of claim 3 , further comprising:

a third RF port;

a third feed network that couples the third RF port to the fifth and sixth linear arrays of second frequency band radiating elements.

5 . The base station antenna of claim 1 , wherein the first and third linear arrays of first frequency band radiating elements are configured to generate a first antenna beam that has a peanut-shaped cross-section in the azimuth plane, and the second and fourth linear arrays of first frequency band radiating elements are configured to generate a second antenna beam that has a peanut-shaped cross-section in the azimuth plane.

6 . The base station antenna of claim 1 , wherein the second frequency band encompasses lower frequencies than the first frequency band.

7 . A base station antenna, comprising:

a first radio frequency (“RF”) port;

a first array of radiating elements that is mounted to extend outwardly from a first backplane; and

a third array of radiating elements that is mounted to extend outwardly from a third backplane,

wherein the first linear array of radiating elements is positioned opposite the third linear array of radiating elements, and

wherein the first and third arrays of radiating elements are configured to generate a first antenna beam that has a first peanut-shaped cross-section in an azimuth plane in response to a first RF signal received from the first radio port.

8 . The base station antenna of claim 7 , further comprising:

a second RF port;

a second array of radiating elements that is mounted to extend outwardly from a second backplane; and

a fourth array of radiating elements that is mounted to extend outwardly from a fourth backplane,

wherein the second linear array of radiating elements is positioned opposite the fourth linear array of radiating elements, and

wherein the second and fourth arrays of radiating elements are configured to generate a second antenna beam that has a second peanut-shaped cross-section in an azimuth plane in response to a second RF signal received from the second radio port.

9 . The base station antenna of claim 8 , wherein a longitudinal axis of the first antenna beam in the azimuth plane is rotated ninety degrees from a longitudinal axis of the second antenna beam in the azimuth plane.

10 . The base station antenna of claim 8 , wherein the first through fourth backplanes form a tubular reflector assembly having a rectangular cross-section in the azimuth plane.

11 . The base station antenna of claim 8 , wherein the first and second antenna beams together provide omni-directional coverage in the azimuth plane.