Antenna arrays may include a first plurality of radiating elements responsive to respective pairs of first radio frequency signals and a second plurality of radiating elements responsive to respective pairs of second radio frequency signals. A shared radiating element is also provided, which is responsive to a corresponding pair of first radio frequency signals and a corresponding pair of second radio frequency signals. This shared radiating element may be equivalent in configuration to the first and second pluralities of radiating elements, or may have a unique configuration relative to the first and second pluralities of radiating elements. The first plurality of radiating elements and the second plurality of radiating elements can be aligned as respective first and second spaced-apart and collinear columns of radiating elements, with the shared radiating element disposed about equidistant between the first and second columns.