An antenna element is provided which responsive in multiple frequency bands, has symmetric beam patterns, and is easily and cheaply fabricated. The antenna element includes at least three conductive plates arranged in a stack At least one pair of adjacent plates contain apertures that are mutually aligned relative to the stacking direction. The antenna element further includes at least one air stripline arranged to create radiative electromagnetic excitations of the apertures when the stripline or striplines are energized by a suitable radiofrequency voltage source or sources.