An antenna system includes: a first patch antenna element that is electrically conductive; a first energy coupler configured to convey first energy to or from the first patch antenna element; a second patch antenna element at least partially overlapping the first patch antenna element, the second patch antenna element defining a first slot through the second patch antenna element; and a second energy coupler configured to convey second energy to, or receive the second energy from, the first slot or a first dipole at least partially overlapping the first slot.