An antenna includes a dielectric material having i) a first side opposite a second side, and ii) a conductive via therein. A first planar conducting element is on the first side of the dielectric material and has an electrical connection to the conductive via. A second planar conducting element is also on the first side of the dielectric material. A gap electrically isolates the first and second planar conducting elements from each other. An electrical microstrip feed line on the second side of the dielectric material electrically connects to the conductive via and has a route that extends from the conductive via, to across the gap, to under the second planar conducting element. The first planar conducting element has a plurality of electromagnetic radiators, each having dimensions that cause it to resonate over a range of frequencies that differs from a range of frequencies over which an adjacent radiator resonates. At least first and second of the radiators bound an open slot in the first planar conducting element. The open slot has an orientation perpendicular to the gap.