Abstract: A superluminal antenna element having a transmission line feed, and an array comprising a plurality of such antenna elements, is presented. In one example, the antenna element includes a dielectric base portion having a cutout area, a mode transition element coupled to the cutout, a stripline transmission line connected to the mode transition, and a dielectric radiator element disposed within the cutout. The cutout of the dielectric base portion has first and second pluralities of steps arranged in opposing pairs. The mode transition element is located below and coupled to the cutout area of the dielectric base portion. The dielectric radiator element is mounted within the cutout area in an opposing pair of steps. Imposing a time-varying signal on the dielectric radiator element by way of the transmission line, mode transition element, and stepped cutout induces a polarization current in the dielectric radiator element.