An antenna comprising a feed (42) for delivering electromagnetic energy to a rotatable combination of a dielectric lens (44) and a reflective surface (46). The combination of the dielectric lens and the reflective surface is placed proximate to and in front of an energy feed, such as a horn (42), to support the scanning of an antenna beam in response to rotation of the lens/reflective surface assembly. The lens typically comprises a dielectric material and the reflective surface can comprise a thin layer of material operable to reflect electromagnetic energy. For example, the lens can comprise a half-cylinder shape of dielectric material and the reflective surface can be applied to the flat portion of the half-cylindrical lens. Alternatively, the antenna can comprise two or more electromagnetic feeds (72a, 72b, 72c, 72d) and a cylindrical lens of dielectric material including a centrally embedded, two-sided reflective surface. A positioning system can be used to rotate the combination of the lens and the reflective material proximate to and in front of the electromagnetic feed(s).