Abstract: An antenna includes a support structure and radiating element. The radiating element includes a dielectric planar substrate having a first and a second surface, at least two conductive spiral arms extending outward from and spiraling about an axis of rotation formed on the first surface, and a feed conductor extending outward from and spiraling about an axis of rotation formed on the second surface. The feed conductor may be substantially aligned with one of the conductive spiral arms. When the support structure is placed upon a substantially planar surface, the radiating element is positioned at height h from the planar surface, wherein height h is about one-fourth the wavelength of the antenna's operating frequency. The antenna may produce an omni-directional antenna pattern in azimuth and a broad antenna pattern in elevation, with both patterns having nulls near the horizon. An external reflector may be operatively coupled to the antenna.