US Patent 7183978 Wideband omnidirectional antenna

A compact antenna includes a disk-type radiating element normal to a ground plane section. Each face of the radiating element may have a third-dimensional characteristic (e.g., a convex outer surface.) Dielectric material may be positioned on the ground plane forward of each face of the radiating element. In other configurations, the third-dimensional characteristic and dielectric material features may be used separately in antennas arranged to provide omnidirectional performance over a wide frequency bandwidth. An input/output port may be provided by a coaxial-type connector coupled to the radiating element.