An antenna that has characteristics of a broadband antenna and is formed by placing two conducting cones of infinite extent together, point to point, with a source placed between the points. In practice the cones are truncated and are formed of a number of cylindrical rods, typically six, to approximate the ideal structure. The truncation, size of the centre gap, and number of rods define the upper and lower frequencies of useful performance.

The bow-tie antenna is a simplified form of this where each cone is formed of a flat triangular sheet of metal or even a tube forming the boundary of this triangle. The bow-tie antenna exhibits lower broadband characteristics than the full biconical. See also Bilog antenna.