A coaxial antenna (often known as a coaxial dipole) is a particular form of a half-wave dipole antenna, most often employed as a vertically polarized omnidirectional antenna. A coaxial antenna (often known as a coaxial dipole) is a particular form of a half-wave dipole antenna, most often employed as a vertically polarized omnidirectional antenna. Arnold B. Bailey was granted the US patent 2,184,729 Antenna System on December 26, 1939 after filing in 1937 for a vertical antenna providing coaxial element sleeve structures. Bonnie Crystal was granted the US patent 7,151,497 Coaxial Antenna System on December 19, 2006 after filing in 2003 for new types of coaxial antennas with reduced size providing efficient broadband, wideband and controlled bandwidths, using radiation by the outside of the coaxial elements.