(Also called aerial; sometimes the more general term radiator is used.) A conductor or system of conductors for radiating and/or receiving radio energy.
As used in radar, the antenna is usually "directional," that is, it has the property of radiating or receiving radio waves in larger proportion in a given direction than in others. It includes both the basic radiating element or feed (such as dipole antenna or horn antenna) and its associated reflector for focusing the energy.
See also waveguide, loop antenna, beavertail antenna.