Metal rod or length or wire which sends or receives electromagnetic waves. Antennas are commonly used in audio/video to receive FM and AM radio signals and to receive television signals. High-power antennas send out electromagnetic waves in an omnidirectional (all directions) pattern. Antennas connected to radio tuners and television tuners are excited by these waves and carry the information down their length to the tuner itself. The tuner then deciphers the information and creates an output.