How Does a Dipole Antenna Work?

Composition

Dipole antennas are composed of two parallel wires. The wires produce a magnetic field that attracts the electrons being broadcast from another antenna. The open circuit of the two parallel wires is closed by the radiation of electrons around the wires. The two wires of a dipole antenna are required to produce the radiation--the two wires give the electrons a return path. Dipoles and monopole differ in that a monopole is a single wire. And like the partnership of the two dipole wires, the monopole needs a partner to produce a magnetic field--it uses a ground or "spike" antenna.

Reception

Radio frequency (RF) signals create a magnetic field around the transmitting signal, and the fluctuating signal of the transmitting antenna is received by the receiving antenna. An inverse of the transmitting field is produced around the receiving antenna to attract the broadcast. The quickly fluctuating RF signals received by the antenna are converted into electrical pulses and eventually sound or video.

Application

Dipole antennas may be used to receive television signals--"rabbit ear" antennas use varying splits, lengths and angles to maximize reception. For use in shortwave radio, wire lengths are often longer to receive signals over a longer range. Shortwave radios may incorporate some sort of folding or looping system for the lengthy antenna. Military units use doubled dipole antennas for transmission over special frequencies.