Dipole antennas are the earliest, simplest and most widely used antennas in radio communication. It consists of a pair of symmetrically placed conductors, and the two ends of the conductors that are close to each other are respectively connected to the feeder. When used as a transmitting antenna, the electrical signal is fed into the conductor from the center of the antenna; when used as a receiving antenna, the received signal is also obtained from the conductor at the center of the antenna.Dipole antennas are the most common type of antenna used and are omni-directional, propagating radio frequency (RF) energy 360 degrees in the horizontal plane. These devices are constructed to be resonant at a half or quarter wavelength of the frequency being applied.