Typically an antenna consists of an arrangement of metallic conductors (elements), electrically connected (often through a transmission line) to the receiver or transmitter. An oscillating current of electrons forced through the antenna by a transmitter will create an oscillating magnetic field around the antenna elements, while the charge of the electrons also creates an oscillating electric field along the elements. These time-varying fields radiate away from the antenna into space as a moving transverse
electromagnetic field wave. Conversely, during reception, the
oscillating electric and magnetic fields of an incoming radio wave exert
force on the electrons in the antenna elements, causing them to move
back and forth, creating oscillating currents in the antenna.