An antenna (plural antennae or antennas), or aerial, is an electrical device which converts electric power into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver. In transmission, a radio transmitter supplies an electric current oscillating at radio frequency (i.e. a high frequency alternating current (AC)) to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic waves (radio waves). In reception, an antenna intercepts some of the power of an electromagnetic wave in order to produce a tiny voltage at its terminals, that is applied to a receiver to be amplified. 

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.
What is the main topic?
Does it have another name?
What would that be?
What does it do?
Is it used alone?
What else needs to be present for radio waves?
Anything else?
What type of electricity does it use?
What is it made of?
What frequency is used?
is it low?
An antenna
An antenna (plural a
yes
 or aerial, is an electrical device which converts electric power into radio waves, and 
aerial
aerial
converts electric power into radio waves
converts electric power into radio waves
No
sed with a radio transmitter or radio receiver
radio transmitter
radio transmitter
radio receiver
radio receiver
alternating current
alternating current 
metallic conductors
an antenna consists of an arrangement of metallic conductors
unknown
unknown
no
high frequency