A cell phone antenna is a key technology in a cellular phone system or any other wireless system. In a wireless system, an antenna converts guided radio wave energy (such as a signal traveling in a coaxial cable for television) to energy that is emitted or “radiated” out into free space. An antenna also does the reverse—it receives radio waves from the air and feeds them into the devices that detect, decode, and amplify them. In a cell phone system, there is one antenna in the handset and another in the base station tower. Both of these antennas transmit and receive waves.