An antenna is a transducer device that converts electric power to radio waves and vice versa. It is generally considered a passive element without external equipment. There are various types of antennas available for different purposes, but panel antennas are commonly used in telecommunications. Panel antennas are made up of multiple long array antennas connected together with separate ports. They are used for 2G, 3G, and 4G networks. The standard size for antenna ports is 7/8 female coaxial with a 50-ohm input impedance.