Microwaves are electromagnetic waves with frequencies above about 3 Ghz. They are used in homes equipped with wireless internet devices, wireless telephones, Bluetooth devices, for satellite radio and television. In addition, industries, governments, and the military use microwaves for communicating from one installation to another.

Microwaves can be transmitted one of two ways. The first is the line-of-sight approach, where the microwave transmitter is pointed at a microwave receiver (these must be no more than 30 kilometers apart). The second method of transmission is to send the signal up to a satellite that receives it and retransmits it back down to a receiving dish.