The first advantage of using microwaves in radar and telecommunications is that they can easily pass through rain, smoke, fog, as well as through the ionosphere which blocks or reflects longer radio waves. The second advantage is that microwaves, which have a higher frequency than radio waves, can carry more information as the frequency increases. Because of their high frequency, microwaves can be accurately directed in a narrow beam from one transmitting antenna to the receiving antenna of the next relay station. The transmitting antennas contain components such as waveguides, horns, lenses, and reflectors. The receiving antenna at the next relay station is used to receive the microwave radiation, which is then directed to appropriate instruments for further processing.
Communication satellites are platforms that house radio receivers and their antenna.
They receive microwave signals from the Earth stations, then amplify and send the signals to another station to create an unobstructed path for transmissions between stations, but unlike a microwave link or a cable, it can interconnect any number of stations that are included within the antenna beams of the satellite rather than just the two ends of the microwave link. The first disadvantage of using microwaves is that they pass directly through the upper atmosphere without being reflected back to Earth. So, a signal from a transmitter cannot normally be picked up by a receiver beyond the horizon because of the natural curvature of the earth s surface. About 100 of these towers are needed to cross the United States. Another disadvantage that was mentioned in Grolier s Electronic Encyclopedia is the danger of being exposed to the low-level microwave radiation that is generated.