Microwave radio signals are electromagnetic waves short wavelengths and high high frequencies between 500 MHz to 300 GHz. About 35 percent of all terrestrial communication is maintained by microwave radio relay systems. There are various types of microwave radio communication systems, operating anywhere between 15 miles to 4,000 miles, including feeder service or intrastate microwave systems and long-haul microwave systems.
Advantage: Able to Transmit Large Quantities of Data
Microwave radio systems can broadcast large quantities of information because of their high frequencies. Microwave repeaters also give microwave communication systems the ability to transmit data over extremely long distances. A repeater receives the transmitting signal through one antenna, converts it into an electrical signal and then retransmits it again as a microwave signal at full strength. Microwave radio communication systems propagate signals through the earth's atmosphere. These signals are sent between transmitters and receivers that lie on top of towers. This allows microwave radio systems to transmit thousands of data channels between two points without relying on a physical medium like fiber optics or wire cables.
Advantage: Relatively Low Costs
Microwave communication systems have relatively low construction costs compared with other forms of data transmission, such as wire-line technologies. A microwave communication system does not require physical cables or expensive attenuation equipment (devices that maintain signal strength during transmission). Mountains, hills and rooftops provide inexpensive and accessible bases for microwave transmission towers.
Disadvantage: Solid Objects
Microwave radio systems do not pass through solid objects. This can be problematic in cities with a lot of tall buildings or mountainous regions if you want to send a signal from one end of the city to the other. There are ways to work around this, like erecting repeaters between two towers if an object is blocking them. Signals can also be bounced off of solid objects and even the ionosphere. It is even possible to bounce microwaves off of the moon, in earth-moon-earth communications known as moon bouncing.
Disadvantage: Subject to Electromagnetic and Other Interference
Electromagnetic interference, or EMI, can obstruct or degrade the performance of microwave signals. Electric motors, electric power transmission lines and wind turbines can all emit EMI that disrupts microwave communication. Wind turbines, for example, scatter and diffract TV, radio and microwave signals when placed between signal transmitters and receivers. Microwave radio communication can also be degraded by heavy moisture in the atmosphere, snow, rain and fog, in a phenomenon known as rain fade.
- National Aviation Reporting Center on Anomalous Phenomena: Disruptive Effects of Electromagnetic Interference on Communication and Electronic Systems
- Washington University: Transmission Media
- Science Clarified: Microwave communication
- Amateur Radio in Australia (VKFAQ): Microwave Communications
- Rural America at the Crossroads : Networking for the Future
- Microwave communication By George Maurice Kizer
- Electronic Communications System: Fundamentals Through Advanced, 5/e