# Microwave Transmission ## What is Microwave Transmission Microwave transmission uses radio waves in the microwave frequency range, typically from 1 gigahertz to 300 gigahertz, for point-to-point communication between two locations. Unlike lower frequency radio waves that can travel in all directions and reflect off the ionosphere, microwave signals travel in straight lines and require an unobstructed line of sight between the transmitter and receiver. Microwave transmission has been used for decades in telecommunications for long-distance telephone calls, television broadcasting, and data communication. It is now also used in WiFi and cellular networks. ## How Microwave Transmission Works Microwave systems use highly directional dish antennas to focus the microwave beam in a specific direction. Because the beam is narrow and focused, microwave transmission is very efficient and can achieve high data transfer rates over long distances. The transmitter converts electrical signals into microwave signals and focuses them into a narrow beam using the dish antenna. The receiver at the other end captures the beam with its own dish antenna and converts the microwave signals back into electrical signals. Because the Earth's surface is curved, microwave relay towers are placed every 30 to 50 kilometers to extend the transmission range. Each relay tower receives the microwave signal, amplifies it, and retransmits it to the next tower. ## Terrestrial Microwave Terrestrial microwave systems transmit signals between towers located on hilltops, tall buildings, or dedicated towers. These systems are used by telephone companies to carry long-distance telephone traffic, by businesses to connect offices in different buildings across a city, and by cellular networks as backhaul connections between cell towers and the central network. Terrestrial microwave requires careful planning to ensure line of sight between towers and to obtain licensing for the frequencies being used. ## Applications of Microwave Telephone companies use microwave links as an alternative to laying fiber optic cable in areas where trenching would be expensive or impractical. Cellular network operators use microwave links to connect their cell towers to the core network. Broadcast companies use microwave to transmit television signals between studios and transmission towers. Businesses use microwave links to connect buildings in different locations without using public infrastructure. ## Advantages and Disadvantages Microwave transmission can cover long distances without the need to lay cables. It provides high bandwidth suitable for modern telecommunications. It can be deployed more quickly than laying fiber optic cable in some situations. The main disadvantages include the requirement for line of sight between transmitter and receiver, which limits where links can be established. Microwave signals can be affected by heavy rain, especially at higher frequencies, a phenomenon called rain fade. Microwave links require frequency licenses in most countries. The directional nature of microwave beams means that a single link only connects two specific points.