repeater

A repeater is a device that receives communication signals and then transmits amplified versions of those signals. This function is crucial in various communication systems, particularly in long-distance transmissions where signal strength can degrade over distance.

In line-of-sight microwave links, repeaters are essential for extending the range of communication. For instance, a microwave radio relay system spanning 2,500 km might utilize a combination of terrestrial and satellite repeaters. These repeaters, often operating at specific frequencies like 4 gigahertz, can transmit multiple channels, each with a substantial bandwidth, at high data rates. The maximum range of land-based systems is limited by the Earth's curvature, necessitating repeaters placed at intervals, typically every 50 to 80 km, depending on tower height. These devices help overcome signal loss and ensure reliable communication over vast distances.12