S-band (2–4 GHz)
Weather radar, surface ship radar, and some communications satellites, especially those of NASA for communication with ISS and Space Shuttle.
C-band (4–8 GHz)
Primarily used for satellite communications, for full-time satellite TV networks or raw satellite feeds. Commonly used in areas that are subject to tropical rainfall
X-band (8-12 GHz)
Primarily used by the military. Used in radar applications including continuous-wave, pulsed, single-polarisation, dual-polarisation, synthetic aperture radar and phased arrays. X-band radar frequency sub-bands are used in civil, military and government institutions for weather monitoring, air traffic control, maritime vessel traffic control, defence tracking and vehicle speed detection for law enforcement.
KU-band (12–18 GHz)
Used for satellite communications. In Europe, Ku-band downlink is used from 10.7 GHz to 12.75 GHz for direct broadcast satellite services, such as Astra.
KA-band (27–40 GHz)
Communications satellites, uplink in either the 27.5 GHz and 31 GHz bands, and high-resolution, close-range targeting radars on military aircraft.