The C band is a designation by the Institute of Electrical and Electronics Engineers (IEEE) for a portion of the electromagnetic spectrum in the microwave range of frequencies ranging from 4.0 to 8.0 gigahertz (GHz);[1] however, this definition is the one used by radar manufacturers and users, not necessarily by microwave radio telecommunications users. The C band (4 to 8 GHz) is used for many satellite communications transmissions, some Wi-Fi devices, some cordless telephones as well as some surveillance and weather radar systems.

The C band (4 to 8 GHz) is used for many satellite communications transmissions, some Wi-Fi devices, some cordless telephones as well as some surveillance and weather radar systems.

  • International Telecommunication Union(ITU) is the worldwide frequency regulator.
  • ITU initially defined C-band to be the first satellite band.
  • Frequencies range from 4Ghz to 8Ghz.
  • This range of frequency is also used widely by terrestrial microwave backhaul links nowadays, especially because the sub 6GHz band is free of license in many countries all over the world. This resulted in a great interference problem between C-band & terrestrial backhauling links. Thus, ITU started to define new frequency bands as Ku-Band .
  • On the other hand, signals in C-band are less focused compared to higher satellite frequencies such as Ku-Band. This is due to the longer wavelength in C Band.
  • Less focused signals means that these signals are less affected by rain (a phenomenon known as rain fade of satellite signals).
  • The attenuation on C-band signal due to rain fading ranges from 0.4 dB to 1 dB only.
  • Moreover, these less focused signals can provide wider range of coverage. However, these signals need larger dish size ( e.g.  2.4 , 3 or 3.7 meters in diameter), so that they can be received from the satellite.
  • Thus, C-band requires more expensive equipment compared to Ku-Band (more Capital Expenditure “CAPEX”).
  • C-band is preferred in some locations where rainfalls are heavy, as the situation in tropical regions of Africa.
  • From a commercial point of view, C-band is better for satellite applications that need larger bandwidth. This is because the license fees for C-band bandwidth are cheaper than Ku-band ( less Operational Expenditure “OPEX”)