C band

The designation C-band is used in the UHF range, but also in the microwave range and in optical transmission technology. Various frequency band designations for electromagnetic waves are used in the literature. The C-band occurs in the older German nomenclature, as well as in the International Telecommunication Union( ITU) and in the newer European nomenclature.

1. In NATO's European frequency band nomenclature, the C-band covers the frequency range between 500 MHz and 1 GHz, which corresponds to wavelengths of 60 cm to 30 cm. With this frequency band, the C-band covers large parts of the UHF frequencies. In terms of frequency, it is above the B-band and below the D-band. Special radar equipment for early warning systems is used in the C-band, as are weather observation systems. The C-band waves are subject to only slight atmospheric free- space attenuation.


Microwave frequency bands according to ITU/IEEE and European nomenclature

2. In the ITU nomenclature, the C-band belongs to the microwave technology and covers the frequency range between 4 GHz and 8 GHz. These are microwaves with wavelengths between 7.5 cm to 3.8 cm. In satellite communications, the C-band is defined as the frequency range between 3.5 GHz and 6.4 GHz. This range is preferably used for satellite transmission with GEO satellites. The frequency band from 3.7 GHz to 4.2 GHz is used as the receive band for the downlink and the frequency band from 5.9 GHz to 6.4 GHz for the uplink. The "C" stands for "Compromise" and represents a compromise between S-band and X-band.
3. In optical transmission technology with Wavelength Division Multiplexing(WDM), the C-band is referred to as the conventional (for C, Conventional) band. It is specified by the ITU in the ITU grid and is located in the third telecommunications window. The optical C-band covers the wavelength range between 1,530 nm and 1,565 nm. The channel sp acing between the two wavelengths is 20 nm. Above the C-band is the L-band (Long).