C band

C band is a portion of the electromagnetic spectrum in the microwave range of frequencies ranging from 4 to 8 GHz.^[1]. It was the first frequency band allocated for commercial ground-to-satellite communications. A typical C-band satellite uses 3.7–4.2 GHz for downlink, and 5.925–6.425 Ghz for uplink.

C band is primarily used for open satellite communications, whether for full-time satellite TV networks or raw satellite feeds, although subscription programming also exists. This use contrasts with direct broadcast satellite, which is a completely closed system used to deliver subscription programming to small satellite dishes connected to proprietary receiving equipment.

C band is highly associated with TVRO satellite reception systems, commonly called "big dish" systems since small receiving antennas are not optimal for C-band systems. Typical antenna sizes on C-band capable systems ranges from 7.5 to 12 feet (2.5 to 3.5 meters) on consumer satellite dishes, although larger ones also can be used.

The 5.4GHz band (5.15–5.35/5.47–5.725/5.725–5.875 GHz) is used for IEEE 802.11a WIFI and cordless phone applications, leading to occasional interference with C-band weather radars.

C band variants

Slight variations of C band frequencies are approved for use in various parts of the world.^[2]

See also

• communications satellite
• big ugly dish
• 4DTV

Notes

1. ^ Peebles, Peyton Z. Jr, (1998), Radar Principles, John Wiley and Sons, Inc., p 20.
2. ^ http://www.tech-faq.com/c-band.shtml

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