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C band
Frequency Range NATO: 500 – 1000 MHz
IEEE: 4 – 8 GHz

ITU Radio Band Numbers

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In biology, a C band is a region of constitutive heterochromatin on a chromosome.

C band is a name given to certain portions of the electromagnetic spectrum, as well as a range of wavelengths of light, used for communications. The IEEE C band and its variations, in particular, are microwave ranges used for certain satellite television broadcasts, and by some Wi-Fi devices, cordless phones, and weather radars. For satellite communications, the lower frequencies used by C Band perform better under adverse weather conditions than the Ku band or Ka band frequencies.[1]

Contents

NATO C band

The NATO C band is that portion of the electromagnetic spectrum between 500 MHz and 1000 MHz.

IEEE C band

The IEEE C band is a portion of the electromagnetic spectrum in the microwave range of frequencies ranging from 4 to 8 GHz.[2].

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 communication satellites over North America typically have 24 transponders spaced 20 MHz apart. [1] 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 5.4 GHz band (5.15–5.35/5.47–5.725/5.725–5.875 GHz) is used for IEEE 802.11a Wi-Fi and cordless phone applications, leading to occasional interference with C band weather radars.

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C band variants

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

C Band Variants Around The World
Band Transmit Frequency
(GHz)
Receive Frequency
(GHz)
Extended C Band 5.850–6.425 3.625–4.200
Super Extended C Band 5.850–6.725 3.400–4.200
INSAT C Band 6.725–7.025 4.500–4.800
Russian C Band 5.975–6.475 3.650–4.150
LMI C Band 5.7250–6.025 3.700–4.000

Optical communications C band

C band is also used in optical communications to refer to the wavelength range 1530 nm to 1565 nm.

Other Microwave bands

The microwave spectrum is usually defined as electromagnetic energy ranging from approximately 1 GHz to 100 GHz in frequency, but older usage includes lower frequencies. Most common applications are within the 1 to 40 GHz range. Microwave frequency bands, as defined by the Radio Society of Great Britain (RSGB), are shown in the table below:

L band 1 to 2 GHz
S band 2 to 4 GHz
C band 4 to 8 GHz
X band 8 to 12 GHz
Ku band 12 to 18 GHz
K band 18 to 26.5 GHz
Ka band 26.5 to 40 GHz
Q band 30 to 50 GHz
U band 40 to 60 GHz
V band 50 to 75 GHz
E band 60 to 90 GHz
W band 75 to 110 GHz
F band 90 to 140 GHz
D band 110 to 170 GHz

Footnote: P band is sometimes incorrectly used for Ku Band. "P" for "previous" was a radar band used in the UK ranging from 250 to 500 MHz and now obsolete per IEEE Std 521, see[2] and [3]. For other definitions see Letter Designations of Microwave Bands

See also

Notes

  1. ^ What is C Band page from tech-faq (accessed Aug. 14, 2008)
  2. ^ Peebles, Peyton Z. Jr, (1998), Radar Principles, John Wiley and Sons, Inc., p 20.

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