Band (radio)

From Wikipedia, the free encyclopedia

A band is a small section of the spectrum of radio communication frequencies, in which channels are usually used or set aside for the same purpose. Examples include:

• AM broadcast band (530–1610kHz, to 1700 in the Americas)
• Shortwave bands (5.9–26.1 MHz)
• Citizens' band
• Television stations 2–6 (54–88 MHz in the Americas)
• FM broadcast band (88–108 MHz, except 76–90 in Japan)
• Aircraft band (108–136 MHz), for air traffic control
• Television stations 7–13 (174–216 MHz in the Americas)
• L band (1452–1492 MHz) for digital radio (DAB) outside the US
• Amateur radio bands among several different frequencies
• Military bands
  • X-Band 8–10 GHz
  • S-Band 1750–2400 MHz
• Radionavigation beacons, such as LORAN and GPS

Each of these bands has a basic bandplan which dictates how it is to be used and shared, to avoid interference and to set protocol for the compatibility of transmitters and receivers.

Note that as a matter of physics, bands are divided at wavelengths of 10ⁿ metres, or frequencies of 3×10ⁿ hertz. For example, 30 MHz or 10 m divides shortwave (lower and longer) from VHF (shorter and higher). These are the parts of the radio spectrum, and not its frequency allocation.