Radio spectrum

A frequency band designated frequency ranges, so portions of the electromagnetic spectrum of the electromagnetic waves used for technical communication.

Divisions by frequency, wavelength or use are common. International are different names of the frequency bands in use, the boundaries were set arbitrarily often on the current state of knowledge in the high frequency physics. In a new standardization by the IEEE, the frequency bands are systematically classified according to the different characteristics of the frequencies with consequently logarithmically increasing band size. Partial but still traditional frequency band designations are used in the literature, which are specified in the following tables.

Radio frequencies

Survey

Remarks:

• Electric wires are fed with low technical alternating currents are due to their compared to the wavelength (several 1000 km! ) Short length very poor radiator. However succeed by high numbers of turns and very massive magnetic coupling ( soft iron or ferrite core ) good energy transfer in the transformer.
• The transition from Hertzian waves ( wavelengths between 1 cm and 10 km ) to the infrared radiation is influenced, inter alia, on the type of detection. Hertzian waves are detected by antennas which provide a high frequency. Infrared ( and higher frequencies ) are detected through their thermal effect or by ionization of molecules and atoms.

Broadcasting

For the radio frequency bands above 30 MHz usually short names are used. This broadcast bands are designated by Roman numerals from I to V. The band limits are defined in different sources and international agreements. Historically, these soft frequency information in part from one another. Whether the respective frequency range for the radio is usable at all and is actually used, in turn, is different from country to country.

Terrestrial broadcast bands and their labels with the ITU and CEPT

OIRT band

In addition to the criteria set by the ITU for radio bands I to V, there is the so-called OIRT band. This is for a long time used by some member countries of the OIRT in Eastern Europe to the spread of FM radio. It ranges from 65.9 MHz to 73.1 MHz and 65.9 MHz overlaps of up to 68 MHz with the broadcast band I. Today, it is only in a few countries (eg in Russia, Belarus and Ukraine ) using.

Japanese VHF broadcast band

In Japan the FM band ranges 76-90 MHz; the immediately subsequent Japanese TV band I ranges 90-108 MHz ( three analog channels).

1.5 GHz band ( "L- band" )

Above Volume V which is 1.5 GHz band - the so-called L-band - intended for terrestrial broadcasting applications. Here still no update from the abovementioned nomenclature has prevailed by Roman numerals. Probably because this frequency range has been about only plans at European level ( CEPT ) and not larger, international ( ITU ) for the terrestrial broadcasting. The term "L- band" is not an official name for this radio frequency range. It is derived from the radar frequency range " L" ( 1-2 GHz).

Terrestrial use of the broadcast bands in Europe

Use of spectrum in the broadband cable

See cable TV.

Microwave range

During World War II high frequencies were used in the GHz range of the radar tracking. For confidentiality, the frequency bands were randomly selected letters. Thus L may have been short for long- band, S for short, C for compromise in between L and S. The abbreviations K and Ku (formerly written as Ku ) Go to the German names short and short back down. Today, the letters indicate the transmission ranges of satellites.

The ITU is trying to unify the frequency assignments to the frequency band name:

In satellite radio, however, this classification is used mostly. (Some frequencies for scientific satellites and space probes are still missing. )

Frequencies and services (selection)

Optical and Infrared Astronomy

Optical data communication