ITU frequency bands: Difference between revisions
imported>Howard C. Berkowitz No edit summary |
imported>Meg Taylor (link) |
||
Line 45: | Line 45: | ||
|} | |} | ||
Millimeter wave frequencies begin at 18 GHz in SHF and go to the lower third of EHF. Submillimeter wave start roughly above 100 GHz; they blur into the longer [[infrared light]] frequencies. | Millimeter wave frequencies begin at 18 GHz in SHF and go to the lower third of EHF. Submillimeter wave start roughly above 100 GHz; they [[blur]] into the longer [[infrared light]] frequencies. |
Revision as of 10:54, 19 September 2009
![](http://s9.addthis.com/button1-share.gif)
The International Telecommunications Union has defined a system of terminology for electromagnetic frequencies used for radio and radar. While it is probably the most user-friendly of the three major systems in use, its categories are too coarsely grained for describing radar uses. It is, however, a good set of terms for frequencies used in communications.
See IEEE frequency bands for radar designations used widely in civilian practice, and the EU-NATO-US frequency bands for a nomenclature that works well in fine-grained radar band discussion.
The very lowest bands have no radar applications, but, among other things, have a critical military application in communicating, at a very low data rate, with submerged submarines.
Frequency range | ITU band |
---|---|
3-30 Hz | ELF (Extremely Low Frequency) |
30Hz to 300Hz | SLF (Super Low Frequency) |
300Hz to 3000Hz | ULF (Ultra Low Frequency) |
3kHz to 30kHz | VLF (Very Low Frequency) |
30-300 KHz | LF (Low Frequency; "longwave") |
300KHz-3 MHz | MF (Medium Frequency; "medium wave") |
3-30 MHz | HF (High Frequency; "shortwave") |
30-300 MHz | VHF (Very High Frequency) |
300 MHz -3 GHz | UHF (Ultra High Frequency) |
3-30 GHz | SHF (Super High Frequency) |
30-300 GHz | EHF (Extremely High Frequency) |
Millimeter wave frequencies begin at 18 GHz in SHF and go to the lower third of EHF. Submillimeter wave start roughly above 100 GHz; they blur into the longer infrared light frequencies.