floyd@brl-smoke.ARPA (Floyd Wofford) (02/11/88)
In response to the request for the letter designations for certain frequency
bands in the electromagnetic spectrum, I'll summarize a table found on page
3 of:
Infrared and Millimeter Waves
Volume 4 - Millimeter Systems
Kenneth J. Button and James C. Wiltse eds.
Academic Press, 1981
For microwave and radar types in the U.S
between 20 and 36 Ghz is K band with a sub band Ka between 33-36Ghz
" 36 " 46 Ghz " Q "
" 46 " 56 Ghz " V "
" 56 " 100 Ghz " W "
The table gives differing nomenclature for the United Kingdom and for the
Military (Official Joint Chiefs of Staff designation).
Another chart on page 24 of the same text gives the following information:
between 1 and 2 Ghz is L band
" 2 " 4 " " S "
" 4 " 8 " " C "
" 8 " 12 " " X "
" 12 " 18 " " Ku "
" 18 " 27 " " Ka "
" 27 " 40 " " K "
" 40 " 300 " " unspecified - generically known as millimeter wave
Millimeter wave bands are between 30 and 300 Ghz ~ 1cm to 1mm in wavelength. Above
300 Ghz is the sub-millimeter wavelength which will meet the near infrared somewhere
in the vicinity of 5Thz (I am interpolating from the chart in front of me).
There is, I believe, no standardized nomenclature for the band designations. This
leads to the two different Ka designations. If you are up that high you are
definitely in K band somewhere. Sorry.
I will quote from Merrill I. Skolnik.
"Early in the development of radar, a letter code such as S, X, L, etc., was
employed to designate radar frequency bands. Although its original purpose was to
guard military secrecy, the designations were maintained, probably out of habit
as well as the need for some convenient short nomenclature. The usage has
continued and is now an accepted practice of radar engineers." page 9,
Introduction to Radar Systems, McGraw-Hill, 1980.
Floyd Wofford
floyd@brl.arpa