K band

K band Frequency range NATO: 20–40 GHz IEEE: 18–27 GHz

ITU Radio Band Numbers 1 2 3 4 5 6 7 8 9 10 11 12 ITU Radio Band Symbols ELF SLF ULF VLF LF MF HF VHF UHF SHF EHF THF NATO Radio bands A B C D E F G H I J K L M IEEE Radar bands HF VHF UHF L S C X Ku K Ka Q V W D

K band designates certain portions of the electromagnetic spectrum, in either the microwave domain or in the infrared domain. The microwave K bands are used primarily for radar and satellite communications while the infrared K band is used for astronomical observations.

NATO K band

The NATO K band is defined as a frequency band between 20 and 40 GHz (0.75 - 1.5 cm wavelength).

IEEE K band

The IEEE K band is a portion of the radio spectrum in the microwave range of frequencies ranging between 18 and 27 GHz. K band between 18 and 26.5 GHz is absorbed easily by water vapor (H₂O resonance peak at 22.24 GHz, 1.35 cm).

Subdivisions

The IEEE K band is conventionally divided into three sub-bands:

• K_a band: K-above band, 26.5–40 GHz, mainly used for radar and experimental communications.
• K-band 18–27 GHz
• K_u band: K-under band, 12–18 GHz, mainly used for satellite communications, terrestrial microwave communications, and radar, especially police traffic-speed detectors.

Amateur radio

The Radio Regulations of the International Telecommunication Union allow amateur radio and amateur satellite operations in the frequency range 24.000 GHz to 24.250 GHz, which is known as the 1.2-centimeter band. It is also referred to as the K band by AMSAT.

Infrared astronomy

In infrared astronomy, the K band refers to a different frequency range atmospheric transmission window centered on 2.2 microns (in the near-infrared 136 THz range).

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 [1] and [2]. For other definitions see Letter Designations of Microwave Bands