The

IEEE The Institute of Electrical and Electronics Engineers (IEEE) is an American 501(c)(3) organization, 501(c)(3) public charity professional organization for electrical engineering, electronics engineering, and other related disciplines. The IEEE ...

K-band is a portion of the

radio spectrum The radio spectrum is the part of the electromagnetic spectrum with frequencies from 3 Hz to 3,000 GHz (3 THz). Electromagnetic waves in this frequency range, called radio waves, are widely used in modern technology, particula ...

in the

microwave Microwave is a form of electromagnetic radiation with wavelengths shorter than other radio waves but longer than infrared waves. Its wavelength ranges from about one meter to one millimeter, corresponding to frequency, frequencies between 300&n ...

range of frequencies from 18 to 27

gigahertz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base un ...

(GHz). The range of frequencies in the center of the K-band between 18 and 26.5 GHz are absorbed by

water vapor Water vapor, water vapour, or aqueous vapor is the gaseous phase of Properties of water, water. It is one Phase (matter), state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from th ...

in the atmosphere due to its resonance peak at 22.24 GHz, . Therefore these frequencies experience high atmospheric

attenuation In physics, attenuation (in some contexts, extinction) is the gradual loss of flux intensity through a Transmission medium, medium. For instance, dark glasses attenuate sunlight, lead attenuates X-rays, and water and air attenuate both light and ...

and cannot be used for long-distance applications. For this reason, the original K-band has been split into three bands: Ka-band, K-band, and Ku-band as detailed below. The K stands for , the German word for 'short'.

Subdivisions

Because of the water vapor absorption peak in the center of the band, the IEEE K-band is conventionally divided into three sub-bands: * Ku-band (K-under band, 12–18 GHz): mainly used for satellite communications, direct-broadcast satellite television, terrestrial microwave communications, and

radar Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...

, especially police traffic speed detectors. * K-band (18–27 GHz): due to the 22 GHz water vapor absorption line, this band has high atmospheric attenuation and is only useful for short-range applications. * Ka-band (K-above band, 26.5–40 GHz): mainly used for satellite communications, radar and experimental communications. NASA's Kepler space telescope is the first NASA mission to use Ka-band NASA Deep Space Network (NASA DSN) communications.

Amateur radio

The Radio Regulations of the

International Telecommunication Union The International Telecommunication Union (ITU)In the other common languages of the ITU: * * is a list of specialized agencies of the United Nations, specialized agency of the United Nations responsible for many matters related to information ...

(ITU) allow

amateur radio Amateur radio, also known as ham radio, is the use of the radio frequency radio spectrum, spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emer ...

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.

References

{{EMSpectrum Microwave bands Satellite broadcasting

Subdivisions

Amateur radio

See also

References