The W band of 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 ...

part of the

electromagnetic spectrum The electromagnetic spectrum is the full range of electromagnetic radiation, organized by frequency or wavelength. The spectrum is divided into separate bands, with different names for the electromagnetic waves within each band. From low to high ...

ranges from 75 to 110

GHz 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, cycle) per second. The hertz is an SI derived unit whose formal expression in ter ...

, wavelength ≈2.7–4 mm. It sits above the U.S.

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 ...

-designated V band (40–75 GHz) in frequency, and overlaps the NATO designated

M band The NATO M band is the obsolete designation given to the radio frequencies from 60 to 100 GHz (equivalent to wavelengths between 5 and 3 mm) during the cold war period. Since 1992 frequency allocations, allotment and assignments are in line to ...

(60–100 GHz). The W band is used for satellite communications, millimeter-wave

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 ...

research, military radar targeting and tracking applications, and some non-military applications.

Radar

A number of passive millimeter-wave cameras for concealed weapons detection operate at 94 GHz. A frequency around 77 GHz is used for automotive cruise control radar. The atmospheric

radio window The radio window is the region of the radio spectrum that penetrate the Earth's atmosphere. Typically, the lower limit of the radio window's range has a value of about 10 MHz (λ ≈ 30 m); the best upper limit achievable from optimal terrestria ...

at 94 GHz is used for imaging millimeter-wave radar applications in astronomy, defense, and security applications.

Heat ray

Less-than-lethal weaponry exists that uses millimeter waves to heat a thin layer of human skin to an intolerable temperature so as to make the targeted person move away. A two-second burst of the 95 GHz focused beam heats the skin to a temperature of at a depth of . The

United States Air Force The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...

and

Marines Marines (or naval infantry) are military personnel generally trained to operate on both land and sea, with a particular focus on amphibious warfare. Historically, the main tasks undertaken by marines have included Raid (military), raiding ashor ...

are currently using this type of

Active Denial System The Active Denial System (ADS) is a directed-energy weapon developed by the United States armed forces, U.S. military, designed for area denial, perimeter security and crowd control. Informally, the weapon is also called the heat ray since it wo ...

Communications

In terms of communications capability, W band offers high data rate throughput when used at high altitudes and in space. (The 71–76 GHz81–86 GHz segment of the W band is allocated by 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 ...

to satellite services.) Because of increasing spectrum and orbit congestion at lower frequencies, W-band satellite allocations are of increasing interest to commercial satellite operators, especially the Starlink satellite constellations which have implemented capabilities in these bands.

References

External links

A cloud radar at 94 GHz
{{EMSpectrum Microwave bands

Radar

Heat ray

Communications

References

Further reading

External links