W band


The W band of the microwave part of the electromagnetic spectrum ranges from 75 to 110 GHz, wavelength ≈2.7–4 mm. It sits above the U.S. IEEE-designated V band in frequency, and overlaps the NATO designated M band. The W band is used for satellite communications, millimeter-wave radar 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 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 130 °F at a depth of 1/64 of an inch. The United States Air Force and Marines are currently using this type of Active Denial System.

Communications

In terms of communications capability, W band offers high data rate throughput when used at high altitudes and in space. Because of increasing spectrum and orbit congestion at lower frequencies, W-band satellite allocations are of increasing interest to commercial satellite operators, although no commercial project has yet been implemented in these bands.