The W-band as defined by IEEE is a frequency range from 75 to 110 GHz. IEEE uses letters to signify a range of frequencies from 1 to 170 GHz. The W band overlaps with the NATO designated M band (60 to 100 GHz). This band is used for a wide range of applications including automotive radars, satellite communication, astronomy, defense, and security applications.

The segment from 71 to 76 GHz and 81 to 86 GHz is designated by the International Telecommunication Union for satellite services. The 77 GHz frequency window is also used for automotive radars.