The V band (vee-band) of the electromagnetic spectrum ranges from 50 to 75 GHz. The V band is not heavily used, except for millimeter wave radar research and other kinds of scientific research. It should not be confused with the 600–1000 MHz range of Band-V (band-five) of the UHF frequency range.
The V band is also used for high capacity terrestrial millimeter wave communications systems. In the United States, the Federal Communications Commission has allocated the frequency band from 57 to 64 GHz for unlicensed wireless systems. These systems are primarily used for high capacity, short distance (less than 1 mile) communications. In addition, frequencies at 70, 80, and 90 GHz have been allocated as "lightly licensed" bands for multi-gigabit wireless communications. All communications links in the V band require unobstructed line of sight between the transmit and receive point, and rain fade must be taken into account when performing link budget analysis.
On Dec. 15, 1995 the V band at 60 GHz was used by the world's first crosslink communication between satellites in a constellation. This communication was between the U.S. Milstar 1 and Milstar 2 military satellites. 60 GHz is attractive for secure satellite crosslinks because it allows for high data rates, narrow beams and, lying in a strong absorption band of oxygen, provides protection against intercept by ground-based adversaries.
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:
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  and . For other definitions see Letter Designations of Microwave Bands