VHFUHF

VHF and UHF refer to two adjacent portions of the radio frequency spectrum used for terrestrial communications. VHF covers roughly 30 to 300 MHz, while UHF covers roughly 300 to 3,000 MHz. The combined term VHF/UHF is often used to describe services and equipment operating in these bands, including broadcasting, mobile communications, and point-to-point links.

Propagation and characteristics vary across the two ranges. Both bands are largely line-of-sight, meaning signals travel directly between transmitter and receiver and are strongly affected by terrain and obstacles. VHF signals can sometimes diffract around hills and, under certain atmospheric conditions, travel farther via tropospheric effects. UHF signals are generally more readily blocked by buildings and foliage but support higher data rates and smaller antennas. Rain and atmospheric absorption increase with frequency, so UHF experiences more attenuation in adverse weather. Antenna design and tower height play a significant role in link performance in both bands.

Applications and typical uses span broadcasting, public safety, aviation, maritime communications, and various data and wireless links. FM radio and many television channels historically reside in the VHF band, while many land-mobile radio systems, satellite uplinks, and wireless point-to-point links operate in UHF. ISM devices and some consumer wireless devices also use portions of the UHF spectrum in different regions.

Regulation and licensing are governed by national authorities and international bodies such as the ITU. Frequency allocations differ by country, with certain sub-bands assigned to licensed services (public safety, broadcast, amateur radio) and others designated for unlicensed or shared use in specific regions. Equipment and operation typically must comply with technical standards and regulatory rules.