UHF

Ultra high frequency (UHF) denotes the portion of the radio spectrum from 300 megahertz to 3 gigahertz. In international and national regulation, UHF sits between the VHF band (about 30 to 300 MHz) and the SHF band (3 to 30 GHz). Wavelengths in this range run from 1 meter down to about 0.1 meter.

UHF is widely used for television broadcasting, mobile and fixed wireless communications, Wi‑Fi and other short‑range devices, as well as radar and satellite uplinks. The specific allocations vary by country; many UHF channels are licensed to broadcasters or service providers, while some bands are allocated for unlicensed use or shared use.

Propagation in the UHF band is generally line‑of‑sight and more affected by terrain, buildings, and rain than lower frequencies. UHF signals can be blocked or reflected by obstacles, leading to multipath effects in urban areas. The wavelengths are short enough to allow compact, efficient antennas and handheld devices, but coverage often requires a greater density of transmitters and repeaters to maintain reliability.

Applications span broadcasting, mobile communications, wireless networking, and sensing. In television, UHF channels above the VHF range were widely used for digital broadcasting. Mobile networks use UHF bands for 3G/4G/5G services in many regions, and Wi‑Fi networks commonly operate at 2.4 GHz, which lies within UHF. Radar, satellite uplinks, public safety radio, and amateur radio also employ UHF bands.

Regulation occurs through the ITU and national regulators, coordinating spectrum allocation, licensing, transmission power limits, and interference protections. Some UHF portions are licensed, others are unlicensed or shared, reflecting national policy and technological needs.