Ultra high frequency designates a range of electromagnetic waves with frequencies between 300 MHz and 3 GHz. Also known as the decimeter band or decimeter wave as the wavelengths range from ten to one decimeters. Radio waves with frequencies above the UHF band fall into the SHF and EHF bands, all of which fall into the Microwave frequency range. Lower frequency signals fall into the VHF or lower bands. See electromagnetic spectrum for a full listing of frequency bands.

Some radio frequency identification ( RFID ) tags utilize UHF. These tags are commonly known as UHFID's or Ultra-HighFID's (Ultra-High Frequency Identification).
Source: Wikipedia