Ultra High Frequency (UHF) technology officially spans a significant portion of the electromagnetic spectrum, ranging from 300 MHz to 3 GHz. However the term UHF is often used to refer primarily to the lower portion of this range, particularly focusing on frequencies between 300 MHz and 600 MHz. This subset is widely used for various radio communication and broadcasting applications due to its medium-long range propagation characteristics.
The UHF band is known for its ability to provide higher bandwidth compared to lower frequency bands like Very High Frequency (VHF), allowing for the transmission of more data, clearer voice communications, and support for a larger number of simultaneous users. One of the key advantages of UHF frequencies is their capacity for penetration into urban environments. UHF signals can penetrate buildings and other structures more effectively than higher frequency signals, making them suitable for indoor communication systems as well as for outdoor use in densely built areas. This feature is particularly beneficial for applications like Land Mobile Radio (LMR) systems used by public service agencies and for commercial two-way radio systems.
Despite these advantages, UHF radio waves do not travel as far as VHF waves and are more likely to be absorbed by atmospheric moisture, leading to potential limitations in range and susceptibility to varying weather conditions. This characteristic has a direct impact on the design and deployment of communication systems within this band, often necessitating the use of repeaters and other infrastructure to extend the effective range of communication.