What is Ultra high frequency?
'''Ultra High Frequency (UHF)''' is a [[electromagnetic radiation]]. Especially its [[frequency]] is between 300 [[MHz]] and 3&nbsp;GHz (3,000&nbsp;MHz). Because of short wavelength, UHF has strong [[directivity]] and it has small area. UHF is commonly used for [[television]] signals. It is strong enough to be protected from other signal, but because of its strong directivity, receiving error by an obstacle occurs more. Hence it needs sensitive [[sensor]]s.[[Image:TheElectromagneticSpectrum.jpg|thumb|800px|Electromagnetic Spectrum]] ==Uses== UHF frequencies have higher attenuation from atmospheric moisture and benefit less from 'bounce', or the reflection of signals off the ionosphere back to earth, when compared to VHF frequencies. The frequencies of 300–3000&nbsp;MHz are always at least an order of magnitude above the MUF (Maximum Usable Frequency). The MUF for most of the earth is generally between 25–35&nbsp;MHz. Higher frequencies also benefit less from ground mode transmission. However, the short wavelengths of UHF frequencies allow compact receiving antennas with narrow elements; many people consider them less ugly than VHF-receiving models == United States == On December 29, 1949 KC2XAK of Bridgeport, Connecticut became the first UHF television station to operate on a regular daily schedule. <br /> In the United States, UHF stations (broadcast channels above 13) originally gained a reputation for being more locally owned, less polished, less professional, less popular, and for having a weaker signal than their VHF counterparts (channels 2–13). The movie [[UHF (movie)|UHF]], starring Weird Al Yankovic, parodied this phenomenon. However, with the emergence of additional broadcast television networks ( Fox, UPN, WB, and PaxThe PAX Network PAX TV PaxNet or simply PAX is a cable television network formed in 1998. PAX, which is owned by Paxson Communications, shows family-oriented programming. Its programming contains little or no sex, violence or strong language. Unlike most), the concentration of media owne