Editing Ultra high frequency (section)

==Antennas==
{{see also|UHF television broadcasting#UHF vs VHF}}

[[Image:Retevis RT49P GMRS version.jpg|thumb|Retevis [[GMRS]] [[two-way radio]]s operating on 462 and 467&nbsp;MHz in the UHF band, showing the short antennas used]]
[[Image:Corner reflector TV antenna.png|thumb|upright|Corner reflector UHF-TV antenna from 1950s]]
The length of an [[antenna (radio)|antenna]] is related to the length of the radio waves used. Due to the short wavelengths, UHF antennas are conveniently stubby and short; at UHF frequencies a [[monopole antenna|quarter-wave monopole]], the most common [[omnidirectional antenna]] is between 2.5 and 25&nbsp;cm long. UHF wavelengths are short enough that efficient transmitting antennas are small enough to mount on handheld and mobile devices, so these frequencies are used for two-way [[land mobile radio system]]s, such as [[walkie-talkie]]s, [[Two-way radio|two-way radios]] in vehicles, and for portable [[wireless device]]s; [[cordless phone]]s and [[cell phone]]s. Omnidirectional UHF antennas used on mobile devices are usually short [[whip antenna|whips]], sleeve [[dipole antenna|dipoles]], [[rubber ducky antenna]]s or the planar [[inverted F antenna]] (PIFA) used in cellphones. Higher gain omnidirectional UHF antennas can be made of [[collinear antenna array|collinear arrays]] of dipoles and are used for mobile base stations and [[sector antenna|cellular base station antennas]].

The short wavelengths also allow [[directional antenna|high gain antennas]] to be conveniently small. High gain antennas for [[point-to-point (telecommunications)|point-to-point]] communication links and UHF television reception are usually [[Yagi-Uda antenna|Yagi]], [[log periodic antenna|log periodic]], [[corner reflector antenna|corner reflectors]], or [[reflective array antenna]]s. At the top end of the band, [[slot antenna]]s and [[parabolic antenna|parabolic dishes]] become practical. For satellite communication, [[helical antenna|helical]] and [[turnstile antenna]]s are used since satellites typically employ [[circular polarization]] which is not sensitive to the relative orientation of the transmitting and receiving antennas. For television broadcasting specialized vertical radiators that are mostly modifications of the slot antenna or reflective array antenna are used: the slotted cylinder, zig-zag, and panel antennas.