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{{redirect|UHF}}
{{Short description|Electromagnetic spectrum 300–3000 MHz}}
{{MWband
| name = Ultra high frequency (ITU)
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{{endplainlist}}
| name2 = Ultra high frequency (IEEE)
| freq2 = 300 MHz to
| wave2 = 1 m to 3 dm
| bands2 = {{startplainlist|class=nowrap}}
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{{endplainlist}}
}}
'''Ultra high frequency''' ('''UHF''') is the [[ITU]] designation for [[radio frequency|radio frequencies]] in the range between 300 [[megahertz]] (MHz) and 3 [[gigahertz]] (GHz), also known as the '''decimetre band''' as the wavelengths range from one meter to one tenth of a meter (one [[decimeter]]). Radio waves with frequencies above the UHF band fall into the [[super-high frequency]] (SHF) or [[microwave]] frequency range. Lower frequency signals fall into the VHF ([[very high frequency]]) or lower bands. UHF radio waves propagate mainly by [[Line-of-sight propagation|line of sight]]; they are blocked by hills and large buildings although the transmission through building walls is strong enough for indoor reception. They are used for [[UHF television broadcasting|television broadcasting]], [[cell phones]], satellite communication including [[GPS]], [[personal radio service]]s including [[Wi-Fi]] and [[Bluetooth]], [[walkie-talkie]]s, [[cordless phone]]s, [[satellite phone]]s, and numerous other applications.
The [[Institute of Electrical and Electronics Engineers|IEEE]] defines the UHF [[Radio spectrum#IEEE|radar band]] as frequencies between 300 MHz and 1 GHz.<ref name=ieee>{{cite web|url=https://standards.ieee.org/ieee/521/768/|title=IEEE 521-2002 - IEEE Standard Letter Designations for Radar-Frequency Bands|website=[[IEEE]]|access-date=17 December 2017}}</ref> Two other IEEE radar bands overlap the ITU UHF band: the [[L band]] between 1 and 2 GHz and the [[S band]] between 2 and 4 GHz.
[[File:UHF TV Antenna 001.JPG|thumb|UHF [[television antenna]] on a residence. This type of antenna, called a [[Yagi–Uda antenna]], is widely used at UHF frequencies.]]
== Propagation characteristics ==
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| url = https://books.google.com/books?id=4LtmjGNwOPIC&q=cross+polarization+discrimination&pg=PA57
| isbn = 0471743682
}}</ref>
Occasionally when conditions are right, UHF radio waves can travel long distances by [[tropospheric ducting]] as the atmosphere warms and cools throughout the day.
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{{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 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.
The short wavelengths also allow [[directional antenna|high gain antennas]] to be conveniently small.
==Applications==
[[UHF television broadcasting]] fulfilled the demand for additional over-the-air television channels in urban areas.
Since at UHF frequencies transmitting antennas are small enough to install on portable devices, the UHF spectrum is used worldwide for land mobile radio systems, [[two-way radio]]s used for voice communication for commercial, industrial, public safety, and military purposes.
Major telecommunications providers have deployed voice and data cellular networks in VHF/UHF range. This allows [[mobile phone]]s and [[mobile computing]] devices to be connected to the [[public switched telephone network]] and the [[Internet]]. Satellite phones also use this frequency in the [[L band]] and [[S band]].
UHF radars are said to be effective at tracking stealth fighters, if not stealth bombers.<ref>{{cite news|url=https://www.defensenews.com/global/asia-pacific/2014/11/22/chinas-anti-stealth-radar-comes-to-fruition/|title=China's Anti-Stealth Radar Comes to Fruition|last1=MINNICK|first1=WENDELL|date=22 November 2014|access-date=25 November 2014|publisher=Gannett|website=Defensenews.com}}</ref>
Wi-Fi operates
== Examples of UHF frequency allocations ==
===Australia===
* 406–406.1 MHz: Mobile satellite service<ref>{{Cite web|url=https://www.acma.gov.au/-/media/Spectrum-Engineering/Information/pdf/Radiocommunications-Assignment-and-Licensing-Instruction-RALI-MS22-400-MHz-Plan.pdf|title=400 MHz Plan|website=acma.gov|url-status=dead|archive-url=https://web.archive.org/web/20190404175218/https://www.acma.gov.au/-/media/Spectrum-Engineering/Information/pdf/Radiocommunications-Assignment-and-Licensing-Instruction-RALI-MS22-400-MHz-Plan.pdf|archive-date=April 4, 2019|access-date=November 3, 2019}}</ref>
* 450.4875–451.5125 MHz:Fixed point-to-point link
* 457.50625–459.9875 MHz: Land mobile service
* 476–477 MHz: [[UHF CB|UHF citizens band]] (Land mobile service)
* 503–694 MHz: [[Australian and New Zealand television frequencies|UHF channels]] for television broadcasting
===Canada===
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* 1452–1492 MHz: [[Digital Audio Broadcasting]] ([[L band]])<ref>{{cite web|url=https://www.broadcasting-history.ca/digital-audio-broadcasting-dab|title=Digital Audio Broadcasting (DAB) - History of Canadian Broadcasting|website=Broadcasting-history.ca|access-date=15 October 2017}}</ref>
* Many other frequency assignments for Canada and Mexico are similar to their US counterparts
===France===
* 380-400 MHz: [[TETRAPOL|Terrestrial Trunked Radio for Police]]
* 430-440 MHz: Amateur radio ([[70-centimeter band|70 cm band]])
* 470-694 MHz: [[Terrestrial television]]
===New Zealand===
* 406.1–420 MHz: Land mobile service
* 430–440 MHz: [[Amateur radio]] ([[70-centimeter band|70 cm band]]) and [[amateur radio satellite]]
* 476–477 MHz: [[UHF CB|PRS]] Personal Radio Service (Land mobile service)
* 485–502 MHz: Analog and [[Project 25|P25]] Emergency services use
* 510–622 MHz: [[Terrestrial television]]
* 960–1215 MHz: [[Aeronautical radionavigation service|Aeronautical radionavigation]]
* 1240–1300 MHz: Amateur radio ([[23-centimeter band|23 cm band]])
===United Kingdom===
*
*
*446.
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**Currently channels
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**791–862 MHz,<ref>{{cite web|url=http://stakeholders.ofcom.org.uk/spectrum/spectrum-awards/awards-archive/completed-awards/800mhz-2.6ghz/|title=800 MHz & 2.6 GHz Combined Award|date=May 9, 2012|publisher=The Office of Communications|access-date=2014-11-21}}</ref> i.e. channels
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===United States===
UHF channels are used for [[digital television transition in the United States|digital television broadcasting]] on both [[North American broadcast television frequencies|over the air channels]] and [[North American cable television frequencies|cable television channels]]. Since 1962, UHF channel tuners (at the time, channels 14
A complete list of US Television Frequency allocations can be found at [[
There is a considerable amount of lawful unlicensed activity (cordless phones, wireless networking) clustered around 900 MHz and 2.4 GHz, regulated under [[Title 47 CFR Part 15]]. These [[ISM band]]
The spectrum from 806 MHz to 890 MHz (UHF channels
In 2009, as part of the [[Digital television#Switch-off time announced|transition from analog to digital over-the-air broadcast of television]], the spectrum from 698 MHz to 806 MHz (UHF channels
*225–420 MHz: Government use, including [[meteorology]], military aviation, and federal two-way use<ref>[http://www.raytheon.com/capabilities/rtnwcm/groups/ncs/documents/content/rtn_ncs_products_arc164_pdf.pdf] {{dead link|date=December 2017}}</ref>
*420–450 MHz: Government radiolocation, [[amateur radio satellite]] and [[amateur radio]] ([[70-centimeter band|70 cm band]]), [[MedRadio]]<ref name="usfed-users">{{Cite web |url=https://www.ntia.doc.gov/page/federal-government-spectrum-use-reports-225-mhz-7125-ghz |title=Federal Government Spectrum Use Reports 225 MHz – 7.125 GHz |publisher=[[NTIA]] |date=Dec 2015 – Aug 2017 |access-date=October 21, 2019}}</ref>
*450–470 MHz: UHF business band, [[General Mobile Radio Service]], and [[Family Radio Service]] 2-way "walkie-talkies", public safety
*470–512 MHz: Low-band TV channels 14 to 20 (shared with public safety [[land mobile]] 2-way radio in 12 major metropolitan areas scheduled to relocate to 700 MHz band by 2023<ref>{{Cite web|url=http://www.npstc.org/download.jsp?tableId=37&column=217&id=2678&file=T_Band_Report_20130315.pdf|title=T-Band Report|date=March 15, 2013|website=Npstc.org|access-date=17 December 2017}}</ref>)
*512–608 MHz: Medium-band TV channels 21 to 36
*608–614 MHz: [[Channel 37]] used for [[radio astronomy]] and wireless medical telemetry<ref>{{Cite web |date=3 November 2011 |title=Wireless Medical Telemetry Service (WMTS) |url=https://www.fcc.gov/wireless/bureau-divisions/broadband-division/wireless-medical-telemetry-service-wmts |access-date=17 December 2017 |website=Federal Communications Commission}}</ref>
*614–698 MHz: Mobile broadband shared with TV channels 38 to 51 [[2008 United States wireless spectrum auction|auctioned in April 2017]]. TV stations were relocated by 2020.
**617–652 MHz: Mobile broadband service downlink
**652–663 MHz: Wireless microphones (higher priority) and unlicensed devices (lower priority)
**
*698–806 MHz: [[United States 2008 wireless spectrum auction|Was auctioned in March 2008]]; bidders got full use after the transition to [[Digital television|digital TV]] was completed on June 12, 2009 (formerly high-band UHF TV channels 52 to 69) and recently modified in 2021 for Next Generation 5G UHF transmission bandwidth for 'over the air' channels 2 thru 69 (virtual 1 thru 36).
*806–816 MHz: Public safety and commercial 2-way (formerly TV channels 70 to 72)
*817–824 MHz: ESMR band for wideband mobile services (mobile phone) (formerly public safety and commercial 2-way)
*
*849–851 MHz: Commercial aviation air-ground systems ([[Gogo Inflight Internet|Gogo]])
*
*862–869 MHz: ESMR band for wideband mobile services (base station) (formerly public safety and commercial 2-way)
*
*894–896 MHz: Commercial aviation air-ground systems ([[Gogo Inflight Internet|Gogo]])
*896–901 MHz: Commercial 2-way radio
*901–902 MHz: Narrowband PCS: commercial narrowband mobile services
*902–928 MHz: [[ISM band]], amateur radio ([[33-centimeter band|33 cm band]]), cordless phones and stereo, [[radio-frequency identification]], datalinks
*928–929 MHz: [[SCADA]], alarm monitoring, meter reading systems and other narrowband services for a company's internal use
*929–930 MHz: Pagers
*930–931 MHz: Narrowband PCS: commercial narrowband mobile services
*
*932–935 MHz: Fixed microwave services: distribution of video, audio and other data
*
*940–941 MHz: Narrowband PCS: commercial narrowband mobile services
*941–960 MHz: Mixed studio-transmitter fixed links, [[SCADA]], other.
*960–1215 MHz: Aeronautical radionavigation
*1240–1300 MHz: Amateur radio ([[23-centimeter band|23 cm band]])
*
*1350–1390 MHz: Military air traffic control and mobile telemetry systems at test ranges
*1390–1395 MHz: Proposed wireless medical telemetry service. [[TerreStar Corporation|TerreStar]] failed to provide service by the required deadline.<ref name=":2">{{Cite web|url=http://transition.fcc.gov/Daily_Releases/Daily_Business/2017/db1010/DA-17-995A1.pdf|title=TerreStar Corporation Request for Temporary Waiver of Substantial Service Requirements for 1.4 GHz Licenses|date=2017-10-10|website=the FCC|access-date=2017-10-11}}</ref>
*
*1400–1427 MHz: Earth exploration, radio astronomy, and space research
*
*1432–1435 MHz: Proposed wireless medical telemetry service. [[TerreStar Corporation|TerreStar]] failed to provide service by the required deadline.<ref name=":2" />
*1435–1525 MHz: Military use mostly for aeronautical mobile telemetry (therefore not available for [[Digital Audio Broadcasting]], unlike Canada/Europe)
*1525–1559 MHz: [[SkyTerra|Skyterra]] downlink ([[Ligado Networks|Ligado]] is seeking FCC permission for terrestrial use<ref name=":0">{{Cite web|url=https://www.fcc.gov/ecfs/file/download/1103057126216/Ligado%20Ex%20Parte%20re%20Iridium%20Analysis%20(PUBLIC%2011-2-2016).pdf|title=Ligado Ex Parte re Iridium Analysis (PUBLIC 11-2-2016)|website=Ecfsapi.fcc.gov|access-date=17 December 2017}}</ref>)
**1526–1536 MHz: proposed Ligado downlink
**1536–1559 MHz: proposed guard band
*1559–1610 MHz: [[Radionavigation-satellite service|Radio Navigation Satellite Services]] (RNSS) Upper L-band
**
**1593–1610 MHz: [[GLONASS]] G1 band
**1559–1591 MHz: [[Galileo (satellite navigation)|Galileo]] E1 band (overlapping with GPS L1<ref>{{Cite web|url=http://www.navipedia.net/index.php/GALILEO_Signal_Plan|title=Galileo Signal Plan|website=Navipedia.net|access-date=17 December 2017}}</ref>)
*
**1610–1618: [[Globalstar]] uplink
**1618–1626.5 MHz: [[Iridium satellite constellation|Iridium]] uplink and downlink<ref name=":0" />
**1626.5–1660.5 MHz: [[SkyTerra|Skyterra]] uplink ([[Ligado Networks|Ligado]] is seeking FCC permission for terrestrial use<ref name=":0" />)
**
***1646.5–1656.5 MHz: proposed Ligado uplink 2
*1660.5–1668.4 MHz: Radio astronomy observations. Transmitting is not permitted.
*1668.4–1670 MHz: Radio astronomy observations. Weather balloons may utilize the spectrum after an advance notice.
*1670–1675 MHz: [[Geostationary Operational Environmental Satellite]] transmissions to three [[earth station]]s in Wallops Island, Virginia; Greenbelt, Maryland and Fairbanks, Alaska. Nationwide broadband service license in this range is held by a subsidiary of [[Crown Castle International Corp.]] who is trying to provide service in cooperation with [[Ligado Networks]].<ref>{{Cite web|url=http://wireless2.fcc.gov/UlsApp/ApplicationSearch/applAdmin.jsp?applID=9585875#attachments|title=Request for waiver and public interest statement|date=2016-06-04|website=FCC|access-date=2018-04-02}}</ref>
*1675–1695 MHz: Meteorological federal users
*1695–1780 MHz: [[Advanced Wireless Services|AWS]] mobile phone uplink (UL) operating band
*
**1710–1755 MHz: AWS-1 blocks A, B, C, D, E, F
**1755–1780 MHz: AWS-3 blocks G, H, I, J (various federal agencies transitioning by 2025<ref>{{Cite web|url=https://www.ntia.doc.gov/category/aws-3-transition|title=AWS-3 Transition|date=January 29, 2015|website=Ntia.doc.gov|access-date=17 December 2017}}</ref>)
*1780–1850 MHz: exclusive federal use (Air Force satellite communications, Army's cellular-like communication system, other agencies)
*1850–1920 MHz: PCS mobile phone—order is A, D, B, E, F, C, G, H blocks. A, B, C = 15 MHz; D, E, F, G, H = 5 MHz
*1920–1930 MHz: [[Digital Enhanced Cordless Telecommunications|DECT]] [[cordless telephone]]
*
*2000–2020 MHz: lower AWS-4 downlink (mobile broadband)
*2020–2110 MHz: Cable Antenna Relay service, Local Television Transmission service, TV Broadcast Auxiliary service, Earth Exploration Satellite service
*
**2110–2155 MHz: AWS-1 blocks A, B, C, D, E, F
**2155–2180 MHz: AWS-3 blocks G, H, I, J
**
*2200–2290 MHz: [[NASA]] satellite tracking, telemetry and control (space-to-Earth, space-to-space)
*
*2300–2305 MHz: Amateur radio ([[13-centimeter band|13 cm band]], lower segment)
*2305–2315 MHz: WCS mobile broadband service uplink blocks A and B
*2315–2320 MHz: WCS block C (AT&T is pursuing [[smart grid]] deployment<ref name=":1">{{Cite web|url=https://www.fcc.gov/ecfs/file/download/011844558710/DA-17-78A1.pdf|title=AT&T Mobility Petition for Limited Waiver of Interim Performance Requirement for 2.3 GHz WCS C and D Block Licenses|website=Ecfsapi.fcc.gov|access-date=17 December 2017}}</ref>)
*2320–2345 MHz: [[Satellite radio]] ([[Sirius XM]])
*
*2350–2360 MHz: WCS mobile broadband service downlink blocks A and B
*2360–2390 MHz: Aircraft landing and safety systems
*2390–2395 MHz: Aircraft landing and safety systems (secondary deployment in a dozen of airports), amateur radio otherwise
*2395–2400 MHz: Amateur radio ([[13-centimeter band|13 cm band]], upper segment)
*2400–2483.5 MHz: [[ISM band|ISM]], [[IEEE 802.11]], 802.11b, 802.11g, 802.11n wireless [[LAN]], [[IEEE 802.15.4-2006]], [[Bluetooth]], [[radio-controlled aircraft]] (strictly for [[spread spectrum]] use), [[microwave oven]]s, [[Zigbee]]
*2483.5–2495 MHz: [[Globalstar]] downlink and Terrestrial Low Power Service suitable for TD-LTE small cells<ref>{{Cite web|url=https://www.globalstar.com/Globalstar/media/Globalstar/Downloads/Spectrum/GlobalstarOverviewPresentation.pdf|title=Globalstar Overview|date=2017|website=Globalstar.com|url-status=live|archive-url=https://web.archive.org/web/20170802042513/https://www.globalstar.com/en/ir/docs/GlobalstarOverviewPresentation.pdf|archive-date=August 2, 2017|access-date=17 December 2017}}</ref>
*2495–2690 MHz: Educational Broadcast and Broadband Radio Services<ref>{{Cite web|url=https://www.fcc.gov/wireless/bureau-divisions/broadband-division/broadband-radio-service-education-broadband-service|title=Broadband Radio Service & Education Broadband Service|website=The FCC|date=February 2016 |access-date=2018-06-05}}</ref>
*2690–2700 MHz: Receive-only range for radio astronomy and space research
==See also==
*[[Digital Audio Broadcasting]] and its [[regional implementations of DAB|regional implementations]]
*[[Digital terrestrial television]]
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