Ultra high frequency ( UHF ) is the ITU designation for 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 ; they are blocked by hills and large buildings although the transmission through building walls is strong enough for indoor reception. They are used for television broadcasting , cell phones , satellite communication including GPS , personal radio services including Wi-Fi and Bluetooth , walkie-talkies , cordless phones , satellite phones , and numerous other applications.
31-708: The MTV Video Music Brazil awards (originally Video Music Awards Brazil), more commonly known as VMB , were MTV Brasil 's annual award ceremony, established in 1995. MTV viewers picked the winners for most categories since 2001. Unlike in the MTV Video Music Awards , the most important category at the MTV Video Music Brazil was the Viewer's Choice, not the Video of the Year; both of these categories merged in 2005. In 2007,
62-679: A must-carry station, for being a full-power broadcast station covering that market. In December 2009, Abril announced it would purchase Viacom's stake in MTV Brasil and gain exclusive rights to use the MTV brand in Brazil. MTV Brasil was one of the few MTV channels around the world that didn't air Laguna Beach or any of its spin-offs (such as The Hills ), since they were picked up by competitor Multishow . On 15 May 2013, journalist Keila Jimenez published an article in her blog "Outro Canal" that Grupo Abril
93-407: A wholly owned subsidiary of Abril. MTV Brasil launched on Sky Brasil on August 19, 1999 for that year's edition of MTV Video Music Brasil . In 2005, due to regulatory requirements that non-Brazilian companies can own only up to 30% of a terrestrial network, Abril acquired 20% of MTV Brasil from Viacom. In late 2006 MTV Brasil released its broadband channel following the international model for
124-428: 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 bands —frequencies with a higher unlicensed power permitted for use originally by Industrial, Scientific, Medical apparatus—are now some of the most crowded in the spectrum because they are open to everyone. The 2.45 GHz frequency
155-530: Is for cellphones , allowing handheld mobile phones be connected to the public switched telephone network and the Internet . Current 3G and 4G cellular networks use UHF, the frequencies varying among different carriers and countries. Satellite phones also use this frequency in the L band and S band . UHF channels are used for digital television broadcasting on both over the air channels and cable television channels . Since 1962, UHF channel tuners (at
186-548: Is seen as a response to NET Brasil (a wholly owned subsidiary of Organizações Globo that distributes channels to NET Serviços – and its affiliates – and SKY Brasil ) dropping MTV from its systems, after disagreeing to MTV conditioning its carriage on cable and satellite to the carriage of Abril owned channels Fiz and Ideal, which, for low viewership (especially since they were never carried by Net or Sky), were closed down in July 2009. MTV remains available on Net cable in markets where it's
217-467: Is still counted by Meio&Mensagem newspaper as the fifth most-viewed TV network in the country. MTV Brasil was the first network in the country dedicated to young people, in addition to being the first TV network in Brazil to broadcast their programming 24-hours-a-day, morning and night. The network ceased their operations on 30 September 2013, being replaced by a new channel operated by Viacom on subscription television . Its last music broadcast
248-452: Is the standard for use by microwave ovens , adjacent to the frequencies allocated for Bluetooth network devices. The spectrum from 806 MHz to 890 MHz (UHF channels 70 to 83) was taken away from TV broadcast services in 1983, primarily for analog mobile telephony . In 2009, as part of the transition from analog to digital over-the-air broadcast of television , the spectrum from 698 MHz to 806 MHz (UHF channels 52 to 69)
279-742: The MTV Overdrive . On 2 December 2007, after the official start of commercial HDTV broadcasts in Brazil, MTV launched MTV HD, a simulcast of the main MTV service, featuring original high-definition series and MTV2 's $ 2 Bill concerts. MTV HD is currently available over-the-air in São Paulo. In January 2008, MTV changed its broadcast frequency in Rio de Janeiro from UHF channel 24 to 48. On 1 September 2008 starts transmitting on satellite Star One C2 (70°W South America coverage) by analog system PAL-M , free-to-air frequency 4010H after being encrypted since 1993. This
310-507: The S band between 2 and 4 GHz. Radio waves in the UHF band travel almost entirely by line-of-sight propagation (LOS) and ground reflection; unlike in the HF band there is little to no reflection from the ionosphere ( skywave propagation), or ground wave . UHF radio waves are blocked by hills and cannot travel beyond the horizon, but can penetrate foliage and buildings for indoor reception. Since
341-494: The wavelengths of UHF waves are comparable to the size of buildings, trees, vehicles and other common objects, reflection and diffraction from these objects can cause fading due to multipath propagation , especially in built-up urban areas. Atmospheric moisture reduces, or attenuates , the strength of UHF signals over long distances, and the attenuation increases with frequency. UHF TV signals are generally more degraded by moisture than lower bands, such as VHF TV signals. As
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#1733092830831372-469: The UHF spectrum is used worldwide for land mobile radio systems, two-way radios used for voice communication for commercial, industrial, public safety, and military purposes. Examples of personal radio services are GMRS , PMR446 , and UHF CB . The most rapidly-expanding use of the band is Wi-Fi ( wireless LAN ) networks in homes, offices, and public places. Wi-Fi IEEE 802.11 low band operates between 2412 and 2484 MHz. A second widespread use
403-491: The VMB. MTV Brasil MTV Brasil was a Brazilian over-the-air television network owned by Grupo Abril focused on the youth and entertainment. The network was launched on 20 October 1990, as the first specialty television network to broadcast over-the-air, becoming the local version of MTV . It was the third MTV iteration launched in the world, and the first to broadcast via terrestrial television. The network headquarters
434-784: The atmosphere warms and cools throughout the day. The length of an 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 quarter-wave monopole , the most common omnidirectional antenna is between 2.5 and 25 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 systems , such as walkie-talkies , two-way radios in vehicles, and for portable wireless devices ; cordless phones and cell phones . Omnidirectional UHF antennas used on mobile devices are usually short whips , sleeve dipoles , rubber ducky antennas or
465-471: The awards have faced a major rebranding, with several categories extinguished (most notably the specific genre divisions) and even the trophies' design changed. From that year, the awards began to focus more on artists rather than music videos and the most important category became the Artist of the Year. However, the Video of the Year award continued to exist. In 2013, due to the closure of MTV Brasil's operations,
496-532: The ceremony was cancelled. In 2014, the second Brazilian version of MTV considered reviving the awards, but the plans were eventually discontinued in order to priorize MTV's international awards, such as the Video Music Awards and the Europe Music Awards . In 2018, MTV started to produce Millennial Awards Brazil as an award focused on Brazilian pop culture, being considered in some ways a successor to
527-409: The channel, confirmed that the brand MTV was returned to Viacom and MTV Brasil was going to continue with new TV shows until the end of September. On 29 July, Viacom International Media Networks announced that the channel would be relaunched on 1 October on pay TV. Grupo Abril announced a goodbye special of the channel from free-to-air television on 30 September. In September, Grupo Abril agreed to sell
558-478: The defunct Rede Manchete and the Clip Clip , broadcast by Rede Globo. MTV Brasil was launched on 20 October 1990, only to metropolitan São Paulo , through UHF channel A32 and metropolitan Rio de Janeiro , through VHF channel A9 (with TV Corcovado as an affiliate station). The first video shown was Garota de Ipanema , sung by Marina Lima . In 1996, Viacom acquired 50% of the network, which was, until then,
589-573: The entire archive (almost 33 thousand VHS video-tapes) to Viacom. Most of the collection is being selected by Zico Góes, who is scheduled to release a book with the My MTV special shows. The last live TV show of MTV Brasil was held on 26 September, with the VJs and employees of the channel making a party around the former MTV building in Perdizes . It was held from 6 pm to midnight ( BRT ). The last TV show aired
620-519: The music industry worldwide with the popularization of music videos, that were showcased by hosts known as video jockeys , or “VJ’s”. In Brazil, the company has partnered with the Rede Bandeirantes for the broadcasting of special events, such as awards shows. The music video itself first came to Brazil through the Rede Globo 's weekly news and entertainment show Fantástico . The news magazine
651-483: The planar inverted F antenna (PIFA) used in cellphones. Higher gain omnidirectional UHF antennas can be made of collinear arrays of dipoles and are used for mobile base stations and cellular base station antennas . The short wavelengths also allow high gain antennas to be conveniently small. High gain antennas for point-to-point communication links and UHF television reception are usually Yagi , log periodic , corner reflectors , or reflective array antennas . At
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#1733092830831682-414: The slot antenna or reflective array antenna are used: the slotted cylinder, zig-zag, and panel antennas. UHF television broadcasting channels are used for digital television , although much of the former bandwidth has been reallocated to land mobile radio system , trunked radio and mobile telephone use. Since at UHF frequencies transmitting antennas are small enough to install on portable devices,
713-517: The time, channels 14 to 83) have been required in television receivers by the All-Channel Receiver Act . However, because of their more limited range, and because few sets could receive them until older sets were replaced, UHF channels were less desirable to broadcasters than VHF channels (and licenses sold for lower prices). A complete list of US Television Frequency allocations can be found at Pan-American television frequencies . There
744-399: The top end of the band, slot antennas and parabolic dishes become practical. For satellite communication, helical and turnstile antennas 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
775-485: The visual horizon sets the maximum range of UHF transmission to between 30 and 40 miles (48 to 64 km) or less, depending on local terrain, the same frequency channels can be reused by other users in neighboring geographic areas ( frequency reuse ). Radio repeaters are used to retransmit UHF signals when a distance greater than the line of sight is required. Occasionally when conditions are right, UHF radio waves can travel long distances by tropospheric ducting as
806-461: Was O Último Programa do Mundo ("The Last Program in the World"). Cuca Lazarotto, who introduced the first music video aired on MTV Brasil, also introduced the last music video, "Maracatu Atômico" by Chico Science & Nação Zumbi . Astrid Fontenelle appeared to give the last message aired by MTV Brasil (which was recorded in the third week of September) and close MTV Brasil's broadcasting. Fontenelle
837-443: Was at 52 Avenida Professor Alfonso Bovero, Sumaré, São Paulo city, which was formerly the headquarters of Rede Tupi . This building was listed by Conselho de Defesa do Patrimônio Histórico (Condephaat) as having an historical heritage, becoming the first to be officially listed in the city. At the beginning of the 2010s, the channel was considered the largest youth network and the seventh largest terrestrial TV network in Brazil; it
868-476: Was known for being the first VJ of MTV Brasil's most famous TV show, Disk MTV . After that, the channel was replaced by Grupo Abril's Ideal TV and MTV Brasil relaunched on pay TV as only "MTV" on the following day. UHF The IEEE defines the UHF radar band as frequencies between 300 MHz and 1 GHz. Two other IEEE radar bands overlap the ITU UHF band: the L band between 1 and 2 GHz and
899-485: Was not going to continue to manage the channel until the end of that year, due to the risk of bankruptcy. On 12 June, Kelia posted that Grupo Abril was going to return the brand MTV to Viacom and was going to release a new channel in its place. This was later confirmed by another journalist, Patricia Kogut. A day later, MTV Brasil canceled three TV shows: Acesso MTV , MTV Sem Vergonha and A Hora do Chay and its VJs were fired. A week later, Zico Góes, head of programming on
930-487: Was the only TV show to produce and broadcast this type of programming, until the early 1980s, when the independent music video producers wanted to escape the standards imposed by the network. At the same time, MTV appeared in the North American market. Throughout the decade, other programs dedicated to music videos were created, like Clip Trip , on TV Gazeta , Som Pop , on TV Cultura , FMTV and Manchete Clip Show from
961-459: Was “Orra Meu” by Rita Lee while its last music video to air was "Maracatu Atômico" by Chico Science & Nação Zumbi . On terrestrial television, the network was replaced by Ideal TV . MTV , acronym of Music Television, debuted in the United States on 20 August 1981 under the control of Warner-Amex Satellite Entertainment . Today owned by Viacom , the subscription network revolutionized