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T4S was the first satellite for DirecTV to employ spot beams. This technology reuses the same frequencies on multiple spot beams to reach the major television markets where DirecTV delivers the signals of local network affiliates. The satellite carried two Ku-band payloads: spot beams for local channels, and a national beam payload.
For example, satellite television signals are transmitted from the satellite on two separate channels at the same frequency using right and left circular polarization. In a home satellite dish, these are received by two small monopole antennas in the feed horn, oriented at right angles. Each antenna is connected to a separate receiver.
The T14 satellite is the sixth satellite built by SSL (Space Systems/Loral) for operator DirecTV. The high-capacity spacecraft is based on the SSL 1300 platform, T14 is a 20-kilowatt class Ka-band and reverse-band digital broadcast satellite that will be used to deliver Ultra HD and other new consumer services for DirecTV.
Patch antenna gain pattern. A directional antenna or beam antenna is an antenna which radiates or receives greater radio wave power in specific directions. Directional antennas can radiate radio waves in beams, when greater concentration of radiation in a certain direction is desired, or in receiving antennas receive radio waves from one specific direction only.
In electromagnetics, directivity is a parameter of an antenna or optical system which measures the degree to which the radiation emitted is concentrated in a single direction. It is the ratio of the radiation intensity in a given direction from the antenna to the radiation intensity averaged over all directions. [ 1 ]
A spot beam, in telecommunications parlance, is a satellite signal that is specially concentrated in power (i.e. sent by a high-gain antenna) so that it will cover only a limited geographic area on Earth. Spot beams are used so that only Earth stations in a particular intended reception area can properly receive the satellite signal. [1]
T10 (formerly DirecTV-10) is a Boeing model 702 direct broadcast satellite that provides high-definition television (HDTV) to DirecTV subscribers in North America. [1] It was launched by International Launch Services on July 7, 2007 from the Baikonur Cosmodrome in Kazakhstan aboard an Enhanced Proton Breeze-M rocket. [2]
Omnidirectional antennas are widely used for radio broadcasting antennas, [3] and in mobile devices that use radio such as cell phones, FM radios, walkie-talkies, wireless computer networks, cordless phones, GPS, as well as for base stations that communicate with mobile radios, such as police and taxi dispatchers and aircraft communications.