Matches in DBpedia 2014 for { <http://dbpedia.org/resource/Transponder_(satellite_communications)> ?p ?o. }
Showing items 1 to 27 of
27
with 100 items per page.
- Transponder_(satellite_communications) abstract "A communications satellite's transponder, is the series of interconnected units which form a communications channel between the receiving and the transmitting antennas. It is mainly used in satellite communication to transfer the received signals.A transponder is typically composed of: An input band limiting device (a band pass filter) An Input low-noise amplifier (LNA), designed to amplify the (normally very weak, because of the large distances involved) signals received from the earth station A frequency translator (normally composed of an oscillator and a frequency mixer) used to convert the frequency of the received signal to the frequency required for the transmitted signal An output band pass filter A power amplifier (this can be a traveling-wave tube or a solid state amplifier)Most communication satellites are radio relay stations in orbit, and carry dozens of transponders, each with a bandwidth of tens of megahertz. Most transponders operate on a "bent pipe" principle, sending back to earth of what goes into the conduit with only amplification and a shift from uplink to downlink frequency. However, some modern satellites use on-board processing, where the signal is demodulated, decoded, re-encoded and modulated aboard the satellite. This type, called a "regenerative" transponder, has many advantages, but is much more complex.With data compression and multiplexing, several video (including digital video) and audio channels may travel through a single transponder on a single wideband carrier. Original analog video only had one channel per transponder, with subcarriers for audio and automatic transmission identification service ATIS. Non-multiplexed radio stations can also travel in single channel per carrier (SCPC) mode, with multiple carriers (analog or digital) per transponder. This allows each station to transmit directly to the satellite, rather than paying for a whole transponder, or using landlines to send it to an earth station for multiplexing with other stations. NASA distinguishes between a "transponder" and a "transceiver", where the latter is simply an independent transmitter and receiver packaged in the same unit, and the former derives the transmit carrier frequency from the received signal. This linkage allows an interrogating ground station to recover the Doppler and thus infer range and speed from a communication signal without allocating power to a separate ranging signal.".
- Transponder_(satellite_communications) wikiPageID "13442133".
- Transponder_(satellite_communications) wikiPageRevisionID "560738183".
- Transponder_(satellite_communications) hasPhotoCollection Transponder_(satellite_communications).
- Transponder_(satellite_communications) subject Category:Communications_satellites.
- Transponder_(satellite_communications) subject Category:Satellite_broadcasting.
- Transponder_(satellite_communications) type Artifact100021939.
- Transponder_(satellite_communications) type CommunicationsSatellite103077741.
- Transponder_(satellite_communications) type CommunicationsSatellites.
- Transponder_(satellite_communications) type Equipment103294048.
- Transponder_(satellite_communications) type Instrumentality103575240.
- Transponder_(satellite_communications) type Object100002684.
- Transponder_(satellite_communications) type PhysicalEntity100001930.
- Transponder_(satellite_communications) type Satellite104137444.
- Transponder_(satellite_communications) type Whole100003553.
- Transponder_(satellite_communications) comment "A communications satellite's transponder, is the series of interconnected units which form a communications channel between the receiving and the transmitting antennas.".
- Transponder_(satellite_communications) label "Transponder (Satellit)".
- Transponder_(satellite_communications) label "Transponder (satellite communications)".
- Transponder_(satellite_communications) label "Transponder (satélite de comunicação)".
- Transponder_(satellite_communications) sameAs Transponder_(Satellit).
- Transponder_(satellite_communications) sameAs Transponder_(satélite_de_comunicação).
- Transponder_(satellite_communications) sameAs m.03c5g2d.
- Transponder_(satellite_communications) sameAs Q1684574.
- Transponder_(satellite_communications) sameAs Q1684574.
- Transponder_(satellite_communications) sameAs Transponder_(satellite_communications).
- Transponder_(satellite_communications) wasDerivedFrom Transponder_(satellite_communications)?oldid=560738183.
- Transponder_(satellite_communications) isPrimaryTopicOf Transponder_(satellite_communications).