Transponder (satellite communications)

Source: Wikipedia, the free encyclopedia.

A

communications channel between the receiving and the transmitting antennas.[1]
It is mainly used in satellite communication to transfer the received signals.

A transponder is typically composed of:

Most communication satellites are

u-bend) principle, sending back to Earth 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, is more complex, but has many advantages, such as improving the signal to noise ratio as the signal is regenerated from the digital domain, and also permits selective processing of the data in the digital domain.

With

audio channels may travel through a single transponder on a single wideband carrier
.

Original

Earth station for multiplexing
with other stations.

NASA distinguishes between a "

carrier frequency is derived from the received signal. The frequency linkage allows an interrogating ground station to recover the Doppler shift and thus infer range and speed from a communication signal without allocating power to a separate ranging signal.[2]

Transponder equivalent

A transponder equivalent (TPE) is a normalized way to refer to transponder bandwidth. It simply means how many transponders would be used if the same total bandwidths used only 36 MHz transponders.[3][4][5] So, for example, the ARSAT-1 has 24 IEEE Ku band transponders: 12 with a bandwidth of 36 MHz, 8 with 54 MHz, and 4 with 72 MHz, which totals to 1152  MHz, or 32 TPE (i.e., 1152 MHz divided by 36 MHz).[6][7]

References

  1. ISBN 0-07-138285-2
    .
  2. ^ Space Network Users Guide Archived 2016-03-05 at the Wayback Machine.
  3. ^ "Commercial Geostationary Satellite Transponder Markets for Latin America". Frost & Sullivan Research Service. 2003-07-03. Retrieved 2015-08-31.
  4. ^ Jacbo Gullish, Futron (February 2011). "The North American Satellite Market New Methodology Required..." www.satmagazine.com. SatMagazine. Retrieved 2015-08-31.
  5. ^ "Transponder". JSat International. Retrieved 2015-08-31.
  6. ^ "ARSAT-1 Telecommunication Satellite, Argentina". Aerospace Technology. Retrieved 2015-08-31.
  7. ^ Belluscio, Alejandro G. (2014-10-06). "ArSat-1: Argentina to communicate its heightened space ambitions". NASA SpaceFlight. Retrieved 2015-08-25.
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