Space Regulatory Glossary Industry

transponder

/trænˈspɒndər/ noun

1. A device on a communications satellite that receives an uplink signal, amplifies it, shifts it to a different frequency, and retransmits it as a downlink signal. Each transponder handles a specific bandwidth segment, typically 36 or 54 MHz.
2. Transponder capacity is the fundamental unit of commercial satellite bandwidth. Satellite operators lease transponders or fractions of transponders to customers, and transponder pricing is a key indicator of satellite industry economics.

Origin A portmanteau of 'transmitter' and 'responder,' originally coined in radar technology during World War II.

Related terms

uplink The transmission path from a ground station to a satellite, or the signal itself. Uplinks carry commands, software… downlink The transmission path from a satellite to a ground station, or the signal itself. In satellite communications, the… earth station A ground-based facility equipped to communicate with one or more satellites. Earth stations transmit uplink signals and…

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