Tag: How does a transponder work?

The term “satellite transponder” refers collectively to a transmitter-receiver subsystem on board the satellite that processes, amplifies and retransmits a range of frequencies (the transponder bandwidth) to another location/terminal/antenna on the earth .

A transponder will send an identifying coded signal in response to a transmitted interrogation from a ground-based radar station . An air traffic controller can then view the identified blip on a screen and know who it is and provide direction to the flight crews maintaining adequate separation with other blips.

A transponder is a wireless communications, monitoring, or control device that picks up and automatically responds to an incoming signal . The term is a contraction of the words transmitter and responder.

Each of this transponder occupy part of the total satellite bandwidth (BW) i.e. 500 MHz . Figure-1 depicts transponder channels with each utilizing 36 MHz of bandwidth from the total BW of 500 MHz. The guard band of 4 MHz is provided between transponders to avoid interference.