Page 45 - SATELLITE AND RADAR COMMUNICATION SYSTEM
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Satellite Payload
The next two sections discuss the key elements of the payload portion of
the space segment, specifically for communications satellite systems; the
transponder and antenna sub-systems.
1. Transponder
The subsystem, which provides the connecting link between
transmitting and receiving antennas of a satellite is known
as Transponder. It is one of the most important subsystem of space
segment subsystems.
Transponder performs the functions of both transmitter and receiver
(Responder) in a satellite. Hence, the word ‘Transponder’ is obtained by
the combining few letters of two words, Transmitter (Trans) and
Responder (ponder) with an example of a satellite of each type.
Transponder performs mainly two functions. Those are amplifying the
received input signal and translates the frequency of it. In general,
different frequency values are chosen for both uplink and down link in
order to avoid the interference between the transmitted and received
signals. The block diagram of transponder is shown in Figure 2.9.
Figure 2.9: Block diagram of transponder
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Satellite System Elements
