Parts of a satellite
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The satellite consists of many parts. The main satellite parts which include transponder, antenna subsystems,
solar cell, battery backup,camera,thrusters.
1. Satellite transponder:
This electronic circuit helps satellite convert received 6 GHz uplink frequency signal to 4 GHz downlink frequency signal. Hence the main task of transponder is to do frequency conversion. This downconverted signal is amplified before being transmitted back to the earth using on power amplifier available on satellite.
On Ku band satellite system, transponder converts 14 GHz to 12 GHz band. A satellite usually will have 12 transponders. Each transponder will have 36 MHz bandwidth.
2. Antenna subsystems:
The antennas help receive and transmit the signals from the earth and towards earth respectively. There are various types of antennas fixed on satellite based on the application of use such as monopole,dipole horn,reflector,parabolic,microstrip etc. Most commonly there will be reflector antenna along with beam to cover one earth station on earth. So to cover more than one earth stations more than one reflector antennas are needed.
3. Solar cell and battery backup- It keeps satellite running in space.
Solar cell converts solar energy to the electrical energy for satellite operation.
During sun light conditions it is very useful. During the absence of sun light battery will take
care of providing power to the satellite for its operation.
NiCd, NiMH2,NiH2,NaS and LiIon based batteries are used in satellite based on need.