Understanding the Key Components of a Satellite

A satellite is composed of various essential components working together to ensure its functionality in orbit. The main parts include the transponder, antenna subsystems, solar cell, battery backup, camera, and thrusters.

1. Satellite Transponder

The satellite transponder is an electronic circuit crucial for frequency conversion. It receives a 6 GHz uplink frequency signal and converts it to a 4 GHz downlink frequency signal.

The primary function of the transponder is, therefore, frequency conversion. This downconverted signal is then amplified before being transmitted back to Earth using a power amplifier onboard the satellite.

In Ku band satellite systems, the transponder converts 14 GHz to 12 GHz.

A typical satellite houses about 12 transponders. Each transponder generally has a bandwidth of 36 MHz.

2. Antenna Subsystems

Antennas play a vital role in receiving signals from Earth and transmitting signals back.

Various types of antennas are mounted on the satellite based on its specific application, including monopole, dipole horn, reflector, parabolic, and microstrip antennas.

Reflector antennas, coupled with a beam, are commonly used to cover one earth station. To cover multiple earth stations, multiple reflector antennas are necessary.

3. Solar Cell and Battery Backup

The solar cell and battery backup are essential for maintaining continuous satellite operation in space.

The solar cell converts solar energy into electrical energy, powering the satellite during sunlight conditions.

When sunlight is unavailable, the battery takes over, providing the necessary power for the satellite’s operation.

Various battery types, like NiCd, NiMH2, NiH2, NaS, and LiIon, are used in satellites, depending on specific requirements.