what is a satellite

Nowadays, if you want to communicate with your old friend who is present thousands of miles away. You just need to make a phone call. How good it is. In earlier days things were not easy as it seems now. Many inventors work to bring this technology to us. These innovations are not only limited to phone calls. As of now, we are using communication and tracking systems to connect the entire world. And it is being possible because of an object which is moving around the Earth, this is Satellite. The satellites are becoming a key that opens the door of communication to connect the worldwide people.

What is a Satellite?

The term satellite is more general than that means a smaller space-based object moving in a loop around a large object. A satellite does not necessarily have to be a mechanical object spinning through space. All of us know that the moon is a natural satellite of our planet and it is moving around the Earth due to gravitational forces. The mechanical objects, which are also moving into Earth orbit, are artificial or human-made satellites. We put satellites in space or Earth orbit to overcome the various geographical limitations of the Earth.

Types of Satellite:

We can categorize satellites based on their services like communication, climate change observation, and more. The three main uses of satellites are given below:

  1. Communication
  2. Scientific surveying
  3. Navigation or tracking


The communication satellites provide communication links between several points on Earth. These satellites are using transponders to transmit and receive data from Earth. The communication satellite redirects data from one Earth station to another to cover the huge area. Typically, a communication satellite works when it receives data from terrestrial or Earth stations in the form of electromagnetic waves. The data is usually sent via huge size dish antennas. Most of the communication satellites are placed in geostationary Earth orbit. Based on the intended destination, communication satellites redirect the signal to the corresponding Earth stations. There are two vital components present in communication satellites Antenna and Transponder.

Earth station

Earth station

Communication satellite Antenna:

Satellite antennas are specifically engineered to concentrate the satellite’s transmitting power into a designed geographical location on Earth and also avoid interference from undesired signals transmitted from outside of the service area. Four main types of antennas are in use in most communication satellites, and these are Wire antennas, Horn antennas, Reflector antennas, and Array antennas.

Wire antennas were used on the initial operational satellites with having antenna gain about 4 dBi for signal reception and 9 dBi for signal transmission. These antennas can provide wide signal bandwidth so as of now they are mostly used in TTC (Teleme