SCOPE OF LEARNING:

The basic components of a satellite system are its antennas which consists of repeaters and receivers also known as transponders. When we transmit a signal from earth to the satellite it refers to up-link and when a signal is received on earth from the satellite it is called down-link. The uplink frequencies are in the range of 5.9 Ghz to 6.4 Ghz and the down link frequencies are in the range of 3.7 Ghz to 4.2 Ghz. These frequencies are used for Transmission from the satellite to the earth station. The uplink frequencies are converted to lower frequencies by the mixer and local Oscillator, the communication satellite acts as a repeater station as it receives the signal, amplifies it and then transmits over next frequency to avoid interference between the uplink signal and down link signal this is how a two way communication is established with the help of a transponder. Communication satellites can have multiple transponders. Transponders per satellite have increased rapidly over years since inception so as to increase the capacity of satellites because earlier a satellite with 2 transponder used to support a signal T.V channel or 240 telephone lines, Similarly a satellite with 48 transponder can accommodate 4000 Telephone Phone lines and 2 T.V channels. Today’s new generation satellites which use digital multiplexing technology can handle 120,000 Telephone lines and more than 500 T.V channels. The Satellite Communication Lab provides an in-depth look at Satellite Communication Techniques and Concepts. It consists of Satellite Uplink Transmitter, Satellite Transponder Link and Satellite Downlink Receiver, which can be conveniently placed in the laboratory for experimentation. The Satellite Transponder Link also called as Satellite Emulator can also be placed at an elevated position if needed. The satellite transponder receives signals from uplink transmitter and retransmits at different frequencies to a downlink receiver. The uplink frequencies are selectable and can carry three signals video/data, audio/voice/tone (A1) and audio/voice/tone (A2) simultaneously. Any broadband signal or digital / analog data or square wave from function generator can be transmitted through this satellite link. A large number of experiments can easily be conducted. PC to PC Communication Link can also be established & studied.