Satellite Communication 2018 Question Paper — Government College of E…
The 2018 Satellite Communication previous year question paper (Government College of Engineering and Technology, Jammu), with every question and its marks.
- University: Government College of Engineering and Technology, Jammu
- Subject: Satellite Communication
- Course: Satellite Communication
- Branch: ELECTRONICS & COMMUNICATION ENGINEERING
- Year: 2018
- Paper: end-term
- Duration: 180 minutes
- Total marks: 100
Instructions
- Attempt five questions in all selecting at least two questions from each Section.
- Each question carries 20 marks.
Questions
Section-A
- QQ1. (a) Explain the elements of Satellite Communication systems with neat diagram. Also explain the earth station Transmitter and Receiver. (12) (b) List the advantages and disadvantages of $6/4\text{ G Hz}$. Also explain the reasons for download frequency to be lower than Uplink frequency. (8) [20 marks]
- QQ2. (a) Explain the method of Locating the Satellite in the orbit and with respect to earth. (10) (b) A Satellite is moving in a circular orbit at a height of $150\text{Km}$ above the surface of the Earth. (10) If the radius of the Earth is $6360\text{Km}$, determine the orbital velocity and orbital period of the satellite. ($G=6.67\times 10^{-11}\text{ Nm}^2/\text{Kg}$, $M=5.98\times 10^{24}\text{ Kg}$) [20 marks]
- QQ3. (a) Explain the Telemetry, Tracking and command systems of Satellite systems in detail. (12) (b) Two satellites are moving in an elliptical eccentric orbit with same perigee but different apogee Distances. Satellite-1 is having an orbital period of $5\text{ hours}$ and semimajor axis, $20000\text{Km}$. While the Orbital period of satellite-2 is $2\text{ hours}$ and $50\text{ min}$. Determine the semimajor axis of the satellite-2. (8) [20 marks]
- QQ4. (a) Explain the Orbit perturbations and the orbital parameters required to determine the satellite orbit. (10) (b) Differentiate between geostationary and geosynchronous orbit. List the advantages and disadvantages of geostationary orbit. (10) [20 marks]
Section-B
- QQ5. (a) Derive general link equation. Find the expression for the C/N and G/T ratio. (10) (b) A receiving system consist of an antenna having a noise temp of $60\text{K}$, feeding directly in to low noise Amplifier (LNA). The amplifier has noise temp of $120\text{K}$ and a gain of $45\text{dB}$. The coaxial feeder Between main receiver and LNA has a loss of $2\text{dB}$ and a noise figure of $9\text{dB}$. Calculate the system noise temp referred to input. (10) [20 marks]
- QQ6. (a) Explain with schematic diagram the TDMA-Frame structure, Frame efficiency, Super frame, burst Structure in detail. (12) (b) What is mean by C/N ratio? The C/N ratio for the satellite circuit are uplink $25\text{ dB}$ and downlink $25\text{ dB}$. Calculate the overall C/N value. (8) [20 marks]
- QQ7. (a) Two amplifiers are connected in cascade each having a gain of $10\text{ dB}$ and a noise temp of $200\text{K}$. Calculate: (i) The overall Gain (ii) The Effective noise temp with referred to input. (10) (b) What are the various interferences that may affect the satellite link performance. (10) [20 marks]
- Q8. Write notes on: (i) VSAT (ii) DBS system, (20) [20 marks]