This document discusses satellite communication systems. It describes how communication satellites operate by relaying signals between two earth stations. It discusses satellite transponders and the different frequency bands used by satellites. The document also covers methods to increase channel capacity on satellites using frequency reuse and polarization. Additionally, it outlines the three main orbital paths for communication satellites - polar, equatorial, and inclined orbits. Finally, it briefly mentions the different types of satellites and applications of geostationary satellites.

1. Chapter 5
1

2. Introduction
2

3. Satellite Communication Systems
3

4. Basic operation of a communication satellite
between two earth stations
4

5. Satellite System Links
5

6. Satellite Transponder
6

7. Satellite Frequency Bands
7

8. Satellite Bandwidth
8
• Bandwidth of the satellite will determine the number
of signals that can be transmitted
• Wider bandwidth can allow many signals to be carried
at a time
• C-band has different frequencies for uplink≈ 500 MHz
• Each transponder is assigned a bandwidth, eg :
MEASAT-1 has a bandwidth of 36 MHz for each
transponder (total of 12 transponders)
• There are 4 MHz guard bands between channels that
are used to minimize adjacent channel interference

9. Increasing Channel Capacity
9
• There is not enough spectrum space for satellite
to use all the transponders unless some form of
frequency reuse is employed
• This method determined that half of the
transponders use vertical polarization and another
half uses horizontal polarization, with overlapping
frequencies

10. Satellite Orbits
10

11. Satellite Orbits
11

12. Satellite Orbits – Orbital Path
12
• There are an infinite
number of orbital paths,
but only three are useful
for communication
satellite
• Three paths that a
satellite can follow as it
rotates around the Earth :
inclined, equatorial or
polar

13. Polar Orbit
13

14. Equatorial Orbit
14

15. Inclined Orbit
15

16. Antenna Tracking and Adjustment
16

17. Azimuth Angle
17

18. Elevation Angle
18

19. Earth Station
19

20. Types of Satellites
 Geostationary satellites - located 22,236
miles or 35,786 km from earth at the
geosynchronous orbit
 Low Orbital Satellites (LEO) located 300 to
1500 km above earth
 Medium Orbital Satellites (MEO) located
8000 to 20000 km from earth
20

21. Application of Geostationary Satellites
21