This is the Coaching materials in Satellite Communications Part 2 as one topic in ECE Board Exam taken from various sources including but not limited to past Board Examination Questions in Electronic System and Technologies (EST), Communications Books, Journals and other Communications References. This particular Coaching Notes in Communications Engineering has random Questions and Answers in random topics. Make sure to familiarize this review notes to increase the chance of passing the ECE Board Exam.
Satellite Communications Coaching Materials Part 2
1.A circular orbit around the equator with a 24-h period is called a(n)
Ans: geostationary orbit
2. The earth area covered by a satellite radio beam.
Ans: Footprint
3. What is Keppler's first law?
Ans: planetary orbits are elliptical with sun at the focus
4. Geostationary satellites are located ______ with respect to the equator.
Ans: 0 degrees longitude
5. The complete bandwidth of a typical multi-purpose satellite is
Ans: 5 KHz
6. What circuit is responsible in activating and deactivating adjacent antenna elements in a mobile satellite array?
Ans: Radial divider
7. Refers to the satellite orientation with respect to the earth.
Ans: Satellite altitude
8. With FDMA, transponder bandwidth is subdivided into bandwidths which are capable of carrying one voice channel.
Ans: Smaller
9. For satellite communication, the lower limit of frequency is
Ans: 10 MHz
10. In a geosynchronous satellite orbital disturbances are caused by which of the following?
- Sun
- Earth
- Moon
- All of these (Correct Answer)
11. The physical location of a satellite is determined by its
Ans: Latitude and longitude
12. The farthest distance from earth, a satellite orbit reaches is called
Ans: Apogee
13. Which of the following is the most effective anti-jamming technique?
Ans: Spread-spectrum modulation
14. Long distance communication system via satellite uses frequency in the range of
Ans: 3 to 6 GHz
15. Before transmitting to the satellite, the wide-band satellite signal is amplified by
Ans: Traveling wave tube
16. It is the typical bandwidth of a satellite band
Ans: 500 MHz
17. Essentially a satellite ______ is a radio repeater in the sky.
Ans: Transponder
18. The energy to power electronic equipment on board in satellite is invariably supplied by
Ans: Solar cells
19. Which of the following statements is correct regarding a communication satellite?
Ans: It is a repeater between many transmitting stations and many receiving stations
20. The lifetime of a geosynchronous satellite is about
Ans: 10 years
21. The most common carrier frequencies used for satellite communications are
Ans: 6/4 and 14/12 GHz bands
22. The frequency of Ku band for satellite communications.
Ans: 14/11 GHz
23. Repeaters inside communications satellites are known as
Ans: Transponders
24. For direct reception of TV signal from a communication satellite, the type of antenna required is
Ans: Chicken-mesh antenna
25. A satellite repeater serves which of the following purposes?
Ans: It translates the signal to new frequency band
26. The signal path from satellite to earth-based receiver
Ans: Downlink signal
27. The ______ angle measured the satellite position clockwise from the direction of true north.
Ans: Azimuth
28. For a satellite with time period of 2 hours, the height above the surface must be
Ans: 2000 km
29. The key electronic component in a communications satellite is the
Ans: Transponder
30. The satellite communications channels in a transponder are defined by the
Ans: Bandpass filter
31. As the height of a satellite orbit gets lower, the speed of the satellite
Ans: Increases
32. What is the basic technique used to stabilized a satellite?
Ans: Spin
33. The round-trip propagation delay between two earth stations through a geosynchronous satellite is
Ans: 500 to 600 ms
34. For satellite communication, the frequency should be ______ the critical frequency of ionosphere.
Ans: More than
35. In this multiple access technique, each earth stations transmissions are assigned specific uplink and downlink frequency bands allotted satellite channel bandwidth.
Ans: frequency division multiple accessing
36. Sputnik 1 was orbiting the earth in
Ans: 90 minutes
37. The distance between the two antennas of a geostationary satellite system is 22,300 miles and is operating at a downlink frequency of 12.2 GHz, what is the free space loss in dB?
Ans: 205 dB
38. A type of satellite that simply reflects a signal back to earth.
Ans: Passive satellite
39. The main function of a communications satellite is as a/an
Ans: Repeater
40. Shannon's law relates which of the following?
Ans: Information-carrying capacity to S/N ratio
41. What is the approximate path loss from satellite-to-earth station?
Ans: 200 dB
42. _____ is the first satellite transponder.
Ans: Moon
43. What is the local oscillator (mixer) frequency of the satellite with an uplink frequency in GHz band?
Ans: 2225 MHz
44. The ______ requires a larger receiving antenna and receivers are often only able to receive C-band signals
Ans: C-band
45. GPS means
Ans: Global Positioning Satellite
46. The first Intelsat satellite that was launched in 1965 was named
Ans: Early Bird I
47. A satellite link can be made to carry ______ information when operating digitally than in analog fashion.
Ans: More
48. Transponder bandwidth commonly used in satellite is
Ans: 36 MHz
49. A satellite battery that has more power but lighter.
Ans: Lithium
50. How can multiple earth stations share a satellite on the same frequencies?
Ans: Frequency reuse
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