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Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 1)Draw the general block diagram of satellite link. SHAPE \* MERGEFORMAT

Satellite

User

Terrestrial system

Earth Station

User

Terrestrial system

Earth Station

 

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2)Frequency bands used in satellite link.

BAND

DOWNLINK(MHz)

UPLINK(MHz)

UHF-military

250-270

292-312

C band- commercial

3700-4200

5925-6425

X band- military

7250-7750

7900-8400

Ku band-commercial

11700-12200

14000-14500

Ka band- commercial

17700-21200

27500-30000

Ka band- military

20200-21200

43500-45500

3) Frequency bands used for satellite link  in  the lab usually?

S band= 2 to 4 GHz

4)What types of antennas used for earth stations and transponder for satellite link?

  • For earth station, paraboloid antenna with focal point feed and cassegrain antenna. Also horn and phased array antenna can be used.
  • For transponder, dual reflector antenna and microstrip antenna will be used.

5)What type of antenna is used in the lab usually?

Helical antenna

6)Explain   C/N ratio of a satellite link?

C/N = EIRP + Gt -Lp-N

Where, EIRP- Effective Isolated Radiated Pattern of the antenna

Gt – Gain of the antenna

Lp- Path Loss

N- noise

7)Why uplink frequency greater than downlink frequency?

Because the uplink frequency is processed at the earth station, where power consumption is not a big deal. Whereas in satellite the power consumption is a important parameter, since the power is generated by the solar cells.

8)What is the uplink frequency of C band and Ku band and downlink frequency of C band and Ku band?.

C band: uplink- 6 GHz ad down link – 4GHz

Ku band: uplink – 14 GHz and downlink – 12 GHz


9) What is the use of satellite link?

  • The coverage area of a satellite greatly exceeds that of a terrestrial system.
  • Transmission cost of a satellite is independent of the distance from the center of the coverage area.
  • Satellite to Satellite communication is very precise.
  • Higher Bandwidths are available for use.

10) Who launched the first satellite? When?


  • Soviet sat sputnik, October 4,1957, soviet scientist.
  • Sputnik II, November 1957