Question

Frequency range used in down linking in satellite communication is

• A. 0.896 to 0.901 GHz
• B. 0.420 to 0.890 GHz
• C. 5.925 to 6.425 GHz
• D. 3.7 to 4.2 GHz

Answer 1

Answer: (D)

3.7 to 4.2 GHz

Uplink frequencies are higher than the corresponding downlink frequencies in the case of satellite communication. In satellite communication, the signals have to cross the atmosphere which presents a great deal of attenuation. The higher the frequency, the more is the signal loss and more power is needed for reliable transmission. A satellite is a light-weight device which cannot support high-power transmitters on it. So, it transmits at a lower frequency (higher the frequency, higher is the transmitter power to accommodate losses) as compared to the stationary earth station which can afford to use very high-power transmitters.