Question

In satellite communication, the uplink frequency band used is :

• A. 76 – 88 MHz
• B. 3.7 – 4.2 GHz
• C. 5.925 – 6.425 GHz
• D. 420 – 890 MHz

Answer 1

The Correct Option is C

The question pertains to satellite communication, specifically addressing the typical frequencies used for uplinks. Let's examine the role of uplink frequency in satellite communication and determine the most suitable option.

**Explanation**:

In satellite communication, the terms "uplink" and "downlink" are used to describe the frequency bands used for transmitting and receiving signals. The uplink frequency is the range of frequencies at which signals are sent from an Earth station to a satellite. The downlink frequency is the opposite; it's used for signals sent from the satellite back to Earth.

The typical frequency ranges used in satellite communications are:

• C-band: The uplink frequency is 5.925 – 6.425 GHz, and the corresponding downlink frequency is typically 3.7 – 4.2 GHz. This frequency band is less affected by rain and atmospheric conditions, making it ideal for reliable communications.
• Ku-band: Generally utilizes frequencies of 12-18 GHz for uplink and 11-14 GHz for downlink.
• Other bands: These include the Ka-band and L-band, each having its own specific frequency ranges.

**Option review**:

• 76 – 88 MHz: This frequency range is typically not used for satellite communication; instead, it's used for FM radio broadcasting.
• 3.7 – 4.2 GHz: This is the downlink frequency in the C-band rather than an uplink.
• 5.925 – 6.425 GHz: Correctly represents the uplink frequency in the C-band used for satellite communication.
• 420 – 890 MHz: This frequency is usually associated with terrestrial communication services and television broadcasting, not typically used for satellite uplinks.

**Conclusion**: The correct answer, based on the standard usage in satellite communication for uplink frequencies, is 5.925 – 6.425 GHz. This option is the conventional uplink frequency range used in the C-band for satellite communication.