Satellite Communications Bands (Uplink/Downlink Ranges) Which of the following options corresponds to a commonly used satellite communication frequency band?
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A10 to 20 MHz
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B50 to 70 MHz
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C3 to 6 GHz
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D100 to 120 GHz
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E200 to 300 kHz
Answer
Correct Answer: 3 to 6 GHz
Explanation
Introduction / Context:Satellite communications use several standardized microwave bands. Classic commercial links include C band, Ku band, and Ka band, with center frequencies chosen to balance atmospheric attenuation and bandwidth needs.
Given Data / Assumptions:
- We are selecting from broad ranges, not precise allocations.
- Atmospheric losses are modest in C band and increase with frequency.
Concept / Approach:
The 3 to 6 GHz range corresponds to the C band, commonly used for satellite downlinks near 3.7–4.2 GHz and uplinks near 5.9–6.4 GHz in many regions. Lower ranges (kHz or MHz) are unsuitable for high-throughput satcom, while extremely high bands (100+ GHz) are specialized and face high atmospheric loss.
Step-by-Step Solution:
1) Identify satcom-standard bands: C (≈ 4/6 GHz), Ku (≈ 12/14 GHz), Ka (≈ 20/30 GHz).2) Compare with options: only 3–6 GHz maps to a widely used band.3) Conclude the correct choice is 3 to 6 GHz.Verification / Alternative check:
ITU and operator band plans document C-band allocations in this range.
Why Other Options Are Wrong:
10–20 MHz and 50–70 MHz are HF/VHF, not satcom carriers. 100–120 GHz is experimental with high atmospheric attenuation. 200–300 kHz is LF.
Common Pitfalls:
Confusing radar bands with satcom bands; overlooking regional allocation differences.
Final Answer:
3 to 6 GHz