Which statement best describes the purpose of antenna diversity in SATCOM?

• A. To eliminate the need for polarisation.
• B. To mitigate fading by using multiple independent paths.
• C. To reduce the size of ground antennas.
• D. To increase data rate by using multiple carriers.

Answer: (B)

Antenna diversity improves link reliability by using multiple independent signal paths to combat fading. In satellite links, the received signal can experience deep fades on a single path due to multipath effects, atmospheric variations, or other propagation anomalies. By having two or more antennas separated in space (or using different polarizations), the fades on each path are unlikely to line up perfectly. When one path weakens, the others may still carry a strong signal, and combining those signals (through techniques like selection or maximal ratio combining) boosts the overall received signal quality and availability.

This approach is not about eliminating polarization, shrinking antenna size, or directly increasing data rate with multiple carriers. Those ideas address other aspects of system design, whereas antenna diversity specifically targets mitigating fading to maintain a robust link.