Which of the following is NOT a common method to mitigate Ka-band rain fade?

• A. Higher elevation angles
• B. Larger antennas
• C. Smaller antennas
• D. Adaptive coding and modulation

Answer: (C)

Ka-band rain fade is all about losses from atmospheric attenuation under rain, so the strategy is to boost the link margin and use adaptive techniques to keep the link alive. Increasing the elevation angle shortens the slant-path through rain, reducing the attenuation reached by the signal. Using a larger antenna raises the antenna gain, which improves the link budget and helps overcome rain-induced losses. Adaptive coding and modulation adjusts the modulation scheme and coding rate in real time to maintain connectivity when conditions worsen, trading some throughput for reliability. Using smaller antennas would reduce gain and worsen the link during rain, so it’s not a common method to mitigate rain fade.