Rain fade

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Rain fade refers primarily to the absorption of a microwave Radio Frequency (RF) signal by atmospheric rain, snow or ice, and losses are especially prevalent at frequencies above 11 GHz. It also refers to the degradation of a signal caused by the electromagnetic interference of the leading edge of a storm front. Rain fade can be caused by precipitation at the uplink or downlink location. However, it does not need to be raining at a location for it to be affected by rain fade, as the signal may pass through precipitation many miles away, especially if the satellite dish has a low look angle. From 5 to 20 percent of rain fade or satellite signal attenuation may also be caused by rain, snow or ice on the uplink or downlink antenna reflector, radome or feed horn.

Possible ways to overcome the effects of rain fade are site diversity, uplink power control, variable rate encoding, receiving antennas larger than the requested size for normal weather conditions, and hydrophobic coatings. Only superhydrophobic, Lotus effect surfaces repel snow and ice.

[edit] See also

• Fresnel zone
• Diversity scheme

v • d • e Radio spectrum ELF 3 Hz 30 Hz SLF 30 Hz 300 Hz ULF 300 Hz 3 kHz VLF 3 kHz 30 kHz LF 30 kHz 300 kHz MF 300 kHz 3 MHz HF 3 MHz 30 MHz VHF 30 MHz 300 MHz UHF 300 MHz 3 GHz SHF 3 GHz 30 GHz EHF 30 GHz 300 GHz