Model for predicting fade time in the Ku- and Ka-band frequencies

Propagation of electromagnetic waves in the atmosphere at frequencies above 10 GHz is susceptible to various degrading effects, the most significant of which is attenuation due to rain. A comprehensive propagation experiment was conducted at Virginia Tech using the OLYMPUS satellite beacons at 12, 20, and 30 GHz. This experiment has resulted in an extensive database which contains beacon, radiometer, microdiversity, scintillation, and weather data for a one year period, thus providing an opportunity for a more thorough examination of propagation effects in the 12-30 GHz frequency range. A comprehensive statistical analysis of fade and inter-fade durations constituted part of this effort. This paper addresses the development of a model for predicting fade time. The predicted and measured fade times are compared. The predicted fade times show good agreement. An alternative model, described by two simpler relationships in two different ranges of fade level, is obtained by simplifying the original model. The simplified model accounts for fades associated with stratiform rain and thunderstorms separately.<>