Measurements of 20-GHz transmission through a radome in rain

An experiment has been designed to study the effects of rain on transmission through large radomes of the type which may be used with ground station antennas in satellite links. Measured transmission data from the experiment are described and compared with predicted values. The nonwetting nature of the radome surface significantly degraded with time, and this was accompanied by a large increase in the 20-GHz transmission loss during periods of rain. The losses were in the range of 6-8 dB for rain rates of 3-40 mm/h. The cumulative distribution of transmission through the radome for a 12-month period is presented.