Rain Attenuation in Millimeter Wave Ranges

The high potential of millimeter-wave communication systems has generated the need to carry out many studies in view of rain and other climatic effects on radio propagation at these frequencies. This paper reviews rain attenuation in millimeter wave ranges. In the present study, a short-range 35 GHz radio link was used to measure rain specific attenuation with simultaneous measurement of rain rate distribution. The rainfall statistics and attenuation caused by rains are discussed, and an empirical model derived from these measurements is suggested in order to observe and investigate the attenuation caused by rains in short-range communications. A millimeter wave propagation experiment at 103 GHZ on a propagation path of 390 m is conducted. The results were compared with the rain attenuation calculations from the Marshall-Palmer, Best, Joss-Thomas-Waldvogel and Weibull distributions for raindrop size. It has been shown that the Weibull distribution has a good agreement with the experiments. Finally the analysis and discussion for measurement results respectively.