Depolarization due to rain on radio relay links

The cross-polarization isolation of a radio relay link using two orthogonal polarizations has been calculated from the statistical distribution of the rain intensity, the raindrop size, deformation and canting angle of raindrops. At frequencies of 18.8 GHz and 28.8 GHz and for a path length of 20 km the results are plotted as a function of the path-averaged rain rate. Furthermore the distribution of the cross-polarization isolation in the worst case for a path perpendicular to the main wind direction are obtained from the statistical distribution of the path-averaged rain rate for linear and circular polarizations.