Use of dual polarisation for point-to-point fixed links operating at 38 GHz

Propagation data pertaining to the use of cross-polar operation at 38 GHz are presented. The data came from one operational and one experimental link, where each were taken over 3 years. The method used to calculate the fade margin required for power-level assignments is examined in terms of its accuracy. The other main propagation-related factor, rain-induced depolarisation, is also considered. Results indicate that the current method used for power level assignment, based on ITUR recommendation 530-7, is accurate to within a few dB, even after considering the year-to-year variability, which is no more than 3 dB for low time percentages, typically 0.01%. The results also indicate that depolarisation in rain will not unduly affect the system performance even if dual-polar operation is implemented on parallel links