Calculations of rain-induced cross-polarisation on line-of-sight systems at 38 GHz

New microwave or millimetre communication systems are designed to use dual-polarisation channels in order to increase the communication capacity without increasing the bandwidth. Even at 38 GHz, which is increasingly being brought into use, since its allocation for the interconnections of PCN base stations, the potential use of both horizontal and vertical polarisations has attracted much attention. A study of rain-induced depolarisation at 38 GHz is presented, including the effects of various rainfall rates, raindrop shape models, and water temperatures. The intervening medium between the two terminals is assumed to have constant rainfall rate and the cross-polar effects are evaluated for various link separations and for various rain intensities. Additionally, data obtained from the Chilbolton radar are used and the depolarisation effects due to typical precipitation events are assessed