Crosspolarisation measurements at 11 GHz

Three years measurements of crosspolarisation and attenuation at 11 GHz are presented. They were taken on a 13.6km terrestrial radio link using horizontal and vertical polarisations. A semi-empirical law based on Oguchi's point-matching attenuation and phase coefficients and relating crosspolarisation discrimination (c.p.d.) to fade depth, is derived. Comparison of this semi-empirical law with measured c.p.d. values shows that the use of an equivalent mean canting angle of 4° gives c.p.d. exceeded for 90% of the time. Typical c.p.d. values for deep fades are given by using an equivalent mean canting angle of 2 or 3°. Yearly cumulative statistics and monthly histograms of c.p.d. and attenuation are presented for the three year period.