The statistics of propagation on the 500 m millimetre wave experiment at Chilbolton

The rapid and continuing expansion in communications is imposing ever-increasing demands on the electromagnetic spectrum, which, although a reusable resource, is becoming over populated, giving rise to additional problems such as interference between adjacent channels and restricted bandwidth (and therefore channel capacity). There is a need to develop communications systems to higher frequencies, extending into the millimetre wavelength regions of the electromagnetic spectrum. The results of a preliminary statistical analysis of propagation conditions obtained during 1993 on the 500 m millimetre wave experimental range at Chilbolton are presented. Examples are given of studies in rainfall attenuation and total attenuation including worst month analysis. The 500 m range comprises a set of single-pass, continuous-wave (CW) transmission links, situated 4 m above flat grassland, operating at frequencies of 57 GHz, 97 GHz, 135 GHz and 210 GHz, with vertical polarization, and at wavelengths of 10.6 /spl mu/m in the infrared and 0.63 /spl mu/m in the optical wavebands, with random polarization.