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 μm in the infrared and 0.63 μm in the optical wavebands, with random polarization