The effects of ground screen termination on OATS site attenuation

A description is given of a 10-m open-area test site (OATS) for measuring radiated electromagnetic emissions from computing devices. The test site, located in southeastern Minnesota, is described. Its performance is analyzed by comparing horizontal and vertical site attenuation measured at the site to a theoretical model. The impact of the ground screen is examined by analyzing site attenuation data from two OATSs. The model developed by A.A. Smith et al. (1982) is used. The effects of the ground screen´s size and the termination of its edges are discussed. Three methods of edge termination are examined. The vertical polarization is more sensitive to imperfections in the ground screen; hence, the bulk of the data presented is from vertically polarized site attenuation measurements