The Reference Ground Plane - A Necessity or a Delusion?

This paper seeks a fundamental reexamination of the meaning of "reference ground planes", as applicable to E.M.C. measurements. It is suggested that the concept of 'ground planes', while meaningful at low frequencies, may have questionable utility at higher frequencies at which the ground plane dimensions are comparable to or much greater than the wavelength. In the light of these considerations the meaningfulness of standards measurement. procedures and of site characterization techniques is questioned.