The statistical field uniformity criterion in transverse electromagnetic waveguides

If the mean and the standard deviation of a normal distribution are unknown then they have to be inferred on the basis of a sample of observations. The larger is the size of the sample the more reliable is the estimate of the mean and the standard deviation and the statistical predictions obtained thereof. This evident and well-known characteristic of statistical inference is neglected by the standard IEC 61000-4-20 when defining the field uniformity criterion in transverse electromagnetic waveguides. An alternative criterion is proposed here that takes into account the limited size of the sample of test points used to assess the field nonuniformity and it is fully consistent with the statistical assumptions and experimental procedures set by the standard.Amore severe limit on the allowed nonuniformity results by applying the proposed criterion.