Comments on "Investigation of the field uniformity of a mode-stirred chamber using diffusors based on acoustic theory"

In the above paper [see ibid., vol. 41, p. 446-51, 1999] a particular type of reflection grating, viz., Schroeder diffusers of the quadratic-residue type (QRDs), was proposed with the aim of improving field uniformity inside mode-tuned or mode-stirred reverberation chambers. While an improvement of the field homogeneity (but not necessarily the field isotropy) was demonstrated, some facts about the design and application of this type of pseudorandom diffractor (PRDs) appear to have been overlooked.