Aperture-sampling requirements [and reply]

Comments on the paper "Aperture-sampling requirements in planar near-field and pattern calculations" by T. Milligan (IEEE Antennas. Propag. Mag., vol.38, no.5, p.60-3, 1996). The comment discusses the case when aliasing errors are significant. The reply shows that the errors are predictable and depend on the edge condition of the aperture. It is possible to extend the sampling of apertures to the errors of numerical integration of an aperture, using either the trapezoidal or Simpson's rule. The errors have a predictable distribution, which depends on the aperture edge condition, because numerical integration is a weighted sampling. A further comment is finally given.