Aberrations in circularly symmetric microwave lenses

The electric field intensity distribution was measured in the image space of solid dielectric microwave lenses at a wavelength of 1.25 cm for various displacements of the source from the principal axis of the system. The experimental results are presented in the form of contours of constant intensity in several receiving planes and also as plots of field intensity versus radial positions of the point of observation. It was found that the deviations of the intensity patterns from the ideal, Airy aberration-free distribution could be interpreted quantitatively in terms of the third order aberrations of optics. The very good agreement obtained with the scalar diffraction theory of aberrations suggests the usefulness of the optical concepts in their application to the centimetric wavelength range.