Far-field prediction of a MM-wave reflector antenna from one planar near-field intensity scan

The performance of a new near-field planar-scan single-intensity phase retrieval minimisation algorithm for predicting the far-field has been presented and compared with holographic measurements. The algorithm requires an aperture estimate with diffraction effects for optimum performance. The approach of combining diffraction modellings, minimisation and error-reduction has been successful and efficient in dealing with substantial astigmatic deformation and diffraction effects in a front-fed reflector. More accurate determination of axial and astigmatic feed misalignments have been obtained from a weighted modulus-error function. At present, the method is clearly capable of useful far-field prediction and the results are therefore very encouraging for the phase retrieval metrology of millimeter and sub-millimeter reflector antennas