Microwave holographic metrology of large reflector antennas

A microwave holographic technique for the determination of amplitude and phase of the principal and cross-polarized aperture fields of large reflector antennas is described. The hologram formation process utilizes the elevation over azimuth scanning system normally associated with these antennas, and, in this respect, appears to be unique among other proposed methods of field probing. The present work describes the means used to obtain vital information on the antenna structure such as
E
- and
H
-plane phase centers of the feed, and rms values of the reflector surface profile errors. Accurate prediction of
E
- and
H
-plane radiation patterns in the near- and far-field is also demonstrated.