Microwave holography

High-quality measurements can be made of antenna surface (aperture illumination) using microwave holographic metrology, a specialized from of bistatic CW inverse synthetic aperture radar (ISAR) imaging that can be readily implemented on both near- and far-field ranges. In most ranges no additional hardware is required, as the microwave holographic technique is compatible with all types of antennas. In reflector antennas it can provide detailed maps of reflector surface currents, aperture illumination and surface shape errors. In phased-array antennas, holography can provide maps of aperture illumination, element weights, and geometric errors. This technique can also be successfully involved in evaluating the performance of antenna far-field test ranges by producing microwave images showing the distribution and level of scattering artifacts