Holographic microantenna array metrology

We describe a holographic or "phaseless" technique for measurement of complex antenna patterns that is particularly suited to planar antennas at very high frequencies - mm-wave thru long-wave infrared - where phase coherent detection is impractical. It has been implemented in a compact automated antenna range, and validated on a previously reported planar slot-ring antenna at 95 GHz. In the IR, the interferometric technique must be refined in order to reduce to acceptable levels the uncertainties due to positioning and alignment errors. This measurement of the complex antenna pattern is the most problematic part of a full accounting for the optical coupling efficiency "budget" in a microantenna-coupled, imaging sensor array.