Microwave Holography for Near-Field Imaging

The relatively long wavelength (from 100 mm to 1 mm) of the microwaves and the millimeter waves allows for penetration in many optically opaque materials such as living tissues, wood, ceramics, plastics, clothing, concrete, soil, etc. Various methods have been proposed for microwave imaging. Among these methods, microwave holography [1] is a fast inversion technique that relies on the measurement of the magnitude and phase of the wave scattered from the imaged target. Knowledge of the magnitude and phase across an aperture allows Fourier-transform (FT) based reconstruction of the target's reflectivity. Microwave holography has been proposed for near-field analysis of antennas [2], biomedical imaging [3], and concealed weapon detection [4].