Near-Field Millimeter Wave and Microwave Tomography Imaging

A near-field millimeter-wave tomography system has been designed and built for imaging of hidden objects located in subsurface areas of different materials and fabrics. In our investigations we used conceptions of near-field microscopy and subsurface tomography. The algorithm is based on the integral representation of the scattered field at the probing line above a lossy half-space containing a cylindrical object of arbitrary cross-section and electrical properties in the case of plane wave incidence. The object function is related to 1D Fourier transform of the measured scattered field by the tomography integral equation. For image reconstruction of objects a part of the spatial spectrum of the scattered field due to nonuniform or evanescent waves was employed.