Precise 2D and 3D Fluoroscopic Imaging by Using an FMCW Millimeter-Wave Radar

This study utilized a multiple-input multiple-output synthetic aperture radar (MIMO-SAR) technology employing a frequency-modulated continuous wave (FMCW) millimeter-wave MIMO radar to execute two-dimensional (2D) and three-dimensional (3D) imaging of objects. By analyzing the intermediate frequency (IF) signal generated from the transmitted and received chirp signals, Range FFT spectra with information on the distance to the object and on the reflection intensity according to frequency were obtained. The integration of reflection intensity provided a comprehensive image at varying distances, while the 2D cross-sectional image of an object inside a concealed cardboard achieved a spatial resolution of less than 1 mm. Through innovative data processing techniques, such as the spatial translation filter, we succeeded in the reconstruction of a monolayered 3D image of a clothed human body's surface. Moreover, the system demonstrated its potential for security checks by effectively identifying dangerous items concealed by human.