Multi-Spectral-Based Imaging with Application to Millimeter Wave Imaging at W-Band

Frequency dependency of the radar cross-section of targets is an interesting topic with numerous applications. In this paper, we present a novel technique at the signal processing level to create high-resolution radar images that can display the behavior of the radar cross-section of targets over the frequency band upon which the imagery system operates. The proposed method is based on partitioning the entire operational bandwidth into 3 sub-bands. The main application of the proposed approach is material characterization.We present the experimental results based on the data collected from our wide-band custom-built Frequency Modulated Continuous Wave (FMCW) radar which operates at W-band with 33 GHz bandwidth. From the experimental results, it is evident that targets such as a spherical reflector exhibits the same response over the entire bandwidth while for frequency-selective materials, the output of each sub-band yields a different value for the estimated radar cross-section.