Computational Millimeter-wave Spotlight Imaging using Holographic Metasurface Antennas

In this paper, a spotlight imaging system integrated with a frequency-diverse aperture is presented for security-screening applications. The spotlight imager consists of holographic metasurface antennas that can dynamically be tuned to radiate spotlight patterns allowing the extraction of high-resolution images from a constrained field-of-view (FOV). The spotlight aperture operates at a single frequency, 75 GHz, within the W-band frequency regime (75 - 110 GHz)and is used for the identification of threat objects while the frequency-diverse aperture operates at K-band frequencies (17.5 - 26.5 GHz)and is used for detection purposes, determining the constrained FOV to be imaged using the spotlight imager at high resolution.