Rising threats of terrorism and contraband smuggling have intensified interest in high-frequency security sensors. This talk presents a non-invasive approach to extract the complex permittivity and thickness of concealed or embedded dielectrics using multi-mode (active–passive) microwave sensing. Two K-band (18–26 GHz) sensors are discussed—an active radar and a passive radiometer. Performance challenges arising from RF front-end imperfections and background clutter are addressed through calibration techniques that (i) correct RF distortion in frequency-modulated continuous-wave radars, (ii) compensate mismatch and temperature-dependent insertion loss in radiometers, and (iii) mitigate background noise in indoor conditions. Electromagnetic models are developed to predict radar and radiometric responses of multilayer dielectric targets and experimentally verified using dielectric stacks backed by a simplified human phantom. These models enable material characterization with about 5% accuracy. Although demonstrated for security sensing, the techniques extend to remote sensing, subsurface fire detection, and food safety applications.
Speaker(s): Arya ,
Room: ECSS 2.306, 800 W Campbell Rd, Richardson, Texas, United States, 75080-3021