Single-Frequency Imaging and Material Characterization Using Reconfigurable Reflectarrays

Conventional security screening systems cannot operate in real time and often suffer from false alarms due to the profile-only imaging without further analysis on the object material properties. Reflectarrays were recently proposed as devices capable of performing real-time security screening using a single-frequency radar signal. This article presents first a physical optics (PO)-based simulation method to facilitate the design of a multireflectarray system. Then, an object material characterization method using geometrical optics (GO) is derived for such a system. The characterization process not only retrieves the complex relative permittivity of the object but also improves its profile reconstruction in terms of a more accurate thickness. Both simulations and experiments are carried out to verify the effectiveness and efficiency of the proposed methods. Primary results show great potentials for security screening, especially in scenarios where the inspection of human bodies for threat materials, such as narcotics and explosives, is required.

Automated summary

The article introduces a method for real-time security screening using reflectarrays and proposes simulation and object material characterization methods based on physical optics and geometrical optics. Results from simulations and experiments demonstrate the potential of this method for detecting threat materials within the human body.