3D Genetic Metamaterials for Scattering Maximization

The rapidly growing volume of drone air traffic demands improved radar surveillance systems and increased detection reliability in challenging conditions. The scattering cross-section, which characterizes a target's radar visibility, is a key element in detection schemes and thus becomes a primary objective in civilian applications. Here, we introduce a concept of genetically designed metamaterials, specifically engineered to enhance scattering for end-fire incidence scenarios. Multi-layer stacks of arrays, encompassing strongly coupled electric and magnetic resonators, demonstrated above 1 m^2 broadband scattering at 10 GHz, despite having an end-fire physical cross-section smaller than one squared wavelength. Those performances, crucial for effective civil radar air traffic monitoring, facilitate exploring highly scattering structures as labels for small airborne targets. This objective has been demonstrated with a set of outdoor experiments with the DJI Mini 2 drone. Lightweight, conformal add-ons with significantly high scattering cross-sections can serve as auxiliary tools to empower passive monitoring systems, thereby providing an additional layer of security in urban airspace.