Multifunctional intelligent surfaces based on volumetric inverse topology design

Intelligent surfaces represent a viable solution to enhance coverage and address signal fading challenges in future wireless communication, which leads to higher bandwidth and data rate. In this context, multifunctional passive intelligent surfaces can significantly reduce energy usage and cost. However, their capability is currently limited to providing different responses for incident signals with different polarizations, frequencies, or propagation directions. Here, we propose inversely designed volumetric dielectric composites (metacrystals) that can broaden the scope of multifunctional structures. In particular, metacrystals can provide independent control of signals with different polarizations and directions (angles of arrival). Such passive multifunctional structures can be designed to operate at millimeter waves and beyond, significantly impacting the future of wireless communication. Positioned on walls, they can effectively redirect waves in both indoor and outdoor communication settings. The possibility of fabrication using additive manufacturing makes the production of metacrystals cost-effective and scalable.