Basements, tunnels, large buildings—a weak Wi-Fi or mobile signal in these hard-to-reach places is frustrating. The usual solution is to add more electronics like routers, repeaters and base stations. Yet, as we move towards a 6G mobile network, this kind of complex infrastructure can be unsustainable and prohibitively expensive. Higher-frequency channels of 6G communications aim to provide vastly more data bandwidth than the current 5G, but those channels are more easily blocked by walls, people and other obstacles.

Basements, tunnels, large buildings—a weak Wi-Fi or mobile signal in these hard-to-reach places is frustrating. The usual solution is to add more electronics like routers,…

Researchers at Aalto University have developed metacrystal panels: affordable 3D-printed devices that passively guide radio waves around physical barriers.