They'll also amplify the signal beyond that: new 3D printing techniques promise "lens" structures that focus and boost whatever signal comes out of the array.

The technology is still young, and there's no mention of if or when it'll come to market. However, it could be crucial to 5G and the next wave of broadband. It'll be particularly vital for cellphones in cities, where a strong signal is crucial to overcoming crowded airspace, but it could also be helpful for bringing gigabit internet access to more homes. Instead of wiring whole neighborhoods with expensive and hard-to-deploy fiber optic lines, you could use these antennas to deliver fixed wireless with relatively little effort.