Did you know that metasurface is essentially flat 2D metamaterial?

We are always searching for miniaturization of our devices and technologies, and metasurface antennas can be very helpful in this area. When building a traditional antenna array, we are restrained by half-lambda distance between neighbor elements to reduce mutual coupling.

But not in metasurface antennas! For example, the featured antenna array has a maximum size of 0.8 x 0.8 lambda with a gain of 9 dBi.