Coating makes EM waves see curved surfaces as flat

According to QMU, the discovery represents a potential a step-change in how antennas are tailored to each platform, benefiting industries that rely on high performance antennas for wireless communications.

The researchers coated a curved surface with a medium where the refractive index varies depending on the position of the wave. Although the coating is only a fraction of a wavelength thick, it can make the curvature appear invisible to surface waves.

The coating can be used as a so-called cloak because the space created underneath the bumpy surface can shelter an object that would ordinarily have caused the wave to be scattered.

In a statement, Professor of Antennas and Electromagnetics and study lead Yang Hao, said: ‘The design is based upon transformation optics, a concept behind the idea of the invisibility cloak. While the cloak is yet to be demonstrated ‘perfect’ in the free space, we have proved that it is possible for surface waves.’