Programmable Metasurface Cloaking for Arbitrarily External Object

Programmable metasurface enables many completely different functions to be realized on a single platform. Here, we propose a programmable metasurface to conceal an arbitrarily external object above the metasurface. The designed element loads with a varactor diode, and the capacitance can be turned electronically. Hence, the element achieves phase control by turning the bias voltage supplied to varactor diode. The metasurface contains 6 × 6 super unit cells and all the 6 × 6 elements in one super unit cell share the same capacitance. With the aid of an external control circuit, each super unit cell can be controlled independently. We select a metallic sphere and right square pyramid to demonstrate the external cloaking function of arbitrary object. As a proof of concept, we utilize genetic algorithm to obtain the optimal phase distributions. Simulation results verify that the deliberate metasurface is capable of hiding any irregular objects.