Multifunctional Adaptive Invisibility Cloak Based on 3-bit Reconfigurable Metasurface

This article proposes a multiangle adaptive invisibility cloak based on a 3-bit reconfigurable metasurface. The phase state switching of the reconfigurable metasurface is controlled by a PIN diode, which works in the 910.5-GHz frequency band. When the PIN tube switches between the on- and off-states, different PIN tube combinations can achieve eight phase state switching with a phase difference of about 45° within a phase range of 360°. The metasurface array designed based on this element can achieve multiphase state distribution, thereby realizing functions, such as direction of arrival (DOA) estimation, invisibility cloak, and radar cross section (RCS) reduction. As the main body of the invisibility cloak, the reconfigurable metasurface can use different coding matrices to adapt to different tilt angles for different invisibility targets to achieve scattering reconstruction invisibility, simulate the electric field distribution of the horizontal plane on the tilted plane, and use its DOA estimation function to determine the arrival angle. In addition, the metasurface could realize the RCS reduction function, so the invisibility cloak would be able to achieve scattering cancellation invisibility and suppress the scattering cross section of the reflection as well.