THz Hybrid Graphene &Metal Patches Metasurface for RCS Reduction and Digital Coding

Metasurface that shows excellent ability in controlling electromagnetic (EM) waves has attracted tremendous attention. Based on the polarization conversion and the Pancharatnam-Berry (PB) phase, a hybrid metasurface that consists of graphene and metal patches (MGMPs) is presented to realize reduction of the radar cross section (RCS) and the beam reconfiguration of terahertz waves. The unit cells of MGMPs are designed for the linearly polarized (LP), the left circularly polarized (LCP) and the right circularly polarized (RCP) waves. The MGMPs can realize the polarization conversion and produce the phase difference by using coding elements "0" and "1" in combination. The MGMPs are generated using random code, which lead to the redistribution of electromagnetic waves energy and achieve RCS reduction in a wide frequency band range and incident angle. In addition, polarization conversion ratio (PCR) of higher than 90% is achieved. The simulation results show that the MGMPs can achieve the RCS reduction in a wide frequency range from 0.35 THz to 1 THz (96.3%) at the normal incidence for THz waves. The super working bandwidth further indicates that the MGMPs have huge application potential in the field of RCS reduction.