Gain Enhancement and RCS Reduction for Patch Antenna by Using Polarization-Dependent EBG Surface

A novel antenna design is proposed to enhance the gain and reduce the radar cross section (RCS) of a patch antenna by using metamaterial surface. A polarization-dependent metamaterial surface composed of blocks of slotted electromagnetic bandgap (EBG) structures are adopted in this letter. The layout pattern of the slotted EBG elements is designed to enhance the gain of the antenna. Chessboard configuration is further equipped for scattering cancellation. The induced currents on the EBG are studied, resulting in the mechanism of the gain enhancement by the EBGs clearly explained for the first time. This enables the strategy of designing a high-gain and low-RCS antenna by using EBGs. Full-wave simulations validate that high gain in the operating frequency band and low-RCS in a broad frequency band for normal incidence are achieved by the proposed antenna.