Design of Low-RCS Antenna Arrays With a Metasurface Matching Layer

In this paper, a new method for designing low-RCS antenna arrays is proposed by introducing a metasurface matching layer on the top of the antenna array. By establishing microwave network models for the radiating and scattering paths, the properties of the antenna-metasurface matching layer can be determined. According to the proposed models, the scattering matrix of the required metasurface matching layer is then obtained for achieving low RCS for the antenna. The metasurface matching layer is designed to achieve impedance matching between the surface impedance of the antenna and the intrinsic impedance of free space, with minor influence on the antenna’s radiation characteristics. Based on the proposed method, a low-RCS antenna array is designed, which achieves significant RCS reduction with a gain deterioration of only 0.35 dB.