Low-RCS Vivald Antenna Based on Formalized Water-based Metasurface

In this paper, the out-of-band monostatic radar cross section (RCS) reduction of a traditional Vivaldi antenna is achieved by loading a water-based metasurface (WBM) consisting of a water column onto the surface of the antenna. The proposed antenna achieves average RCS reduction of -6 dB and -10 dB in (6–12 GHz) and (6–18 GHz) when the copolarized plane wave incident along the -z and -y axes, respectively. The working band of the proposed antenna is 2–6 GHz, in which the performance of the antenna is not affected by the WBM.