Wideband RCS Reduction of a Slot Array Antenna Using Phase Gradient Metasurface

In this letter, a slot array antenna loaded with a phase gradient metasurface (PGM) for a monostatic radar cross-section (RCS) reduction is presented. The PGM, which has stable a phase gradient and a 2π-phase variation range in a wide operating bandwidth, is placed over the slot array antenna. Due to the anomalous reflection and diffuse reflection of the PGM, the RCS of the antenna array is reduced in 7-20 GHz for a normal incidence. Meanwhile, the radiation characteristics are well kept. Antenna samples are fabricated and tested. Measurements show a good agreement with simulations.