A 3-D-printed antenna array with integrated all-metal stealth metasurface for S-band radiation and X-band RCS reduction

In this paper, an all-metal antenna array with integrated all-metal stealth metasurface for S-band radiation and X-band radar cross section (RCS) reduction is investigated. This design realizes integrated radiation-stealth functionality within a single aperture by integrating X-band all-metal stealth metasurface unit cells (ASMUCs) into the S-band antenna. These ASMUCs are configured in a chessboard arrangement with alternating rotations to form arrays, effectively utilizing the phase cancellation principle to reduce X-band scattering energy. For verification, a 2 × 2 antenna array is monolithically fabricated using stereolithography apparatus (SLA) 3-D printing technology. The measured results demonstrate that the proposed design achieves impedance matching in the S-band (2.28–2.94 GHz), with a peak gain of 13.4 dBi. The monostatic RCS of the proposed low-RCS antenna array is reduced by more than 10 dB across the entire X-band (8.0–12.0 GHz) under normal incidence. The advantages of superior out-of-band RCS reduction, low cost, large power capacity, and scalable architecture make it highly suitable for radar stealth systems.