A Broadband Circularly Polarized Low RCS Metasurface Antenna Array

This paper proposes a low-profile metasurface antenna design that achieves wideband circularly polarized radiation while significantly reducing radar cross-section (RCS). A novel patch structure is designed without increasing structural complexity; it functions both as a polarization conversion metasurface (PCM) and as an antenna element for a 4×4 array. By combining a chessboard-shaped unit arrangement with sequential rotation feeding of subarrays, excellent radiation and scattering performance are achieved. Simulation results reveal that the antenna array operates with a 74.7% impedance bandwidth (6–13.1 GHz). Within this range, the 3 dB axial ratio (AR) and gain bandwidths span 48.5% (7.8– 12.8 GHz) and 32.5% (8.5–11.8 GHz), respectively, indicating robust circular polarization and stable radiation performance. In addition, the monostatic RCS is suppressed by 8 dB over a 45.5% fractional bandwidth (9.5–15.1 GHz), with the maximum reduction peaking at 28.9 dB. This research delivers a functional strategy for X-band stealth applications, notably satellite communications and electronic warfare, where adaptable polarization and suppressed detectability are indispensable.