Low RCS circularly polarized antenna with integrated absorption and polarization conversion metasurface

This paper proposes a circularly polarized (CP) metasurface antenna array integrating absorbers with polarization conversion metasurfaces (PCMs). By synergistically deploying PCM units and absorber units, the antenna array combines the scattering control properties of PCM units with the electromagnetic energy absorption characteristics of absorber units and ultimately achieves broadband radar cross section (RCS) reduction. Simulation results indicate that the array exhibits an impedance bandwidth of 12% (11.8-13.3 GHz), a 3 dB axial ratio (AR) bandwidth of 12.9% (11.78-13.4 GHz), and a 3 dB gain bandwidth of 9.7% (11.64-13 GHz). Within the wideband range of 10.2-20.9 GHz (68.8%), the array achieves 10 dB RCS reduction both out-of-band and in-band, with a maximum reduction of 33.2 dB. A prototype of the antenna array was fabricated and tested, with measured results showing good agreement with simulations, validating the design effectiveness.