A Broadband Low-RCS Circularly Polarized Meta-Antenna

A low-profile circularly polarized (CP) meta-antenna with a broadband low-RCS feature is proposed in this article. Our design is the combination of a CP antenna with a chessboard polarization conversion metasurface (CPCM) for balancing the radiation property and stealth feature. To relieve the adverse effect of the CPCM on the entire radiation performance, several redundant meta-atoms with the opposite phase state were removed to enhance the realized gain within the operation bandwidth (8.0-9.0 GHz). The proposed meta-antenna showed excellent radiation performance: -10 dB impedance relative bandwidth was 26.48% (6.78-8.85 GHz), and 3-dB axial ratio relative bandwidth was 22.03% (7.27-9.07 GHz). In addition, RCS reduction over 5 dB was achieved via our design from 8.5 to 21.5 GHz (86.67%) with the help of the deliberately designed CPCM. The final measured results demonstrate great consistency with the simulated ones.