Metasurface-Based Wideband Low-RCS Circularly Polarized Antenna

In this paper, a broadband low radar cross-section (RCS) circularly polarized (CP) antenna based on metasurface is proposed. The proposed metasurface unit has the ability of broadband polarization conversion, which is further arranged into a
$\boldsymbol{2}\times \boldsymbol{2}$
chessboard metasurface and fed by a sequential rotating feed network to achieve broadband CP radiation and low RCS performance. For the proposed CP antenna, simulation results exhibit that an impedance bandwidth and a 3 dB axial ratio bandwidth of 56.1% (5-8.9 GHz) and 26.7% (6.25-8.18 GHz), respectively, with a peak gain of 9.4 dBi. Additionally, the proposed CP antenna obtains at least 5 dB RCS reduction over a wide frequency range of 6.23-18.6 GHz (99.6%).