Wideband and low RCS planar circularly polarized array based on polarization conversion of metasurface

In this article, a planar wideband circularly polarized (CP) slot antenna array based on metasurface (MS) with low radar cross section (RCS) is proposed. The array is comprised of CP MS‐based antennas fed with a sequentially rotated feeding network. For each CP antenna, the CP radiation is achieved due to polarization conversion of the MS. Simultaneously, the total MS patches of the array can be viewed as checkerboard composed of MS array and mirror array. A phase difference between the MS units and the mirror units ensures RCS reduction. Simulated results demonstrate that about 34.6% operating bandwidth in the frequency of 4.3–6.1 GHz (both S11 –10 dB and AR < 3 dB). In addition, over 5 dB RCS reduction is obtained in the entire operation band under normal incidence with respect to the array without MS for both x‐ and y‐polarizations. The simulated monostatic RCS less than −30.9 dBsm is observed at 5.0 GHz. A prototype of the array is fabricated and measured, which are in good agreement with simulated results.