A Wideband Circularly Polarized Metantenna With Low Radar Cross Section

This letter proposes a low-profile metantenna that achieves broadband circularly polarized radiation and significant radar cross-section (RCS) reduction performance. A bowtie-shaped patch with a bent slit is utilized as not only the unit of a polarization conversion metasurface but also the antenna element of a 4 × 4 array. Based on the arrangement of the chessboard-like metasurface atoms and sequentially rotated feeding for the subarrays, the metantenna achieves excellent radiation and scattering performance simultaneously. The measured results show that the antenna operating band covers from 7.28 GHz to 12.28 GHz, in which the reflection coefficient is lower than −10 dB, the axial ratio is better than 3 dB, radiation patterns are stable, and the antenna gain ranges from 9.7 dBic to 12.7 dBic. In addition, it reduces the monostatic RCS by 10 dB from 9.95 GHz to 22.48 GHz.