Broadband Polarization Conversion Metasurface for Antenna RCS Reduction

A broadband polarization conversion metasurface (PCM) is proposed for reducing radar cross section (RCS) of antenna. The unit cell of the PCM consists of two pairs of tapered L-shaped strips, a layer of air, and a ground plane. The PCM unit achieves polarization rotation (PR) bandwidth of 117.2% with the polarization conversion ratio (PCR) of 90%. The broadband characteristics of the PCM are studied by an equivalent circuit. The chessboard PCM reduces RCS under a linear polarized (LP) incident wave. The PCM is integrated into a dual-polarized 2
$\times $
2 H-shaped slot array antenna for RCS reduction. The measured results show that the monostatic RCS of the antenna is reduced by about 10 dB in the frequency range of 9.6–33.1 GHz and 9.8–33.2 GHz for
$x$
- and
$y$
-polarization under normal incidence, respectively, while the radiation performance of the antenna remains unchanged.