Wideband radar cross section reduction for a dual-band antenna based on a polarization conversion metasurface

Abstract A novel polarization conversion metasurface (PCM) is designed and used for radar cross section (RCS) reduction. The PCM unit can implement polarization conversion ratio over 97% from 10.1 to 21.1 GHz. By loading the PCM array into the centre of the dual-band CP antenna which works in the X- and Ku-band simultaneously, a new low-RCS antenna is proposed. Two bands are at 9.8 GHz (relative bandwidth 18.0%) and 15.2 GHz (relative bandwidth 11.0%) respectively. The corresponding 3 dB axial ratio bandwidth is 5.1% and 4.6%. Meanwhile, other radiation performances are also well maintained. In particular, the scattering ability is effectively enhanced. The average monostatic RCS reduction reaches 10.3 dB at normal incidence from 7.3 to 21.7 GHz (99.3%). Furthermore, bistatic RCS also shows apparent reduction under different incidence angles which greatly improves its practical value.