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

Abstract A novel polarization conversion metasurface (PCM) is designed to reduce radar cross section (RCS). The PCM unit has a polarization conversion ratio (PCR) of over 97% from 10.1 to 21.1GHz. By loading PCM array into the centre of a dual-band circularly polarized (CP) antenna which works in X- and Ku-band simultaneously, a new low-RCS CP antenna with two working bands is proposed. Two bands are located around 9.8GHz (relative bandwidth 18.0%) and 15.2GHz (relative bandwidth 11.0%) respectively. And the corresponding 3dB axial ratio (AR) bandwidth is 5.1% and 4.6%. Meanwhile, other radiation performances are also well preserved. Especially, the scattering ability is effectively enhanced. The average monostatic RCS reduction reaches 12.0dB for normal incident θ-polarized wave from 7.3 to 21.7GHz (99.3%). What’s more, bistatic RCS also shows apparent reduction under different incidence angles, which greatly improves its practical value. The results indicate that PCM can provide excellent monostatic and bistatic concealment for antennas in wideband and wide-angle range. It means that the dual-band CP antenna has good stealth capabilities when operating in radar and satellite communication systems, which may have extraordinary enlightenment for various fields like stealth antennas, target camouflage, and communication platforms.