Ultra-wide band and high efficient Polarization converting metasurface employing Bell-shaped unit cell for RCS reduction

• A simple unit cell is designed which performs polarization conversion in the frequency band of 14 GHz-25.5 GHz. • The unit cell along with its mirror will have a phase difference of 180 ± 37°. • The two unit cells PCMS 1 and PCMS 2 will be arranged in triangular chessboard configuration and due to destructive interference will contribute for reducing Radar cross section. • Radar cross section is reduced significantly in the frequency range of 4GHz to 24.8 GHz which obtains 144% fractional Bandwidth. Polarization is a dominant parameter regarding communication systems in recent times. The standard polarization techniques can be used only to a certain extent because of their huge size and limited bandwidth constraints. A design of bell-shaped polarization converting metasurface (PCMS) is presented in this paper which is highly efficient for Radar cross section (RCS reduction) and also operates in ultra-wideband. The designed PCMS attains a polarization conversion ratio of more than 90% by demonstrating the transformation of the linear polarization wave to its orthogonal counterpart. The PCMS is arranged in a triangular chessboard configuration to reduce the RCS. RCS reduction is obtained by achieving destructive interference, accomplished by two unit cells. The two unit cells, PCMS and its mirror will have a phase difference of 180 ± 37°. The phase cancellation is obtained by rotating and arranging the proposed PCMS at 90°, 180° and 270°. RCS reduction is obtained in a frequency range from 4 GHz to 24.8 GHz with 144% FBW. This PCMS is verified experimentally. A good agreement is found between the simulation and the experimental results.