Dual-Functional Reflective-Metastructure Array for Polarization Conversion and Stealth Application

This work proposes a compact, single-layered dualfunctional reflective meta-structure array to convert incident X/Ypolarized EM waves to cross-polarized waves in a portion of Kaband spectrum and to obtain circularly polarized (CP) waves with broadband characteristics in the Ku and K band frequency spectrum. The unit cell comprises of a symmetrical I-shaped metallic resonator with a single rectangular split ring resonator at the centre. The rotation of the induced surface currents on the meta-structure and the phase profile of the reflected waves confirms the presence of left-handed CP waves. When rotated in XY plane around Z-axis by 90°, this meta-atom reflects cross polarized waves with 180° phase difference compared to the original meta-atom across the entire operational bandwidth. This phase profile is utilized to realize a checkerboard metasurface and it is observed that significant RCS reduction is achieved in the cross-polarization conversion band. The overall size of the optimized unit cell is 0.26 × 0.26 × 0.07 λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</inf><sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> and reflects CP waves with an axial ratio (AR) less than 3 dB from 15.3 GHz to 26.03 GHz. At the same time, cross-polarization conversion is observed from 28.33 GHz to 35.4 GHz, which makes the design best suitable for future wireless communication and RCS reduction application simultaneously.