Multi-Functional Metamaterial with Polarization and Wide Oblique Angle Insensitivity for X-Band.

An optimal blend of relatively high frequency and effective atmospheric penetration renders the X-band a versatile selection for a wide range of applications. Hence, metamaterial absorber and frequency selective surface (FSS) as a band-stop filter and shielding element play a significant role in X-band. This article proposes a cost-effective, wide oblique and polarization-insensitive metamaterial, whose applications as an absorber and FSS having band-stop characteristics for X-band are explained. The isotropic unit cell of the proposed metamaterial is designed by an array of two subunit cells, where one is the 90° rotated version of the other with diagonal symmetry. Equivalent circuits of both subunit cells and array structure are systematically designed and analyzed, which provides scope for future modification according to the required frequencies. The proposed absorber provides three absorption peaks and absorptivity of more than 90% up to 60° oblique incidence angle. A good agreement between experimentally measured and simulated results is observed. For the use of the structure as FSS, it has been optimized to provide band-stop characteristics precisely for the X-band up to a wide oblique incidence angle. The proposed design can be used as an absorber, band-stop filter, reflector, and shielding element for the X-band. [ABSTRACT FROM AUTHOR]