A Low-Profile Multifunctional Metasurface Reflector for Multiband Polarization Transformation

This brief proposes a low-profile multifunctional metasurface reflector for simultaneous linear to linear (LP-to-LP) and linear to circular (LP-to-CP) polarization conversion over multiple bands. The metasurface unit cell comprises a split ring resonator-loaded cross-diagonal pattern printed at the top of a dielectric substrate and a thin air space that separates the metallic bottom plate. The proposed reflector exhibits tri-band LP-to-LP conversion at 5.47-5.68, 7.86-8.84, 14.68-16.83 GHz, and quad-band LP-to-CP conversion at 5.30-5.41, 5.77-7.58, 9.27-13.91, 17.53-19.59 GHz frequency range. The response of the surface is analyzed through an equivalent circuit model (ECM), which gives physical insight into the metasurface. Moreover, the metasurface is explored through the characteristics mode (CM), where significant modes are determined based on the modal behaviors. Thereafter, modal behaviors are further investigated for simultaneous linear and circular polarization. Furthermore, the proposed structure and its mirror symmetric configuration are employed to develop the checkerboard surface. Such surface essentially realizes the phase gradient mechanism, which results in radar cross-section (RCS) reduction in the frequency range of 5.85-5.95, 9.2-10.3, and 16.6-18.5 GHz. The measured results are in good agreement with the simulated response.