Analysis of a Wideband Hybrid Metamaterial as an Absorber vis-a-vis a Polarizer

Metamaterial structures are often used as microwave absorbers however, anisotropic structures are not suitable for the design of metamaterial absorbers. To verify this, a hybrid metamaterial absorber composed of a cross-loaded circular split ring resonator is analyzed in this article. It is noticed that the linearly polarized incident electromagnetic wave is proficiently converted into its orthogonal components because of the anisotropic geometry of the design. Under this scenario, the cross-polarized reflection coefficient is considered for the calculation of absorptivity, and a significant drop (from 90% to less than 30%) of the absorptivity is observed in the frequency band of interest. However, it can be used as an efficient broadband cross polarizer with a polarization conversion ratio (PCR) of more than 90%. The mechanism of cross-polarization, polarization efficiency with the variation of oblique incidence, polarization insensitivity, and optimization with respect to some parameters are also presented in this article. In addition, it is observed that the cross-polarization reflection coefficient value is high for anisotropic geometry, and both co- and cross-polarization reflection coefficients should be considered for the calculation of absorptivity.