Multiband Fractal Metasurface with Linear to Linear and Linear to Circular Polarization Conversion

Recently, metasurface has attracted growing attention due to its unprecedented properties in controlling the phase, amplitude, and polarization states of electromagnetic waves. In this paper, an ultrathin and multiband fractal metasurface in reflection mode with strong inter-metamolecular interactions is presented, designed and measured to accomplish simultaneous manipulations from a linear polarization to another and from a linear polarization to left- and right-circular polarizations. The simulated Stokes parameter and axial ratio demonstrate the excellent multiband polarization conversions, which are attributed to the strong coupling effects of the fractal metasurface. Both simulated and measured results demonstrate good performance of the multiband and ultrathin fractal metasurface.