Metamaterials’ structures have recently generated great interest among the global research community as they exhibit unusual electromagnetic properties. These structures satisfy effective homogeneity conditions when exposed to the electromagnetic wave as they consist of arrays of sub-wavelength periodic structures. In case of metasurface, the arrays have been considered to be extended in a two-dimensional surface, satisfying ultra-thin nature of the thickness. They have been found their wide applications in absorbers, polarization converters, antennas, etc., which have been discussed in detail in this chapter.

The retrieved effective permittivity and effective permeability of the medium can be made equal to each other with the proper choice of the geometrical dimensions of the unit cell to minimize the co-polarized reflection coefficients for absorber applications. The unit cell is asymmetric in nature for a cross-polarization conversion applications to exhibit chirality. Various metasurface designs have been discussed for both transmittive and reflective-type polarization conversion structures in this chapter. Further, metsurface structures have been incorporated in the design of antennas too to achieve wide bandwidth as well as high gain.