Synthesis of Spherical Metasurfaces Based on Susceptibility Tensor GSTCs

The bianisotropic susceptibility generalized sheet transition conditions (GSTCs) synthesis method is extended from planar to spherical metasurfaces. Properties specific to the nonzero intrinsic curvature of the spherical shape are pointed out and different types of spherical transformations are described. Finally, the susceptibility GSTC method and exotic properties of spherical metasurfaces are validated and illustrated with three examples: illusion transformation, ring focusing, and birefringence.