Synthesis of Spherical Metasurfaces Based on Susceptibility Tensor GSTCs

Abstract

The bianisotropic susceptibility Generalized Sheet Transition Conditions (GSTCs) synthesis method is extended from planar to spherical metasurfaces. Properties specific to the non-zero intrinsic curvature of the spherical shape are highlighted and different types of corresponding 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.

Comparison of Tensor Boundary Conditions With Generalized Sheet Transition Conditions

“…The TBCs, as given by Eqs. (4) or (5), have an obvious disadvantage compared to susceptibility-based GSTCs for handling complex sheets, such as metasurfaces or magnetized two-dimensional materials: They are not directly expressed in terms of bianisotropic medium parameters, and therefore provide little insight into the physics of the problem.…”

“…R Ecently, the Generalized Sheet Transition Conditions (GSTCs) have been abundantly and successfully used as an electromagnetic model to synthesize and analyze metasurfaces [1], [2]. GSTCs are generalizations of the conventional boundary conditions [3], relating the field differences at both sides of a sheet discontinuity not only to surface currents but also to surface polarisations [4] (Eqs. (1)- (3) and Appendix A therein).…”

Fast Analysis of Spherical Metasurfaces Using Vector Wave Function Expansion

“…Metasurface synthesis equations for planar metasurfaces and spherical metasurfaces are described in [10] and [16] respectively. Similar to [10] and [16], the normal polarization current densities are ignored are this work. Following the bianisotropic susceptibility-GSTC approach [16], the metasurface synthesis equations for a spherical metasurface of radius a reads…”

“…The vast majority of metasurfaces reported to date are planar. Other canonical shapes such as cylindrical metasurfaces and spherical metasurfaces [16] are now being studied. It is expected that conformal metasurfaces (metasurfaces of irregular shape) will become a subject of active research [16].…”

“…Other canonical shapes such as cylindrical metasurfaces and spherical metasurfaces [16] are now being studied. It is expected that conformal metasurfaces (metasurfaces of irregular shape) will become a subject of active research [16]. Some of the applications of spherical metasurfaces include mantle cloaking [17] and radiation pattern control [18].…”