Electromagnetic characterization of bianisotropic metasurfaces on refractive substrates: General theoretical framework

Abstract

We present a general methodology for electromagnetic homogenization and characterization of bianisotropic metasurfaces formed by regular or random arrangements of small arbitrary inclusions at the interface of two different isotropic media. These topologies can provide the most general electric and magnetic surface-bound dipolar responses to incident electromagnetic waves. The approach unites and generalizes the earlier theories developed independently by two research groups: the joint group of profs. Holloway and Kuester and the joint group of profs. Simovski and Tretyakov. We demonstrate the use of both formalisms in several example cases and discuss the differences between the two approaches. Furthermore, we generalize the known theories for the bianisotropic metasurfaces located at interfaces between two different media or on a substrate. The generalized framework allows characterization of both periodical or amorphous metasurfaces. The developed analytical theory can be used in the analysis and synthesis of metasurfaces for a wide variety of applications.

Illusion mechanisms with cylindrical metasurfaces: A general synthesis approach

“…Next, similar to Refs. [22,23,[25][26][27], we express the metasurface response in terms of effective electric, magnetic, magnetoelectric, and electromagnetic polarizability tensorsᾱ ee ,ᾱ mm ,ᾱ em , andᾱ me , respectively. These surface polarizability ten-sors relate the polarization surface-density vectors P and M to the incident electric and magnetic fields E i and H i through the constitutive relations [42]…”

“…Similarly to what was done for planar metasurfaces [25][26][27], we start from the boundary conditions for cylindrical metasurfaces which read (see Eqs. (4.3a)-(4.3d) in Ref.…”

“…We first expand it in terms of the cylindrical harmonics as given by Eqs. (27) and (28) to obtain the unknown coefficients a n , b n , c n , and d n .…”

“…(24)] plus the field created from the cylindrical metasurface [see Eq. (27)]. Note that the metasurface shall not create any cross component scattered field, i.e., the ρ-and φ-components of the electric field simply vanish in Eq.…”

“…Note that the metasurface shall not create any cross component scattered field, i.e., the ρ-and φ-components of the electric field simply vanish in Eq. (27). Now we assume the fictitious source is located at ρ and φ = 0.…”