A Generalized Additional Boundary Condition for Mushroom-Type and Bed-of-Nails-Type Wire Media

Dual capacitive-inductive nature of periodic graphene patches: Transmission characteristics at low-terahertz frequencies

“…1, since the dimensions of the unit cell are assumed to be subwavelength, the patch array surface in each layer can be characterized by a homogeneous surface impedance Z s , [42][43][44][45] …”

“…(4). [42][43][44][45] If the surface impedance expression was exact and the structure was laterally infinite, the transfer-matrix method would yield the exact solution of Maxwell's equations. The results obtained using the above analytical model are validated using full-wave finite-element-based numerical simulations (HFSS), 37 in which case a surface impedance for the patch array is not specified and the actual patch geometry is modeled (both methods use the same intraband and interband graphene conductivity models).…”

Multilayered Wire Media: Generalized Additional Boundary Conditions and Applications

“…Although, the GABCs derived in [13] are applied at the wire-to-patch connection with the finite size of the patch (with certain restrictions imposed on the size of the gap between the patches with respect to the separation of adjacent patch arrays), these boundary conditions are valid only for perfect electric conductor terminations. However, when the metallic terminations (patches) are thin (resistive) (or for no patch case [10]), the charge accumulation and diffusion at the wire-to-patch interface (or charge accumulation at the open wire end interface) becomes important (spatial dispersion effects have to be considered), necessitating a new additional boundary condition at this interface [16], which takes into account the finite conductivity of the material at the connection points. Upon homogenization, these charge effects are reflected in the nonlocal slab permittivity.…”

“…The ABC derived in [16] can only be applied to a single-layer wire-medium slab terminated with either PEC or thin resistive (metal/graphene) patches or a combination of both. It is derived under the hypothesis that the material adjacent to it is either free space or a dielectric filled material.…”

“…However, for a more general configuration shown in Fig. 1 (where the metallic wires of one wire-medium slab are connected to another wire medium with a thin resistive patch at the junction), the ABC proposed in [16] cannot be applied.…”