Simple admittance expression derivation of an electrically dense loaded slot array at a material interface

The equivalent circuit admittance of a lumped element periodically loaded electrically dense array of slots at a material interface is derived for both, parallel and perpendicular, polarizations. The derivation is based on the methodology of Casey for deriving the equivalent circuit impedance of an unloaded wire mesh at a dielectric interface using the Wait-Hill formulation. Using the derived equivalent circuit admittance, a Booker type relation for unloaded wire grid and slot arrays, at general isotropic media interfaces, is obtained.