Reflection characteristics of a parallel wire grid embedded in a general bi-isotropic medium.

A periodic wire grid composed of infinitely long thin parallel conducting wires with a bi-isotropic background is considered. The reflection properties of this wire grid have been investigated using numerical calculations. The analytic expressions for the surface impedance and reflection coefficient have been derived using the wave field decomposition approach and with the application of impedance boundary conditions for a wire grid. The influences of various background media upon the reflection magnitude and phase have been studied. The considered background media are taken to be bi-isotropic, Tellegen, and chiral. It is investigated if the zero reflection for a wire grid with a free space background under normal illumination vanishes for bi-isotropic, Tellegen, and chiral background media. It is found that, for a specific type of realistic bi-isotropic background medium, an equivalent wire grid of ideally conducting wires becomes nearly a perfect reflector. It is also studied if this type of perfect reflector is almost independent of incident angles.