Research on EBG structure consisting of bianisotropic media

The paper reviews a computational model developed for the analysis of EBG structures consisting of bianisotropic media. It is based on the plane wave expansion (PWE) method. A typical EBG structure, made of a triangular lattice of air cylinders embedded in a uni-axial chiral medium, is considered. Simulation results show that the structure with a uni-axial chiral host (whose permittivity and/or chirality are/is uni-axial) possesses a wider band-gap than that with a traditional biisotropic chiral host. However, the permeability, whether with uni-axial anisotropy or not, always plays a negative role on the width of the band-gap. Further studies show that other forms of permittivity, permeability and chirality, such as in the biaxial crystal with principle axes coinciding with the universal coordinates or not, the gyrotropic crystal, contribute nothing to the width of the band-gap.