Homogenization of biaxial composite materials: bianisotropic properties

We explore in detail the conceptualization of biaxial bianisotropic mediums through the process of homogenization. Biaxial bianisotropy is found to ar ise when (i) the component mediums undergoing homogenization present two no n-collinear distinguished axes and (ii) the most basic form of magnetoelect ric coupling in the form of isotropic chirality is present in at least one of the component mediums. Two possible sources of directionality in the com ponent mediums are considered: (i) topological and (ii) electromagnetic. Ex amples of these are investigated by considering the homogenization of parti culate components with (i) non-spherical topologies and isotropic electroma gnetic properties and (ii) uniaxial bianisotropic electromagnetic propertie s and spherical topologies. A generalized biaxial bianisotropic structure, characterized by 45 real-valued parameters, is presented. Complex symmetrie s are found in the constitutive dyadics of the homogenized composite medium s which would not be anticipated from a familiarity with the dielectric or dielectric-magnetic case.