Homogenization of metamaterials from a Bloch mode perspective

We discuss the homogenization of metamaterials consisting of periodically arranged unit-cells from a Bloch mode perspective. This theory provides clear answers to the important questions of whether a metamaterial can be homogenized, which effective properties can be assigned, and how they are linked to properties of the Bloch mode. It is shown that material parameters can only be assigned to the metamaterial under certain circumstances, i.e. only if the propagation constant and the impedance obey a strict functional dependency. To achieve homogenous metamaterials fewer efforts are necessary but they still require a carefully balanced design.