A Method to Determine the Permittivity of Anisotropic Thin Sheet Absorber Materials

Thin sheet EMC suppression material is often manufactured in multiple layers. These artificial materials can be made by mixing metal flakes into polymers. This leads to anisotropic behavior in the electromagnetic properties of the material. This paper presents a new method for determining the anisotropic behavior of magneto-dielectric thin film materials, focusing on a measurement of both in-plane and normal-to-plane permittivity. In this procedure, the in-plane permittivity and permeability are measured using the well-known material characterization technique, and then the normal to plane permittivity is measured using the proposed technique. This method determines the value of the dielectric constant using a simple microstrip line structure. Simulation and measurement are used to verify the validity of the method.