Homogenization and Realization of Periodically structured Materials

By Niels Christian Jerichau Clausen

The electromagnetics community has recently devoted a significant attention to the rapidly emerging field of structured materials – these materials are unit-cell based periodic structures with unusual dispersion properties which can be tailored to realize metamaterials for microwave as well as optical frequency applications. A central and significant challenge in the structured materials research, that is still a matter of controversy, is the homogenization of these, i.e., the determination of their effective material parameters. A number of homogenization techniques have been developed and applications hereof to many realizations of structured materials have been reported. However, a large part of these reports are based on questionable and sometimes incorrect interpretation of calculated and/or measured data of unknown accuracy. In consequence hereof, there is a strong need for a detailed and systematic clarification of the issue of homogenization of structured materials.

The purpose of this Ph.D. project is to further develop electromagnetic homogenization techniques for structured materials and apply them to improve the design, realization, and experimental characterization of a broad range of MTMs. It is expected that this study will provide additional insight into the general behavior of 1D periodic structures and the homogenization conditions for realistic structured dielectrics in 2D and 3D (such as MTMs) which typically consist of resonant unit-cell inclusions. A noticeable advantage of these designs, as compared to previous arrangements of conducting wires and split ring resonators, is their potential of providing low-loss, isotropic, and spatial dispersion-free MTMs.

 Completed: 2014