Modal properties of layered metamaterials

This chapter addresses modal properties of layered structures composed by metamaterials and their basic applications in waveguiding and radiating devices. In Section 13.2 an overview of results appeared in the literature on this topic is presented, without aim of completeness, to provide the reader some background information. The attention is then focused on a specific structure, i.e., a grounded metamaterial slab, which, as is well known, constitutes a basic building block in a variety of planar microwave components. This is described in Section 13.3, where the theoretical approach used for its analysis and the models adopted for the metamaterial parameters are illustrated. In Section 13.4, the surface-wave propagation on a grounded metamaterial slab is discussed and simple sufficient conditions for surface-wave suppression are given, showing their application to reduce edge-diffraction effects in planar antennas and to achieve unimodal propagation in nonradiative dielectric waveguides. In Section 13.5, complex (leaky) waves supported by the same reference structure are studied illustrating some of their peculiar radiative properties.