Читать книгу Introduction To Modern Planar Transmission Lines - Anand K. Verma - Страница 198

The characteristics of material media and EM‐waves propagation in unbounded media are discussed in the previous chapter 4. Continuing the topics, this chapter is about the normal and oblique incidence of EM‐waves at the interface of two media. The characteristics of both the normal and oblique incident EM‐waves are obtained using an analytical method and convenient equivalent transmission line models. Under certain conditions, the interface surface of two media could acquire the property of a perfect electric conductor (PEC), or perfect magnetic conductor (PMC), or even a reactive impedance surface (RIS). These surfaces play a significant role in the modern microwave and antenna technologies. Some electromagnetic characteristics of the engineered composite materials, with negative permittivity and permeability, are also presented in the present chapter. These artificially structured materials are known as metamaterials. The realization, circuit modeling, and some applications of the metamaterials and metasurfaces are further presented in chapters 21 and 22, respectively. The properties of natural and artificial dielectrics are further examined in chapter 6.