The properties of artificial dielectrics at centimetre wavelengths

The properties of an artificial dielectric at centimetre wavelengths are compared with those of a solid material, and the possible definitions of the refractive index and the wave impedance are examined. It is concluded that the most appropriate definition of the latter is in terms of the reflection coefficient at an interface between the artificial dielectric and free space. The reactive fields which are set up near such an interface are discussed qualitatively, and a number of ways in which they may be represented are given. The paper concludes with suggestions for further applications of artificial dielectrics.