Achieving PMC boundary conditions through metamaterials

In this paper, we show how metamaterials with extreme values of permittivity and permeability may be effectively used to design artificial magnetic conductors (AMC) at a given frequency. Depending on the polarization of the field, it is shown that different values of the constitutive parameters are needed to get AMCs. In particular, following a theoretical analysis based on the equivalent transmission line representation, it is shown that in the case of TEM and TE polarizations, a large value of the permeability is enough to obtain an AMC boundary condition. In the case of the TM polarization, instead, the AMC boundary condition is effectively achieved by using a material with vanishing permittivity. The role of the permittivity in the three polarizations is discussed. Finally, possible implementations and applications at microwave and optical frequencies are presented.