Effective negative refraction index in periodic metal–ferrite–metal film composite

Abstract

We analyze the refraction index of periodic metal–ferrite–metal film composite in microwave frequencies by the transfer matrix method. We show that the composite can be equal to a homogeneous material with a negative effective refraction index in certain frequencies. Two negative index states have been found in the composite. One has the negative effective permittivity and negative effective permeability simultaneously, and the other only has negative effective permeability. The transition between them can be controlled by the values of electron damping coefficient in the metal films.