Negative refractive index and negative refraction of waves in lossy metamaterials
An experimental study of the conditions for negative energy refraction and negative phase refraction in lossy metamaterials is provided. In hypothetical non lossy metamaterials, the angles of phase and energy refraction are one and the same. Using measured S parameters of split ring resonator wire metamaterial samples, it is shown that negative refractive index is not a requirement for negative energy refraction in lossy metamaterials. It was assumed that the sample is effectively homogeneous and isotropic in the direction of wave propagation. For transverse electric polarisation, negative energy refraction with a positive refractive index was demonstrated.