Transmission line metamaterials based on strongly coupled split ring/complementary split ring resonators.

We experimentally studied the coupling between a double split ring resonator and a complementary split ring resonator. The greatest coupling occurs when the two resonators are separated by the average ring radius, and the dimensionless coupling is as large as 0.1, allowing a novel planar metamaterial based on this hybrid structure. The coupling strength can be varied up to a factor of 2 by changing the relative orientation of the split ring resonators. A 2×2 waveguide structure with -10 dB coupling factor can be achieved, and showing multi-mode plasmon-induced transparency. It can be considered one-dimensional metamaterials exhibiting negative permeability and permittivity simultaneously.