Tailoring double-negative metamaterial responses to achieve anomalous propagation effects along microstrip transmission lines

The design of a double-negative metamaterial loaded microstrip transmission line (DNG MTM-TL) to tailor the propagation characteristics at S- and C-band frequencies is presented. Guided-wave propagation along this DNG MTM-TL was studied numerically. The scattering parameters of the DNG MTM-TL were obtained with Ansoft´s High Frequency Structure Simulator. A two-port network realization of the DNG MTM-TL is established. The effective permittivity and permeability for the DNG MTM-TL is extracted using this two-port network representation. It is shown that both a negative permittivity and a negative permeability and, hence, a negative index of refraction exist in the design frequency range. These material parameters are dispersive and conform to a two-time derivative Lorentz material model type of resonance behavior. This form of the index of refraction may be very suitable for applications dealing with phase and dispersion compensation along a microstrip transmission line.