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

Several double negative (DNG) metamaterials, artificial materials with simultaneous negative permittivity and permeability, have been fabricated and tested experimentally at X-band frequencies. These include a negative index of refraction slab matched to free space and a perfect magnetic conducting slab. The basic concepts of propagation in DNG metamaterials, their designs and experimental verifications will be reviewed. These DNG metamaterials may indeed be very suitable for a variety of electromagnetic applications dealing with guided wave environments, sensors, and antennas. The use of a DNG metamaterial to tailor the propagation characteristics of a microstrip transmission line will be described in detail. It will be demonstrated that a DNG-loaded microstrip transmission line segment that exhibits a negative index of refraction can be matched to an ordinary microstrip fine.