Backward-wave meta-materials-a brief review

One of the currently most active areas in electromagnetics deals with artificial materials that support propagation of backward-waves (´left-handed´, ´backward-wave´ or ´double negative´ materials). This paper reviews some representative research results published in period since introduction of ´backward-wave´ materials (May 2000) until now (May 2003). It appears that majority of published reports are still concerned with very fundamental issues which involve mathematical formulation, experimental verification and understanding of new, not previously observed physical phenomena. So far, there have been very few successfully realised engineering applications of backward-wave materials, mainly in technology of planar microwave circuits. The other applications, which would involve more striking phenomena such as negative refraction, ´amplification´ of evanescent waves and ´super-resolution´ focusing, although already proposed, are yet to be seen.