This paper discusses the general concept of using metamaterials in microwave lenses. The different optics afforded by
the inclusion of metamaterials in the lens structure produce new features such as reduced size and new beam formations.
The use of negative refractive index materials is discussed in reference to the original concept of the perfect lens, leading
to the Rotman lens and the Luneburg lens. In Rotman lens, negative refractions help reducing the lens size and a
broadband electromagnetic band gap (EBG) surface is used to prevent reflections off the sidewalls. Verification of
negative refraction and simulation of isotropic material performance are presented, as well as an example of broadening
the band of an EBG surface.