Miniaturization methods for narrowband and ultrawideband antennas

A strong interest exists in the commercial and military sectors for small ultra-wide band antennas, such as the spiral. In this paper, we consider novel methods for miniaturizing spirals and other antennas using dielectric loading, artificial lumped loads, textured dielectrics and other approaches within the context of metamaterials. Our aim is to achieve miniaturization without compromising gain and by retaining as much bandwidth as possible. The spiral antenna, operating in the slot or wire mode, is a good choice to start with.