Design of miniaturized double-negative microstrip antennas using electromagnetic parameter retrieval

In this paper the analysis of a microstrip antenna loaded with a double-negative (DNG) material is shown. The presented results can be applied easily to the design of planar antennas, arrays and frequency selective surfaces (FSS). The advance in planar radiating structure design using non-conventional material with the objective of size reduction is carried out. A DNG material realized with a periodic repetition of split ring resonators (SRR) and metallic rods is adopted as the substrate of a 10 GHz microstrip antenna to achieve size reduction and improving the performance. The design is then compared with one that uses isotropic substrate (i.e. FR4). Comparison shows that the introduction of such a non-conventional medium allows the patch size to be reduced approximately by 57% and the bandwidth to be increased. Issues about size reduction and negative refractive index effects are further presented and discussed.