A Novel High-Directivity Microstrip Patch Antenna Based on Zero-Index Metamaterial

In this letter, a novel high-directivity microstrip patch antenna (MPA) based on planar zero-index metamaterials is presented. An averaging effect over the metamaterial structure yields an effective permittivity that approaches zero at 8.75 GHz, which results in a metamaterial with zero index of refraction. Both the simulation and experimental results show that the directivity of the antenna is effectively enhanced based on the zero refraction characteristics of the metamaterial.