Gain Enhancement in Microstrip Patch Antenna With High Negative Refractive Index 3D-Metamaterial Inspired Superstrate for Wireless Applications

This article presents a 3D-metamaterial (3D-MTM) structure to enhance microstrip patch antenna gain. A 3D-MTM unit cell exhibits an MNG ( $\mu $ -negative) property with a high negative refractive index over the 2.36-2.53 GHz frequency range resonating at 2.45 GHz. Therefore, a $4\times 4$ array of the proposed 3D-MTM unit cell is analyzed and used as a superstrate over a patch antenna and a $2\times 2$ array antenna to achieve high gain for wireless applications. The simulated and measured results of the designed antenna show that the gain is enhanced by about 5dBi and 3.2dBi. In addition, the half power beam width reduced in E-plane is 23° and 12.85° for a patch antenna and $2\times 2$ array antenna, respectively.