“…Over the past few years, the unusual property like negative permittivity, negative permeability and negative refractive index of metamaterials (MTMs) finds tremendous applications in RF, microwave, THz, and even at the optical frequency regime. 6 Recently, different novel characteristics of the MTM structures are successfully utilized to enhance the directivity of various radiating sources such as dipole, 7 monopole, 8 dipole array, 9 microstrip patch, 10 and slot antennas 11,12 by using as the superstrate. Moreover, the presence of air gap between the antenna and MTM superstrate makes the antenna configuration thick in profile.…”