In this paper, a near zero-index metamaterial (NZIM) unit cell, for gain improvement of a two-element antenna array is proposed, designed, and fabricated. The near-zero refractive index characteristics of metamaterial superstrate are used, which gathers the radiated waves from the source antenna and collimates them toward the normal direction. The array elements are formed by constructing a dual triangle Koch fractal (DTKF) to the periphery of a square patch, to benefit miniaturization and mutual coupling reduction properties of fractals. Fractal geometry leads to a 300MHz reduction in resonance frequency of the unloaded antenna array, which means an acceptable miniaturization. A prototype of this antenna has been fabricated and measured. Measured results are in good agreement with the simulation. The simulated and measured results have shown a gain enhancement at the corresponding resonance frequency of the antenna array. It is seen that at 3.15 GHz, where the refractive index is near its minimum value, the simulated broadside gain is 2 dB higher than that of an unloaded antenna array. The NZIM antenna also exhibits an HPBW reduction of about 20^0 and 14^0 in the E plane and H plane, respectively.