Metasurface characteristic of fractal fishnet structure and closed ring resonator

This paper presents the characteristics of metasurface which is composed of fishnet structure and closed ring resonator on different side of square unit cell. Also, Minkowski fractal pattern is applied on fishnet side structure for metasurface miniaturization. Obviously, the downward tendencies on the both of resonant frequency and effective parameters (permittivity, permeability, refraction index) are observed and performed. For material classification, the metasurface can exhibit three unusual properties around the resonant frequency. They are including of negative permittivity (ENG), negative permeability (MNG), and near-zero refraction index (NZI).