The realization of circulation performance using reciprocal metamaterial in free space

In this letter, magnetless reciprocal metamaterials are used to realize the circulation performance in free space. The metamaterials we used in the paper are ideal phase gradient metasurfaces, which is realized by different materials with different index of refraction. The anomalous refraction feature of the phase gradient metasurface is utilized to realize circulation characteristics. In free space, three metasurfaces array in 60 degree angle from each other. With the help of metamaterial, the EM (electromagnetic) wave is refracted in special direction instead of other directions. So some areas have EM wave in strong intensity, while other areas do not. That makes the circulation performance. This work can reduce the weight and is compatible with integrated circuit technologies. Moreover, it is also insensitive to temperature. The circulator provides a way to overcome the major drawbacks of the traditional circulators. The workhas potential value in the future.