Anomalous refraction in an all-dielectric gradient metasurface

We present an all-dielectric resonant metasurface with full 2π phase control at microwave frequency. Through numerical simulation, we show that by overlapping its magnetic and electric resonances, the dielectric resonator can achieve a full 2π phase modification. A metasurface working at 6.4 GHz is further designed, consisting of eight different sizes of discrete blocks to cover a gradient refraction phase from 0 to 2π. Numerical simulation clearly shows the anomalous refraction, with refraction angle in good agreement with the theoretical prediction.