On the reflection efficiency of metasurface

A metasurface with double square loops is studied in this paper. Moreover, an equivalent circuit model of the metasurface is proposed. The input impedances and reflection coefficients of both the unit cell and its equivalent circuit agree reasonably well, which proves the validity of the equivalent circuit. Therefore, the operation principle of the unit cell can be understood through observing the difference between the input impedance and the characteristic impedance of the surrounding material. In addition, the equivalent circuit provides good guidelines for optimizations to realize a high or low reflection efficiency that can be applied in different areas.