Wideband Coding metasurfaces based on low Q resonators

The operation bandwidth of coding measurfaces (CMs) is an important factor for practical application. And the operation bandwidth is related to phase response of the resonator with uniform amplitude. How does the quality factor (Q) of resonator affect the phase shift is analyzed using equivalent circuit model. Then a low Q resonator is employed to constitute CM, and the operation bandwidth of CM is studied by analyzing the quality factor and phase shift of resonator. And the operation bandwidths are ranged from 14 GHz to 27 GHz and 13 GHz to 20 GHz for 1-bit and 2-bit CMs, respectively. The relationship between Q value and bandwidth is validated. Finally, two CMs are designed for radar cross section (RCS) reduction. The measured results agree well with the simulated results, and both demonstrate that the designed CMs can achieve RCS reduction in operation bandwidth.