Liquid Metal-Enabled Multilayered Multifunctional Switchable Frequency Selective Surface

In this paper, a multilayered multifunctional switchable frequency selective surface based on liquid metal (LM) is proposed. The structure comprises three microfluidic layers. The switching among three operating states, including full-band transmission, highly-selective bandpass, and full-band reflective is achieved by exploiting the mobility of LMs. It is demonstrated that the proposed design is capable of achieving an insertion loss of less than $\mathbf{- 1} \mathrm{dB}$ from 11.53 GHz to 13.53 GHz in the highly-selective bandpass state. The reflectivity of the structure can be increased to over 92% in the full-band reflection state. The full-band transmission coefficient of the structure is less than -1dB in the full-band transmission state. The proposed design is insensitive to different polarizations angles due to rotationally symmetric pattern.