An Ultra-broadband Reconfigurable Absorber Based on Water-Resonator

A fluidically reconfigurable absorber with ultra-broadband working area is presented in this manuscript. With help of water resonator, the absorptivity higher than 80% is realized from 5.6 GHz to 20 GHz. The major innovation lies in the switching status between ultra-broadband absorption and transmission. By pumping the water out of the substrate, this design exhibits perfectly transparent performance over the corresponding absorption band. Furthermore, both states are quite insensitive to the oblique incidence wave. All these results confirm the promising potential applications in multifunctional devices.