Broadband water-based metamaterial absorber for millimeter-wave, high-power applications

An all-dielectric metamaterial absorber based on water resonator encapsulated in resin container is proposed. The absorber can afford the maximum absorption up to 98% at 190 GHz, as well as the wide absorption frequency range from 115 GHz to 300 GHz and a nearly 90% relative absorption bandwidth. The role of water resonator sealed in the resin shell in improving absorption capability is demonstrated by the comparison result that the proposed absorber is superior to pure water or pure resin absorber with the same dimension and interpreted by a further study on the fields and power loss density distributions. Moreover, the proposed absorber can remain excellent absorption performance even for the oblique incidence with large angles. Besides the outstanding absorption performance, the proposed absorber has the advantage of low cost endowed by the use of water, which makes it promising for EM compatibility in the millimetre-wave and high-power cases.