Ultra-wideband Transmissive Water-Based Metamaterial Absorber with Wide Angle Incidence and Polarization Insensitivity

A transmissive water-based metamaterial absorber(TWMA) is designed, simulated, and measured, which uses 3D-printing to manufacture. The TWMA uses a circular column and rectangular water layer structure and has no metal backplane. We have proved theoretically and experimentally that the TWMA has absorption rate exceeds 90% in the frequency ranging from 6.5 to 21.4 GHz. Furthermore, the TWMA is thermo-tunable when temperatures change from 10 to 60 °C and has the characteristics of wide angle incidence and polarization insensitivity. It can be applied to a variety of electromagnetic applications, such as reducing broadband scattering and collecting electromagnetic energy in a variable temperature environment.