Ultra-broadband transmission absorption of the all-dielectric water-based metamaterial

In this paper, a structurally simple transmissive all-dielectric metamaterial absorber is designed, fabricated and measured. The unit cell consists of photosensitive resin and water, which the water layers composed of rectangle loop, rectangular block and traffic circle. It achieves over 90% absorption of electromagnetic waves in the frequency range between 11.0 and 27.3 GHz. Meanwhile, three absorption peaks are located at 12.5, 18.4, and 26.0 GHz, which the absorptive are 97.4%, 98.3%, and 98.5%, respectively. In addition, the characteristics of the designed metamaterial reveal wide-incident angle absorption and polarization-insensitive properties. The experimental sample is measured by using the free-space method, and the experimental results are verified to be in well agreement with the simulation data. Observing the distribution of electric and magnetic fields at different resonance frequencies, the physical mechanism of the absorption is attributed to strong magnetic resonance. Therefore, the proposed metamaterial has potential for widespread use in the fields of civilian and military.