Water-injected all-dielectric ultra-wideband and prominent oblique incidence metamaterial absorber in microwave regime

We present a water-injected all-dielectric metamaterial that can offer an extremely wide bandwidth of electromagnetic absorption and prominent wide incident angle range. Different from conventional metal-dielectric based metamaterial absorbers, the absorption mechanism of the proposed all-dielectric metamaterial absorber is to take advantage of the dispersion of water, rather than electric or/and magnetic resonance, which thoroughly overcomes the defects of narrow bandwidth and oblique incidence from metal-dielectric based metamaterial absorber. The simulated absorption was over 90% in 8.1–22.9 GHz with the relative bandwidth of 95.5% when the incident angle reaches 60°, and the corresponding microwave experiment is performed to support the simulations. The obtained excellent absorption performance reveals a possible application of the proposed absorber, which can be exploited for electromagnetic stealth purposes, especially for electromagnetic stealth of sea targets.