3D-Printed Dielectric-Resonator-Based Ultra-Broadband Microwave Absorber Using Water Substrate

We have proposed an ultra-broadband dielectric-resonator-based microwave absorber with a water substrate. A dielectric resonator, which comprises two stacking cubic cavities and one cross-shaped cavity, was filled with water to provide ultra-broadband microwave absorption. The simulation results show that the absorptivity of the proposed absorber is greater than 90% in the frequency range from 16.52 GHz to the upper microwave frequency band of 100.00 GHz, with the relative absorption bandwidth of 143.3%. Moreover, the absorber is insensitive to wave polarization and has high absorptivity over a wide frequency range under oblique incidences. Thanks to the 3D-printing technology, the proposed microwave absorber can be fabricated precisely and cost-effectively. The experimental results demonstrated that the structure is capable of broadband absorption and wide-incident-angle stability. The proposed design of ultra-broadband absorbers has much potential in the fields of electromagnetic shielding and stealth technology.