Ultra-wideband microwave absorber based on multilayer patterned resistive film

In this work, two ultra-wideband microwave absorbers are proposed. The absorptivity of the proposed original absorber can achieve 90% in a wide bandwidth from 2.41 GHz to 18 GHz at normal incidence. This design has been extended to enhance absorption performance and angular stability by respectively incorporating a high-dielectric substrate and adding metal vias. As a result, the absorptivity of over 90% can be achieved from 0.6 to 18 GHz in transverse magnetic (TM)-incident cases even if the incident angle goes up to 60°, which realizes a relative bandwidth of 153%. While in the transverse electrical (TE) polarization, the absorption of the new absorber performs better than the original one in the entire operational bandwidth. A prototype of the proposed absorber is fabricated and measured, good agreement is obtained between measured and simulated results, indicating the usability of our design in practical electromagnetic wave absorbing scenes.