A Low-Profile Third-Order Electromagnetic Absorber With High Selectivity

In this article, a low-profile third-order absorber with high selectivity is proposed. Compared with traditional absorbers that perform similar functions using a multilayer composite structure, the developed absorber utilizes the slot-line loading technique to obtain a third-order multimode resonance response with only one resonator. As well, the absorber has relatively better polarization insensitivity and large incidence angle stability. With the detailed analysis of surface current distribution in different modes, the action mechanisms of multimode resonance, rectangularity, and effective absorption are revealed. Finally, the absorbers are fabricated for demonstration. From 15.58 to 16.60 GHz, the absorber can attain an absorption bandwidth of 6.3% under an absorption ratio of >90%. Due to the increase in order, the rectangularity can be up to 67%. As expected, the proposed absorber has the attractive advantages of high-selectivity, low profile, and third-order performance, which is of great application potential in radar stealth and solving electromagnetic interference technology.