3D printed propeller-like metamaterial for wide-angle and broadband microwave absorption

It is a challenge to design an absorber which can simultaneously satisfy comprehensive demands of broad absorption band, wide incident angle range, and low-profile. In this work, we designed a metamaterial absorber (MMA) based on the antenna reciprocity theory to achieve the above goals. Firstly, a three-dimensional (3D) propeller-like structure with reference to a typical magneto-electric dipole (MED) an-tenna was proposed and analyzed by the characteristic mode (CM) theory to realize near-omnidirectional radiation. Then, the radiation-absorption conversion was realized by introducing lossy materials into this structure, and the absorption performance was further improved by optimizing the dispersion feature of the lossy materials. Finally, the propeller-like metamaterial absorber with a thickness of 0.113 lambda L was manufactured efficiently and integrally through 3D printing technology. Simulation results showed that the proposed absorber can achieve broadband absorption with the efficiency more than 90% in the fre-quency band of 3.4-10 GHz. It also has excellent wide-angle absorption capacity, with Transverse Electric (TE) polarization of 0 degrees to 50 degrees and Transverse Magnetic (TM) polarization of 0 degrees to 80 degrees. With the increase of incident angle, the upper limit of absorption bandwidth can be gradually extended to 18 GHz. Moreover, the effectiveness in the range of 0 degrees to 60 degrees incident angle is verified by measuring the reflectivity of the 3D printed absorber.(c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.