Equivalent electromagnetic parameters extraction method for graded honeycomb absorbing materials

An extraction method for the equivalent electromagnetic parameters (EEP) of grading honeycomb absorbing materials (GHAM) is proposed based on the asymmetric property of GHAM, EEP was modified by gradient factors related to its physical parameters in this paper. Considering that the strength of electromagnetic wave loss is dominated by the imaginary part of the complex dielectric constant, the EEP extraction method is built by optimizing the imaginary part of the complex dielectric constant according to the GHAM’s physical properties, such as the coating thickness of each layer for the GHAM, the increment between two adjacent gradient coatings, the layers of the GHAM, and the total axial height of graded honeycomb. The GHAM were prepared by the immersion process, and the reflectance measured by the free space method was consistent with that calculated by the EEP extraction method proposed in this paper within 2–18 GHz. The proposed EEP extraction method is simple, convenient, high precision, and it has played a certain role in solving the problems in actual engineering applications.