Abstract: Compared to analogous regular hexagonal honeycombs with the same relative density, the heteromorphic honeycomb has advantages in mechanical properties and has more obvious anisotropy, but its high geometric complexity would bring troubles to the design of radar absorbing materials. Based on the equivalent medium theory, simulation software was used to simulate the electromagnetic parameters of the heterogeneous honeycomb to obtain the equivalent electromagnetic parameters. The complex permittivity and microwave-absorbing properties were investigated in the frequency range of 2 GHz~18 GHz. The calculated data were in good agreement with the experimental results. Based on the model, honeycombs of 15 mm thickness with different draw ratios were optimized in the case of the same absorber increment. The band width can reach nearly 12 GHz as the microwave-absorption reflectivity was below than -10 dB with thickness of 15 mm. The minimum reflectivity of -30 dB, -22 dB were obtained at 4 GHz and 12 GHz, respectively, for the i=0.68 honeycomb with 41.25wt% absorbers. The calculated results have certain practical value and wide applicability for similar honeycomb structure design and absorbing performance optimization.

Key words: honeycomb absorbing structure, draw ratio, electromagnetic parameters, microwave absorption property