| With the development of radar technology and the increasing complication of electromagnetic environment,wave-absorbing materials have become an indispensable part of the military and civilian field.As a new multi-functional wave-absorbing material with good mechanical and absorptive performance,the honeycomb wave-absorbing structure has become an important direction of research on absorbing materials.This paper mainly combines the theory of equivalent electromagnetic parameters and the characteristics of multi-layer dielectric wave-absorbing structure and consider the two cases of normal incidence and transverse incidence to study the design and preparation of honeycomb wave-absorbing structure.The main work includes the following:（1）Through simulative design,the effects of each structural parameter of homogeneous honeycomb wave-absorbing structure and gradient honeycomb wave-absorbing structure on its absorption performance of normal incidence was studied respectively.And the honeycomb wave-absorbing structure with good absorption performance was optimized.Studies have shown that: for homogeneous honeycomb wave-absorbing structures,As the side wall of honeycomb core becomes thicker,the absorption peak moves to a low frequency range.As the increase of honeycomb size,the absorption peak moves to a high frequency range,and the absorption performance is enhanced.As the thickness of absorbing coating increases,the absorption performance of the structure increases first and then decreases.The height of the structure increases,the number of absorption peaks increases,and the absorption bandwidth become wider.The best absorption performance of gradient honeycomb structure reaches-10 dB in 2-18 GHz,and the average of reflectivity is-19.09 dB.（2）From three aspects of homogeneous honeycomb wave-absorbing structure,multi-layer honeycomb wave-absorbing structure,and gradient honeycomb wave-absorbing structure,an experimental study on the performance of normal incident is carried out.The results show that: the absorbing coating of a homogeneous honeycomb structure prepared by the experiment has a relatively uniform distribution.The multi-layer structure can effectively improve the absorption performance.A gradient honeycomb wave-absorbing structure with a thickness of 20 mm prepared in this paper has an absorption bandwidth of-10 dB exceeding 83%（at least 13.32GHz）of the whole frequency band,and the average reflectivity in 2-18 GHz reaches-18.62 dB at least.（3）According to requirements of the actual application,the design scheme of honeycomb wave-absorbing structure with the resistance film fullly covered,half covered,and half covered with gradient distribution,and the realized method of impregnating absorbing slurry is proposed.The research shows that when the resistance film is fully covered,the absorption performance of the structure is weak.After the half coverage design of the resistance film is used,the absorption performance is significantly improved.For transverse incident honeycomb structure,when the gradient distribution is Rs31=550Ω/sq and Rs32=100Ω/sq,the structure has the best absorption performance,in the TE mode,the reflectivity of honeycomb wave-absorbing structure reaches-10 dB in the frequency range of 2.64-18 GHz,and in the TM mode,the reflectivity reaches-10 dB in the frequency range of 2.64-18 GHz,and the absorption bandwidth of-10 dB reaches 96%.In addition,the honeycomb wave-absorbing structure based on absorbing slurry has a-10 dB absorption bandwidth exceeding 95% of the entire frequency band,and the average reflectance is below-20 dB. |
