Abstract: The absorbing performance of 2~18 GHz electromagnetic wave aperture incidence and radial incidence carbon black segmented gradient impregnated honeycomb was tested by bowing method. With the increase in the number of impregnation honeycomb structure, there is an optimal immersion number of impedance matching, and the absorption performance is better than that of radial incidence honeycomb structures. Radial incidence gradient impregnated honeycomb, due to the anisotropy of the honeycomb structure, the performance difference between the two directions is large, the honeycomb structure can increase the number of reflections of electromagnetic waves in the honeycomb cavity, with the increase in the number of impregnation honeycomb structure wave absorption performance first weakened and then improved. At the same time, the honeycomb height has a great impact on the honeycomb performance, increase the hole to the incidence of the last section of the impregnated honeycomb height, the overall honeycomb height increases, the overall wave absorption performance of the honeycomb improved, impedance matching effect becomes better, at this time to increase the number of steps of each section impregnated, there is the optimal number of impregnation, impedance matching effect is the best, the best wave absorption performance. Honeycomb structure is widely used in military electromagnetic stealth, gradient impregnation can effectively improve the impedance matching effect, radial gradient impregnation honeycomb to cope with electromagnetic wave large angle incidence has great development prospects.

Key words: cellular structure, gradient impregnation, radial incidence, hole incidence, carbon black impregnation, composites