A novel two-layer honeycomb sandwich structure absorber with high-performance microwave absorption

A novel method for fabricating the two-layer honeycomb sandwich structure absorber (THSSA) was developed. The honeycomb cores with different pore sizes coated with epoxy resin filled with conductive carbon black as lossy filler have been fabricated by dipping processes. The microwave absorption properties of the honeycomb sandwich structure absorber (HSSA) with one-layer honeycomb core and two-layer honeycomb core have been designed and measured using arch measurement system within 2-18 GHz. The matching layer on the top of the honeycomb core can enhance the microwave absorption properties. The value of reflection loss can reach -10 dB in the frequency range of 4.9-18 GHz with an absorber thickness 9 mm for the fabricated THSSA with the flaky carbonyl iron powder (FCIP)/epoxy resin composite at the bottom. It was shown that the THSSA with lightweight and broadband absorption properties have a promising future in decreasing electromagnetic wave irradiation and interference.