Design of broadband microwave absorber using honeycomb structure

A novel broadband microwave absorber design concept using a honeycomb sandwich structure is proposed. Unlike the conventional microwave absorbing honeycomb sandwich structure, the newly proposed design concept uses the transverse direction of a honeycomb structure with a coated lossy material. When the incident waves reach the inside of the honeycomb coated with the lossy material, multiple scattering occurs inside the honeycomb due to the two different refractive indices. Then, the trapped electromagnetic (EM) waves lose energy due to the coated lossy walls. Thus, the honeycomb structure can be used in the transverse direction and the effective thickness in terms of the incident EM waves becomes very large. This considerable thickness represents a very effective way to sufficiently attenuate the trapped waves. This way, a lightweight and broadband absorber could be implemented without use of a magnetic material and without any limitations on the thickness.