Electromagnetic absorber composite made of carbon fibers loaded epoxy foam for anechoic chamber application

•Carbon fibers loaded epoxy foam composites are proposed as microwave absorbers.•Dielectric properties (ε′, tanδ) of composites increase with carbon fibers content and length.•S11 coefficient of a pyramidal prototype was characterized in anechoic chamber.•Epoxy prototype shows better absorption performance than commercial absorber.•S11 of the prototype is lower than −30dB (4–18GHz) at normal and oblique incidences.