Electromagnetic wave absorption properties of amorphous alloy-ferrite-epoxy composites in quasi-microwave band

Reports on the electromagnetic wave absorption properties of amorphous alloy-ferrite-epoxy composites with various amorphous alloy fractions in the frequency range from 1 to 5 GHz. We varied the fraction of amorphous alloy in amorphous alloy-ferrite-epoxy composites from 0 to 50 vol.% at a fixed 50 vol.% fraction of epoxy resin polymer. We measured the complex permeability μ and permittivity ε of composites by the reflection/transmission technique, and determined the theoretical matching frequency and thickness with maximum reflection loss by plotting the measured μ and ε on an impedance matching solution map. The increasing amorphous alloy fraction in amorphous alloy-ferrite-epoxy composites resulted in a larger matching frequency and thinner thickness than those of ferrite-epoxy composite. On the basis of these results, we propose a new, thinner wave absorber, made by optimizing the amorphous fraction and thickness in amorphous alloy-ferrite-epoxy composites.