Microwave absorber properties of magnetic and dielectric composite materials

Abstract

SUMMARYIn recent years, because of rapid progress in wireless technology, microwave absorbers or noise suppressors have become necessary for an environment with safe electromagnetic wave levels. To design microwave absorbers or noise suppressors, it is necessary to have a knowledge of the complex permittivity ε r * and permeability µ r *. In this report, we present the values of the complex permittivity ε r * and permeability µ r * for composite materials including a magnetic component (iron, Fe coated with Fe 3 O 4 ) and a dielectric component (titanium oxide, TiO 2 ) obtained by varying the Fe/TiO 2 volume fraction ratio. By varying this ratio, we can change the values of the complex permeability (µ r * = µ r g − jµ r gg ) and complex permittivity (ε r * = ε r g − jε r gg ). The results are applied to the design of a microwave absorber in order to tailor the reflection loss and the central frequency to particular requirements, for example, the conditions required for ETC (5.8 GHz) use in Japan.

Polymer matrix composites as broadband radar absorbing structures for stealth aircrafts

“…Joon An et al . have reported the electromagnetic properties of dielectric and magnetic fillers and their combinations.…”