Microwave Dielectric Properties of Lossy Dielectric Composite Materials

In recent years, because of the rapid progress in wireless technology, microwave absorbers or noise suppressors have become necessary for a safe-electromagnetic-wave-level environment. To design microwave absorbers or noise suppressors, it is necessary to have knowledge of complex permittivity and permeability. To this end, we used the coaxial waveguide method between 500 MHz–18 GHz and the free space method with a dielectric lens in the K-band (18–26.5 GHz). In this report, we show the complex permittivity, ε_r^* and permeability, µ_r^* of lossy dielectric composite materials such as barium titanate oxide (BaTiO₃)/rubber and titanium oxide (TiO₂)/rubber. The real part of the complex permittivity, ε'_r is available for changing the trimming weight ratio of rubber and replacing TiO₂ or BaTiO₃.