Abstract
The purpose of this study is to control the input impedance of the composite electromagnetic wave absorbers without changing their composition using ITO thin film as resistive thin film, which coats electromagnetic wave absorbers made of Ni-Zn ferrite and ferrite composites (spinel-type Ni-Zn ferrite, SiO2). The electromagnetic characteristics and absorption characteristics of these wave absorbers were evaluated. Compared with ferrite composites without ITO thin film, absorbing center frequency with the band width of the absorption above 90% of ferrite composites with ITO thin film was shifted to the lower frequency region. The range of the thickness for which electromagnetic wave is absorbed above 90% became broad using ITO thin film. These results shows that electromagnetic wave absorbers coated with ITO thin film with the requested center absorbing frequency can be made by choosing the suitable thicknesses of both the film and the ferrite composite without changing the composition of the absorber.
