Abstract
The 10m and 3m semi anechoic chambers are in widespread use for the electromagnetic compatibility (EMC). The hybrid EM wave absorber consisting of the sintered ferrite tiles and the dielectric lossy materials has been usually used for these semi anechoic chambers. In the past, Suetake, Naito, and Shimizu's studies played a key part in providing the basis for the hybrid EM wave absorber. The reflectivity of the hybrid EM wave absorber can be calculated from the multi-layered approximate structure. Especially, each layer occupied partly the dielectric lossy materials can be replaced by the homogeneous plate having the equivalent relative complex permittivity, which is determined through the synthesized capacitance model in the large wavelength range. But, there was a problem that the equivalent relative complex permittivity differs with the process of the synthesized capacitance model.
We propose a new method which can be applied to the equivalent relative complex permittivity by the Finite Difference Method (FDM). Moreover, the reflectivity of the hybrid EM wave absorber using the thin corrugated dielectric lossy sheet is calculated and measured. As the result, it is confirmed that the measured reflectivity agree with the calculation one.
