Structure and circuit modeling of frequency domain polarization characteristics for porous composite material

Abstract

The relationship between the permittivity of a two-phase porous composite material and its structure forms the basis for the adjustment and analysis of the permittivity of the porous material. However, existing calculation models exhibit significant errors at low frequencies. A wide-frequency equivalent model is proposed in this paper based on the geometrical structural characteristics of porous materials, considering the effects of interface polarization and dielectric relaxation process. The relationship between the two-phase porosity material and the dielectric response of its framework and filling medium in a wide-frequency range can be calculated. Furthermore, the modified Cole–Cole model is adopted to analyze the dielectric spectrum characteristics of cellulose and aramid, thereby exhibiting the effects of polar bonds in the molecular structure and impurity ions in the material on the polarization strength and polarization process. The results obtained from this study can provide key parameters and a basis for the analysis of the polarization process of two-phase combined porous materials and the design of low-permittivity insulating paper.