A Study On Dielectric Properties Behaviours Of Dielectric Materials

The dielectric properties of wave-transparent material areassociated with the performance of wave-transparent, however, the measurement of radome materials in the conditions of high temperature and frequency is difficult as the limitations of the actual conditions. Otherwise, the data is difficult to collect because of the expensive spacecraft and missile. So that we analyze the dielectric performance of radome material in the conditions of high temperature and frequency from the microstructure through combined methods of mathematical modeling and dielectric theory. We deeply analyze several types of polarization mechanism and discuss the dielectric constant and dielectric loss at several special temperature and frequency which are based on the classic dielectric physics theories. In addition, we analyze the dielectric parameters of porous ceramics which is applied with the combination method of percolation phase transition theory and effective medium theory. Meanwhile, we also apply the binary phase equivalent circuit to analyze the dielectric loss. In the final, we analyze the principle of the specific experimental test complex dielectric parameters combined with the electromagnetic wave theory. Research contents are as follows:(1)We deeply analyze the mechanisms ofelectronic displacement polarization, ion displacement polarization and thermionic polarization and dipole orientation polarization by applying the dielectric physics. We also discussed the loss characteristics of the relaxation loss and the conductance loss. Several methods were adpted to comparatively discuss the theoretical advantages and disadvantages of composite media. Described model established by using the two-phase circuit element.(2) Analysis of the effective field correction of the problem, a brief introduction to the nature of silicon nitride, the analysis of the density/porosity silicon nitride ceramic dielectric properties with temperature, frequency variation, also described how this affects the porosity of porous silicon the dielectric properties, compared simulation data and experimental data, and analyzes several reasons causing error.(3) First discussed the overall performance of solid oxide silicon dioxide, from microscopic to build complex data models and describes the relationship between the media start density/dielectric properties with temperature, frequency, impurities, such as porosity porous silicon oxide, comparative tests differences between data and simulation data.(4) Theory explains the mechanism of normal temperature, high temperature test system, derived from a mathematical point of quality factorwhy related the dielectric loss and the complex permittivity, a briefly discussed the entire testing process.