Microwave Measurements of High Dielectric Constant Ceramics by Powder Mixture Equations - A Further Study

摘要

The measurements of the real parts (dielectric constants) of complex permittivity of composite samples at microwave frequencies made by titanium dioxide ceramic filler dispersed in the polyethylene matrix are studied in this research. The dielectric constant of pure ceramic was deduced from the experimental dielectric constants of composites under different filler percentages by mixture equations. The titanium dioxide ceramic has a dielectric constant of 100 at microw ave frequencies. Five well known mixture equations and a newly published mixture equation which was derived from one of the five equations were adopted in this study. The matching condition of the six mixing equations with measured dielectric constant values of the mixtures was investigated. The theoretical errors of various equations for the calculation of dielectric constant of pure ceramic were derived and studied. The best candidate equation for measuring the dielectric constants of pure ceramic materials is then suggested.