Dielectric properties of modified SrTiO3/PTFE composites for microwave RF antenna applications

SrTiO3/PTFE composites with high dielectric constant and low loss properties were prepared via powder processing technique. The structure, morphology, dielectric and thermal properties of the composites were characterized by X-ray diffraction, scanning electron microscope, coefficient of thermal expansion, and network analyzer. SrTiO3/PTFE composites with 60 wt% SrTiO3 are of high epsilon(r) and high Q: epsilon(r) = 12.19, Q x f = 1930 GHz. Additionally, theoretical models like Logarithmic mixture rule, Maxwell-Garnet, Effective medium theory and Smith's model were also used to predict the dielectric constant of these composites. The values obtained by the EMT model are in well agreement with the experimental values.