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

BNT/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. BNT/PTFE composites with 70 wt% BNT are of high epsilon (r) and high Q: epsilon (r) = 10.56, Q x f = 2872 GHz. Additionally, theoretical models like Logarithmic 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 Logarithmic model are in well agreement with the experimental values.