ZrTi_2O_6 filled PTFE composites for microwave substrate applications

摘要

A new kind of ZrTi_2O_6 filled polytetrafluoroethylene (PTFE) microwave composite substrates was fabricated through the hot-pressing process. The microwave dielectric properties of ZrTi_2O _6/PTFE composites were measured using stripline resonator method. The relative dielectric constant (ε _r) and loss tangent (tanδ) of the composites increase with an increase of the volume fraction of ZrTi_2O_6 ceramic (0-46 vol%). The experimental dielectric constants of the composites match well with theoretically predicted values by Lichtenecker mixing rule. As the volume fraction of ZrTi _2O_6 ceramic increases, the thermal expansion coefficient and the temperature coefficient of dielectric constant decrease. The ZrTi _2O_6 filled PTFE composite exhibits a dielectric constant of 7.42 with a loss tangent of 0.0022 (10 GHz) at an optimum filler loading of 46 vol%.