The microstructures and the microwave dielectric properties of the (1-x)(Mg0.95Zn0.05)TiO3-xSrTiO3 ceramic system were investigated. (Mg0.95Zn0.05)TiO 3 possesses high dielectric constant (εr ∼ 17.05), high quality factor (Q × f value ∼ 264 000 at 9 GHz), and negative τf value (-40.31 ppm/°C). In order to achieve a temperature-stable material, SrTiO3, having a large positive τf value of 1700 ppm/°C, was added to (Mg 0.95Zn0.05)TiO3. Two-phase system was confirmed by the X-ray diffraction patterns and the measured lattice parameters. Evaporation of Zn occurred at temperatures higher than 1300°C and caused an increase in the dielectric loss of the system. As the x value varies from 0 to 0.1, (1-x)(Mg0.95Zn0.05)TiO3-xSrTiO3 ceramic system has the dielectric properties as follows: 17.05 < εr < 26.35, 20 000 < Q × f < 264 000, and -41 <τf<140. By appropriately adjusting the x value in the (1-x)(Mg0.95Zn0.05)TiO3-xSrTiO3 ceramic system, zero τf value can be achieved. A new microwave dielectric material, 0.96(Mg0.95Zn0.05)TiO 3-0.04SrTiO3 applicable in microwave devices is suggested and possesses the dielectric properties of a dielectric constant εr ∼ 20.96, a Q × f value ∼ 135 000 GHz (at 9 GHz), and a τf value ∼0 ppm/°C. A compact band-pass filter using two open-loop ring resonators with asymmetric tapping feed lines is designed and fabricated using the proposed dielectric to study its performance.
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Materials Chemistry