Enhanced microwave dielectric properties of CeO2–TiO2 ceramics by adding Al2O3 for microstrip antenna application

Abstract

Ti-related oxide ceramics often exhibit excellent microwave dielectric properties and are widely applied in the microwave communication field. However, their microwave dielectric properties are often influenced by unstable defects, which are caused by the relatively low oxygen partial pressure at high sintering temperatures. In this work, Al2O3 was introduced to improve the defect structures of the 0.85CeO2-0.15TiO2 ceramics. According to the XPS pattern and AC conductivity analysis, Al2O3 doping could stabilize the valence state of Ti but increase the oxygen vacancy concentration. Q × f first increased and then decreased as the Al2O3 content increased. The highest Q × f value of 54361 GHz was obtained for the CTA0.015 sample sintered at 1275 °C, as well as the εr of 29.41 and τf of +7.8 ppm/°C. Finally, the CTA0.015 sample was used to prepare a microstrip antenna via the screen-printing process, which exhibited a good temperature-independent resonant frequency and indicated good application prospects.