Improved high-Q microwave dielectric resonator using ZnO-doped La(Co1/2Ti1/2)O3 ceramics

The microwave dielectric properties and the microstructures of ZnO-doped La(Co1/2Ti1/2)O3 ceramics prepared by conventional solid-state route have been studied. Doped with ZnO (up to 0.75 wt%) can effectively promote the densification of La(Co1/2Ti1/2)O3 ceramics with low sintering temperature. At 1320 °C, La(Co1/2Ti1/2)O3 ceramics with 0.75 wt% ZnO addition possesses a dielectric constant (ɛr) of 30.2, a Q × f value of 73,000 GHz (at 8 GHz) and a temperature coefficient of resonant frequency (τf) of −35 ppm/°C.