Improved High-Q Dielectric Resonator Sintered at Low Firing Temperature

Abstract
The microwave properties of Ba(Co1/3Nb2/3)O3-Ba(Ni1/3Nb2/3)O3 ceramics were investigated. Ba(Co1/3Nb2/3)O3 has a low sintering temperature. However, the Q value is too low for application requirements at microwave frequencies. A new composition, Ba(Ni1/3Nb2/3)O3, which shows a positive temperature coefficient of resonant frequency was used as a compensator to improve the dielectric properties of the complex perovskite-type ceramic. Both sintering and crystallization of Ba(Co1/3Nb2/3)O3-Ba(Ni1/3Nb2/3)O3 were accelerated compared to those of Ba(Co1/3Nb2/3)O3 alone. The Q value at microwave frequencies was also improved. The dielectric ceramics with Ba(Co, Ni)1/3Nb2/3O3 system were found to be fired at a low temperature below 1400° C and to have a low temperature coefficient of resonant frequency τ f and high Q value. Dielectric properties of the ceramic resonator made of Ba(Co0.6Ni0.4)1/3Nb2/3O3 are a dielectric constant of 31, Q value of 10000 at 9 GHz, and temperature coefficient of resonant frequency τ f of -4 ppm/° C.