Microwave dielectric properties of magnesium modified zinc titanates

Abstract

The microwave dielectric properties of newly developed zinc magnesium titanates, Zn1-xMgxTiO3 (x = 0 similar to 1), have been investigated. The positive temperature coefficient of resonant frequency, tau(f), in zinc titanate was adjusted to near zero at x = 0.15, where the dielectric constant, Q factor at 9 GHz, and tau(f) were 26, 5000, and 0 +/- 5 ppm/degrees C, respectively. The Q factor was increased to 15000 at x = 0.25 similar to 30 even in the low temperature of 1100 degrees C sintered specimens. The Q and K values dropped to 4000 and 22 in the specimens sintered above 1160 degrees C due to the microcracks induced by the decomposition. The tau(f) values, however, were not influenced by the decomposition. Maximum Q value of 18000 were obtained at x = 0.95 specimens sintered at 1150 degrees C-4h, where K and tau(f) were 19 and -60 ppm/degrees C. The temperature stability of Q factors in (Zn, Mg)TiO3 increased as the amount of Mg increased.