The effects of B2O3additive on the microstructures, the phase formation and the microwave dielectric properties of MgTiO3–CaTiO3ceramics were investigated. The sintering temperature of B2O3-doped 0.95MgTiO3–0.05CaTiO3ceramics can be lowered to due to the liquid phase effect. Formation of second phase MgTi2O5can be effectively restrained through the addition of B2O3. The microwave dielectric properties are found strongly correlated with the sintering temperature as well as the amount of B2O3addition. At , 0.95MgTiO3–0.05CaTiO3ceramics with 10 wt% B2O3addition possesses a dielectric constant of 18.3, aQ×fvalue of 20,000 (at 7 GHz) and a value of −6.12 ppm/. In comparison with pure 0.95MgTiO3–0.05CaTiO3ceramics, the doped sample shows not only a 22% loss reduction but also a lower sintering temperature. That makes it a very promising material to replace the present one for GPS patch antennas.
