Abstract

The microwave dielectric properties of conventional solid-state route prepared (1 − x)(Mg_0.95Co_0.05)₂TiO₄–x(Ca_0.8Sr_0.2)TiO₃ ceramic system have been investigated. A two-phase system was confirmed by the X-ray diffraction patterns. (Mg_0.95Co_0.05)TiO₃ was also detected as a second phase in the system. The microwave dielectric properties are strongly related to the density and the morphology of the specimens. The presence of the second phase, however, would cause no significant variation in the dielectric properties of the specimen because it possesses similar properties compared to that of the main phase (Mg_0.95Co_0.05)₂TiO₄. Specimen using 0.92(Mg_0.95Co_0.05)₂TiO₄–0.08(Ca_0.8Sr_0.2)TiO₃ leads to a good combination of microwave dielectric properties with an _r of 19.22, a Q × f of 123,200 GHz (at 9.2 GHz) and a τ_f value of 2.8 ppm/°C. It is proposed as a candidate dielectric for applications in GPS patch antennas and 3G passive components.