The effect of WO 3 additive on the microstructures, the phase formation and the microwave dielectric properties of MgTiO 3 –CaTiO 3 ceramics system were investigated. The sintering temperature of WO 3 -doped 0.95MgTiO 3 –0.05CaTiO 3 (95MCT) ceramics can be lowered to 1175°C. The microwave dielectric properties are found strongly to correlate with the sintering temperature as well as the amount of WO 3 addition. At 1250°C 95MCT ceramics with 0.5wt% WO 3 addition gives a dielectric constant ɛ r of 20.3, a Q×f value of 66,000 (GHz) and a τ f value of −8.2ppm/°C. A band-pass filter is designed and simulated using the proposed dielectric to study its performance.