Microwave Dielectric Properties of (Mg _0.95 Ni _0.05 )TiO ₃ –SrTiO ₃ Ceramics with a Near‐Zero Temperature Coefficient of Resonant Frequency

The microwave dielectric properties of a (1− x )(Mg _0.95 Ni _0.05 )TiO ₃ – x SrTiO ₃ ceramics system were investigated. The system was prepared using a conventional solid‐state ceramic method. To produce a temperature‐stable material, SrTiO ₃ was added, which led to a near‐zero temperature variation in resonant frequency. The variation in microwave dielectric properties of the (1− x )(Mg _0.95 Ni _0.05 )TiO ₃ – x SrTiO ₃ ceramics system significantly depends on the amount of SrTiO ₃ present. As x was varied from 0.01 to 0.1, the microwave Q × f value decreased from 105,000 to 31,000 GHz and the dielectric constant (ɛ _r ) increased from 18.74 to 26.5. A microwave dielectric material with a dielectric constant (ɛ _r ) of 21, a Q × f value of 73,000 GHz, and a τ _f value of 1 ppm/°C were obtained from the compound 0.96(Mg _0.95 Ni _0.05 )TiO ₃ –0.04SrTiO ₃ sintered at 1300°C for 4 h. To verify the performance of the 0.96(Mg _0.95 Ni _0.05 )TiO ₃ –0.04SrTiO ₃ ceramics, a band‐pass filter with traditional hairpin resonators was designed and simulated on different dielectric materials [such as FR4, alumina, and 0.96(Mg _0.95 Ni _0.05 )TiO ₃ –0.04SrTiO ₃ ].