Dielectric Properties and Applications of Low‐Loss (1−x)(Mg0.95Ni0.05)2TiO4‐xSrTiO3 Ceramic System at Microwave Frequency

Abstract

The microwave dielectric properties of conventional solid‐state route prepared (1−x)(Mg0.95Ni0.05)2TiO4–xSrTiO3 ceramic system have been investigated. A two‐phase system was confirmed by the X‐ray diffraction patterns. (Mg0.95Ni0.05)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 with that of the main phase (Mg0.95Ni0.05)2TiO4. Specimen using 0.93(Mg0.95Ni0.05)2TiO4–0.07SrTiO3 leads to a good combination of microwave dielectric properties with an εr of 24.88, a Q×f of 98,400 (at 9.8 GHz) and a τf value of 1.43 ppm/°C. It is proposed as a candidate dielectric for applications in GPS patch antennas, 3G and 4G passive components. Moreover, an open stub band‐pass filter with central frequency of 2.4 GHz was also designed and fabricated employing the proposed dielectric to study its performance. It also showed a substantial reduction in both insertion loss and size in comparison with other dielectrics FR4 and alumina.