Improved temperature stability of Li 3 Mg 2 NbO 6 microwave dielectric ceramics by using CaTiO 3 additives

Niobate-based microwave ceramics with low loss are expected to be used in 5G communication devices such as antennas, resonators and dielectric filters. In order to obtain a thermally-stable dielectric ceramic, (1- x ) Li 3 Mg 2 NbO 6 - x CaTiO 3 -4wt%LiF system were fabricated. The results of crystal structure and microstructure showed specimens possessed a two phase system with Li 3 Mg 2 NbO 6 and CaNbO 3 . The microstructure and dielectric performances of niobate-based ceramics are closely related to the amount of CaTiO 3 added. An optimum dielectric property of epsilon r -15.8, Q x f -84430 GHz and tau f -6.5 ppm/ degrees C was obtained at 1050 degrees C for 0.925Li 3 Mg 2 NbO 6 -0.075CaTiO 3 -4wt%LiF ceramic.