Microwave dielectric properties of Bi2(Li0.5Ta1.5)O7–TiO2-based ceramics for 5G cellular base station resonator application

The solid-state sintering route was employed for the production of (1-x)Bi 2 (Li 0 .5 Ta 1.5 )O 7 -xTiO 2 (x = 0, 0.02, 0.04, 0.06, 0.08) ceramics. The phase, microstructure and microwave dielectric properties of each ceramic composition were determined via X-ray diffraction, scanning electron microscopy and Haki Colmon resonator technique, respectively. The dielectric constant, tan δ and AC conductivity were also determined for the composition of x = 0.04. The TiO 2 addition developed new phases of Bi 3 Ti 4 O 12 and Bi 3 TaTiO 9 for x = 0.04 along with Bi 2 (Li 0 . 5 Ta 1.5 )O 7 phase which disappeared for x = 0.08. The τ f of Bi 2 (Li 0 . 5 Ta 1.5 )O 7 was tuned through zero by TiO 2 addition and good microwave dielectric properties ε r ~67.2, Q u f õ 13,767 GHz and τ f  ~ −1.45 ppm/ ° C can be obtained for the composition of x = 0.04 sintered at 1050 °C for 2 h. This ceramic composition is a suitable candidate for 5G cellular base station resonator application.