BaO‐TiO ₂ ‐WO ₃ Microwave Ceramics and Crystalline BaWO ₄

Abstract

Microwave ceramic resonators composed of BaO‐TiO 2 ‐WO 3 were developed. The effect of WO 3 addition on the system of BaO·xTiO 2 ·(1+x)yWO 3 (x=4 and 4.5, y=0 to 0.04) was studied. The ceramics of this system are composed of crystallines including Ba 2 Ti 9 O 20 , BaTi 4 O 9 , BaWO 4 , and TiO 2 . At y=0.02, the BaO·4TiO 2 ·0.1WO 3 ceramic was found to have excellent microwave properties such as ε=35, Q=8400 at 6 GHz, and nearly 0 ppm/°C of τ f .