Abstract: V₂O₅ doping and complex V₂O₅-CuO doping BiNBO₄ ceramics were studied. The experimental results indicate that complex doping is more efficient in decreasing the sintering temperature,preventing exaggerated grain growth and improving the dielectric loss of the BiNbO₄ -based ceramics. This complex doping BiNbO₄ has more homogeneous grain size and higher density than that of V₂O₅-doped one, and their microwave properties are ε_r=44, Q=2000(3MHz).

Key words: BiNbO₄ dielectric ceramics, two-steps synthetic processing, low-firing