BiNbO_4 Dielectric Ceramics at Microwave Frequencies

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 er=44, Q=2000(3MHz).