The microwave dielectric properties and the microstructures of (1 - x)BiNbO4-xBiTaO4 ceramics (x = 0, 0.15, 0.2, 0.4, and 0.6) doped with 0.5 wt% CuO are investigated. Ta is substituted for Nb in order to adjust the temperature coefficient of the resonant frequency (τf) and improve the quality factor (Q). All BiNb(1-x)TaxO4 compositions can be sintered to achieve a 96% theoretical density below 960°C. The sintering temperatures of BiNb(1-x)TaxO4 increase with increasing of x values. The dielectric constants (εr) of all compositions saturate at 44-45 in spite of the Ta content. Q × f values of 13000-22000 (GHz) are obtained for all compositions when the sintering temperatures are in the range of 920-940°C. By increasing the amount of the doped Ta, the temperature coefficient of the resonant frequency τf can be adjusted from a positive value of + 15 ppm/°C to a negative value of -30 ppm/°C. The BiNb(1-x)TaxO4 ceramics can be applied to multilayer microwave devices with low sintering temperatures.
|Number of pages||4|
|Journal||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|Publication status||Published - 1999|
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)