| 摘要 |
PURPOSE:To provide a composition suitable for high frequency resonators, etc., and having a formula; (1-x)[BaO.a{(1-a) Nd2O3.alphaSm2O3}.bTiO2]. x(0.5Bi2 O3.0.75TiO2). CONSTITUTION:A dielectric ceramic composition suitable for high frequency resonators, etc., has a formula; (1-x)[BaO.a{(1-a) Nd2O3.alphaSm2O3}.bTiO2]. x(0.5Bi2O3.0.75TiO)2) wherein x, a, b, alpha are defined as 0.5<=x<=0.65, 0.80<=a<=0.90, 4.0<=b<=4.5, 0<=alpha<=1, respectively. Since x of the composition is as high as 0.5-0.65, specific dielectric constant (epsilontau) of the composition becomes as high as 120 or higher and fQ value also becomes 500GHz or higher, which is sufficient for practical use, and moreover the temperature coefficient of resonance frequency (tauf)becomes 1000ppm/ deg.C and thus the composition has excellent temperature stability. In the case a resonator is actually made of the composition and used for frequency in a range from several hundred MHz to 2GHz, since the dielectric loss of the resonator due to electrodes, surface roughness, etc., is much higher than the dielectric loss of the dielectric ceramic composition itself, the fQ value of the dielectric ceramic affects extremely slightly the Q value of the resonator and the fQ value is thus deteriorated little and the function as a resonator becomes satisfactory. |
