| 摘要 |
PROBLEM TO BE SOLVED: To make the dielectric loss in a high frequency band small and to lessen the temp. coefficient of frequency, in a ceramic consisting essentially of alumina. SOLUTION: This ceramic composition consists essentially of Al2 O3 , TiO2 and Ta2 O5 and a composition ratio of each component in the mol ratio is prepared so as to be in the range described with segments of lines connecting points; A, B, C, D, A in an Al2 O3 -TiO2 -Ta2 O5 three component composition diagram shown in the figure and by allowing at least α-Al2 O3 and TiO2 to deposit as a crystal phase, excellent dielectric characteristics having 11-30 dielectric constant, <=1×10<-3> dielectric loss at 8GHz measuring frequency, and <=30ppm absolute value |τf| of temp. coefficient of resonance frequency at 25-85 deg.C, are obtained. |
