High-frequency dielectric ceramic composition, dielectric resonator, dielectric filter, dielectric duplexer, and communication apparatus

Abstract

A high-frequency dielectric ceramic composition that has excellent dielectric properties, such as a large εr, a large Q-value, and a small absolute value of τf, even in a high-frequency region, such as a microwave region or a millimeter wave region, and that can be fired at 1400° C. or less, which is much lower than before, is provided. The high-frequency dielectric ceramic composition contains 100 parts by weight of main component and 0.005-0.300 parts by weight (on a B2O3 basis) of accessory boron compound. The main component has a composition formula of (1−y)xCaTiaO1+2a−(1−y)(1−x)Ca(M1z/3M22/3)bO1+2b-yLnAlcO(3+3c)/2, wherein x and y denote moles , and x, y, z, a, b, c, and α (wherein α=(1−y)x) satisfy the following relationships: 0.56≦x≦0.8, 0.08≦y≦0.18, 0.980≦z<1.000, α≦0.65, 0.985≦a≦1.05, 0.9≦b≦1.02, and 0.9≦c≦1.05.

Dependencies are inferred from the claim text.