| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide dielectric ceramics which can be inexpensively produced, have a relative permittivity of 38 to 44 excluding rare earths in raw material, have high Qf value in dielectric characteristics, have small temperature coefficient τf of resonant frequency in a wide-range temperature region, and have small difference (Δτf) of temperature coefficients τf of resonant frequencies in a low temperature area (-40 to 25°C) and a high temperature area (25 to 85°C); and to provide a dielectric filter comprising the ceramic. <P>SOLUTION: In the dielectric ceramic, when representing a composition formula to be αZrO<SB POS="POST">2</SB>βTiO<SB POS="POST">2</SB>γMgOδNb<SB POS="POST">2</SB>O<SB POS="POST">5</SB>, the molar ratios α, β, γ and δ satisfy 0.3200≤α≤0.5700, 0.2800≤β≤0.5300, 0.0101≤γ≤0.0774, 0.0199≤δ≤0.1526, respectively, and satisfy α+β+γ+δ=1, and 0.5<γ/δ≤1. The ceramic includes Ca of >0.01 mass% but ≤0.3 mass% in terms of CaO based on 100 mass% of the composition. <P>COPYRIGHT: (C)2013,JPO&INPIT |
