Abstract: A ceramic material suitable for use as a microwave band filter for telecommunications equipment comprises oxides of titanium, barium, neodymium, samarium, and optionally, bismuth, and containing, on an elemental weight basis: about 28 to about 31 weight % titanium, about 19 to about 21 weight % barium, about 11 to about 18 weight % samarium, about 7 to about 13 weight % neodymium, up to about 3 weight % of bismuth, and the remainder substantially being oxygen. The ceramic compositions have a resonant frequency, f, in the range of about 2000 MHz to about 2300 MHz, a quality factor, Q, of at least about 4000, a dielectric constant, K, in the range of about 50 to about 70, and a temperature coefficient of resonant frequency, Tf, in the range of about 0 ppm to about +20 ppm. Calcined metal oxide powders useful for preparing the microwave ceramic materials, a method of making the ceramic materials, and devices containing the ceramic materials are also described.

Abstract: A ceramic material suitable for use as a microwave band filter for telecommunications equipment comprises oxides of titanium, barium, neodymium, samarium, and optionally, bismuth, and containing, on an elemental weight basis: about 28 to about 31 weight % titanium, about 19 to about 21 weight % barium, about 11 to about 18 weight % samarium, about 7 to about 13 weight % neodymium, up to about 3 weight % of bismuth, and the remainder substantially being oxygen. The ceramic compositions have a resonant frequency, f, in the range of about 2000 MHz to about 2300 MHz, a quality factor, Q, of at least about 4000, a dielectric constant, K, in the range of about 50 to about 70, and a temperature coefficient of resonant frequency, Tf, in the range of about 0 ppm to about +20 ppm. Calcined metal oxide powders useful for preparing the microwave ceramic materials, a method of making the ceramic materials, and devices containing the ceramic materials are also described.

Abstract: The present invention provides a dielectric ceramic composition comprising a base material represented by the general formula: (x) Al2O3+(y) TiO2, where x and y are percentages of the total weight of the base material, with x being in the range of about 60 to about 96 and y being in the range of about 4 to about 40. Also provided is a first additive material comprising Nb2O5 and a second additive material comprising BaZrO3. In another embodiment the present invention provides a sintered dielectric ceramic composition comprising a base material represented by the general formula: (x) Al2O3+(y) TiO2, where x and y are percentages of the total weight of the base material, with x being in the range of about 60 to about 96 and y being in the range of about 4 to about 40. Also provided is a first additive material comprising Nb2O5 and a second additive material comprising BaZrO3.

Abstract: The present invention provides a dielectric ceramic composition comprising a base material represented by the general formula: (x) Al2O3+(y) TiO2, where x and y are percentages of the total weight of the base material, with x being in the range of about 60 to about 96 and y being in the range of about 4 to about 40. Also provided is a first additive material comprising Nb2O5 and a second additive material comprising BaZrO3. In another embodiment the present invention provides a sintered dielectric ceramic composition comprising a base material represented by the general formula: (x) Al2O3+(y) TiO2, where x and y are percentages of the total weight of the base material, with x being in the range of about 60 to about 96 and y being in the range of about 4 to about 40. Also provided is a first additive material comprising Nb2O5 and a second additive material comprising BaZrO3.