44results about How to "High quality factor Qf" patented technology

The invention discloses a microwave dielectric ceramic material for a multi-layer ceramic capacitor and a preparing method of the microwave dielectric ceramic material, and belongs to the technical field of electronic ceramic. The ceramic material is prepared from calcium-doped (MgZn)TiO3 system ceramic and a composite burning improver through ball milling mixing, granulating, forming, glue discharging and sintering, wherein the main crystal phase of the calcium-doped (MgZn)TiO3 system ceramic is MgTiO3, and the composite burning improver is prepared from BaCO3, B2O3, SiO2 and one or more of Li2CO3, Nb2O5 and Nd2O3. The prepared ceramic material has the advantages that a medium dielectric constant is achieved, sintering can be carried out at the medium temperature, a high Qf value is achieved, and the frequency temperature coefficient is stable. The preparing process is environmentally friendly and free of pollution, and the ceramic material can be used at the microwave frequency band of 300 M-300 GHz, can be widely applied to filters, oscillators and other microwave devices, and is especially suitable for the multi-layer ceramic capacitor.

The invention discloses a low-temperature sintering temperature-stable microwave dielectric ceramic ZnY3VO8 with an ultralow dielectric constant and a preparation method of the microwave dielectric ceramic ZnY3VO8. The preparation method comprises the following steps of (1) weighing initial powder of ZnO, Y2O3 and V2O5 according to the composition of ZnY3VO8, and proportioning, wherein the purities of ZnO, Y2O3 and V2O5 are larger than 99.9wt%; (2) carrying out wet-type ball milling on the raw materials in the step (1) by virtue of distilled water serving as a ball milling medium, mixing for 12 hours, and presintering in an atmospheric environment with the temperature of 900 DEG C for 6 hours after drying; and (3) adding an adhesive in the powder prepared in the step (2), granulating, then, carrying out compression molding, and finally, sintering in an atmospheric environment with the temperature of 950-990 DEG C for 4 hours, wherein the adhesive is a polyvinyl alcohol solution with the mass concentration of 5%, and the additive amount of polyvinyl alcohol accounts for 3% of the total mass of the powder. The ceramic prepared by using the preparation method can be favorably sintered at the temperature of 950-990 DEG C, has the dielectric constant of 7.3-7.9 and is high in quality factor Qf value up to 73000-96000GHz and small in temperature coefficient of resonance frequency so as to have an extremely high application value in industry.

The invention discloses a low dielectric constant microwave dielectric ceramic NaBi2Sb3O11 capable of being sintered at low temperatures and a preparation method of the ceramic. The preparation method comprises the following steps: (1) weighing and dosing original powder of Na2CO3, Bi2O3 and Sb2O5 with the purities which are over (99.9wt%) based on composition of NaBi2Sb3O11; (2) carrying out wet type ball-mill mixing on the raw material for 12 hours, wherein the ball-milling medium is distilled water, and pre-sintering for 6 hours in atmosphere at 850 DEG C after being dried; and (3) adding an adhesive into the power prepared by the step (2) and granulating, then compression-moulding, and finally sintering for 4 hours in atmosphere at 900-930 DEG C, wherein the adhesive is a 5% polyvinyl alcohol solution, the addition of polyvinyl alcohol accounts for 3% of total weight of the powder. The ceramic disclosed by the invention is well sintered at 900-930 DEG C, and the dielectric constant reaches 28.4-29.3, the quality factor Qf value reaches 59600-64200GHz, and the temperature coefficient of resonance frequency is small, so that the ceramic has extremely huge application value in industry.

The invention discloses an application of a phosphor-containing compound Li4P2O7 serving as a low-temperature sintering available microwave dielectric ceramic. The microwave dielectric ceramic is prepared by the following steps: (1) preparing original powders of 99.9% Li2CO3 and 99.9% NH4H2PO4 according to the chemical formula of Li4P2O7; (2) mixing the raw material in the step (1) and carrying out wet ball milling for 12 hours, baking, and then pre-sintering for 6 hours in the atmosphere at 820 DEG C, wherein the ball milling medium is ethanol; and (3) adding adhesive into the powder prepared in the step (2), granulating, pressing to mold, and finally sintering for 4 hours in the atmosphere at 880-900 DEG C, wherein the adhesive is a 5% polyvinyl alcohol solution, and accounts for 3 percent of the total mass of the powder. The ceramic prepared by the method can be excellently sintered at 880-900 DEGC, the dielectric constant is 13-14, the quality factor Qf value is up to 67,000-79,000GHz; the temperature coefficient of resonance frequency is small, and the microwave dielectric ceramic has a great application value in industry.

The invention discloses a low-dielectric-constant microwave dielectric ceramic Ag3LiTi2O6 which can be subjected to low temperature sintering and has a near-zero resonance frequency temperature coefficient and a preparation method thereof. The preparation method comprises the following steps: weighing and batching original powder of AgNO3, Li2CO3 and TiO2 of which the purity is more than 99.9% (in percentage by weight) according to the composition of Ag3LiTi2O6; (2) performing wet ball milling and mixing on raw materials in the step (1) for 12 hours by using distilled water as a ball milling medium, drying, and then pre-sintering for 6 hours in an atmosphere at 800 DEG C; and (3) adding a binding agent into powder prepared in the step (2) and pelletizing, then performing compression molding, and finally sintering for 4 hours in the atmosphere at 850-880 DEG C, wherein the binding agent adopts a polyvinyl alcohol solution with the mass concentration of 5%, and the addition amount of polyvinyl alcohol accounts for 3% of the total mass of the powder. The ceramic prepared by using the method disclosed by the invention is good in sintering performance at 850-880 DEG C, ensures that the dielectric constant reaches 28.7-29.4, the quality factor (Qf) value reaches 53000-57000GHz, and the temperature coefficient of resonance frequency is close to zero, and has extremely large application values in industry.

The invention discloses temperature stable ultra-low dielectric constant microwave dielectric ceramic BaBi2W6O22 which can be sintered at low temperature and a preparation method thereof. The method comprises the following steps: (1) weighing the following original powder with purity of over 99.9wt%: BaCO3, Bi2O3 and WO3 according to the composition of BaBi2W6O22; (2) mixing the raw materials in the step (1) by wet grinding for 12 hours by adopting distilled water as the grinding medium, baking, and pre-burning in the atmosphere at 700 DEG C for 6 hours; (3) adding a binder into the powder prepared in the step (2), granulating, pressing and forming, and sintering in the atmosphere at 750-780 DEG C for 4 hours, wherein the binder is prepared from polyvinyl alcohol solution with mass concentration of 5 percent, and the additive amount of polyvinyl alcohol is 3 percent of the total mass of the powder. The ceramic prepared by the method is well sintered at 750-780 DEG C, has the dielectric constant being 17.8-18.4 and the quality factor Qf value being up to 55000-67000GHz, has a small temperature coefficient of resonance frequency, and has a great application value in the industry.

The invention discloses temperature-stable type ultralow-loss microwave dielectric ceramic Li3V2B3O11 and a preparation method thereof. The preparation method comprises steps as follows: (1), raw material powder of Li2CO3, V2O5 and H3BO3 with the purity of higher than 99.9% in percentage by weight is weighed and proportioned according to composition of Li3V2B3O11; (2), the raw material powder of the step (1) is subjected to wet type ball milling and mixing for 12 h, the ball milling medium adopts absolute ethyl alcohol, and the raw material powder is dried and pre-sintered in the air atmosphere at the temperature of 700 DEG C for 6 h; and (3), after a binding agent is added to the powder prepared in the step (2) and granulation is performed, the powder is subjected to compression forming and sintered in the air atmosphere at the temperature of 750-800 DEG C for 4 h finally, the binding agent adopts a polyvinyl alcohol solution with the mass concentration of 5%, and the adding amount of polyvinyl alcohol accounts for 3% of the total mass of the powder. The prepared ceramic is sintered well, the dielectric constant reaches 7.5-7.9, the qualify factor (Qf) value is up to 191,000-247,000 GHz, the temperature coefficient of resonance frequency is small, and the prepared ceramic has great industrial application value.

The invention discloses a microwave dielectric ceramic K2SnW4O15 with an ultralow dielectric constant and a near-zero resonance frequency temperature coefficient and a preparation method of the microwave dielectric ceramic. The preparation method comprises the following steps: (1) weighing and burdening original powder of K2CO3, SnO2 and WO3 with the purity more than 99.9% (in percentage by weight) according to constituents of K2SnW4O15; (2) using a wet ball mill to mix the raw materials in the step (1) for 12 hours, adding distilled water as a ball milling medium in the ball mill, after drying, preburning the dried substance in the atmosphere at 750 DEG C for 6 hous; (3) adding a binding agent to the powder prepared in the step (2), pelletizing, carrying out compression molding on the pellets, and finally sintering the molded product for 4 hours in the atmosphere at 820-840 DEG C, wherein the binding agent is a polyvinyl alcohol solution with a mass concentration of 5%; the addition amount of the polyvinyl alcohol is 3% of the total mass of the powder. The ceramic prepared by the invention is well sintered at 820-840 DEG C; the dielectric constant of the ceramic is up to 7.4-8.2, the Qf (quality factor) is highly up to 57100-59600 GHz; the resonance frequency temperature coefficient is close to zero; the ceramic has the great application value in the industry.