High-quality-factor microwave dielectric ceramic Bi3Y2Ga3O12

Abstract

The invention discloses high-quality-factor temperature-stable ultralow-dielectric-constant microwave dielectric ceramic. The high-quality-factor temperature-stable ultralow-dielectric-constant microwave dielectric ceramic is characterized in that the chemical composition of the microwave dielectric ceramic is Bi3Y2Ga3O12. The preparation method of the microwave dielectric ceramic comprises the following steps: (1) weighing and batching original powder of Bi2O3, Y2O3 and Ga2O3 with purity being above 99.9 percent by weight according to the composition of Bi3Y2Ga3O12; (2) performing wet ball milling and mixing on the raw materials in the step (1) for 12 hours, and presintering for 6 hours under the air atmosphere of 1250 DEG C after drying, wherein the ball-milling medium is absolute ethanol; and (3) adding a binding agent into the powder prepared in the step (2), pelleting, performing compression molding, and sintering for 4 hours under the air atmosphere of 1300 to 1350 DEG C, wherein the binding agent adopts a polyvinyl alcohol solution with the mass concentration being 5 percent and the adding amount of polyvinyl alcohol accounts for 3 percent of the total mass of the powder. The ceramic prepared by the method is good in sintering, the dielectric constant is 13.4 to 14.3, the quality factor Qf value is up to 109000 to 158000 GHz, the resonant frequency temperature coefficient is small, and a high application value is achieved in industry.

Description

technical field [0001] The invention relates to a dielectric ceramic material, in particular to a dielectric ceramic material for manufacturing microwave components such as ceramic substrates, resonators and filters used in microwave frequencies and a preparation method thereof. Background technique [0002] Microwave dielectric ceramics refer to ceramics that are used as dielectric materials in circuits in the microwave frequency band (mainly UHF and SHF bands) and perform one or more functions. They are widely used as resonators, filters, and dielectric substrates in modern communications. Components such as chips and dielectric waveguide circuits are the key basic materials of modern communication technology. They have been used in portable mobile phones, car phones, cordless phones, TV satellite receivers and military radars. They are used in modern communication tools. It is playing an increasingly important role in the process of miniaturization and integration. [00...

AI Technical Summary

Problems solved by technology

[0008] Due to the three performance indicators of microwave dielectric ceramics (ε r with Q f and τ f ) is a mutual restrictive relationship (see literature: The restrictive relationship between the dielectric properties of microwave dielectric ceramic materials, Zhu Jianhua, Liang Fei, Wang Xiaohong, Lu Wenzhong, Electronic Components and Materials, Issue 3, March 2005), satisfying three There are very few single-phase microwave dielectric ceramics with individual performance requirements, mainly because their resonant frequency temperature coefficient is usually too large or the quality factor is too low to meet the practical application requirements.

At present, most of the research on microwave dielectric ceramics is a summary of experience obtained through a large number of experiments, but there is no complete theory to explain the relationship between microstructure and dielectric properties. Predict the microwave dielectric properties such as its resonant frequency temperature coefficient and quality factor, explore and develop near-zero resonant frequency temperature coefficient (-10ppm / ℃≤τ f ≤+10ppm / °C) and a series of different dielectric constant microwave dielectric ceramics with higher quality factors are difficult problems that those skilled in the art have been eager to solve but have always been difficult to achieve, which largely limits the use of microwave dielectric ceramics and device development

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