Microwave medium ceramic with low dielectric constant and low loss and preparation method thereof

Abstract

The invention discloses a microwave medium ceramic with a low dielectric constant and a low loss and a preparation method thereof and belongs to the technical field of a microwave medium ceramic material. The microwave medium ceramic has the characteristics of low dielectric constant, low loss, high temperature stability, continuously adjustable dielectric constant and high machining property. The composition of the microwave medium ceramic is expressed by a general formula: (Zn1-xLi2x)O.ySiO2+a weight percent of TiO2, wherein x is more than or equal to 0 and less than or equal to 1; y is more than or equal to 0.5 and less than or equal to 1; a is more than or equal to 0 and less than or equal to 20; and a is mass percentage in (Zn1-xLi2x)O.ySiO2. The microwave medium ceramic is prepared by the following steps of: 1) confecting zinc oxide, lithium carbonate and silicon dioxide according to the general formula (Zn1-xLi2x)O.ySiO2+a weight percent of TiO2, mixing and pre-burning the mixture to synthesize a main component and crushing the main component into powder; 2) putting powdery TiO2 into the main component and mixing to obtain a powdery mixture; and 3) blanking and sintering the powdery mixture. A specific tau f modifier TiO2 is selected, so the material has a dielectric constant of between 7 and 9, a high quality factor value of Q*f0 and adjustable frequency temperature coefficient tau f. Simultaneously, the material has the advantages of simple preparation process, no special requirement on equipment and workshop environment and contribution to batch production, application and popularization.

Description

technical field [0001] The invention belongs to the technical field of microwave dielectric ceramic materials, and in particular relates to ceramic materials used for microwave components such as dielectric antennas and dielectric substrates in communication systems and a preparation method thereof. Background technique [0002] In recent years, low dielectric constant microwave dielectric ceramic materials have been widely used in civil and military applications because they can be used to make dielectric antennas, dielectric substrates and other key components in microwave communication systems and microwave circuits. The requirements of these applications for low dielectric constant microwave dielectric ceramic materials are: (1) a certain dielectric constant (Er); (2) low loss (ie high quality factor or Q*f0 (GHz) value); (3 ) The resonant frequency temperature coefficient (τf) tends to zero, which is used to ensure that the device has good stability when the temperature...

AI Technical Summary

Problems solved by technology

These requirements greatly limit the application of most ceramic materials in practical devices

Although a variety of low dielectric constant microwave dielectric ceramic materials have been developed, for a certain microwave dielectric ceramic material, when the resonant frequency tends to zero, its dielectric constant is generally a certain value. When the dielectric constant needs to be changed, it is often necessary to reselect the material series

Moreover, in general, the dielectric antenna and the dielectric substrate are required to have coupling holes. The traditional method of producing holes through a mold is not only complicated to make the mold, but also has low yield and production efficiency in the production process of the dielectric antenna and the dielectric substrate, which is not conducive to Mass production