High-Q-value lithium-based microwave medium material prepared through Mg/Nb-codoping

Abstract

The invention discloses a high-Q-value lithium-based microwave medium material prepared through Mg/Nb-codoping. A chemical formula of the material is Li<2>Ti<1-x>(Mg<1/3>Nb<2/3>)xO3, x = 0.05-0.4. The preparation method includes the steps of: 1) dosing Li2CO3, TiO2, MgO and Nb2O5 according to the stoichiometric equation, ball-milling and drying the mixture, and pre-sintering the mixture at 700-900 DEG C; 2) adding 0.7 wt% of a PVA powder, mixing and granulating the mixture, and pressing the mixture powder into a green body through a powder tablet machine; and 3) sintering the green body at 1200-1300 DEG C to obtain the high-Q-value lithium-based microwave medium material with Mg/Nb-codoping. Under microwave frequency band, the product reaches 94,010-115,424 GHz in Qf value and has low dielectric consumption. The preparation method is simple and is free of a high oxygen pressure atmosphere during sintering. The product has controllable dielectric constant (16.12-21.92) and temperature coefficient of resonance frequency (-36.61 to +7.96 ppm/DEG C), so that a microwave filter produced therefrom has great application prospect.

Description

technical field [0001] The invention belongs to a ceramic composition characterized by components, in particular to a high-Q lithium-based microwave dielectric material and a preparation method thereof. Background technique [0002] As a key device in microwave circuits, microwave filters can effectively filter signals of specific frequencies, and are widely used in systems such as microwave communications, radar navigation, electronic countermeasures, satellite relays, missile guidance, and test instruments. With the vigorous development of information technology and wireless communication systems, high-quality microwave filters must have good frequency selection characteristics and bandwidth, while developing towards miniaturization and low cost. [0003] The microwave filter made of high-Q microwave dielectric material can effectively reduce the insertion loss of the device, improve the corresponding jitter and frequency band utilization of the passband edge signal freque...

AI Technical Summary

Problems solved by technology

Among them, lithium-based Li with a rock-salt structure 2 TiO 3 Microwave dielectric materials have excellent microwave dielectric properties in the millimeter wave band (ε r ~22.14, Qf~63,525GHz, τ f ~+20.3ppm / ℃), the raw materials are relatively cheap, and the preparation process is simple and easy, but it is prone to cleavage on the (002) surface, and there are microcracks on the surface, resulting in low bulk density. The relative oxygen partial pressure decreases, some Ti 4+ is reduced to Ti 3+ , accompanied by the generation of free electrons, the above situation seriously affects the Li 2 TiO 3 Qf value

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