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CN-122010543-A - Ultra-high performance ceramic material suitable for millimeter wave communication and preparation method thereof

CN122010543ACN 122010543 ACN122010543 ACN 122010543ACN-122010543-A

Abstract

An ultra-high performance ceramic material suitable for millimeter wave communication and a preparation method thereof. The chemical formula of the microwave dielectric ceramic is Mg 2‑x Ga 0.5x Li 0.5x SiO 4 , wherein x is more than 0 and less than or equal to 0.06. The ceramic is prepared from MgO, ga 2 O 3 、Li 2 O and SiO 2 serving as raw materials through pretreatment of the raw materials, primary ball milling, presintering, secondary ball milling, granulating, pressing, glue discharging and sintering. The material provided by the invention can be suitable for high-frequency millimeter wave dielectric resonance antennas, dielectric resonators, filters and other low-dielectric-loss wireless communication devices, and provides a ceramic material with reliable performance for the field of high-frequency millimeter wave communication.

Inventors

  • MAO MINMIN
  • She Yuxuan
  • SONG KAIXIN

Assignees

  • 杭州电子科技大学

Dates

Publication Date
20260512
Application Date
20260414

Claims (10)

  1. 1. The microwave dielectric ceramic material suitable for millimeter wave communication is characterized in that the chemical formula of the microwave dielectric ceramic material is Mg 2-x Ga 0.5x Li 0.5x SiO 4 , wherein x is more than 0 and less than or equal to 0.06, and the Ga and Li elements are used for cooperatively replacing Mg ion sites of forsterite in a molar ratio of 1:1 and in ion forms with different valences.
  2. 2. The microwave dielectric ceramic material suitable for millimeter wave communication according to claim 1, wherein the chemical formula of the microwave dielectric ceramic material is Mg 2-x Ga 0.5x Li 0.5x SiO 4 , wherein x is 0< 0.04 or less.
  3. 3. The microwave dielectric ceramic material according to claim 2, wherein the dielectric constant of the microwave dielectric ceramic material is 6.8-7.0, the qf value is 204000~238600 GHz @12.8 GHz, and the temperature coefficient of resonance frequency is-48 to-42 ppm/°.
  4. 4. The microwave dielectric ceramic material according to claim 2, wherein the microwave dielectric ceramic material has a microwave dielectric property Qf value of 221000~295000 GHz at a millimeter wave frequency band of 24-25 GHz, a dielectric constant of 6.7-7.0, and a resonant frequency temperature coefficient of-48 to-42 ppm/°c.
  5. 5. A method of preparing a microwave dielectric ceramic material according to any one of claims 1 to 4, comprising the steps of: (1) MgO, ga 2 O 3 、Li 2 O and SiO 2 are taken as raw materials, and the raw materials are weighed and mixed according to the stoichiometric ratio of Mg, ga, li and Si in a target chemical formula Mg 2-x Ga 0.5x Li 0.5x SiO 4 to obtain a mixed raw material; (2) Performing first ball milling, drying and presintering on the mixed raw materials obtained in the step (1) to obtain presintering powder; (3) Performing secondary ball milling, drying, grinding and sieving on the presintered powder, adding a binder, granulating, sieving and press forming to obtain a green body; (4) And (3) discharging glue and sintering the green body obtained in the step (3) to obtain the microwave dielectric ceramic material.
  6. 6. The method according to claim 5, further comprising the following pretreatment steps before the weighing in step (1): For other raw materials except MgO, the raw materials are used after being dried at 85 ℃; For MgO, use after calcination at 1100 ℃ for 3 h; the ball milling in the step (2) and the step (3) adopts ethanol as a medium and zirconium balls as a ball milling medium, the ball milling time is 24 h, and the ball milling speed is 240 r/min.
  7. 7. The preparation method of the high-strength plastic composite material is characterized in that the presintering temperature is 1100-1150 ℃ and the heat preservation time is 3h, 10 wt% polyvinyl alcohol aqueous solution is adopted as a binder for granulation, and the granules are sieved by a 100-mesh sieve and then a 60-mesh sieve.
  8. 8. The preparation method of the plastic film according to claim 5, wherein the molding pressure is 40-100 MPa, and the plastic film discharging specifically comprises heating to 650 ℃ at 2 ℃ per minute and preserving heat for 3 h.
  9. 9. The method according to claim 5, wherein the sintering comprises heating to 1350-1550 ℃ at 4 ℃ per min, maintaining the temperature at 3h, cooling to 800 ℃ at 2 ℃ per min, and cooling in a furnace.
  10. 10. Use of a microwave dielectric ceramic material according to any one of claims 1 to 4 for the manufacture of a millimeter wave dielectric resonator antenna, a dielectric resonator, a filter or a low dielectric loss wireless communication device.

Description

Ultra-high performance ceramic material suitable for millimeter wave communication and preparation method thereof Technical Field The invention belongs to the technical field of microwave dielectric ceramic materials, and particularly relates to Mg 2-xGa0.5xLi0.5xSiO4 microwave dielectric ceramic for 5G/6G high-frequency millimeter wave communication and a preparation method thereof. Background With the development of 5G/6G communication, vehicle millimeter wave radar, satellite communication and high-frequency passive devices, the millimeter wave frequency band has higher requirements on dielectric materials. The material not only needs to have low dielectric constant to reduce transmission delay and device parasitic effect, but also needs to have ultralow dielectric loss and near zero resonant frequency temperature coefficient to ensure the frequency stability of the device in complex temperature environment. Forsterite (Mg 2SiO 4) is a typical low-dielectric-constant microwave dielectric ceramic, has the advantages of low dielectric constant, low loss, low raw material cost and the like, and is an important candidate material for communication devices such as millimeter wave dielectric resonators, antennas and the like. However, the system has two long-term bottlenecks, namely one that the high sintering temperature exceeding 1500 ℃ is usually required for complete densification, and the other two that the temperature coefficient of the resonance frequency is usually a large negative value, so that the requirement of engineering application on temperature stability is difficult to directly meet. Disclosure of Invention Aiming at the bottleneck in the prior art, the invention provides a preparation method of Mg 2-xGa0.5xLi0.5xSiO4 microwave dielectric ceramic, which realizes the reduction of densification temperature of ceramic and the balanced improvement of microwave dielectric property by introducing aliovalent ions into Mg to replace the aliovalent ions, and can be applied to improving the service stability and environmental adaptability of millimeter wave dielectric resonant antennas, dielectric resonators, filters or low dielectric loss wireless communication devices. The technical scheme of the invention is as follows: The chemical formula of the microwave dielectric ceramic material is Mg 2-xGa0.5xLi0.5xSiO4, and the Ga and Li elements are synergistically substituted for Mg ion sites of forsterite in a molar ratio of 1:1 and ion forms with different valence, wherein x is more than 0 and less than or equal to 0.06, and preferably more than 0 and less than or equal to 0.04. The preparation method comprises the following steps: (1) MgO, ga 2O3、Li2 O and SiO 2 are taken as raw materials, and the raw materials are weighed and mixed according to the stoichiometric ratio of Mg, ga, li and Si in a target chemical formula Mg 2-xGa0.5xLi0.5xSiO4; (2) Performing first ball milling, drying and presintering on the mixed raw materials obtained in the step (1) to obtain presintering powder; (3) Performing secondary ball milling, drying, grinding and sieving on the presintered powder, adding a binder, granulating, sieving and press forming to obtain a green body; (4) And (3) discharging glue and sintering the green body obtained in the step (3) to obtain the microwave dielectric ceramic material. As a preferable scheme, the presintering temperature in the step (2) is 1100-1150 ℃, so that the influence of higher presintering temperature on the performance of the final ceramic is avoided. Preferably, the doping amount x of the Ga 3+/Li+ is 0.04, and the ceramic obtains the optimal microwave dielectric property under the condition. Preferably, the dielectric constant of the microwave dielectric ceramic material is 6.8-7.0, the qf value is 204000~238600 GHz@12.8 GHz, and the temperature coefficient of the resonant frequency is-48 to-42 ppm/°c. The invention also provides application of the microwave dielectric ceramic material in preparing millimeter wave dielectric resonance antennas, dielectric resonators, filters or low dielectric loss wireless communication devices. Compared with the prior art, the invention has the following beneficial effects: (1) The Ga 3+/Li+ synergistic valence substitution is beneficial to forming stable Mg 2SiO4 single-phase solid solution; (2) This substitution strategy may advance the optimal densification temperature of the material from about 1500 ℃ to about 1400 ℃; (3) While maintaining a low dielectric constant, qf can be significantly increased and τ f can be improved, wherein the x=0.04 component exhibits the best overall performance and extremely excellent low loss characteristics at the 24-25 GHz millimeter wave frequency band. Research has shown that in the field of microwave dielectric ceramics, a simple and stable corresponding relation is difficult to form among densification temperature, qf value and resonance frequency temperature coefficient tau f, and simultaneous optimiz