51 results about "Microwave dielectric properties" patented technology

The invention relates to the technical field of recycled asphalt mixture recovery, in particular to a mixing uniformity monitoring method adaptive to a recycled asphalt mixture, which comprises the following steps: S101, performing time-space fusion on infrared thermal radiation field dynamic capture and microwave dielectric property synchronous monitoring bimodal sensing to jointly perform mixing defect alarm; s102, based on the dynamic sequence of the infrared thermal radiation field, judging the particle motion consistency through the standard deviation of the motion direction angle, integrating the infrared temperature field and microwave dielectric data, constructing a three-dimensional feature vector, comprehensively evaluating the uniformity through a weighting function, judging defects according to the maximum contribution term, and generating an optimization instruction; and S103, setting a grading standard based on the multi-modal features, and feeding back and adjusting the process according to a grading result. According to the invention, infrared thermal radiation and microwave dielectric characteristics are combined, temperature uniformity and material component distribution are evaluated synchronously, and the problem of monitoring that the thermal uniformity of the recycled asphalt is not equal to the component uniformity is solved.

The invention discloses a low-loss temperature-stable type celsian-based microwave dielectric ceramic material and a preparation method thereof. The low-loss temperature-stable type celsian-based microwave dielectric ceramic material is prepared by sintering the following raw materials in parts by weight: 265 to 272 parts of graphite tailings, 160 to 165 parts of BaCO3, 104 to 112 parts of Al2O3, 5 to 8 parts of TiO2 and 1 to 2 parts of CuO. The preparation method comprises the following steps: crushing, grinding, sieving, calcining and cooling the graphite tailings to obtain graphite tailing powder; weighing the raw materials, and ball-milling and mixing; drying, calcining and cooling along with a furnace; carrying out secondary ball milling and drying; sintering after preparing a blank. According to the invention, in-situ synthesis of a CaTiO3 performance enhanced phase is realized, the temperature excursion characteristic of the celsian-based ceramic material is improved, the temperature coefficient of resonance frequency can be controlled within + / -2ppm / DEG C, and the microwave dielectric property of the ceramic material is comprehensively improved, so that the ceramic material meets the application requirements of millimeter wave communication devices.

The invention discloses a multi-mineral microwave dielectric ceramic material and a preparation method thereof, and the multi-mineral microwave dielectric ceramic material is prepared by sintering the following raw materials in parts by weight: 192-224 parts of black talc, 160-192 parts of wollastonite, 8-12 parts of MgO, 4-8 parts of SnO2 and 2-4 parts of kaolin tailings. The preparation method comprises the following steps: crushing, grinding and sieving to obtain black talc mineral powder, wollastonite mineral powder and kaolin tailing powder; the preparation method comprises the following steps: weighing black talc mineral powder and MgO powder, and carrying out ball milling and mixing; wollastonite mineral powder is added, and ball milling continues; drying, calcining, preserving heat and cooling along with a furnace; carrying out ball milling on the obtained powder and SnO2 powder and kaolin tailing powder which are weighed in proportion, uniformly mixing, and drying; and preparing the powder into a blank and sintering. The microwave dielectric property of the ceramic material is improved, the kaolin tailing powder is selected as the sintering aid, and the sintering temperature is reduced on the premise that the dielectric property of the ceramic is not reduced.

The invention provides olivine type lithium-containing silicon-based compact ceramic and a preparation method thereof. The chemical general formula of the lithium-containing silicon-based compact ceramic is LiIn1-xMxSiO4 (x is greater than or equal to 0.35 and less than or equal to 0.8), M must contain a Yb element and also comprises at least one element of Zn, Ni, Ga, Y, Eu, Ho, Er and Tm, and the sum of lower corner marks of the elements in M is equal to the value of x. According to the method, a traditional solid-phase reaction sintering method is adopted, the process is simple, and the olivine type lithium-containing silicon-based compact ceramic with excellent comprehensive microwave dielectric properties can be obtained under the condition of not additionally adding a sintering aid or carrying out hot pressing sintering.

The invention belongs to the field of microwave dielectric ceramic materials, and particularly provides a method for improving the performance of zinc aluminate microwave ceramic based on an LBSCA (Li2O-B2O3-SiO2-CaO-Al2O3) composite sintering aid, so that the prepared zinc aluminate microwave dielectric ceramic material has a low dielectric constant and a high thermal expansion coefficient, and is suitable for manufacturing a ceramic substrate with excellent performance. According to the invention, a Zn < 0.90 > Co < 0.10 > Al < 2 > O < 4 > system is adopted, an LBSCA (Li2O-B2O3-SiO2-CaO-Al2O3) composite sintering aid is introduced, and sintering and dielectric properties are optimized through a plurality of mechanisms. The doping of the LBSCA glass has obvious influence on the microstructure and density of the ceramic, and the microwave dielectric property of the ceramic is further improved. According to the invention, when the sintering temperature is 1175 DEG C and x is equal to 1.5 wt%, the optimal performance is as follows: epsilon r is equal to 5.25, Q * f is equal to 7334 GHz, and tauf is equal to-25.18 ppm / DEG C; the CTE value is the maximum value of 11.18 ppm / DEG C.

This invention discloses a low-loss, temperature-stable microwave dielectric ceramic and its dielectric resonant antenna, belonging to the field of microwave dielectric ceramic technology. Addressing the technical problem that existing rock-salt structure microwave dielectric ceramics struggle to simultaneously achieve a near-zero resonant frequency temperature coefficient and a high quality factor, this invention provides a material with the chemical formula (1-x)Li. 2.5 Mg 2.5 Ti 0.5 Nb 0.5 O 12 A ceramic material of -xLi₂TiO₃, where 0.2 ≤ x ≤ 0.85, was prepared by a solid-state reaction method. Based on a two-phase composite strategy, its microwave dielectric properties were optimized through the dual synergistic regulation of composition and crystal structure. The ceramic exhibited optimal overall performance at a sintering temperature of 1320 °C and x = 0.8. r =17.07, Q×f=76,546 GHz, τ f =-8.3 ppm / °C, possessing both near-zero temperature coefficient and low dielectric loss characteristics. The dielectric resonator antenna made from this ceramic exhibits high gain, high efficiency, and excellent radiation performance at 5.72 GHz (C-band), and can be widely used in C-band and 5G / 6G wireless communication devices.

The present application belongs to the field of ceramic technology, and in particular relates to a microwave dielectric ceramic material, a preparation method thereof, and an application thereof. The microwave dielectric ceramic material comprises a ceramic solid solution having a chemical formula of xAMoO4‑yLi2MoO4; wherein the A position comprises at least five transition metal elements, the total molar content of the transition metal elements is 100%, 0<x<1, 0<y<1, and x+y=1. Through the combined action of the components in the ceramic solid solution, the sintering temperature of the microwave dielectric ceramic material is reduced to below 700°C, and the material has microwave dielectric properties such as a higher relative dielectric constant and quality factor, and a lower temperature drift coefficient, thereby improving the transmission efficiency of microwave communications, reducing signal loss, and reducing interference. The material can more effectively store and release energy, and the ceramic material is less affected by temperature changes, thereby improving the stability of microwave dielectric properties and service life.

The application discloses a kind of multi-element mineral microwave dielectric ceramic materials and preparation method thereof, multi-element mineral microwave dielectric ceramic materials, by the following weight fraction raw materials sintering is obtained: 192~224 parts black talc, 160~192 parts wollastonite, 8~12 parts MgO, 4~8 parts SnO2, 2~4 parts kaolin tailings.Preparation method includes the following steps: broken fine sieving, obtain black talc powder, wollastonite powder and kaolin tailings powder;Take black talc powder and MgO powder, ball milling is mixed;Add wollastonite powder, continue ball milling;Drying, calcination, heat preservation, with furnace cooling;The obtained powder and proportionally weighed SnO2 powder, kaolin tailings powder, ball milling is uniformly mixed, drying;After powder preparation blank, sintering.The application improves the microwave dielectric properties of ceramic material, selects kaolin tailings powder as sintering additive, reduces sintering temperature under the premise of not reducing ceramic dielectric properties.

A CaO-B2O3-SiO2-CaF2 glass-ceramic and its preparation method and application belong to the technical field of chip-type and integrated passive components. The present invention provides a CaO-B2O3-SiO2-CaF2 glass-ceramic comprising the following components in molar percentage: CaO 40-50mol%, B2O3 3-18mol%, SiO2 35-45mol%, and CaF2 5-18mol%. The particle size D of the CaO-B2O3-SiO2-CaF2 glass-ceramic is 200-3000 nm. 50 The nanostructured CaO-B2O3-SiO2-CaF2 glass-ceramics has a low softening point, a wide sintering window, a high degree of densification, and excellent microwave dielectric properties, and is even better compatible with co-firing electrodes.

The application relates to the field of electronic information functional ceramics and electronic devices, and discloses a kind of ultra-low dielectric constant microwave dielectric ceramic and preparation method thereof, the composition expression of the ultra-low dielectric constant microwave dielectric ceramic is: xMg2SiO4-(1-x)LiAl 0.925 B 0.075 O2+ywt.%MO, MO is sintering aid, wherein: 0.2<=x<=0.4, 0.5<=y<=1, the sintering temperature of the ultra-low dielectric constant microwave dielectric ceramic is 1000~1100 DEG C, the dielectric constant of the microwave dielectric ceramic prepared by the application can reach 4.9~5.8, Qxf value can reach 51539~60754 GHz, frequency temperature coefficient Tf can reach-16.2~-11.3ppm / DEG C, the ultra-low dielectric constant microwave dielectric ceramic can be prepared at lower sintering temperature, meanwhile Qxf value is high, better microwave dielectric performance can be obtained, and the resonant frequency temperature coefficient is low, and temperature stability is good.

The invention belongs to the field of microwave dielectric ceramic materials, and particularly discloses low-temperature low-dielectric-loss microwave dielectric ceramic CoTeMoO6 and a preparation method thereof.On the basis of a traditional solid phase method, ultralow-loss CoTeMoO6 ceramic is synthesized under the condition of ultralow-temperature sintering (only 500-620 DEG C), so that energy consumption is greatly reduced, and the cost is reduced; the overall period of the material from preparation to finished product is obviously shortened; due to the adoption of the low-temperature sintering technology, the whole production process becomes more efficient and faster, the production period is short, the production efficiency is improved, and the production cost is reduced; the prepared CoTeMoO6 ceramic has good microwave dielectric properties, the dielectric constant epsilon r is equal to 11.36-13.88, the product Q * f of the quality factor and the frequency is equal to 6849-44110 GHz, the temperature coefficient tauf is equal to-90.8-72.4 ppm / DEG C, and the characteristics provide possibility for application of the CoTeMoO6 ceramic in microwave devices.

The present invention discloses a low-loss temperature-stable celsian-based microwave dielectric ceramic material and a preparation method thereof. The low-loss temperature-stable celsian-based microwave dielectric ceramic material is sintered from raw materials in the following weight parts: 265-272 parts of graphite tailings, 160-165 parts of BaCO3, 104-112 parts of Al2O3, 5-8 parts of TiO2, and 1-2 parts of CuO. The preparation method includes the following steps: crushing, grinding, and sieving the graphite tailings, calcining and cooling to obtain graphite tailings powder; weighing the raw materials, ball-milling and mixing; drying, calcining, and cooling with the furnace; performing secondary ball-milling and drying; preparing a blank and sintering. The present invention realizes the in-situ synthesis of a CaTiO3 performance enhancement phase, improves the temperature drift characteristics of the celsian-based ceramic material, the temperature coefficient of resonant frequency can be controlled within ±2 ppm / °C, comprehensively improves the microwave dielectric properties of the ceramic material, and enables it to meet the application requirements of millimeter-wave communication devices.

The application discloses a preparation method of low-dielectric-loss high Q × f value lithium titanate-based microwave dielectric ceramic material and a product thereof.The application takes Li2CO3, TiO2, Sc2O3 and Nb2O5 as raw materials, substitutes Ti in Li2TiO3 with (Sc 1 / 2Nb 1 / 2 ) 4+ , forms a lithium titanate-based microwave dielectric ceramic material with a chemical formula of Li2Ti 4+ (Sc 1‑x Nb 1 / 2 ) 1 / 2 x O3, effectively adjusts the phase structure of the microwave dielectric ceramic, optimizes the temperature frequency characteristics and dielectric loss, and obtains excellent comprehensive microwave dielectric performance with moderate dielectric constant, super high Q × f value and near-zero resonance frequency temperature coefficient, so that the lithium titanate-based microwave dielectric ceramic material has great application potential in the fields of next-generation mobile communication and satellite communication.

The present invention belongs to the field of ceramic materials, and particularly relates to a laminated microwave dielectric ceramic and a preparation method thereof. The laminated microwave dielectric ceramic provided by the present invention comprises a first ZnWO4 layer, a TiO2 layer, and a second ZnWO4 layer which are laminated in sequence; the mass proportion of the TiO2 layer in the laminated microwave dielectric ceramic is ≤2%. The laminated microwave dielectric ceramic provided by the present invention has a "sandwich" structure; the top layer and the bottom layer are ZnWO4, serving as the matrix of the ceramic material; the interlayer is TiO2, serving as the temperature compensation component of the ceramic material. Compared with the traditional multi-phase mixed ZnWO4-based ceramic, the present invention can achieve near-zero τ f adjustment of the ZnWO4 ceramic with a relatively small content of TiO2, and keep the ceramic material at a relatively high Q × f value, realizing the coordinated control of microwave dielectric properties. In addition, the present invention can realize the co-firing preparation of the laminated microwave dielectric ceramic at a relatively low temperature.

The present invention belongs to the field of microwave dielectric ceramic materials, and specifically discloses a low-temperature and low-dielectric-loss microwave dielectric ceramic CoTeMoO6 and a preparation method thereof. Based on the traditional solid-phase method, CoTeMoO6 ceramics with ultra-low loss are synthesized under the condition of ultra-low temperature sintering (only 500-620 °C). This not only significantly reduces energy consumption, but also remarkably shortens the overall cycle from material preparation to finished product; the adoption of this low-temperature sintering technology makes the entire production process more efficient and fast, with a short production cycle, improving production efficiency and reducing production costs; the CoTeMoO6 ceramics prepared by the present invention have good microwave dielectric properties: relative dielectric constant ε r = 11.36-13.88, quality factor and frequency product Q×f = 6849-44110 GHz, temperature coefficient τ f = -90.8-72.4 ppm / °C, and these characteristics provide the possibility for its application in microwave devices.

The invention discloses a low-temperature sintering temperature-stable oxyfluoride nanocrystalline ceramic and a preparation method thereof, the chemical formula of the nanocrystalline ceramic is Li3Mg2SbO5. 8F0.4, the crystal structure of the nanocrystalline ceramic is composed of an orthorhombic-phase primary crystal phase and a cubic-phase secondary crystal phase, and the average grain size is 220-240 nm. A proper amount of MgF2 is introduced into Li3Mg2SbO6 to serve as a magnesium source, so that the Li3Mg2SbO6-based ceramic crystal structure and the grain size are changed, and meanwhile, the Li3Mg2SbO6-based ceramic has low-temperature sintering (1t, 900 DEG C) and good microwave dielectric properties: tau f is-13.1 to-9.5 ppm / DEG C, Q * f is 33300 to 56600 GHz, and epsilon r is 9.8 to 10.4. The ceramic material is simple in preparation process, rich in raw materials, low in cost and beneficial to industrial production, and can be widely applied to manufacturing of low-temperature co-fired ceramic systems, dielectric resonators, dielectric antennas and other electronic components.

The invention relates to an environment-friendly scheelite high-entropy microwave dielectric ceramic material and a preparation method thereof, the structural expression of the ceramic material is Na0.5 (LaPrNdX) 0.5 / NMoO4, X is selected from at least two of Bi, Ce, Sm, Eu and Y, and N is the sum of the number of elements of La, Pr, Nd and X. The ceramic material simultaneously has at least five elements of La, Pr, Nd and X at one element position, high-entropy component design is realized, the dielectric property of the material can be directionally designed through component selection, the sintering temperature of the material is effectively reduced under the condition that a sintering aid is not added, and the performance of the material is improved. The microwave dielectric ceramic has a reasonable dielectric constant, a high quality factor and a near-zero temperature coefficient of resonance frequency, and shows excellent microwave dielectric properties.

This invention relates to the field of dielectric ceramics technology, specifically to a low-dielectric-high-entropy microwave dielectric ceramic with a garnet structure and its preparation method. The chemical composition formula of the low-dielectric-high-entropy microwave dielectric ceramic with a garnet structure is Ca. 3 (Co 0.2 Cu 0.2 Mg 0.2 Zn 0.2 Ni 0.2 ) 2 SiV 2 O 12 By introducing the high-entropy effect into the garnet structure and optimizing the sintering temperature, a Ca with a garnet structure was successfully synthesized. 3 (Co 0.2 Cu 0.2 Mg 0.2 Zn 0.2 Ni 0.2 ) 2 SiV 2 O 12 Pure-phase low-dielectric-high-entropy microwave dielectric ceramics. They exhibit a dielectric constant of 6.5–10.4, a quality factor of 12490–62440 GHz, and a temperature coefficient of resonant frequency of -9.2–-7.4 ppm / ℃. These ceramics possess excellent microwave dielectric properties and have significant practical application value.

The present invention relates to a microwave dielectric ceramic material with a medium dielectric constant and a preparation method thereof. Specifically, by using a low-melting-point sintering aid in the preparation process of the ceramic material, the present invention realizes the low-temperature sintering of the ceramic material and obtains a microwave dielectric ceramic material with excellent microwave dielectric properties.

The present invention discloses a low-temperature sintered modified molybdenum-based microwave dielectric ceramic and a preparation method thereof, belonging to the production technology field of microwave dielectric ceramics. The raw materials of the modified molybdenum-based microwave dielectric ceramic are Al2O3, MoO3, MnCO3 and TiO2, and its chemical formula is Al2Mo 3‑x (MnTi) x O 12 , wherein x = 0.01 to 0.02; a method for preparing a modified molybdenum-based microwave dielectric ceramic, comprising the following steps: batching; ball milling, drying, screening, pre-sintering; re-ball milling, drying, granulation; pressing, debinding, and heat preservation to obtain a low-temperature sintered modified molybdenum-based microwave dielectric ceramic, the chemical formula of which is Al2Mo 3‑x (MnTi) x O 12 , wherein x = 0.01 to 0.02. The present invention utilizes (MnTi) 6+ The composite ions partially replace the lattice position of Mo, and with the help of the low melting point of MnCO3, the Al2Mo3O 12 The crystal structure was improved and its optimal sintering temperature was lowered. Finally, the system achieved excellent microwave dielectric properties at a lower sintering temperature (725℃).

The invention relates to a molybdenum-based microwave dielectric ceramic material and a preparation method and application thereof. The structural expression general formula of the ceramic material is NaX (MoO4) 2, and X is one or more of Pr, Sm and Eu. The preparation method of the ceramic material comprises the following steps: S1, weighing Na2CO3, MoO3 and rare earth oxide as raw materials according to a structural expression general formula NaX (MoO4) 2 of the ceramic material; s2, uniformly mixing the raw materials through a primary ball-milling process to obtain primary ball-milled powder; s3, the primary ball-milled powder is pre-sintered, and pre-sintered ceramic powder is obtained; s4, performing secondary ball milling on the ceramic powder to obtain secondary ball-milled powder; and S5, tabletting and sintering the secondary ball-milled powder through a tabletting and sintering process to obtain the ceramic material. The ceramic material can be prepared by sintering in a relatively low sintering temperature range, has a relatively low dielectric constant, a relatively high quality factor and a near-zero temperature coefficient of resonance frequency, and shows excellent microwave dielectric properties.

The invention discloses a microwave-energy storage integrated dielectric ceramic material with a multiphase structure as well as a preparation method and application thereof, and the method comprises the following steps: 1, weighing Ca2CO3, MgO and TiO2, mixing, and sequentially carrying out ball milling, drying and calcining to obtain Ca0. 8Mg0. 2TiO3 powder; 2, weighing Sm2O3 and Al2O3, mixing the Sm2O3 and the Al2O3, and sequentially carrying out ball milling, drying and calcining on the Sm2O3 and the Al2O3 to obtain SmAlO3 powder; 3, weighing Ca0. 8Mg0. 2TiO3 powder and SmAlO3 powder according to a stoichiometric formula (1-x) Ca0. 8Mg0. 2TiO3-xSmAlO3, x is greater than or equal to 0.28 and less than or equal to 0.40, mixing the Ca0. 8Mg0. 2TiO3 powder and the SmAlO3 powder, and sequentially carrying out ball milling, drying, grinding and sieving to obtain a sieved material; 4, the sieved material is subjected to compression molding and calcination, the microwave-energy storage integrated dielectric ceramic material with the multiphase structure is obtained, the dielectric constant epsilon r of the microwave-energy storage integrated dielectric ceramic material is 35-85, the breakdown electric field intensity Eb is 300-700 kV / cm, the energy storage density U is 1.5-3.5 J / cm < 3 >, the Qf is 23000-34000 GHz, in the temperature range of-150-350 DEG C, the variation delta epsilon r of the dielectric constant is smaller than or equal to + / -5%, the loss tangent tan delta is smaller than or equal to 5 * 10 <-3 >, and the microwave-energy storage integrated dielectric ceramic material with the multiphase structure is obtained. The microwave dielectric property and the energy storage property are excellent.

The invention discloses a preparation method of Li3Mg2SbO6 ceramic with improved sintering characteristic and microwave dielectric property, which comprises the following steps: weighing Li2CO3, MgO and Sb2O5 according to the stoichiometric ratio of the general chemical formula Li3Mg2SbO6, mixing, ball-milling until the materials are uniformly mixed, drying and sieving to obtain a primary ball-milled material; the primary ball-milled material is placed in a box-type furnace for high-temperature presintering, the presintering temperature is 800-1000 DEG C, the presintering time is 2-6 hours, and secondary ball-milled material is obtained after ball milling, drying and sieving are conducted again; performing cold isostatic pressing on the secondary ball-milled material to obtain a ceramic green body; the ceramic green body is placed in a box-type furnace for high-temperature sintering, the sintering temperature ranges from 1350 DEG C to 1500 DEG C, the sintering time ranges from 2 hours to 6 hours, and the Li3Mg2SbO6 microwave dielectric ceramic is obtained. The preparation process is simple, the sintering characteristic of the ceramic is improved, the obtained microwave dielectric ceramic is a pure phase, the density is relatively high, and the commercialization of Li3Mg2SbO6 ceramic is favorably realized.

The invention discloses an Mg3TiO5 microwave dielectric material and a preparation method thereof, and belongs to the field of microwave dielectric materials, the chemical formula of the microwave dielectric material is Mg3TiO5, the Q * f of the microwave dielectric material is 198000GHz, and the fluctuation of the microwave dielectric property within the range of-50 DEG C to 200 DEG C is less than or equal to 5%; the preparation method comprises the following steps: (1) proportioning MgO or basic magnesium carbonate with the purity of more than 99% and the particle size of 400-600nm and TiO2 according to product element composition to obtain initial powder; (2) carrying out ball milling, drying, sieving and presintering on the initial powder obtained in the step (1), and then carrying out secondary ball milling, drying and sieving; and (3) adding a polyvinyl alcohol solution into the powder obtained in the step (2) for granulation, then carrying out compression molding, and sintering the obtained green body in the air atmosphere of 1320-1440 DEG C to obtain the Mg3TiO5 microwave dielectric material.

The application provides an olivine-type lithium-containing silicon-based dense ceramic and a preparation method thereof. 1‑x M x SiO4 (0.35≤x≤0.8), wherein M must contain Yb element and further comprises at least one of Zn, Ni, Ga, Y, Eu, Ho, Er and Tm, and the total of the subscripts of the elements in M is equal to the value of x. The application adopts a traditional solid-phase reaction sintering method, and the process is simple. Without additional sintering aids or hot-press sintering, the olivine-type lithium-containing silicon-based dense ceramic with excellent comprehensive microwave dielectric performance can be obtained.

The invention discloses a high-entropy perovskite microwave dielectric ceramic with medium and high dielectric constants and a preparation method and application thereof, the stoichiometric formula of the high-entropy perovskite microwave dielectric ceramic is (Ca < 0.2 > Li < 0.2 > Sm < 0.2 > Mg < 0.2 > Me < 0.2 >) TiO3, Me is Zn, Ba or Sr; the microwave dielectric constant of the microwave dielectric ceramic is 50-115, the quality factor is 2000-11000 GHz, and the temperature coefficient of resonance frequency is 40-140 ppm / DEG C. The high-entropy perovskite microwave dielectric ceramic with excellent microwave dielectric properties is prepared through a simple, green and environment-friendly process, and the sintering temperature is effectively reduced under the condition that a sintering aid is not added; the method has important significance in promoting the application of the perovskite structure microwave dielectric ceramic in microwave antennas and 6G base stations in the field of mobile communication.

The present invention discloses a high-dielectric aluminum-doped perovskite-structured high-entropy microwave dielectric ceramic and a preparation method thereof, belonging to the technical field of ceramic materials in the communication field. The chemical general formula of the high-entropy microwave dielectric ceramic is (Zn 1 / 6 Ba 1 / 6 Ca 1 / 6 Sr 1 / 6 La 1 / 3 )Ti 1‑ x Al x O3, where: x = 0 - 0.1. Based on the unique effect of high entropy, the present invention first introduces the high-entropy concept into the perovskite-structured microwave dielectric ceramic to attempt to regulate the dielectric properties, and successfully synthesizes the aluminum-doped high-entropy microwave dielectric ceramic by controlling process parameters such as sintering temperature, reaction time, and doping content. Its dielectric constant is 74 - 91, the dielectric loss is 0.001 - 0.002, and the temperature coefficient of resonant frequency is 175 - 217 ppm / °C, obtaining excellent microwave dielectric properties. The high-dielectric microwave dielectric ceramic obtained by the present invention is expected to be applied to mobile terminals and communication base stations, etc.

The application discloses a non-metallic mineral matter cordierite type microwave dielectric ceramic material, which is sintered from the following raw materials: black talc powder, coal-based kaolin ore powder, bauxite powder and Sm-Mn composite sintering additives, wherein the Sm-Mn composite sintering additives are prepared by pre-sintering Sm2O3 and Mn(NO3)2.4H2O, and the mass percentage of each raw material in the total amount of black talc powder, coal-based kaolin ore powder, bauxite powder, Sm2O3 and Mn(NO3)2.4H2O is as follows: the black talc powder accounts for 46-49%, the coal-based kaolin ore powder accounts for 15-19%, the bauxite powder accounts for 27-31%, the Sm2O3 accounts for 0.5-1.5%, and the Mn(NO3)2.4H2O accounts for 4.5-5.5%, and the main phase of the non-metallic mineral matter cordierite type microwave dielectric ceramic material is cordierite Mg2Al4Si5O 18 12, the secondary phase is SmMn2O5 and MnO2. The application further discloses a preparation method, wherein the Sm-Mn composite sintering additives are sintered first, and then mixed with the mineral raw materials in proportion to prepare by a solid phase sintering method. The non-metallic mineral matter microwave dielectric ceramic material prepared by the application solves the problem of microwave dielectric performance deterioration caused by impurities in the mineral raw materials.

The invention relates to the field of electronic information functional ceramics and electronic devices, and discloses a low-temperature sintered microwave dielectric material and a preparation method thereof.The composition expression of the microwave dielectric material is xLi [Mg0. 98 (Li2 / 3Sn1 / 3) 0.02] 3TiO6-(1-x) Ca0. 8Sm0. 4 / 3TiO3 + ywt.% MO, MO is a sintering aid, x is larger than or equal to 0.1 and smaller than or equal to 0.5, y is larger than or equal to 0.4 and smaller than or equal to 1, y is larger than or equal to 0.4 and smaller than or equal to 1, and y is larger than or equal to 1 and smaller than or equal to 1. A microwave dielectric ceramic material prepared from the prepared microwave dielectric material at the sintering temperature of 1100-1250 DEG C has excellent microwave dielectric properties, the dielectric constant can reach 40-55, the Q * f value can reach 45000-60000 GHz, and the frequency temperature coefficient tau f can reach 0.8-4.9 ppm / DEG C.

The invention belongs to the technical field of microwave dielectric ceramic materials, and particularly relates to a magnesium and tungsten ion substituted ZnTiNb2O8 microwave dielectric ceramic material and a preparation method thereof, the material uses (Mg0. 5W0. 5) 4 + ions to replace Ti sites in ZnTiNb2O8 crystals, the chemical formula is Zn (Ti1-x (Mg0. 5W0. 5) x) Nb2O8, 0.03 < = x < = 0.15, the dielectric constant of the microwave dielectric ceramic material is 28-34, the quality factor is 29000-39300 GHz, and the temperature coefficient of resonance frequency is-73.5--47.1 ppm / DEG C. The microwave dielectric property of the original ceramic can be improved by replacing Ti site with (Mg0. 5W0. 5) 4 < + > ions, and the microwave dielectric ceramic is suitable for being used as a substrate material for microwave resonators, antennas and related electronic circuits. The temperature coefficient of resonance frequency and the quality factor of the ceramic are improved, the improvement of the temperature coefficient of resonance frequency can ensure the environmental stability of a device, and the high quality factor ensures the low loss and the low heat effect of the device in work.