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326 results about "Microwave dielectric properties" patented technology

Low-temperature sintered LTCC microwave dielectric ceramics material and preparation method thereof

InactiveCN101224977AImprove performanceInherently low sintering temperatureDielectric ceramicsCo-fired ceramic
The invention discloses a low temperature co-fired ceramic LTCC microwave dielectric ceramic MWCD material, which is prepared by Li2CO3, Nb2O5 and TiO2 by the moral ratio that Li2CO5:Nb2O5:TiO2 = x:1:y, wherein, x is more than 5.5 and less than or equal to 6, y is more than 7 and is less than or equal to 7.5; the expression of structure for the made up modular is Li1+m-nNb1-m-3nTim+4nO3, wherein m is more than or equal to 0.1 and is less than or equal to 0.15, n is more than or equal to 0.2 and less than or equal to 0.25. The LTCC MWCD prepared by the invention has low sintering temperature (approx. 1,100 DEG C) and excellent microwave performance: the dielectric constant (Epsilon r) is that x is more than 32 and less than or equal to 52, Q multiplied by f value is high and Tf is small; the sintering temperature can be decreased to 900 DEG C and the microwave dielectric property can be maintained for excellence without any reaction to a Ag by adding a plurality of low melting point oxides. The pure silver can be taken as a electrode for sintering which can greatly reduce manufacturing cost for the components and applied in manufacturing of the microwave components such as a low temperature co-fired ceramic LTCC system, a multi-layer media resonator, a microwave antenna and a wave filter etc.
Owner:XI AN JIAOTONG UNIV

Low-temperature sintered microwave medium ceramic material and preparation method thereof

The invention discloses a low-temperature sintered microwave medium ceramic material and a preparation method thereof. The material comprises the raw materials with the mol ratio: BaCO3:ZnO:TiO2:Q=1:x:(4+y):z, wherein x=0.01-0.5, y=0.01-0.5, z=0.01-0.1, and Q is glass combustion-supporting agent or BaCu (B2O5); the glass combustion-supporting agent comprises the raw materials with the mol ratio being Li2O:ZnO:B2O3=1:2:7 or Li2O: B2O3-1:2:7=3:2:5. The material can be obtained through traditional solid phase reaction synthesis. The material has lower sintering temperature (is capable of being fired at the temperature below 900 DEG C to form ceramics), is capable of being fired at the temperature of 900 DEG C to form ceramics and has better microwave dielectric property, wherein Epsilon r is equal to 25-35, Q*F is larger than 12,000, and Pi f is equal to -10ppm/DEG C to +30ppm/DEG C; in addition, the material has stable process and good repeatability and can be better co-fired and matched with a silver electrode. The low-temperature sintered microwave medium ceramic material can be used for manufacturing microwave devices, such as lower temperature co-fired ceramic (LLCC) systems, multilayer medium resonators, microwave antennae, wave filters, and the like.
Owner:XI AN JIAOTONG UNIV

Method for testing microwave dielectric property of high-loss dielectric substance

ActiveCN102798766AOvercome the defect of low test accuracyReduce lossResistance/reactance/impedenceReference sampleElement analysis
The invention discloses a method for testing microwave dielectric property of a high-loss dielectric substance. According to the method, a small-size sample to be tested is used, and a large-size and low-loss reference sample is introduced, so that the high loss of the sample to be tested is reduced, and the resonance peak is ensured to be observed. According to the changes of the resonance peak of a TE01 delta model when only the reference sample is arranged in a resonant cavity and the reference sample and the sample to be tested are simultaneously arranged in the resonant cavity, and the distribution of an electromagnetic field under the two conditions can be simulated by using finite element analysis, so that the dielectric constant and the dielectric loss of the sample to be tested at the resonance frequency can be obtained. According to the method, the characteristics of high test precision of the microwave resonance method is utilized, and the influence on the distribution of the electromagnetic field caused by the introduction of the sample to be tested, is considered, so that the defects of low precision of other conventional methods can be overcome from the test principle, and the accurate test of the microwave dielectric property of the high-loss substance can be realized. Meanwhile, the resonance frequency is decided by the reference sample with large size, so that the frequency conversion test can be realized by changing the dielectric constant or the size of the reference sample.
Owner:ZHEJIANG UNIV

Low-temperature co-fired microwave dielectric ceramic material and preparation method thereof

A low-temperature, high stability co-fired microwave dielectric composite of ceramic and glass, including 85-99 wt % microwave dielectric ceramic of formula [1-y-z[(1−x)Mg2SiO4−xCa2SiO4]−yCaTiO3−zCaZrO3, wherein 0.2≦x≦0.7,0.05≦y≦0.3 and 0.02≦z≦0.15], and 1 to 15 wt % with Li2O—BaO—SrO—CaO—B2O3—SiO2 glass respectively made at a low sintering temperature of ceramic for co-firing with Ag or Cu electrode, employing eutectic phase of ceramic oxides to reduce its melting temperature, a low melting-point glass material with high chemical stability as a sintering aid added to oxides and raw material powders of Li2O, BaO, SrO, CaO, B2O3 and SiO2, obtained by combining and melting the ingredients in the temperature range between 1000 to 1300° C., quenching and crashing, and then adding it to the main ceramic oxides to form the final composition. This ceramic/glass composite material may be co-fired with an Ag and Cu electrode at 900° C.-970° C. for 0.5-4 hours in a protective atmosphere. After sintering, this dielectric material possesses efficacious microwave dielectric properties, dielectric constant between middle-K to low-K at 815, high quality factors, low dielectric loss, low temperature-capacitance coefficient and superior chemical stability suitable for manufacture of multilayer ceramic devices.
Owner:WALSIN TECHNOLOGY CORPORATION

Low temperature co-fired microwave dielectric ceramic material and preparation method thereof

The invention discloses a low temperature co-fired microwave dielectric ceramic material and a preparation method thereof. The ceramic material comprises a main powder material Li2ZnTi3O8, an auxiliary component TiO2 and low-melting-point LZB (Li2O-ZnO-BiO2) or LBS (Li2O-B2O3-SiO2) glass powder. The preparation method comprises the following steps of: adding TiO2 and the glass powder into the Li2ZnTi3O8 powder in a powder form; and then evenly mixing in a ball mill, drying, pelleting and sintering so as to obtain the ceramic material. In the invention, based on the Li2ZnTi3O8 powder as a reference, batching is carried out according to the proportions that the mass of the glass powder is 0.5-3wt% of that of Li2ZnTi3O8 and the mass of the TiO2 powder is 0-5wt% of that of Li2ZnTi3O8; and thematerial of the invention can be obtained by a traditional solid phase reaction method. The low temperature co-fired microwave dielectric ceramic material prepared by the method of the invention has low sintering temperature (about 875 DEG C) and good microwave dielectric property, and can be well co-fired with a Ag electrode; pure silver with high electricity conductivity and low cost is used asan electrode material, thus the manufacturing cost of a device can be greatly reduced; and the low temperature co-fired microwave dielectric ceramic material can be used for a low temperature co-fired ceramic (LTCC) system and manufacturing of microwave devices such as multilayer dielectric resonators, microwave antennas, filters and the like.
Owner:GUILIN UNIV OF ELECTRONIC TECH

Middle-low temperature sintering middle-dielectric constant microwave medium ceramics and preparation method thereof

The invention discloses medium dielectric constant microwave medium ceramics sintered by medium-low temperature, and a preparation method thereof. When in preparation, ZnO and Nb2O5 are mixed and added with grinding aid for ball milling; after being dried, the mixture is presintered at the temperature of 900 to 1000 DEG C for 2 to 8 hours; then the presintered powder lot is dried after being ball-milled with TiO2, a sintering auxiliary agent, and the grinding aid; afterwards, an adhesion agent is added, granulation and pressing molding are carried out, and sintering is carried out for 2 to 8 hours within the range of 900 to 1000 DEG C, thus obtaining the microwave medium ceramics. The microwave medium ceramic material provided by the invention has good microwave dielectric property: the dielectric constant is 35 to 50, Q multiplied by f equals to 10000 to 30000GHz, temperature coefficient of resonance frequency is small and adjustable and insulating resistivity is high, therefore, the material can be used for preparing resonators, filters, phase shifters and the like, and can also be used as the dielectric material of multilayer chip ceramic capacitors, thus having important industrial application value.
Owner:SOUTH CHINA UNIV OF TECH

Device and technology for industrial waste salt multi-level harmless treatment

The invention discloses a device and technology for industrial waste salt multi-level harmless treatment. A first inlet is formed in a rotary kiln drying desorption device, the desorption device is connected with a mixing device, and an outlet of the mixing device is connected with a microwave splitting decomposition device; the microwave splitting decomposition device is connected with a refiningdevice, a second output of the refining device is connected with the microwave splitting decomposition device, and after waste salt enters the rotary kiln drying desorption device and the microwave splitting decomposition device, a large amount of organic matter is removed, and the waste salt flows into the refining device; an inlet of a tail gas treatment device is connected with an outlet of asecond-level incineration device, and a second outlet of the refining device is connected with a second inlet of the microwave splitting decomposition device. The technology comprises the processes offirst-level thermal desorption, second-level splitting decomposition, third-level salt refining, tail gas treatment and the like. According to the device and technology for industrial waste salt multi-level harmless treatment, refined salt is obtained after treated by the refining device, the device is simple in structure, residual microwave dielectric property substances can be recycled, the treatment cost is lowered, the waste salt is subjected to second-level harmless treatment, and the organic matter and water in the waste salt can be removed.
Owner:JIANGSU KEHANG ENVIRONMENT ENG TECH

Low-temperature co-fired Li2MgTi3O8 microwave dielectric ceramic material and preparation method thereof

The invention discloses a low-temperature co-fired Li2MgTi3O8 microwave dielectric ceramic material and a preparation method thereof. The material comprises a main powder material Li2MgTi3O8 and low-melting-point Li2O-MgO-B2O3 (LMB) glass powder. The glass powder is added into Li2MgTi3O8 powder in the form of powder and then the mixture is evenly mixed in a ball mill and is dried, granulated and fired to obtain the material. The proportions of components for preparing the material are determined by taking the Li2MgTi3O8 powder as a reference, wherein the weight of the glass powder accounts for 0.5-3 percent of the weight of Li2MgTi3O8 powder. The material can be obtained through the traditional solid-phase reaction synthesis method. The low-temperature co-fired microwave dielectric ceramic material prepared by adopting the preparation method has the advantages that the firing temperature is low (approximate 875 DEG C), the microwave dielectric performance is excellent, the dielectric constant (epsilon r) is large, the quality factor (Q-f) is high, the resonant frequency-temperature factor (tf) is close to zero, the effect of co-firing with an Ag electrode is good, high-conductivity low-cost pure silver can be used as an electrode material, the manufacturing cost of devices can be greatly reduced, and the low-temperature co-fired microwave dielectric ceramic material can be used for manufacturing microwave devices such as low-temperature co-fired ceramic (LTCC) systems, multilayer dielectric resonators, microwave antennas and filters.
Owner:GUILIN UNIV OF ELECTRONIC TECH

Temperature frequency characteristic regulator of microwave medium ceramic and LTCC material thereof

The invention discloses a microwave dielectric ceramic, a temperature frequency characteristic regulator of the microwave medium ceramic and an LTCC material thereof. The microwave dielectric ceramic comprises a principal crystalline phase. The chemical formula of the principal crystalline phase is BaSixO2(x+1)(x is greater than or equal to 1.56 but less than or equal to 1.85). The ceramic has a low dielectric constant (epsilon r is equal to 7.1-7.9), a relatively high quality factor (Q*f is equal to 10973-20350GHz) and a relatively wide sintering temperature (750-1250 DEG C). Meanwhile, the principle crystalline phase which is sintered in a reductive atmosphere N2-1vol%H2 still has an excellent microwave dielectric property and is the microwave dielectric material with good reduction resistance. The microwave dielectric material can be used as the temperature frequency characteristic regulator of the microwave medium ceramic and can keep a stable phase structure and a good microwave dielectric property (reduction resistance) in the reductive atmosphere. Compared with a conventional adjustor, the microwave dielectric ceramic has an obvious advantage and is a novel temperature frequency characteristic regulator which can be applied to BME-MLCC.
Owner:HUAZHONG UNIV OF SCI & TECH

High dielectric constant BaO-Ln2O3-TiO2 system microwave dielectric material and preparation method thereof

The invention provides a high dielectric constant BaO-Ln2O3-TiO2 system microwave dielectric material and a preparation method of the high dielectric constant BaO-Ln2O3-TiO2 system microwave dielectric material. The high dielectric constant BaO-Ln2O3-TiO2 system microwave dielectric material is composed of a major component (namely, (Ba1-m-nMgmSrn)6-3X(Sm1-yNdy)8+2XTi18O54), a sintering aid and a modified dopant. The major component, namely the (Ba1-m-nMgmSrn)6-3X(Sm1-yNdy)8+2XTi18O54 is solid solution, wherein the X is equal to 0-0.02; Y is equal to 0-0.05; m is equal to 0.002-0.025; and n is equal to 0.05-0.03. The sintering aid comprises one of or a mixture of more than one of low-melting-point oxides of Bi2O3, B2O3, CuO, Li2O, ZnO, SiO2, and the like and low-melting-point glass dust. The modified dopant comprises different metallic oxides and carbonate, such as one of or the mixture of more than one of ZrO2, BaCO3, TiO2, MnO2, SrO, and the like. The microwave dielectric material finally prepared through reasonable formula, optimized synthesis and ball-milling process can be sintered in the temperature range of 1250 DEG C to 1330 DEG C. The produced microwave capacitor has excellent microwave dielectric properties, wherein epsilon r is equal to 100; Q*f is more than or equal to 5500GHZ(3.5-4.5GHZ); and tau f(-40 DEG C-25 DEG C/25 DEG C-125 DEG C) is less than or equal to 10PPM/DEG C.
Owner:XIAMEN SUNYEAR ELECTRONICS CO LTD

New method for finely preparing ixiolite structure MgTiNb2O8 microwave dielectric ceramic by using chemical process

The invention belongs to the technical field of electronic ceramic preparation and application, and particularly relates to a method for fine synthesis of a ternary MgO-Nb2O5-TiO2 system microwave dielectric ceramic by using a sol-gel method. The technical scheme comprises adopting a sol-gel method to finely synthesize a ternary MgO-Nb2O5-TiO2 system microwave dielectric ceramic, and specifically comprises: 1) preparing a citric acid aqueous solution of Mg ions; 2) preparing a citric acid aqueous solution of Ti ions and Nb ions; and 3) synthesizing a ternary MgTiNb2O8 microwave dielectric ceramic nanometer precursor, and preparing the ceramic. The ternary MgO-Nb2O5-TiO2 system microwave dielectric ceramic has significant advantages of low synthesis temperature, uniform ceramic particles, good ceramic particle dispersity, pure phase, nano-scale powder (particle size of about 50 nm), high specific surface energy, high activity and the like. In addition, compared with the conventional solid-phase method, the method of the present invention has the following characteristics that: the sintering temperature can be significantly reduced by 100-200 DEG C so as to achieve low temperature sintering, maintain the good microwave dielectric property, and meet the LTCC application requirements.
Owner:UNIV OF JINAN
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