30results about How to "Resonant frequency temperature coefficient adjustable" patented technology

The invention provides microwave dielectric ceramic powder and a preparation method thereof. The microwave dielectric ceramic powder comprises 95-100 parts by weight of (1-x)La(Mg1 / 2Ti1 / 2)O3-xCaTiO3 and 0-5 parts by weight of ZnO, wherein x is equal to 0.35-0.45. Compared with the existing microwave dielectric ceramic powder, the microwave dielectric ceramic powder combines the advantages of two material systems, namely CaTiO3 and La(Mg1 / 2Ti1 / 2)O3, so that the dielectric constant of the microwave dielectric ceramic powder is medium, the loss is lower, the quality factor is higher and the temperature coefficient of resonance frequency is adjustable. In particular, the density of the systems and the microstructure can be improved as a certain amount of zinc oxide is compounded, so that the loss of the microwave dielectric ceramic powder is lower and the quality factor is further improved. Moreover, the microwave dielectric ceramic powder is rich in raw material source, is widely applied and is lower in cost.

The invention provides a nano-microwave dielectric ceramic material prepared from a mixture comprising a composite oxide and a sintering aid; the composite oxide has a general formula shown in formula (I): xLn 2 o 3 ‑yBaO‑zAl 2 o 3 ‑wTiO 2 ; In formula (I), 0<x≤10, 0≤y≤10, 0≤z≤1, 0<w≤20. Compared with the prior art, the nano-microwave dielectric ceramic material provided by the present invention takes the composite oxide of the above-mentioned specific general formula as the main component, and its crystal structure changes from the perovskite structure as the ratio of x, y, z, and w changes. Transforming to the composite perovskite structure and then to the black bronze structure, the BaO‑Ln 2 o 3 -TiO 2 (Ln: La\Sm\Nd) system microwave dielectric ceramic material is effectively improved; the nano-microwave dielectric ceramic material also has a high dielectric constant, extremely low dielectric loss and good sintering stability, and at the same time resonant The frequency temperature coefficient is adjustable, and it has very broad application prospects in the field of microwave communication.

The invention discloses a low temperature sintered high dielectric constant microwave dielectric ceramic material. The component of the microwave dielectric ceramic material is [(1-x)(Ca0.61Nd0.26)(Ti1-ySny)O3+x(Li1 / 2 Nd1 / 2)TiO3]+a(H3BO3-CuO)+b Li2CO3, wherein x is more than or equal to zero and less than or equal to 0.7, y is more than or equal to zero and less than or equal to 0.1, a is more than zero and less than or equal to 15 percent, b is more than or equal to zero or less than or equal to 5 percent, and a and b represent, respectively, the weight percent of H3BO3-CuO and weigh percent of Li2CO3 against the weight of [(1-x)(Ca0.61Nd0.26)(Ti1-ySny)O3+x(Li1 / 2 Nd 1 / 2)TiO3]. The invention also discloses a method for preparing the ceramic material. By adding a small amount of low melting point sintering assistant, the method reduces the sintering temperature to between 850 and 1,100 DEG C and maintains excellent microwave dielectric property and, therefore, meets the requirement for cofiring with low cost Ag electrodes. The method can be used to manufacture multilayer dielectric resonators, microwave antennae, filters and other microwave elements and greatly reduce the manufacture costs of the microwave elements.

The invention discloses a scheelite type molybdenum-based ultralow temperature-sintered microwave dielectric ceramic material and a preparation method thereof. The structure expression of the ceramic material is (Li0.5-0.5MxBi0.5-0.5x)MoO4, wherein M is equal to Ca2+, Zn2+, Sr2+ or Ba2+, 0.0(x(1.0. The scheelite type molybdenum-based ultralow temperature-sintered microwave dielectric ceramic material has the characteristics of adjustable relative dielectric constant (10.8 to 44), low dielectric loss under low frequency (tan delta(5*10-4, 1 MHz), high microwave performance (Qf is equal to 3,200 GHz to 84,000 GHz), low sintering temperature (560 to 1,050 DEG C), adjustable temperature coefficient of resonance frequency (-55 to +250 ppm / DEG C) and simple chemical composition and preparation process.

The invention disclose a microwave medium ceramic, including main component: p[m(aCaO.bNd2O3) .cMgO.TiO2].q[1 / 4Li2O.1 / 4Sm2O3.TiO2], where according to mol percent, p+q=100mol%, m+c=1, a+3b=1, q is not less than 30 mol% and not greater than 55 mol%, a not less than 0.3 mol and not greater than 0.75 mol, and m not less than 0.8 mol and not greater than 0.95 mol; auxiliary component ZnO, 0.5-20wt% of the main component. It also provides preparing method. Its dielectric constant is 90-120, and it has low-loss and adjustable harmonic frequency temperature coefficient, and can make microwave devices such as medium resonator and filter adaptive to higher frequency. It can be applied to high frequency ceramic capacitor or temperature compensating capacitor, and so on.

The invention discloses a low-loss high-strength microwave dielectric ceramic whose composition expression is xCaTiO 3 ‑ySmAlO 3 ‑(1‑x‑y)CaSmAlTiO 6 , wherein, x, y, (1-x-y) all represent molar ratio, x=0.6, 0≤y<0.4. The invention also discloses a preparation method of low-loss high-strength microwave dielectric ceramics. In the microwave dielectric ceramic provided by the present invention, CaSmAlTiO is used 6 Partial or full replacement of SmAlO 3 , so that the temperature stability can be improved while reducing the dielectric constant, and the processing strength can be increased by increasing the sintering temperature; CaSmAlTiO 6 and SmAlO 3 The dielectric constants of the two substances are similar, and CaSmAlTiO 6 The resonant frequency temperature coefficient is closer to zero, and CaSmAlTiO 6 The hardness is higher, through CaSmAlTiO 6 Partial or full replacement of SmAlO 3 , and adjusting the ratio of the components can obtain a high-hardness ceramic material with a dielectric constant of about 35, low loss and a near-zero temperature coefficient of the resonant frequency.

The invention discloses a low-temperature sintered microwave dielectric ceramic material, a preparation method and a microwave device. The material comprises (Ba (1-a)Sra)5 (Nb (1-b) Sbb) 4O15 and zinc borosilicate glass, wherein a is not larger than 0.05 and b is not larger than 0.1. The material disclosed by the invention overcomes the problem in the prior art that a copper element is introduced to increase the dielectric loss, the material is insoluble in such solvents as water, ethanol and the like, generates no gelation reaction with such adhesives as PVA (Polyvinyl Alcohol), PVB (Polyvinyl Butyral) and the like and meets the LTCC (Low Temperature Co-Fired Ceramic) process requirements, and the material disclosed by the invention is high in quality factor, adjustable in frequency resonance temperature coefficient, capable of being prepared to a microwave device with a multilayer or single-layer dielectric layer structure and is more suitable for application in the field of high-frequency and high-temperature microwave communication; the related raw materials are wide in source, low in cost, simple in process, low in production cost and suitable for industrial production of microwave dielectric ceramic devices; and the microwave dielectric material is low in dielectric loss, high in quality factor, adjustable in frequency resonance temperature coefficient and capable of meeting the requirements of the application field of high frequency, variable temperature and high reliability.

The invention discloses a Ti-based microwave medium ceramics material by low-temperature sintering. The Ti-based microwave medium ceramics material takes rutile TiO2 as a main phase. The general formula of the prescription of the invention is that: (AxM2x)(NyTi1-y)1-3xO2, (BxM3x)(NyTi1-y)1-4xO2, (CxMx)(NyTi1-y)1-2xO2 or (1-m) TiO2-mBi2Ti4O11, wherein, the A is one of bivalent ions such as Zn<2+>,Cu<2+>, Ni<2+>, the B one of univalent ions such as Li<+>, the C one of trivalent ions such as Al<3+>, Fe<3+>, M is one of pentavalent ions such as Nb<5+>, Ta<5+>, Sb<5+>, N one of quadrivalent ions such as Zr< 4+ >, Sn< 4+ >, Mn< 4+ >; the X is more than or equal to 0 and less than or equal to 0.25, the Y more than or equal to 0 and less than or equal to 0.5, the m more than or equal to 0 and less than or equal to 0.15, the n is more than or equal to 0 and less than or equal to 2. The microwave medium ceramics material by low-temperature sintering has the advantages of high dielectric constant, low dielectric loss, wide covering range of temperature coefficient of resonant frequency, low sintering temperature, simple preparation technique and adjustable temperature coefficient of resonantfrequency according to materials. The invention can be used for Low Temperature Co-fired Ceramics System (LTCC system) and used for producing microwave devices such as multi-media resonators, filters, etc.