36results about How to "Continuously adjustable dielectric constant" patented technology

The invention discloses a low-temperature co-fired glass ceramic composite material with adjustable dielectric constant and a preparation method thereof. The composite material is prepared from the following raw materials in percentage by mass: 0.5 to 20 percent of BaxSrl-xTiO3(x=0.3-1) and 80 to 99.5 percent of fluorinated aluminosilicate glass; wherein, the fluorinated aluminosilicate glass is prepared from the following raw materials in percentage by mass: 30 to 70 percent of SiO2, 20 to 50 percent of AlF3, and 5 to 30 percent of CaF2. After being mixed by the ratio, the components are added with ethanol or water, ball milled for 24h and dried to obtain low-temperature co-fired glass ceramic powder. The low-temperature co-fired glass ceramic composite material has the advantages that: (1) the sintering temperature is low (750 to 850DEG C) and the sintering shrinkage rate is 8 to 15 percent; and (2) the dielectric constant is adjustable from 8 to 50 (1GHz), and the dielectric loss is below 0.002 and the mechanical strength is higher. Consequently, the invention is applicable to low-temperature co-fired ceramic materials and electronic packaging materials.

The invention discloses a low-dielectric constant low-loss low-temperature co-fired ceramic material and a preparation method thereof. The ceramic material comprises the following components in partsby mass: 10-40 parts of Al2O3, 0-40 parts of SiO2, 0-60 parts of powder A, 0-60 parts of powder B, and 8-30 parts of powder C, and the material has at least one of the powder A and the powder B; the powder A comprises the following raw materials by parts: 40-70 parts of Bi2O3, 10-30 parts of ZnO, and 15-45 parts of H3BO3; the powder B comprises the following raw materials: a BaO precursor, CuO andH3BO3 which have a mol ratio being 1:1:2; and the powder C comprises the following raw materials: MgO and SiO2 which have the mol ratio being 2:1. The preparation method comprises the following steps: mixing the raw materials in proportion, performing steps of ball milling, drying, granulation, tabletting, glue discharging and sintering, and finally preparing the low-temperature co-fired ceramicmaterial which has the advantages that the dielectric constant is adjustable in a scope of 5.2-10, the dielectric loss is less than 0.002, and the insulation resistivity is higher than 1*1014 omega.cm.

The invention discloses a substrate-integrated waveguide microwave tunable filter based on liquid crystal material, which belongs to the technical fields of wireless communication, satellite communication, radar system, etc., and specifically relates to a filter based on liquid crystal material. Solve the problem of leakage of liquid crystal material in the existing packaging process, solve the problem of impedance mismatch by means of interlayer through-hole interconnection and strip line ladder impedance transformation, use direct contact feeding to add modulation voltage, through The split resonant ring structure is etched on the metal layer on the upper surface of the chip integrated waveguide to realize the bandpass filter, and the metal layer on the upper surface of the chip integrated waveguide is inverted and in contact with the liquid crystal material to form a substrate integrated waveguide tunable filter based on the liquid crystal material. It solves the problem of liquid crystal leakage in the traditional packaging method, and has the effects of impedance matching and frequency response of the filter being continuously adjustable.

The invention provides a composite microwave dielectric ceramic, which has the general formula shown in the following formula: Mg x Zn y al 2 o 4 —zSr 2 TiO 4 ; Wherein, x+y+z=1, z≤0.35. Compared with the prior art, the present invention will have Mg with negative resonant frequency temperature coefficient x Zn y al 2 o 4 Ceramic and Sr with positive resonant frequency temperature coefficient 2 TiO 4 The ceramics are composited, so that the dielectric constant of the composite microwave dielectric ceramics can be adjusted between 8.5 and 18.63, and Q×f>59200GHz can be as high as 97534GHz. Compared with other microwave dielectric ceramics with the same dielectric constant, the Q of this system is The value of ×f is large, and the dielectric loss is low; at the same time, the temperature coefficient of the resonant frequency is continuously adjustable between ‑77~+39PPM / ℃, the formula can be adjusted flexibly, there is no risk of titanium reduction, high reliability, and suitable for large-scale commercial use.

The invention relates to the technical fields of electronic materials and devices, and particularly relates to a composite microwave ceramic material with dielectric adjustable characteristic and low-temperature co-firing characteristic and a preparation method of a low-temperature co-firing ceramic device. The composite microwave ceramic material with dielectric adjustable characteristic and low-temperature co-firing characteristic comprises the following components in percentage by weight: 50-88wt% of Ba[1-x]SrxTiO3 (x=0.4-0.6), 10-48wt% of AMoO4(A=Ba, Sr or Ca) and 2-10wt% of yB2O3.zLi2O (y / z=0.5-1). The composite material disclosed by the invention is characterized in that the Ba[1-x]SrxTiO3 is simultaneously subjected to compound doping modification by a AMoO4 modifying agent and a yB2O3.zLi2CO3 glass sintering additive so as to obtain the composite microwave ceramic material with low sintering temperature (900-950DEG C). The composite microwave ceramic material is suitable for being applied to a low-temperature co-fired ceramic (LTCC) technology and a microwave adjustable device.

A high-dielectric adjustable strontium barium titanate-based composite aluminosilicate ceramic dielectric material is characterized in that the component general formula of the high-dielectric adjustable strontium barium titanate-based composite aluminosilicate ceramic dielectric material is is: (1‑m%)Ba 1‑z Sr z TiO 3 +m%(Sr 1‑x Ba x ) 2 Al 2 SiO 7 , where the value range of x is 0≤x≤0.9; the value range of z is 0.4≤z≤0.6; the value range of m is 10wt%≤m%≤90wt%, and BaCO 3 , SrCO 3 、TiO 2 , SiO 2 and Al 2 o 3 The powder is compounded, ball milled, dried, and pre-fired at high temperature to obtain a mixed powder. After tableting, it is pre-fired at a temperature of 550°C~600°C, and then fired at a temperature of 1200°C~1500°C. The highly dielectrically adjustable strontium barium titanate-based composite aluminosilicate ceramic dielectric material can be continuously adjusted in a wide range and has high comprehensive performance.

The invention discloses a microwave medium ceramic with a low dielectric constant and a low loss and a preparation method thereof and belongs to the technical field of a microwave medium ceramic material. The microwave medium ceramic has the characteristics of low dielectric constant, low loss, high temperature stability, continuously adjustable dielectric constant and high machining property. The composition of the microwave medium ceramic is expressed by a general formula: (Zn1-xLi2x)O.ySiO2+a weight percent of TiO2, wherein x is more than or equal to 0 and less than or equal to 1; y is more than or equal to 0.5 and less than or equal to 1; a is more than or equal to 0 and less than or equal to 20; and a is mass percentage in (Zn1-xLi2x)O.ySiO2. The microwave medium ceramic is prepared by the following steps of: 1) confecting zinc oxide, lithium carbonate and silicon dioxide according to the general formula (Zn1-xLi2x)O.ySiO2+a weight percent of TiO2, mixing and pre-burning the mixture to synthesize a main component and crushing the main component into powder; 2) putting powdery TiO2 into the main component and mixing to obtain a powdery mixture; and 3) blanking and sintering the powdery mixture. A specific tau f modifier TiO2 is selected, so the material has a dielectric constant of between 7 and 9, a high quality factor value of Q*f0 and adjustable frequency temperature coefficient tau f. Simultaneously, the material has the advantages of simple preparation process, no special requirement on equipment and workshop environment and contribution to batch production, application and popularization.

The invention provides a MAS-LT composite microwave dielectric ceramic, which has the general formula shown in the following formula: Mg 2‑x Ba x al 4 Si 5 o 18 -Li 2 TiO 3 ; In the formula, x=0~0.16; In the MAS‑LT composite microwave dielectric ceramics, Li 2 TiO 3 The mass percentage content is 6%~24%. Compared with the prior art, the MAS-LT composite microwave dielectric ceramic provided by the present invention takes the composite oxide of the above-mentioned specific general formula as the main material, and by adjusting Li 2 TiO 3 The content of the dielectric constant can be between 4 and 6, and the frequency temperature coefficient can be continuously adjusted; moreover, the MAS‑LT composite microwave dielectric ceramic has a stable structure, a specific dielectric constant and a high Q×f value, At the same time, the resonant frequency temperature coefficient is continuously adjustable. Experimental results show that the dielectric constant of the MAS-LT composite microwave dielectric ceramic provided by the present invention is 4-5.8, Q×f≥35800GHz, and can be as high as 87600GHz. Compared with other microwave dielectric ceramics with the same dielectric constant, this system High Q×f value and low dielectric loss; at the same time, the resonant frequency temperature coefficient is continuously adjustable between ‑12ppm / ℃~+13ppm / ℃, the sintering temperature is as low as 950 degrees, and the formula can be flexibly adjusted.