632results about How to "Small dielectric loss" patented technology

The invention discloses a preparation method for high-wave permeability and super-hydrophobic moisture-proofing coating for an antenna housing material. The preparation method is characterized by comprising the following steps of: preparing hole-sealing emulsion; preparing super-hydrophobic moisture-proofing emulsion; coating the hole-sealing emulsion on the antenna housing material, surface-drying the film coating under a room temperature, and then curing the film coating under the temperature of 100 DEG C to 140 DEG C; cooling and immersing the film coating to the super-hydrophobic moisture-proofing emulsion; surface-drying the film coating under the room temperature, and curing the film coating under the temperature of 80 DEG C to 160 DEG C to acquire the high-wave permeability and super-hydrophobic moisture-proofing coating for the antenna housing material. Micron-level silicon dioxide and fluorine-containing polymer are used in the method to perform accumulating and hole-sealing;a micron surface structure with certain roughness is provided, and epoxy resin with good viscosity is added to the hole-sealed coating, so that the mechanical property of the hole-sealed coating is improved; a self-growth method is adopted for depositing micron-level fluorine-containing polymer, which is in-situ packaged by organic silicon resin and attached with hydrophobic nanometre silicon dioxide, to the surface of the hole-sealed coating, so that the high-wave permeability and super-hydrophobic moisture-proofing coating of the antenna housing material is prepared.

Provided is a classified-desliming pressurized-feeding three-product dense medium cyclone coal preparation process. The process comprises the steps that wet classification and primary desliming are carried out on raw coal after prescreening, gangue predischarging and breaking are carried out on the raw coal, secondary desliming is carried out on the screen underflow of the raw coal after the screen underflow is concentrated, the oversize products of the secondary desliming and the screen underflow of the primary desliming are together fed in a pressurized three-product cyclone, three products are obtained after separation, and clean coal, middle coal and gangue are obtained after medium separation and dehydration are carried out on the three products. Part of qualified suspension liquid and dilute suspension liquid are obtained when the medium separation is carried out on the three products, magnetic concentrate is obtained after the dilute suspension liquid is recovered by a magnetic separator, and the magnetic concentrate and the qualified suspension liquid are directly fed in a medium blending barrel. The magnetic tailings of the dilute suspension liquid and the undersize mixtures of pre-desliming, the overflow of concentration classifying equipment and a secondary desliming screen enter a coal slime recovery processing system together. The process is high in separation efficiency, flexible in product structure, low in producing and operating cost and prone to achieving the large-scale single system, the modularization and the integrating intellectualization of plant layout.

Multilayer ceramic chip capacitors (MLCC's) which satisfy X7R TCC requirements and which are compatible with silver-palladium internal electrodes. The MLCC's exhibit desirable dielectric properties—high capacitance, low dissipation factor, high insulation resistance, stable TCC—and excellent performance on highly accelerated life testing, and good resistance to dielectric breakdown. The dielectric layers comprise a lead-free and cadmium-free barium titanate base material doped with other metal oxides such oxides of zinc, boron, bismuth, barium, titanium, praseodymium, cerium, tungsten, neodymium, tungsten, tin, niobium, copper, and / or manganese in various combinations. The dielectric ceramic materials herein can be fired at less than 1150° C. with an inner electrode having 70 wt % or more Ag and 30 wt % or less Pd to form an MLCC.

The invention discloses a borosilicate glass-spherical alumina low temperature co-fired ceramic (LTCC) green tape and its preparation method. The green tape is composed of a glass-ceramic composite material and a casting medium. Specifically, the glass-ceramic composite material consists of borosilicate glass and spherical alumina. The casting medium consists of a mixed solvent, a monomer binder, a plasticizer and a dispersing agent. The low temperature co-fired ceramic green tape prepared in the invention has a level and smooth surface, a solid content up to 88-92wt%, and a firing shrinkage rate of 9-11%. The difference between the sintering shrinkage rate of each direction is small. And the green tape can achieve wiring co-firing with Au, Ag and other low melting point metals at 850DEG C. The raw material tape sintered ceramic body provided in the invention has excellent dielectric properties. Under the condition of less than 10GHz, the dielectric constant (epsilon r) of 7-8, the dielectric loss (Tan delta) is less than 2*10<-3>, and effectively solves the anisotropy problem of traditional LTCC green tape sintering shrinkage.

An aromatic liquid-crystalline polyester with good moldability into a film is provided. The resulting film has small dielectric loss. The polyester comprises repeating units represented by formulae (I), (II), (III) and (IV), and the molar amounts of repeating units (I)–(IV) are 40–74.8%, 12.5–30%, 12.5–30% and 0.2–15%, respectively, wherein the molecular amounts of repeating units (III) and (IV) satisfy the relation of (III) / [(III)+(IV)]≧0.5.

The invention discloses a microstrip slot coupling fed three-frequency dielectric resonant antenna. A dielectric resonant cavity is made of a high-dielectric-constant material and is formed on a dielectric floor; an air resonant cavity is embedded on the upper part in the center of the inside of the dielectric resonant cavity and is filled with air serving as a dielectric; metal patches are placed in the centers at the upper ends of the dielectric resonant cavity and the air resonant cavity; a microstrip coupling slot feed source comprises a slot and a microstrip; the slot is formed in the dielectric floor; and the lower surface of the dielectric floor is provided with the microstrip and is vertically crossed with the slot. In the invention, three structures, namely the dielectric resonant cavity, the air resonant cavity and the metal patches, are integrated together to provide three different frequency points, so that the antenna has the characteristics of small size and wide frequency band, can be excellently applied to an antenna array and other aspects, namely various communication equipment and systems such as mobile terminals, wireless access points, base stations and the like, and can also be widely applied to some national defense tactical systems such as radars and the like.

An aromatic liquid-crystalline polyester having a small dielectric loss in a wide frequency region is provided. An aromatic liquid-crystalline polyester is provided that can manufacture a film having a small volume expansion by heating. An aromatic liquid-crystalline polyester substantially comprising a repeating structural unit originating in 2-hydroxy-6-naphthoic acid 30 to 80 mol %, a repeating structural unit originating in aromatic diol 35 to 10 mol %, and a repeating structural unit originating in aromatic dicarboxylic acid 35 to 10 mol %.

Disclosed is a nonreducible dielectric composition. Provided is a highly reliable TC based dielectric composition prepared by adding a sintering additive having excellent qualities to a conventional (Ca1-xSrx)m(Zr1-yTiy)O3 based dielectric composition, so that it can be sintered under a reducing atmosphere to be used in formation of a nickel electrode, can be sintered at a temperature of less than 1,300° C., and even more, at a low temperature of 1,250° C., and has a small dielectric loss and a high resistivity. The composition of the present invention includes a nonreducible dielectric composition comprising a main component expressed by the general formula, (Ca1-xSrx)m(Zr1-yTiy)O3, which has the ranges of 0<=x<=1, 0<=y<0.09, and 0.7<=m<=1.05; and 0.5-10 wt % of a minor component expressed by the general formula, aMnO-bSiO2-dR1O-eR2O2 (a+b+d+e=100, R1 is at least one element selected from the group consisting of Mg, Ca, Sr and Ba, and R2 is at least one element of Zr and Ti), which has the ranges of 20<=a<=60, 10<=b<=65, and 0<(d+e)<=65.

The invention discloses a millimetre wave planar antenna and an array thereof, wherein the millimetre wave planar antenna includes a metal patch, a medium substrate, a metal floor board and ground poles, the metal patch is placed on an upper surface of the medium substrate, and a lower surface of the medium substrate is fixed with an upper surface of the metal floor board; the metal patch is parallel to the upper surface of the metal floor board; the metal patch is provided with at least one pair of same first bar-shaped channels, each pair of first bar-shaped channels are distributed in bilateral symmetry form, symmetrical centre lines of each pair of bar-shaped channels are superposed, a centre line in a length direction of each first bar-shaped channel is parallel to each other, and length of each first bar-shaped channel is 1 / 2 of an operating wavelength; the ground poles vertically penetrate through the medium substrate, the ground poles are circularly distributed at intervals at the periphery of a region where the first bar-shaped channels are distributed, and two ends of each ground pole are respectively contacted with the metal patch and the metal floor board. The invention can reduce loss of a millimetre wave antenna, improve radiation efficiency of the millimetre wave antenna, simultaneously, guarantee work bandwidth of the antenna, and improve antenna gain.

There is provided a highly dielectric film which has highly dielectric property, can be made thin, being excellent in winding property (flexibility) and assures a small dielectric loss, and the highly dielectric film comprises a vinylidene fluoride type polymer (A), and compound oxide particles (B) represented by the formula: MaTibOc, wherein M is a metallic element of the group II of from the second period to the fifth period in Periodic Table; a is from 0.9 to 1.1; b is from 0.9 to 1.1; c is from 2.8 to 3.2, and the compound oxide particles (B) are contained in an amount of 10 to 500 parts by mass based on 100 parts by mass of the vinylidene fluoride type polymer (A).

The invention discloses a method for manufacturing a high frequency copper-clad plate. The high frequency copper-clad plate is manufactured by taking a high frequency material, namely polytetrafluorothylene (PTFE) as a base material and cladding a copper clad on two surfaces of the PTFE through PFA. The manufacturing method comprises the steps of cutting, pretreatment, laminating hot pressing, edge cutting and the like. The method adopts the PTFE with low dielectric constant as a medium for filling the high frequency material, and the manufactured high frequency copper-clad plate has lower dielectric constant and less dielectric loss; and by testing, the dielectric constant can reach 2.0 to 2.2, the dielectric loss is lower, and the high frequency copper-clad plate makes the information transmit more clearly and really during information transmission, and can meet the requirement of 3G information development.

The invention provides a method for manufacturing a CEM (Composite Epoxy Material Grade)-3 copper-clad plate with a high dielectric constant and low loss. The method for manufacturing the CEM-3 copper-clad plate with the high dielectric constant and the low loss comprises the following steps of: firstly, preparing epoxy resin liquid; carrying out surface treatment on composite fillers; preparing composite resin liquid; preparing a bonding sheet; and finally, pressing a lamination plate. The method provided by the invention uses bisphenol A epoxy resin with low cost, good manufacturability and good dielectric properties as main resin, and the problems of the cost and the manufacturability of a product can be solved; the high-dielectric fillers are partially composited by using a special curing agent, so that a curing article has a high dielectric constant, low loss, good thermal resistance, and high mechanical strength; and the CEM-3 copper-clad plate manufactured by the method disclosed by the invention has the advantages of simple process, low cost and good properties.

The invention relates to explosion-proof vacuum pressure impregnated insulation device and its process which is used in high-tension motor winding loop impregnated insulation paint, it characterized in that: condensator connected with refrigerator is set on the vacuum tube between the impregnating vessel and vacuum set, and collecting vessel is set on bottom of the impregnating vessel, one end of the collecting vessel is connected with the impregnating vessel, the another end is connected with the paint pipelines of storing vessel via transferring valve and returning valve. Using the device and the process, the remained insulation paint and dissolvent in the impregnating vessel can be solved, when the vacuum set vacuumizes the impregnating vessel, the explosive fuel phenylethene deflocculating agent can not be sucked to the vacuum set to gel and jam, it possesses practical effects of explosion-proof, safe reliability, saving raw material.

The invention relates to a prepreg manufactured from aromatic synthetic fiber paper used as a printed circuit board, and a copper clad board as well as printed circuit board manufactured from the prepreg. The synthetic fiber paper used as the base material of the base board of the circuit board is manufactured from the following materials in percentage by weight: 10-90% of structural fiber (para-position aramid fiber) and 90-10% of tacky fiber (para-position aramid fibrid or pulp). In the invention, the base board of the circuit board and the printed circuit board using the synthetic fiber paper as the base material have the advantages of light weight, good temperature tolerance, high thermal stability and fine processability.

The invention discloses a microstrip line filter, which comprises a chamber which is provided with a PCB plate; the top and bottom inner wall of the PCB plate and the chamber are provided with a certain air height; the two sides of the PCB plate are both provided with corresponding cross cascaded transmission line and the cross cascaded transmission line arranged on one side of the PCB plate is connected with the transmission line on the other side through a hole. The invention also discloses a corresponding duplexer and a radio-frequency device. The embodiment of the invention has the advantages of simple producing processing, high quality rate, low transmission loss, low cost, etc.

The invention provides an antenna housing substrate and a preparation method thereof. The antenna housing substrate is prepared by mixing substrate resin with any one of hollow microspheres, aerogel, a foaming agent and mixture of the hollow microspheres and the aerogel and applying an extrusion forming or injection molding technology. The antenna housing substrate prepared by the method is provided with no glass fiber reinforcing layer, so that the dielectric loss is low, the dielectric constant is low; meanwhile, substrates of different performances can be prepared through design of the formula; the industrial production requirements are met; and the antenna housing substrate has good development and application prospect.

The invention discloses a making method of a microwave and high frequency multilayer circuit board, and the method comprises the following steps: step one, making gerber templates and outer graphics; step two, making inner graphics; step three, laminated making and surface coating. The making method is high in precision and steady in the performance of the made circuit board, and besides dielectric constants are stable and dielectric loss is small.

The invention relates to a thermosetting resin composition and prepreg and laminate prepared therefrom. The thermosetting resin composition contains the following ingredients in parts by weight: 50-150 parts of cyanate, 30-120 parts of epoxy resin, 20-70 parts of allyl benzene-maleic anhydride, 20-100 parts of polyphenyl ether, 30-100 parts of halogen-free flame retardant, 0.05-5 parts of curing accelerator and 50-200 parts of filler. The prepreg and the laminate, which are manufactured from the thermosetting resin composition, have the comprehensive properties of low dielectric constant, low dielectric loss, excellent flame retardance, heat resistance and wet resistance and the like, and are suitable for being applied to halogen-free high-frequency multilayer circuit boards.

Multilayer ceramic chip capacitors which satisfy X8R requirements and which are compatible with reducing atmosphere sintering conditions so that non-noble metals such as nickel and nickel alloys thereof may be used for internal and external electrodes are made in accordance with the invention. The capacitors exhibit desirable dielectric properties (high capacitance, low dissipation factor, high insulation resistance), excellent performance on highly accelerated life testing, and very good resistance to dielectric breakdown. The dielectric layers comprise a barium titanate base material doped with other metal oxides such as BaO, Y2O3, ZrO2, SiO2, MgO, MnO, MoO3, CaO, Lu2O3, Yb2O3, or WO3 in various combinations.

A nanometer ceramic material dopant, medium material of ceramic capacitor and their production are disclosed. The formula of the dopant consists of aA.bB.cC.dR2 O3.eSiO2; A contains Na2O; B contains one or multiple of MgO and CaO; C contains one or multiple of MnO2 and Co3O4; R contains one of multiple of Y, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, among them a, b, c, d and e are coefficient, by computing mol%, 0<=a<=10%, 0<=b<=25%, 0<=c<=15%, 20%<=d<=60%, 10%<=e<=50% and b and c can't be zero at same time. Its advantages include large capacity, adjustable material formula, low sintering temperature, less medium loss, high dielectric constant and better reliability.

An aromatic liquid-crystalline polyester with good moldability into a film is provided. The resulting film has small dielectric loss. The polyester comprises repeating units represented by formulae (I), (II), (III) and (IV), and the molar amounts of repeating units (I)-(IV) are 40-74.8%, 12.5-30%, 12.5-30% and 0.2-15%, respectively, wherein the molecular amounts of repeating units (III) and (IV) satisfy the relation of (III) / [(III)+(IV)]≧0.5.

The invention discloses a high-frequency resin composition. The high-frequency resin composition comprises the following components in parts by weight: (a), 15-80 parts of anhydride-modified benzoxazine resin prepolymer, (b),10-60 parts of halogen-free epoxy resins, (c), 5-40 parts of fire retardant, (d), 0.001-2 parts of accelerant and (e), 0-70 parts of inorganic fillers, wherein the number-average molecular weight of the anhydride-modified benzoxazine resin prepolymer is 400-20000. The preparation method of the anhydride-modified benzoxazine resin prepolymer comprises the following steps of: getting and placing benzoxazine and anhydride compounds in a reaction bottle, heating up to 60 DEG C to 200 DEG C, adding a catalyst which is 0%-2% of the total weight of the reactants, and reacting for 10minutes-150minutes to obtain uniform and transparent anhydride-modified benzoxazine resin prepolymer. According to the high-frequency resin composition as well as a semi-cured sheet and a laminated board manufactured by the high-frequency resin composition, the anhydride-modified benzoxazine resin prepolymer is used for lowering concentration of hydroxyl groups generated by the epoxy resin curing process by the anhydride, so that the content of benzene ring is relatively improved, and the dielectric constant and the dielectric loss of the product are greatly lowered.

The invention discloses a cavity bubble system of the rubidium atom frequency standard. Integrated filtering absorption bubbles are fixed in a medium tube through heat conduction silicone grease and are arranged on one side of a microwave cavity, the direction of a microwave magnetic field is perpendicular to a coupling ring, one end of a heating tube is a full closed end, a heating power tube is fixed on the heating tube through a screw, a C field coil is wound around the medium tube, and two ends of the C field tube are fixed through insulation clamping rings. the integrated filtering absorption bubbles, the C field coil, the insulation clamping rings are placed in the microwave cavity, a microwave circuit plate covers one open end of the microwave cavity and is placed in the heating tube with the microwave cavity, one end of the coupling ring is connected with a phase step diode, and the other end of the coupling ring is connected with an external radio frequency signal wire. The phase step diode is welded on a microwave circuit board, a photoelectric cell is bonded to the microwave circuit board, and the heating power tube is fixed on the microwave cavity through a screw. The cavity bubble system is simple in structure, small in size, simple in cavity frequency micro-adjustment, high in performance index and easy to process.

Multilayer ceramic chip capacitors which satisfy X8R requirements and which are compatible with reducing atmosphere sintering conditions so that non-noble metals such as nickel and nickel alloys thereof may be used for internal and external electrodes are made in accordance with the invention. The capacitors exhibit desirable dielectric properties (high capacitance, low dissipation factor, high insulation resistance), excellent performance on highly accelerated life testing, and very good resistance to dielectric breakdown. The dielectric layers comprise a barium titanate base material doped with other metal oxides such as BaO, Y2O3, ZrO2, SiO2, MgO, MnO, MoO3, CaO, Lu2O3, Yb2O3, or WO3 in various combinations.

The invention relates to the technical field of inorganic nonmetallic materials, in particular to a barium calcium zirconate titanate leadless piezoelectric ceramic material. A formula comprises components as follows: 91wt.%-98 wt.% of (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3, 0.1 wt.%-7.0wt.% of BiFeO3, 0.01 wt.%-1wt.% of Bi2WO6, 0.1wt.%-4wt% of Ba(Yb1 / 2Nb1 / 2)O3 and 0.01wt.%-1.8wt.% of Co2O3, wherein (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 is prepared from ordinary chemical raw materials for piezoelectric ceramics, the leadless piezoelectric ceramics which are cadmium-free and have a high-tension electricity property are prepared, the sintering temperature of the piezoelectric ceramics can be greatly reduced, the barium calcium zirconate titanate leadless piezoelectric ceramic material is suitable for preparing a piezoelectric ceramic sensor, and the cost of the piezoelectric ceramics can be greatly reduced.

The invention provides a dielectric medium of a ceramic capacitor, which is prepared from the following raw materials in percentage by weight: 54 to 91 percent of BaTiO3, 2 to 13 percent of SrTiO3, 2 to 15 percent of BaZrO3, 0.05 to 1 percent of Nb2O5, 0.03 to 1.0 percent of CeO2, 0.1 to 1.0 percent of ZnO, 0.03 to 1.0 percent of Co2O3, and 2 to 15 percent of BaSiO3. The invention also provides apreparation method of the dielectric medium of the ceramic capacitor. The dielectric medium of the ceramic capacitor has high dielectric constant and high withstand voltage, generates no pollution tothe environment in the process of preparation and use, and can reduce the cost of the ceramic capacitor, so the dielectric medium is suitable for preparing monolithic ceramic capacitors and multilayer chip ceramic capacitors.

The invention provides a production method of a polyoxazolidone laminated board, comprising the following steps: reacting diisocyanate with epoxide resin by taking imidazole compounds as catalyst for producing polyoxazolidon resin during the gradual rise of temperature; and then producing the polyoxazolidone laminated board by using the polyoxazolidon resin. The polyoxazolidone laminated board the end of which is sealed with isocyanate has better mechanical strength, favorable heat resistance and high glass transition temperature above 155 DEG C; and when in use at 180 DEG C or 200 DEG C, the mechanical property and electrical propertye of the polyoxazolidone laminated board are over 70 percent.

This invention relates to a ceramic-based wave-permeable loading body used in micro-wave heating conditions. The components of this invention products have the representation of: xMeO.yAl2O3.zSiO2, wherein Me=magnesium or yttrium, and the specific (weight percentages) of the components: 2%<=x<=8; 35%<=y<=45%; 50%<=z<=60%, and x+y+z=100%. After that, it is added with adhering agent of 5-8% of the total raw materials above-mentioned, and making blanks and being sintered to obtain final products. This inventive products have advantages of: dielectric constant=6-10, very low expansibility during heating, excellent thermal shock-resistance, its softening point during loading>=1600deg.C, can be used for making tubes, plates, bricks and crucibles.

The invention discloses a preparation method of polyimide / CCTO@Ag nanoparticle composite material with high dielectric and low loss. According to the method, polyimide is used as matrix, the prepared CCTO@Ag nanoparticles are ultrasonically dispersed in absolute ethyl alcohol, then is blended with polyimide monomer in solvent, then in situ polymerization reaction is carried out on the monomer at room temperature to simultaneously realize copolymerization of polyimide and intercalation recombination with the CCTO@Ag nanoparticles, obtained stock solution is subjected to gradient annealing according to a coating method to finally obtain the polyimide / CCTO@Ag nanoparticle composite film. Compared with pure polyimide, the polyimide / CCTO@Ag nanoparticle composite material prepared according to the preparation method has the dielectric constant (103) increased by 30 times, also has low dielectric loss (0.006) and can be widely applied in fields of high energy storage capacitors, artificial organs, high speed integrated circuits, and the like.