2772 results about "Dielectric loss" patented technology

The invention discloses a distribution network cable dielectric loss withstand voltage partial discharge intelligent detection and evaluation method and system, and relates to the technical field of power equipment state monitoring, and the method comprises the steps: synchronously collecting a dielectric loss spectrum, a withstand voltage leakage current curve and a partial discharge spectrum of a distribution network cable through a phase resolution measurement device; processing the partial discharge spectrum by using a frequency domain adaptive filter to generate a denoised partial discharge characteristic spectrum; constructing a cable multi-dimensional parameter normal domain hyperspherical model, and calculating a deviation distance value; and inputting the deviation distance value into a fuzzy inference engine, performing nonlinear conversion according to a preset fuzzy rule base, generating an insulation state evaluation index and a fault risk probability distribution diagram of the distribution network cable, and realizing accurate evaluation of the cable insulation state. According to the invention, the accurate evaluation of the cable insulation state and the accurate positioning of the fault position are realized, and the operation reliability and maintenance efficiency of the power distribution network are improved.

The invention discloses a cable oscillation ultralow-frequency withstand voltage and partial discharge integrated test method and system, and relates to the technical field of distribution network cable detection, and the method comprises the steps: applying an oscillation ultralow-frequency voltage signal to a tested cable; the oscillation ultra-low frequency voltage signal is optimized and adjusted through a manifold learning algorithm and is used as a common excitation source for a withstand voltage test, dielectric loss detection and partial discharge detection; acquiring a voltage signal and a current signal of the tested cable under the excitation of the oscillation ultralow-frequency voltage signal, analyzing the deviation degree of the voltage signal and the current signal from the pre-established characteristic manifold, and extracting a dielectric loss characteristic signal and a partial discharge pulse signal; calculating a dielectric loss parameter based on the dielectric loss characteristic signal, determining a partial discharge position based on the partial discharge pulse signal, and generating a cable insulation state diagnosis report according to the dielectric loss parameter and the partial discharge position. According to the invention, the cable testing efficiency is improved, the equipment burden and the testing time are reduced, comprehensive evaluation and accurate fault positioning of the insulation state are realized, and a scientific basis is provided for preventive maintenance of a power system.

The invention relates to the technical field of bushing detection, and discloses a bushing insulation state detection method based on multi-parameter real-time monitoring. The method comprises the following steps: acquiring multi-dimensional monitoring data such as a partial discharge pulse sequence, dielectric loss angle tangent value fluctuation data and surface leakage current density distribution in a bushing operation environment in real time; carrying out insulation defect feature extraction on the data set, and generating an insulation defect distribution map containing a creeping discharge track, an internal air gap position mark and a carbonization channel density index; high-risk and potential defect areas are divided by adopting a dynamic threshold segmentation algorithm, boundary coordinates are determined, and an insulation state evaluation vector containing parameters such as a surface discharge intensity index and the like is constructed according to the boundary coordinates; and inputting the vector into a pre-trained insulation aging prediction model, and outputting a bushing residual insulation life estimated value and a defect development priority sequence. According to the method, all-around accurate monitoring and pre-judgment of the insulation state of the sleeve are achieved, and scientific support is provided for operation and maintenance decision making of the sleeve.

The invention relates to the technical field of ceramic substrates, and provides a low-dielectric-loss multilayer ceramic substrate and a preparation method thereof. The low-dielectric-loss multilayer ceramic substrate is prepared from, by weight, 90-100 parts of aluminum oxide, 1-3 parts of plasticizer, 3-5 parts of sintering aid, 6-10 parts of binder, 1-3 parts of dispersing agent and 50-60 parts of water, the aluminum oxide is composed of first aluminum oxide and second aluminum oxide, and the first aluminum oxide and the second aluminum oxide are different in form. According to the technical scheme, the problem of high dielectric loss of the multilayer ceramic substrate in the prior art is solved.

The invention relates to the technical field of low-dielectric heat-conducting functional materials, in particular to a nano silicone rubber composite material as well as a preparation method and application thereof. According to the preparation method, a modified vinyl silsesquioxane coupling agent is taken as a bridge, and boron nitride nanosheets, silicon carbide nanowires and the modified vinyl silsesquioxane coupling agent are covalently connected through hydrolysis reaction, so that a heterostructure is constructed, and the nano heat-conducting filler is obtained; the preparation method comprises the following steps: dispersing a nano heat-conducting filler in vinyl silicone oil, and constructing a covalent cross-linked network through addition cross-linking reaction and curing treatment to obtain the nano composite silicone rubber material. According to the processing method, the filling amount, the dielectric constant and the dielectric loss can be reduced, meanwhile, the heat conduction capacity is improved, and the problems that in the prior art, the dielectric constant and the dielectric loss are low due to simple mixing of the boron nitride nanosheets and the silicon carbide nanowires are solved.

The invention provides a terahertz horn antenna and a preparation method thereof, and relates to the technical field of mobile communication systems. The antenna layer is arranged to be the antenna layer with the horn antenna groove structure, and due to the advantages of the horn antenna, the terahertz horn antenna has the advantages of being simple in structure, convenient to control gain, excellent in frequency characteristic, small in loss and the like. Moreover, the antenna layer and the radio frequency layer provided by the invention are fixed through bonding of the radiation electrode and the metal film, so that a low-reflection interconnection channel is realized, THz waves can be limited in a bonding area, the problem of electromagnetic leakage caused by stacking of the antenna layer and the radio frequency layer is avoided, and the performance of the terahertz horn antenna is improved. According to the terahertz horn antenna, the antenna layer and the radio frequency layer both adopt the glass substrates, the glass substrates have the advantages of high mechanical strength, small dielectric loss and the like, and the glass substrates can bear higher temperature, so that the problems of warping and deformation of the substrates are reduced, and the preparation quality of the terahertz horn antenna can be improved.

The invention relates to the technical field of capacitor films, in particular to a high-temperature-resistant polypropylene capacitor film and a preparation method thereof.The high-temperature-resistant polypropylene capacitor film is prepared from, by weight, 94-98 parts of polypropylene resin, 1-3 parts of filler-doped modified balance adjusting agent, 0.5-2 parts of boron nitride-glass fiber combined agent, 0.05-0.4 part of nucleating agent, 0.2-0.4 part of antioxidant and 0.1-0.4 part of silane coupling agent; the high-temperature-resistant polypropylene capacitor film is obtained through the processes of melting extrusion molding, cooling shaping, preheating, two-way stretching, heat shaping, rolling and the like of the raw material composition. The polypropylene resin, the nucleating agent, the antioxidant and the silane coupling agent are blended, the filler-doped modified balance adjusting agent and the boron nitride-glass fiber coupling agent are added, and the raw materials are blended and coordinated, so that high feasibility of a two-way stretching process is guaranteed, breakdown resistance, mechanical strength and dielectric loss performance of the product are optimized, and the product has good mechanical properties. And meanwhile, the high-temperature-resistant and corrosion-resistant stability effects are remarkable.

The invention relates to a preparation method of spherical silicon dioxide micropowder with ultralow dielectric loss. The preparation method comprises the following steps: preparing an organic silicon polymer; preparing slurry; performing solid-liquid separation on the synthetic slurry to obtain concentrated slurry, and drying the concentrated slurry to obtain spherical silica powder; carrying out low-temperature heat treatment on the obtained spherical silica powder at 1500-7000 DEG C for h to remove residual organic matters and free water in the powder; then, high-temperature densification is carried out at the temperature of 3000-28000 DEG C for h, and moisture is further removed; adding a modifier into the stirring equipment for surface modification; and after surface modification, drying at 55-300 DEG C for h, and removing modified micromolecular byproducts to obtain the spherical silicon dioxide micro powder with ultralow dielectric loss. The method is simple in production process, short in production period, low in production cost, high in yield and capable of effectively reducing the dielectric loss of the spherical silicon dioxide micro powder.

The invention provides a low-dielectric glass fiber composition, a low-dielectric glass fiber and a preparation method thereof, and the low-dielectric glass fiber composition comprises the following components in molar percentage: 54 to 60 percent of SiO2, 21 to 32 percent of B2O3, 1.0 to 9.5 percent of Al2O3, 3 to 16 percent of alkaline earth metal oxide, 0.01 to 4.0 percent of ZrO2, 0.1 to 4.0 percent of TiO2, 0.01 to 2.0 percent of LiO2 and 0.5 to 5.0 percent of F2. Wherein the alkaline earth metal oxide comprises CaO and MgO, and according to the molar percentage, the CaO accounts for 0.01%-4.0%, and the MgO accounts for 0.5%-8.0%. According to the glass fiber, SiO2 and B2O3 are taken as main components of the glass, SiO2 can be taken as a network former of a glass structure, on one hand, part of B2O3 can form a [BO4] tetrahedral structure to enter a glass silica network structure so as to play a role in reinforcing a net, and on the other hand, B2O3 can effectively inhibit ion polarization so as to reduce the dielectric constant and dielectric loss of the glass fiber; according to the present invention, the specific type of the alkaline earth metal oxide is added, and the certain content of the Al2O3, the ZrO2, the TiO2, the LiO2 and the F2 is supplemented so as to further reduce the dielectric constant and the dielectric loss of the glass fiber, and the cooperative control of the components is beneficial to the improvement of the glass processing property and the guarantee of the glass fiber drawing stability.

The invention discloses an automobile wire harness parameter performance test method and system, and relates to the field of intelligent monitoring and predictive protection of electrical equipment, and the method comprises the steps: extracting the trend intensity, fluctuation characteristics and abnormal frequency of resistance change based on a high-precision micro-resistance change rate data stream, and carrying out the fusion to generate a three-dimensional characteristic electric pulse signal; according to the three-dimensional characteristic electric pulse signal, a decision result is converted into a control instruction to drive an execution mechanism to execute safety diagnosis regulation and control, and an equipment operation log is generated; based on an equipment operation log, positioning an overheat area by combining a Brillouin scattering principle, measuring dielectric loss change of an insulating material, and generating a diagnosis verification report; according to the diagnosis verification report and the decision result, the neural pathway connection weight is dynamically optimized, and a wire harness performance report is generated; intelligent extraction and compression coding of resistance change characteristics under complex working conditions are realized by adaptively adjusting threshold control parameters, and three-level response decisions are driven to complete fault grading judgment and execution in a millisecond-level time window.

The invention discloses a motor insulation breakdown voltage prediction method based on a continuous hidden Markov model, and the method comprises the steps: taking a plurality of groups of obtained experimental data of an insulating material of a motor in different motor operation time periods as a training set, and enabling the experimental data to comprise capacitance, insulation resistance, dielectric loss, maximum discharge capacity and breakdown voltage; constructing a continuous hidden Markov model by taking the test parameters as an observation sequence and taking the discretized breakdown voltage as a hidden state; performing iterative calculation on parameters of the continuous hidden Markov model through a Baum-Welch algorithm based on the training set, and determining optimal parameters of the continuous hidden Markov model; and based on the continuous hidden Markov model of the optimal parameters, determining a hidden state sequence with the maximum probability under the observation sequence at the current moment through a Viterbi algorithm, and determining the breakdown voltage at the current moment based on the hidden state sequence with the maximum probability. According to the invention, the breakdown voltage of the motor insulating material in the motor operation process can be effectively predicted.

The invention discloses an electronic communication cable detection device in the technical field of cable detection, and the device comprises a workbench, an insulation tester and a dielectric loss tester, the workbench is provided with a darkroom, the axial side wall of the darkroom is symmetrically provided with ports, the ports are internally and fixedly connected with window shades, and the interior of the darkroom is fixedly connected with a defect detection assembly. A roller assembly is fixedly connected to the outer side wall of the darkroom, multi-stage clamping assemblies located on the two sides of the darkroom are symmetrically and fixedly connected to the top of the workbench, a controller is fixedly connected to the workbench, and the flaw detection assembly, the roller assembly, the multi-stage clamping assemblies, the insulation tester and the dielectric loss tester are all in signal connection with the controller. According to the invention, through multi-stage screw-in self-adaption to cables with different diameter specifications, the clamping stability is ensured, and the pressure sensor cooperates with the electrical performance detection instrument and the camera to integrate various detections, so that the detection cost is reduced, the detection accuracy is improved, and the cable to be detected is prevented from being damaged in the detection process.

The invention discloses a power capacitor bank dielectric loss on-line monitoring method, particularly relates to the technical field of power system equipment insulation state monitoring, and is used for solving the problems of insufficient signal synchronization precision and large dielectric loss calculation error under complex electromagnetic interference in the existing method. The method comprises the following steps: acquiring voltage and current signals in real time and dynamically tracking fundamental frequency; intercepting a main period waveform, constructing phase space trajectory analysis complexity, and generating distortion features in combination with symbol sequence transfer entropy; dynamically adjusting filtering parameters based on the distortion characteristics and the Lyapunov exponent gradient; calculating a high-precision phase difference through zero crossing point interpolation correction and sliding window filtering, and finally determining a dielectric loss value; through dynamic frequency tracking, nonlinear feature collaborative analysis and an adaptive filtering strategy, noise interference is effectively suppressed, phase synchronization precision and dielectric loss calculation reliability are improved, and accurate and real-time monitoring support is provided for insulation performance evaluation of the power capacitor bank.

The invention discloses an extra-high voltage DC bushing insulation state monitoring system and method, and belongs to the technical field of bushing monitoring, and the system comprises a monitoring platform, a bushing partial discharge monitoring device, and a bushing dielectric loss, capacitance and leakage current monitoring device. The bushing partial discharge monitoring device comprises a high-frequency partial discharge acquisition module and a high-frequency pulse current sensor, and the high-frequency pulse current sensor, the high-frequency partial discharge acquisition module and the monitoring platform are in signal connection in sequence; the bushing dielectric loss, capacitance and leakage current monitoring device comprises a dielectric loss acquisition module, a leakage current sensor and a signal sampling unit, the leakage current sensor and the signal sampling unit are both in signal connection with the dielectric loss acquisition module, and the dielectric loss acquisition module is in signal connection with the monitoring platform. According to the invention, through integration of the monitoring platform and the monitoring equipment, comprehensive real-time monitoring of the running state of the sleeve is realized.

The invention relates to the technical field of radio frequency integrated circuits and advanced semiconductor packaging, in particular to a multilayer spiral inductor structure based on an RDL process and a preparation method. The preparation method comprises the steps of seed layer deposition, gradient line width coil formation through photoetching and electroplating, alternate dielectric layer deposition, through hole etching to form vertical interconnection copper columns, air bridge forming through a photoresist sacrificial layer process and silicon nitride passivation packaging. Through fan-shaped topological layout, dielectric material collaborative optimization and three-dimensional interconnection structure design, the self-resonant frequency bandwidth is effectively improved, conductor and dielectric loss is reduced, and miniaturization integration and high reliability of high-frequency inductance elements are achieved.

The invention discloses a polypyrrole / cobalt / nitrogen-doped carbon composite material with a coaxial hollow structure and a preparation method thereof, and belongs to the technical field of advanced functional composite materials. The method comprises the following steps: firstly, synthesizing a hollow polypyrrole nanotube by a soft template method; secondly, cobalt / nitrogen-doped carbon is synthesized by adopting a template guiding method; and finally, secondarily coating the outer surface of the cobalt / nitrogen-doped carbon with a polypyrrole layer by adopting an in-situ oxidative polymerization method to construct the polypyrrole / cobalt / nitrogen-doped carbon composite material with a coaxial hollow heterostructure, and the polypyrrole / cobalt / nitrogen-doped carbon composite material has a coaxial sandwich structure: the inner core is a nitrogen-doped carbon hollow tube, the middle layer is a nitrogen-doped porous carbon matrix embedded with cobalt nanoparticles, and the outer surface of the cobalt / nitrogen-doped carbon composite material is a porous carbon matrix embedded with cobalt nanoparticles. And the outer layer is a conductive polypyrrole coating layer. The preparation method provided by the invention can successfully realize in-situ confinement growth and stable combination of ZIF-67, and has the advantages of high repetition rate, high yield and simple method; by adjusting the proportion of polypyrrole in the composite material, good impedance matching and large dielectric loss can be realized, and excellent electromagnetic wave absorption performance can be obtained.

The invention discloses a method and system for testing the electrical performance of a semiconductor chip, and the method comprises the steps: building a mapping relation between dielectric loss and loss frequency through obtaining the dielectric loss data, internal material characteristics and dynamic load power factors of the chip under each frequency band, recognizing a loss abnormal region, and analyzing the influence of the loss abnormal region on the performance of the chip; correcting test data by adopting a minimum mean square error algorithm, and optimizing the impedance of the power supply network and the dynamic switching characteristic of a functional module; calculating the breakdown voltage distribution of each layer in the chip, identifying a high-voltage risk region, optimizing the voltage distribution by using a gradient descent algorithm, and dynamically adjusting the working voltage and current; power factor fluctuation is analyzed through a sliding window algorithm, an abnormal area is identified, a power factor is optimized through a PID algorithm, and the working state and transient response of a chip in a dynamic load are improved. According to the method, the problems of nonlinearity of high-frequency dielectric loss, non-uniform breakdown voltage distribution and unstable power factor response under a dynamic load are solved, and comprehensive and accurate evaluation and optimization of chip performance are realized.

The invention discloses a transparent antenna for microwave energy transmission and a preparation method and application thereof, and belongs to the technical field of antennas. The transparent antenna comprises a radiation patch, a radiation patch substrate, a dielectric substrate, a reflection backboard substrate and a reflection backboard which are arranged in sequence. Wherein the radiation patch and the reflection backboard are copper nets; the dielectric substrate is of a hollow frame-shaped structure. The preparation method is simple, the adopted materials and the preparation process are both existing mature technologies, large-scale industrial production is easy to achieve, metal copper is adopted to replace traditional transparent metal (ITO), the cost of raw materials is reduced, high-transparency PET and PDMS are adopted as the preparation materials, it is guaranteed that the antenna has high transmittance in the visible light wave band, and the antenna is suitable for large-scale industrial production. Through the combination of the optimized pattern design of the antenna radiation layer and the dielectric substrate with the frame-shaped structure, the energy transmission efficiency and radiation performance of the antenna are remarkably improved, and the dielectric loss of the antenna is reduced.

The utility model relates to an antenna unit, an antenna array, an antenna device and a base station system.The antenna unit comprises an insulating base material plate, a feed network, a metal ground layer, a reflecting plate, an insulating base material arm, a radiation arm and a feed balun, the feed network is connected to the insulating base material plate, the metal ground layer is connected to the insulating base material plate, and the metal ground layer and the feed network are located on the same side of the insulating base material plate; at least part of the reflecting plate is arranged on the side, away from the insulating base material plate, of the metal ground layer, the reflecting plate is in coupling connection with the metal ground layer and the feed network, the insulating base material arm is connected to the insulating base material plate and located on the side, away from the feed network and the metal ground layer, of the insulating base material plate, and the radiation arm is arranged on the insulating base material arm. The feed balun is arranged on the insulating base material arm, one end of the feed balun is electrically connected with the feed network, the other end of the feed balun is electrically connected with the radiation arm, and the feed balun is used for feeding the radiation arm. According to the antenna unit, the dielectric loss of the feed network can be reduced, the coupling between the feed network and the radiation arm is reduced, and the radiation performance and isolation of the antenna unit are improved.

The invention discloses spherical silicon dioxide, a high-frequency high-speed copper-clad plate and a preparation method of the spherical silicon dioxide. The dielectric constant Dk of the spherical silicon dioxide is 3.5 F / m-4. 0F / m, the dielectric loss Df is 0.0001-0.005, the amorphous state proportion is larger than or equal to 99%, the spheroidization rate is larger than or equal to 99%, and the porosity is 0.1%-2%. During preparation, the hydrolysis degree is controlled till partial polycondensation is achieved, then under the oxygen introduction condition, pre-oxidation is conducted at the low temperature to remove alkyl, gradient calcination is conducted at the high temperature, local crystallization influence and defect influence caused by powder spontaneous combustion are prevented, meanwhile, viscous bodies in the microspheres are accurately controlled to flow to fill nanoscale pores, and the particle size is reduced. The spherical silicon dioxide with high purity, high spheroidization rate and low dielectric loss is obtained, the dielectric property of the high-frequency and high-speed copper-clad plate can be met, and the high thermal stability and high reliability of the high-frequency and high-speed copper-clad plate are improved.

The invention discloses a C-band ultralow-loss self-bias hexagonal gyromagnetic ferrite material, and belongs to the technical field of ferrite material preparation. The ferrite material comprises a BiCaZrVIn-YIG gyromagnetic ferrite material and a LaScBiCu-BaM hexagonal gyromagnetic ferrite material, wherein the weight ratio of the BiCaZrVIn-YIG gyromagnetic ferrite material to the LaScBiCu-BaM hexagonal gyromagnetic ferrite material is 0.1 to 10; the doping agent accounts for the weight percentage of the ferrite material, and the doping agent comprises the following components in percentage by weight: 0.3-0.7 wt% of La2O3, 0.4-0.8 wt% of SiO2 and 0.5-0.9 wt% of SrTiO3. According to the invention, LaScBiCu-BaM hexagonal gyromagnetic ferrite with high Mr / Ms and Hc characteristics is grown on the surfaces of low-loss BiCaZrVIn-YIG gyromagnetic ferrite particles, and a hexagonal gyromagnetic ferrite material with high and adjustable anisotropic field Ha, high coercive force Hc and residual magnetism ratio Mr / Ms, ultralow ferromagnetic resonance line width H and dielectric loss tan delta epsilon characteristics is developed. And the engineering requirements of low loss and wide bandwidth of the C-band miniature integrated device are met.

The invention provides a current transformer dielectric loss anti-interference measurement method based on a variable frequency power supply, and relates to the technical field of power detection, and the method comprises the steps: constructing an excitation channel, collecting a background response signal, recognizing a main interference frequency through combining a frequency tracking algorithm, and dynamically constructing a frequency deviation parameter; generating a pair of non-power-frequency excitation frequency control variable-frequency power supplies to output sine wave excitation signals; excitation voltage and response current signals are synchronously collected to form sampling signals, notch frequency is set according to frequency deviation parameters, main interference is filtered out, and first processing signals are obtained; performing weighting processing by constructing a window function matched with the frequency band characteristic to generate a second processing signal; the complex amplitude and phase information at the target frequency is extracted, the complex impedance is calculated based on the complex current method, the dielectric loss value of the current transformer is finally output, and the anti-interference capability and precision of measurement are effectively improved. According to the invention, the interference in the dielectric loss measurement of the current transformer can be processed, so that the measurement precision is improved.

The invention discloses a carbon-loaded high-entropy oxide and a preparation method thereof, the carbon-loaded high-entropy oxide is of a core-shell structure formed by coating carbon with a high-entropy oxide, and the high-entropy oxide comprises at least five metal elements of chromium, manganese, iron, cobalt, nickel and copper. The carbon-loaded high-entropy oxide has the advantages of low density, high dielectric loss and excellent wave-absorbing performance, and is expected to be widely applied to electromagnetic absorption and elimination in the fields of electronics, communication civil affairs and aerospace military.

According to the capacitor health state evaluation method and device, the storage medium and the computer equipment provided by the invention, the capacitor health state evaluation model is determined, and the capacitor health state evaluation model is used for controlling the fault-free sample capacitor to perform multi-state operation, and obtaining the electrical parameters of the sample capacitor in the multi-state operation; the temperature rise value of the sample capacitor under the multi-state operation is obtained, according to the electrical parameters and the temperature rise value corresponding to the sample capacitor, a classification prediction algorithm based on XGBoost is adopted, and the electrical parameters comprise the capacitance, the dielectric loss angle tangent value and the equivalent series resistance value; and acquiring an electrical parameter and a temperature rise value of the to-be-evaluated capacitor, and inputting the electrical parameter and the temperature rise value into the capacitor health state evaluation model to obtain a health state evaluation result of the to-be-evaluated capacitor. Therefore, the blank of the multi-parameter fusion evaluation method for the health state of the capacitor for the flexible direct current converter valve is filled, and different health states of the capacitor can be quickly and accurately identified.

The invention discloses a power transmission line insulator defect identification method based on deep learning, relates to the technical field of insulator defect identification, and aims to solve the technical problem that an existing identification method is low in identification precision under a photovoltaic fluctuation working condition. Comprising the following steps: S1, multi-modal data acquisition: synchronously acquiring image data, line harmonic time sequence data, insulator dielectric loss value data and photovoltaic power fluctuation data of a power transmission line insulator; s2, data preprocessing: performing scene adaptive enhancement on the image data, and performing fluctuation correlation interference filtering on harmonic time series data to obtain preprocessed data; and S3, constructing and training a deep learning model: constructing a dynamic weight fusion deep learning model containing a power fluctuation-feature sensitivity mapping mechanism, and training the model by adopting cross-scene and cross-component type labeling samples. The method has the advantage of improving the defect identification accuracy of the insulator in the photovoltaic station.

The invention discloses a phased-array antenna, the phased-array antenna comprises a plurality of antenna module units, each antenna module unit comprises a PCB and an integrated radome module, and the integrated radome module is arranged on the surface of the PCB; a feed network, a dielectric substrate and an antenna radiation patch are arranged on the PCB, and the PCB is used for realizing feed and partial radiation functions; the integrated antenna housing module comprises a honeycomb support, an antenna patch, a PET film and an antenna housing, the antenna patch is etched on the PET film, the honeycomb support, the PET film and the antenna housing are mutually connected to form an integrated structure, and the integrated antenna housing module is used for realizing wave transmission, bandwidth broadening and impedance matching. According to the phased-array antenna, the use cost of PCB materials is reduced, and the problem that the electrical performance of the phased-array antenna is reduced due to dielectric loss caused by excessive use of PCB materials is solved.

[Problem] To provide a thermosetting adhesive sheet, the cured product of which exhibits excellent adhesive properties and dielectric properties. [Solution] A thermosetting adhesive sheet having a 10-100 µm-thick adhesive layer composed of an adhesive composition that contains component A and component B, below, wherein the cured product of the adhesive layer exhibits a breaking elongation of 350-700% and a tensile stress of 1.2-6.5 MPa when elongated by 50% in a tensile test, and exhibits a dielectric loss tangent of 0.0001-0.01 and a relative permittivity of 1.0-3.0 at 23°C, 50% RH, and 28 GHz.　Component A: A resin composition containing a styrene elastomer　Component B: An inorganic filler

The invention provides a high-performance glass fiber composition and a method for preparing glass fiber by using the high-performance glass fiber composition, and the high-performance glass fiber composition comprises the following components in molar percentage: 61 to 67 percent of SiO2, 7.0 to 16.0 percent of B2O3, 0.1 to 16.0 percent of Al2O3, 3.0 to 12.5 percent of MgO, 0.02 to 9.0 percent of CaO, 0.01 to 5.0 percent of ZnO, 0.1 to 5.0 percent of ZrO2, 0.1 to 4.0 percent of TiO2, 0 to 3.0 percent of F2 and 0 to 4.0 percent of P2O5. Wherein F2 and P2O5 are not 0 at the same time. According to the invention, a plurality of specific component oxides with high ion field intensity and low polarizability are combined, and the proportion and addition amount of each component are controlled, so that the elastic modulus of the glass fiber is improved under the condition that the dielectric constant and dielectric loss are not improved, and the processing property of the glass fiber is ensured; the dielectric constant of the glass fiber is not more than 4.75, the dielectric loss is not more than 0.0035, and the elasticity modulus of the glass is not less than 75 GPa.

The invention discloses an insulation state evaluation method for a voltage transformer online monitoring device, and the method comprises the following steps: obtaining an original dielectric loss angle tangent value through a dielectric loss tester, and collecting the temperature and relative humidity through an environment sensor; performing temperature and humidity compensation on the collected dielectric loss angle tangent value to obtain a compensated dielectric loss angle tangent value; performing trend prediction on the compensated dielectric loss angle tangent value based on an autoregressive integral moving average model to obtain a predicted value; judging an abnormal state by comparing a predicted value with a dynamic threshold value; performing risk assessment by integrating the equipment state parameters, and outputting a corresponding maintenance decision according to an assessment result; according to the invention, the interference of environmental factors on the measurement of the dielectric loss angle tangent value is eliminated, and the measurement accuracy is improved; the abnormal change trend of the dielectric loss value is found in advance through trend prediction, and early warning is realized.

The invention discloses an all-dielectric structure type broadband wave-absorbing metamaterial and a design method thereof. The all-dielectric structure type broadband wave-absorbing metamaterial comprises a substrate and a plurality of resonators, the plurality of resonators are periodically and uniformly arrayed on the surface of the substrate, the adjacent resonators are connected with each other, each resonator comprises a pyramid structure unit and a grid structure unit, the pyramid structure units are nested in the grid structure units to form a pyramid-grid composite resonator, and the substrate and the resonators are both made of a high dielectric loss composite material. Based on the brand new design angle of wave absorbing performance complementation, the limitation of the wave absorbing performance of a single structure is broken through, the wave absorbing performance is improved from the microstructure level, meanwhile, efficient electromagnetic wave energy absorption is achieved in a wider frequency range, multi-stage dissipation and broadband impedance matching of incident electromagnetic waves are achieved, and the wave absorbing performance is improved. And the technical limitation of thickness constraint and narrow-band response of the traditional wave-absorbing material is broken through.