3847 results about "Impedance matching" patented technology

The invention relates to a multi-channel signal integrity optimization method and system for a passive copper cable, and the method comprises the steps: obtaining channel characteristic parameters and signal transmission requirements of the passive copper cable, and carrying out the impedance matching, and obtaining an optimized transmission channel; acquiring real-time transmission data of the passive copper cable, and performing equalization processing on the real-time transmission data through the optimized transmission channel to obtain a stable transmission signal; acquiring crosstalk interference data acquired by the passive copper cable, and carrying out shielding analysis on the crosstalk interference data and the optimized transmission channel to obtain a crosstalk suppression measure; performing frequency characteristic analysis on the crosstalk interference data to obtain frequency compensation information, and performing transmission prediction on the frequency compensation information based on the crosstalk suppression measure to obtain a frequency compensation parameter; and performing multi-channel optimization on the initial signal optimization result according to the frequency compensation parameter to obtain a multi-channel optimization signal. According to the invention, complex and changeable transmission environments can be coped, and stable transmission of signals is ensured.

The invention provides a self-adaptive impedance matching method and system of a microwave frequency band. The method comprises the following steps: performing initial impedance measurement on a plurality of microwave component ports to obtain a complex impedance parameter as a matching reference; in the operation process, a current impedance state and a reflection coefficient are collected through a reflection monitoring mechanism, and a dynamic impedance state vector is constructed; inputting the state information into an adaptive algorithm module, generating a matching parameter vector and configuring an adjustable device to realize real-time adjustment of a matching network; calculating a matching error according to the current reflection state and a target reference value, and driving parameters to be iteratively updated; after the matching precision requirement is met, the final parameters are loaded to the controller to complete actual configuration; meanwhile, the system periodically collects environmental parameters and matching effects, and dynamically judges whether rematching is needed or not so as to maintain long-term stable operation of the system. The method has the capabilities of automatic sensing, closed-loop optimization and environmental change adaptation, and can improve the matching efficiency and signal transmission quality of a microwave system under multi-band and high-dynamic working conditions.

The invention provides a graphene super-capacitor capacity energy-saving control method based on an intelligent algorithm, and the method comprises the steps: obtaining the harmonic content data of a power grid, carrying out the spectrum analysis of the harmonic content through a Fourier transform algorithm, and obtaining the change trend of the harmonic content; acquiring historical capacitor bank impedance characteristic data and a corresponding harmonic content change trend, and calculating impedance matching degrees of the graphene super capacitor under different load conditions; according to the impedance matching degree of the graphene super capacitor, generating a capacitor bank switching sequence by adopting a dynamic programming algorithm, and determining a target switching sequence of the graphene super capacitor; switching of the graphene super capacitor according to the target switching sequence is executed through an edge calculation unit, the access state of the graphene super capacitor is adjusted in real time, and harmonic wave changes of a power grid are dynamically matched; the method comprises the following steps: acquiring transient current data of a system, and decomposing the transient current data by adopting a wavelet transform algorithm to obtain a frequency component of transient current;

The invention discloses a self-adaptive impedance matching method for a high-frequency signal transmission connector of a new energy vehicle, and relates to the technical field of signal processing, and the method comprises the steps: 1, obtaining the physical parameters of the high-frequency signal transmission connector of the new energy vehicle; calculating an electromagnetic field feature vector, and calculating a transmission line distribution vector of the high-frequency signal transmission connector; 2, calculating a propagation constant of a high-frequency signal transmission connector of the new energy vehicle; calculating the characteristic impedance of a high-frequency signal transmission connector of the new energy vehicle; 3, calculating a reflection coefficient; calculating an impedance error; step 4, calculating a compensation parameter vector, and generating a control signal by using an adaptive control theory according to the compensation parameter vector; and calculating the impedance matching degree according to the control signal. According to the invention, impedance change in a complex environment can be accurately dealt with, signal reflection and energy loss are significantly reduced, and transmission efficiency and signal integrity are improved.

The invention relates to the technical field of battery control, and discloses an energy storage battery output power self-adjusting system, which comprises a data acquisition module used for acquiring working parameters of an energy storage battery in real time; the historical database is used for storing previous operation data of the energy storage battery and the load equipment; the data processing and analyzing module is used for cleaning and normalizing the historical data; a self-adaptive adjustment strategy generation module; the invention discloses an energy storage battery output power self-adjusting method. The method comprises the following steps: S1, collecting battery pack data through a CAN bus; s2, establishing a load equipment priority list; s3, constructing a multi-time scale optimization model; s4, implementing dynamic impedance matching; s5, generating a power distribution instruction set; according to the invention, the output power prediction model is established by using the machine learning algorithm in combination with the previous operation data in the historical database, and the load demand trend in a period of time in the future can be accurately predicted.

The invention relates to a modeling and optimizing method for inter-layer signal crosstalk of a PCB (Printed Circuit Board). Frequency response data of all dielectric layers of the PCB under different temperature and humidity conditions are collected, and a mapping model with the temperature gradient and the humidity diffusion gradient as input and the dielectric constant as output is established. And calculating the dynamic distribution of mutual capacitance and mutual inductance under the environment change by combining the spatial layout parameters of the differential signal pair, and constructing a crosstalk sensitivity evaluation model with coupled frequency, environment and layout. And high-risk areas with crosstalk sensitivity caused by environment change are identified, and the crosstalk change rate of each area is quantified. For a sensitive area, a temperature and humidity compensation medium structure is introduced to stabilize local dielectric characteristics and reduce the influence of the environment on crosstalk. And according to the compensated medium distribution, adjusting a differential signal wiring path and impedance matching by adopting an optimization method with the aim of minimizing the crosstalk change rate, and generating a wiring layout with environmental robustness. According to the invention, the signal integrity and the transmission reliability of the multi-layer PCB in a temperature and humidity changing environment can be effectively improved.

Embodiments provided herein generally include apparatus, plasma processing systems and methods for tuning in a radio frequency (RF) plasma processing system for improving substrate processing metrics. Some embodiments are directed to an apparatus for processing a substrate in a plasma processing system. The apparatus generally includes: an impedance for a match circuit configured to perform impedance matching for a plasma load; a diode-based switch coupled to the impedance for the match circuit; at least one signal generator coupled to the diode-based switch and configured to bias the diode-based switch to a first position based on a first impedance generated in the plasma load; and a second position based on a second impedance generated in the plasma load and an RF signal generator configured to provide an RF signal to the plasma load.

The invention provides an intelligent harmonic dynamic compensation method and system for a data center. According to the method, server heat source surface temperature field distribution is monitored in real time through a distributed optical fiber temperature measurement array, and a dynamic impedance spectrum is generated; when the temperature gradient exceeds the flash evaporation critical value of the fluorinated cooling liquid, an active filter is activated to carry out dynamic impedance matching compensation on high-frequency harmonic current in the liquid cooling tank cabinet, and a pulse width modulation control signal of a circulating pump is generated; the compensation power of the filter and the turbulence intensity of the cooling liquid are synchronously adjusted by analyzing the coupling relation between the flowing vortex intensity of the cooling liquid and the dielectric polarization loss; when phase mismatch of a temperature field is caused by heat dissipation of multiple heat sources, a multi-band compensation strategy is reconstructed by utilizing frequency domain characteristics of a pulse width modulation signal and a compensation power historical value, and a cooling liquid branch flow distribution ratio and a filter frequency response curve are cooperatively adjusted. According to the technical scheme, the thermal stability and the electrical safety of the data center cooling machine room are improved.

The invention relates to the technical field of electromagnetic materials, and discloses a lossy multimode resonant metasurface unit and a multifunctional active coding wave absorber. The lossy multimode resonant metasurface unit comprises a lossy metal pattern layer, a supporting dielectric layer, an impedance matching dielectric layer and a metal ground layer which are sequentially arranged from top to bottom; the lossy metal pattern layer comprises a multi-mode resonator and a radio frequency PIN diode, the multi-mode resonator is used for realizing a plurality of resonance modes and playing a role in electromagnetic wave frequency selection, and the radio frequency PIN diode is used for playing a role of an adjustable resistor and adjusting the electromagnetic wave loss so as to realize intensity adjustment of reflected electromagnetic waves; every two adjacent multi-mode resonators are connected in a cascading mode through a radio frequency PIN diode and are combined to form a closed-loop pattern. The multifunctional electromagnetic wave absorber is simple in structure, has the constant phase scattering cancellation characteristic, and can independently regulate and control the reflection amplitude so as to solve the technical problem of an existing multifunctional electromagnetic wave absorber.

The invention discloses an ultrasonic transducer characteristic parameter test system, which belongs to the technical field of ultrasonic detection and comprises an excitation signal generation module, an impedance matching adjustment module, a resonance characteristic extraction module, a signal acquisition and processing module, a temperature control loading module, a physical vibration isolation module and a frequency spectrum calibration module. The excitation signal generation module is combined with an off-chip frequency locking feedback loop through an on-chip oscillator to generate a multi-frequency-point sweep frequency pulse array, the multi-frequency-point sweep frequency pulse array is connected to the resonance characteristic extraction module after passing through the impedance matching adjustment module, the multi-frequency-point sweep frequency pulse array and the frequency spectrum calibration module construct a bidirectional feedback path and share harmonic node synchronous calibration logic, and coupling offset compensation is achieved; the frequency spectrum calibration module performs bidirectional real-time error correction on the excitation output frequency and the resonance input phase; and the transducer is arranged in the thermal convection temperature equalizing cabin of the temperature control loading module and is overlapped with the physical vibration isolation module. The method has the advantages that high-precision, low-interference and full-frequency-domain dynamic testing of characteristic parameters of the ultrasonic transducer is achieved, and testing stability is improved.

The embodiment of the invention provides a data center energy consumption prediction method and system based on DCIM. Real-time operation parameters of an electric quantity monitoring module, a refrigeration equipment control module and an environment sensing module are synchronously obtained through a heterogeneous data bus, a dynamic topology calibration mechanism is adopted to carry out space-time alignment processing so as to generate a dynamic topology matrix, and a propagation path weight matrix is constructed; according to a timestamp sequence of a historical equipment start-stop event and an energy consumption fluctuation curve phase offset, an event trigger signal is injected into a propagation path weight matrix to form a multi-dimensional prediction map, a key propagation path identifier is positioned by using a path traceability mechanism based on transient peak distribution and real-time environmental parameter phase deviation in the prediction map, and a target propagation path is obtained. And adjusting an impedance coefficient and a pressure loss threshold value in the propagation path weight matrix so as to generate a refrigeration equipment power gradient adjustment instruction and a power supply link impedance matching instruction. According to the technical scheme provided by the embodiment of the invention, the energy efficiency management and operation stability are effectively improved.

The invention is suitable for the technical field of fault diagnosis, and provides a distributed power transmission line fault diagnosis method based on ground potential end transient information perception, and the method comprises the steps: collecting a broadband transient signal of each node ground potential end of a power transmission line; synchronously acquiring an electromagnetic transient signal and an environmental parameter through the composite sensing unit; performing dynamic filtering correction on the broadband transient signal according to a preset transmission line impedance matching model; a deep learning model is adopted to perform hybrid processing on the corrected broadband transient signals and electromagnetic transient signals, traveling wave head time-frequency features and power frequency abrupt change features are extracted, and fault probability and type classification results are output; verifying a fault positioning result through a multi-stage verification mechanism; the extracted characteristic quantity is preprocessed at the edge side of the detection terminal, and the processed data is transmitted to a master station system through an encryption protocol, so that the fault diagnosis accuracy of the distributed power transmission line is effectively improved.

The invention relates to the technical field of power system testing, in particular to a transformer simulation test current optimization method based on dynamic impedance matching, which comprises the following steps: performing low-power scanning on a tested transformer to establish a nonlinear model capable of predicting harmonic waves; actively synthesizing the virtual impedance of the target power grid; and a feed-forward compensation current is generated by using a harmonic prediction model and is injected into the transformer after being superposed with a fundamental wave instruction. According to the method, accurate identification modeling is carried out on nonlinear characteristics of a tested unit, active synthesis of virtual impedance of a target power grid is combined, and harmonic compensation current is generated in real time by utilizing a feedforward control thought so as to optimize finally injected test current. According to the method, the problems of inaccurate power grid simulation and insufficient nonlinear response coupling of the transformer in a traditional test are solved, high-fidelity current injection is realized, real electrical behaviors of the transformer under various complex power grid working conditions can be accurately simulated, and the flexibility, accuracy and safety of the test are remarkably improved.

The invention relates to a heterogeneous honeycomb wave-absorbing structure, and belongs to the field of stealth materials. The structure is composed of a plurality of hexagonal honeycomb units comprising a plurality of different electromagnetic materials, the incident direction of electromagnetic waves mainly aims at radial incidence, large effective depth exists in the direction, and the structural layer is in uneven periodic distribution. The propagation path of electromagnetic waves in the structure is expanded, multiple reflection is easier to occur, and absorption of the electromagnetic waves is facilitated; the heterogeneous honeycomb wave-absorbing structure is divided into four layers in the radial direction, and the dielectric constant of each layer of absorbing material is in gradient change on the whole, so that the heterogeneous honeycomb wave-absorbing structure has a better impedance matching characteristic; according to the design method, the particle swarm optimization algorithm is utilized to optimize the wave-absorbing material in the optimization layer, so that the degree of freedom of the honeycomb wave-absorbing structure is increased, and the advantage of radial length is fully utilized. The heterogeneous honeycomb wave-absorbing structure provided by the invention meets impedance matching, has broadband wave-absorbing performance, and can realize good absorption of 2-18GHz electromagnetic waves, so that the heterogeneous honeycomb wave-absorbing structure has greater application potential in related fields.

The invention discloses a self-adaptive fault reflection method and device based on adjustable excitation frequency, and belongs to the technical field of cable fault detection and positioning. The method comprises the following steps: injecting an excitation signal which can be adjusted in a range of 1kHz-10MHz through an adjustable impedance matching network; collecting a reflected signal and calculating an SNR (f) curve; optimizing by adopting a particle swarm optimization algorithm and taking maximization of a signal-to-noise ratio as a target, and determining an optimal excitation frequency; and finally, calculating the fault position and type based on the optimal frequency. The particle swarm optimization algorithm is adopted to perform adaptive optimization on the excitation frequency, and the adjustable impedance matching network is combined to form a closed-loop adaptive detection framework of excitation-acquisition-analysis-optimization-re-excitation, so that the excitation frequency can be automatically adjusted according to a real-time detection result, and the detection accuracy is improved. And the fault detection sensitivity, the positioning precision and the energy efficiency are obviously improved.

The invention relates to the technical field of information, and discloses a fault current suppression method and system for a direct-current deicing device, fault current data of the direct-current deicing device are analyzed through fast Fourier transform, and direct-current bus voltage drop data are obtained based on an analysis result and are processed through a support vector regression algorithm, so that a fault current suppression result is obtained. Obtaining a voltage stress sudden increase trend and further determining stress distribution data of a switching device in the device; processing the stress distribution data by a Kalman filtering algorithm to obtain a processing result so as to determine a dynamic correction coefficient of a bridge arm switching time sequence, and processing the dynamic correction coefficient and element response delay data of the device by a particle swarm optimization algorithm to generate a bridge arm switching time sequence so as to determine a real-time adjustment parameter influencing the discharge rate of a buffer capacitor in the device; and comparing voltage oscillation characteristics before and after matching to determine an impedance compensation value of a commutation path for execution, thereby realizing effective suppression of current oscillation in the DC deicing device.

The embodiment of the invention provides a closed-loop control method for power driving and protection, and the method comprises the steps: constructing a voltage feedback type circuit through a high-speed operational amplifier, and forming a closed-loop gain structure through a feedback network of the voltage feedback type circuit; the load current of the output end of the voltage feedback type circuit is monitored in real time, and when the load current exceeds a first set threshold value, a protection mechanism is triggered to turn off the output stage; the power-on surge current is limited through the soft start control circuit; phase information of a load reflection coefficient is obtained, an inductance / capacitance combination of the variable dynamic impedance matching network is selected according to phase information table look-up, inductance / capacitance parameters are switched through a relay, and the transmission standing-wave ratio between the power amplifier and a load is optimized; monitoring the temperature of the radiating fin of the power tube, and dynamically adjusting the resistance value of the feedback network; and performing cooperative control of short-circuit protection, over-temperature protection and surge suppression according to the priority. According to the embodiment of the invention, the performance bottleneck in a load fluctuation scene is broken through.

According to the broadband single-layer dual-polarization microstrip antenna, a radiation patch and a short-circuit metal column are combined to form an EBG structure, and the working bandwidth is greatly improved. And the two ports are connected with the circular parasitic patch through the coaxial line, so that radiation energy coupling is realized, and impedance matching is improved. And two ports are orthogonally arranged, so that the isolation is improved. The four slits suppress the coupling current between the adjacent antenna units, an additional decoupling structure is not needed, the polarization purity is ensured, and the cross polarization is less than-15dB. The antenna is compact in structure, a single-layer substrate is adopted, the profile of the antenna is 0.08 working wavelength, miniaturization, dual polarization, broadband and high isolation are achieved, processing is simple, the antenna works in the 16.7 GHz Ku frequency band, and the-10 dB impedance bandwidth is about 16%. According to the invention, a miniaturized, dual-polarized, broadband, high-isolation and monopole-like radiation mode is realized, the radiation mode is stable, and the antenna can be used as a phased array unit.

The invention discloses a land energy storage container self-adaptive liquid cooling heat dissipation device and method, the device comprises a liquid cooling unit, a self-adaptive circulation pipeline, a variable flow pump valve group, a distributed temperature sensing module and a BMS main control module, through data monitoring, model establishment, thermal load prediction, selection of a proper cooling mode, and introduction of reasonable compensation, the self-adaptive liquid cooling heat dissipation of the land energy storage container is realized. And the variable-frequency circulating pump and the valve body are adjusted and combined for execution. Through multi-parameter fusion control, dynamic impedance matching and intelligent algorithm optimization, a cooperative control mode of a variable orifice regulating valve and a variable frequency circulating pump is innovatively adopted, and dynamic matching of cooling loop impedance is achieved; through temperature field modeling, heat dissipation demand grading prediction, a cooling parameter self-optimization algorithm and fault self-diagnosis, the balance degree of the temperature field is effectively improved, heat dissipation energy consumption is reduced, environmental adaptability is enhanced, and meanwhile the method has the advantages of being high in reliability, wide in environmental adaptability and low in operation and maintenance cost.

The invention discloses an impedance matcher, a radio frequency power supply system and a plasma source system. The impedance matcher comprises an impedance matching module, a control module and a plurality of adjustable capacitor modules which are connected in parallel, the first end of each adjustable capacitor module is electrically connected with the first end of the impedance matching module, and the second end of each adjustable capacitor module is grounded; each adjustable capacitor module comprises an adjustable capacitor unit and a switch unit which are connected in series; the control module is used for controlling the switch unit in the at least one adjustable capacitor module to be switched on and controlling the switch unit in the at least one adjustable capacitor module to be switched off when the load is in the current impedance; and the capacitance value of the adjustable capacitor unit in the adjustable capacitor module where the at least one disconnected switch unit is located is adjusted according to the next impedance of the load. According to the invention, impedance matching between the radio frequency power supply module and the load can be realized while the impedance of the load is changed, and impedance matching can be quickly realized.

According to embodiments, provided is an antenna comprising: a substrate of a square shape including first to fourth corners; a radiation unit disposed on the substrate and including a first radiation unit and a second radiation unit that radiate a wireless signal; a first feed line that applies the wireless signal to the first radiation unit; a second feed line that applies the wireless signal to the second radiation unit and has an extension line that perpendicularly intersects with an extension line of the first feed line; and a ground portion disposed on the substrate and spaced apart from the radiation unit and having at least a portion of a boundary area including a step shape, wherein the ground unit includes a shared ground unit that is disposed diagonally from a first edge to a third edge, is located between the first radiation unit and the second radiation unit, and performs impedance matching of the first radiation unit and the second radiation unit.

The invention belongs to the technical field of unmanned aerial vehicle full-aviation electromagnetic detection, and particularly relates to a full-aviation frequency domain electromagnetic emission system and a control method. A broadband frequency mixing and matching circuit is connected in series between an H-bridge power inverter and an emission coil of an unmanned aerial vehicle electromagnetic emission system; the broadband mixing and matching circuit comprises a first resonance unit formed by connecting a fixed capacitor and an adjustable inductor in parallel and a second resonance unit formed by connecting a fixed capacitor and an adjustable inductor in parallel, and the first resonance unit and the second resonance unit are connected in series. The adjustable inductor is matched with the dynamic impedance of the inductive load by adjusting the inductance value, and the broadband frequency mixing and matching circuit can adjust the impedance in real time, so that the matching of different resonant frequencies is realized, and the frequency range of a matching signal can be obviously widened.

The invention discloses a frequency division control radio frequency power supply solid-state impedance matcher and a method thereof, and aims to solve the problems that a traditional mechanical impedance matcher is slow in response, low in adjustment precision and difficult to adapt to a dynamic load. According to the system, an all-solid-state impedance matcher is adopted, impedance dynamic adjustment is achieved through a matching network composed of an adjustable inductance module and a switched capacitor module, closed-loop control is constructed in combination with a radio frequency signal detection module and a digital signal processor, and a frequency division control strategy is adopted, and the high-frequency band realizes high-precision matching through a control strategy of coarse adjustment of the adjustable inductance module and fine adjustment of the switched capacitor module. The device has the advantages of high response speed, wide frequency band coverage and the like, and is particularly suitable for industrial plasma application scenes with remarkable dynamic impedance characteristics.

The invention discloses a broadband wave-absorbing material based on an MAX-phase metasurface structure and an impedance matching optimization method of the broadband wave-absorbing material. The wave-absorbing material comprises an MAX-phase ceramic substrate and periodic metasurface structures which are arranged on the surface of the MAX-phase ceramic substrate in an array mode and composed of conductive resonance units. The resonance units are isolated through gaps, an equivalent R1L1C1 series resonance circuit is formed in an electromagnetic field, and a base body is equivalent to a parallel resistor R2. By establishing an equivalent circuit model and optimizing parameters R1, L1, C1 and R2, impedance matching of the wave-absorbing material in a target frequency band can be regulated and controlled, so that the wave-absorbing material at least has an absorption peak of which the reflection loss is less than-10 dB. According to the optimization method, electromagnetic simulation and circuit simulation are combined, optimized circuit parameters are reversely mapped into structure geometric parameters, material preparation is guided, and accurate design and broadband absorption of the wave absorbing performance are achieved.

A system and method for extending and holding aloft a long-wire radio antenna using an unmanned aerial vehicle (UAV), optimizing high-frequency (HF) radio communication where ground-based infrastructure is impractical. The UAV-based system pulls an antenna wire from a reel vertically and hovers in place holding the antenna at a length resonant on the transmitting frequency, enabling effective skip propagation. The system includes mechanisms for precise impedance matching and standing wave ratio (SWR) tuning through automatic adjustments of antenna length, facilitated by onboard sensors and control systems. The antenna wire is connected to a reel anchored to the ground and connected to a wire-mesh ground plane. In one embodiment, the system constantly feeds electric power to the UAV, with filters isolating RF and power currents, enabling both antenna and power transmission functions on the same wire. This system addresses the challenges of maintaining HF communication in remote or disaster-stricken regions.

The invention belongs to the technical field of antenna engineering, and particularly relates to an ultra-wide-band low-profile phased-array antenna, which realizes broadband impedance matching characteristics and effectively expands the working bandwidth of the antenna by optimizing a dipole arm structure and introducing a matching branch knot and linear tapered slot composite structure on a radiation unit layer; on the array architecture level, an electromagnetic metasurface technology is adopted, array current distribution is improved through a periodic artificial electromagnetic structure, the active standing-wave ratio is remarkably reduced, the scanning angle of an array is widened, and meanwhile high compression of a system profile is achieved; on the structural design level, a three-dimensional composite structure of a transverse metal floor, a longitudinal radiation layer and a transverse metasurface layer is innovatively constructed, and the overall section height is reduced to 0.137 lambda Low (lambda Low is the lowest working frequency wavelength) through electromagnetic coupling and space folding technologies; in conclusion, the ultra wide band (the relative bandwidth is greater than or equal to 90%) and the low profile (lt; and the method is suitable for a new generation of broadband phased array radar system.

The invention provides a self-detection signal acquisition circuit based on analog quantity current and voltage mixed input, which comprises a surge protection circuit, a switch selection circuit, a clamping protection circuit, a follower circuit, an impedance matching circuit and an ADC acquisition chip which are connected in sequence, and also comprises a microcontroller, the microcontroller is connected with the ADC acquisition chip and the switch selection circuit, and the ADC acquisition chip is connected with the switch selection circuit. The microcontroller is used for acquiring the output voltage of the impedance matching circuit through the ADC acquisition chip, performing periodic detection on the output voltage of the impedance matching circuit, and periodically outputting a high level or a low level to the switch selection circuit based on the periodic detection result of the output voltage of the impedance matching circuit. Therefore, the switch selection circuit is controlled to switch gears. The technical problems that in the prior art, due to the fact that only a plurality of analog quantity signal input collecting modules of different types can be used for collecting a plurality of sensors with different output signals, the workload of sensor wiring work is large, the work efficiency is low, and the error rate is high are solved.

The invention discloses a column type distribution transformer winding abnormity detection system and detection method. The detection system comprises a frequency response detection instrument, a signal coupling assembly, an impedance matching module and a data processing module. The frequency response detection instrument is used for outputting a frequency sweep excitation signal and collecting a winding response signal; the signal coupling assembly is used for isolating power frequency voltage and filtering low-frequency interference; the impedance matching module is used for adjusting output impedance and input impedance to realize matching with electrical characteristics of different windings; and the data processing module is used for constructing an equivalent detection loop model, completing frequency response simulation calculation and carrying out frequency domain analysis and anomaly identification on an actually measured response curve. According to the invention, electrified state diagnosis of distribution transformer winding structure abnormity (such as deformation and loosening) can be realized.

According to the capacitance-enhanced circular isolator structure provided by the invention, common-ground electric connection is realized by forming a ground metal boss structure, the distance between a grounding metal and a multi-path impedance adding structure is remarkably reduced, the ground capacitance of the multi-path impedance adding structure is remarkably improved, and meanwhile, bandwidth expansion is realized through capacitance-inductance cooperative tuning; a second-order LC matching network is adopted in three radio frequency ports, a slotting part of a matching capacitor can enable a matching inductor and the matching capacitor to share space to a certain extent, so that the size of the matching network is effectively reduced, a first-order LC matching network is adopted in an absorption port, impedance matching of the absorption port is realized under the condition that only a single resistor is added, and the impedance matching performance of the absorption port is improved. The size of the matching network can be reduced while a good absorption effect is achieved, and the size of the non-reciprocal central junction structure can be reduced; in addition, the first non-reciprocal central junction structure and the second non-reciprocal central junction structure are subjected to conjugate matching by adopting an L-C-L type matching network, so that good isolation performance is realized.

The invention relates to a wave-absorbing honeycomb composite material with absorbents in spatial gradient distribution and a preparation method of the wave-absorbing honeycomb composite material, and belongs to the technical field of preparation of wave-absorbing materials. In combination with the characteristics of a multi-layer wave-absorbing honeycomb, wave-absorbing adhesive film layers with different electromagnetic properties are pressed into pores of a semi-cured honeycomb core material according to the electrical property design, and the electromagnetic properties change in a gradient manner along the pore direction to obtain an impedance matching structure; the wave-absorbing honeycomb is attached to the surface (curved surface) of a product or a mold for curing, and a heat-set wave-absorbing honeycomb core material is obtained; the upper surface and the lower surface are respectively bonded with the wave-transparent skin, so that the wave-absorbing honeycomb composite material with excellent performance is obtained, and the stealth requirement of curved-surface products is met. According to the wave-absorbing honeycomb composite material and the preparation method thereof, the process is easy to control, the wave-absorbing performance and the mechanical performance are excellent, the wave-absorbing honeycomb composite material can be used for curved surface forming, and the absorbent space gradient distribution is achieved, and the wave-absorbing honeycomb composite material has the excellent wave-absorbing performance in the ultra-wide frequency range.