558 results about "Input impedance" patented technology

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.

The invention relates to the technical field of antennas, in particular to a multi-level intelligent overheating protection system and method based on a gallium nitride module antenna. According to the method, a thermal load optimal migration path is analyzed based on a virtual thermal capacity network model, and an input impedance matching network of a target unit is synchronously tuned according to the thermal load optimal migration path to compensate beam phase distortion caused by thermal migration; and according to the boundary constraint condition of the real-time threat scene feature injection virtual thermal capacity network model, dynamically solving a game equilibrium solution of a thermal load migration path and a beam parameter tuning amount, and generating a thermal-radio frequency combined control instruction set. According to the method, full-process closed-loop control from thermal inertia characteristic analysis, thermal network modeling to thermal-radio frequency collaborative optimization is realized, so that the gallium nitride antenna system can intelligently plan an optimal thermal migration path and compensate thermally induced performance distortion in real time in a complex thermal environment and a threat scene, and finally dual optimization of heat dissipation efficiency and radio frequency indexes is achieved.

The invention provides a method for extracting equivalent parameters of a cavity resonant wireless power transmission system. The method comprises the following steps: S1, acquiring system input impedance spectrum data; s2, taking the input impedance spectrum data of the system as input, and utilizing a trained LSTM regression model to obtain a preliminary predicted value of an equivalent parameter of the system; s3, based on the preliminary prediction value of the equivalent parameters of the system, performing regression fitting by adopting a nonlinear fitting algorithm to obtain an accurate value of the equivalent parameters of the system; the system equivalent parameters comprise cavity internal resistance and cavity equivalent inductance of the resonant cavity and a mutual inductance value between the coil and the resonant cavity. The method has the advantages that equivalent parameters of the cavity resonant wireless power transmission system in all current mainstream modes can be effectively extracted; the NLS algorithm is prevented from convergence failure or falling into local optimum due to the fact that an initial value seriously deviates from a real value, and the fitting precision and stability are extremely high.

The invention discloses a sensor array acquisition system for detecting gas, and relates to the field of gas sensors. The sensor array acquisition system for detecting gas comprises a gas sensor array, a signal conditioning circuit, an analog-to-digital conversion module, a control module and a power supply module. According to the sensor array acquisition system for detecting the gas, the voltage follower circuit with high input impedance is adopted, so that the problem of attenuation during signal acquisition of a high-impedance sensor is effectively solved, and the signal acquisition precision is improved. Through the adjustable direct-current bias circuit and the differential amplification circuit, the dynamic adjustment of the measurement range is realized, the gas detection requirements of different concentration ranges can be met, and hardware does not need to be replaced. A constant-current driving chip is adopted to control a sensor heating circuit, heating current can be accurately set by adjusting external resistance, it is ensured that the sensor works at the optimal temperature, and the stability and response speed of the sensor are improved.

The invention discloses a cable defect detection method and device, and relates to the field of power equipment fault detection, and the method comprises the steps: generating N electric signals with different frequencies in a preset frequency range, inputting the electric signals into a target cable, testing the input impedance of the target cable under the N electric signals with different frequencies, the broadband impedance of the target cable in the frequency range is obtained; according to the broadband impedance, generating an impedance amplitude and an impedance phase of the target cable at each preset frequency point, and constructing an impedance matrix; inputting the impedance matrix into a fault classification model, and identifying and outputting the category of the target cable through the fault classification model; and if the target cable has a fault, extracting the resonant frequency with the maximum amplitude in the broadband impedance amplitude spectrum of the target cable, and determining the fault position of the target cable through a fault positioning model according to the resonant frequency with the maximum amplitude and the typical wave velocity of the target cable. According to the invention, the fault of the target cable can be automatically, quickly and accurately identified, and the fault position can be positioned.

Aspects of the present disclosure provide a circuit configured to adjust an input impedance of an amplifier such as a low-noise amplifier. In certain aspects, the circuit is coupled to a node, wherein the node is between a first transistor and a second transistor of the amplifier. The circuit may include an inductor and a capacitor coupled in series, wherein the inductor is coupled with one or more load inductors of the amplifier through negative magnetic coupling.

The invention discloses a cable high-frequency impedance characteristic analysis method based on bipolar trapezoidal wave excitation, and belongs to the technical field of power equipment state monitoring and fault diagnosis. In order to solve the problems of low test efficiency, insufficient high-frequency parameter modeling precision and weak anti-interference capability in cable high-frequency impedance characteristic analysis of a traditional sine wave excitation method, the method comprises the following steps: generating an odd-symmetry bipolar trapezoidal wave excitation signal with specific frequency and amplitude, and injecting the signal into the head end of a cable to be tested through a coupling device after power amplification; synchronously acquiring a high-frequency response signal of the key position of the cable under the excitation of the bipolar trapezoidal wave by using a data acquisition system; preprocessing the high-frequency response signal, converting the high-frequency response signal into a frequency domain through Fourier transform, calculating input impedance of the cable under different harmonic frequencies, and synthesizing a broadband impedance spectrum; based on the broadband impedance spectrum, the amplitude-frequency characteristic and the phase-frequency characteristic of impedance are analyzed, and cable state evaluation, partial discharge detection, insulation defect diagnosis or fault point positioning are realized. The method is used for an electric power system.

The present application discloses a low-cost and high-performance radio-frequency amplifier, comprising an input stage circuit, a common-gate stage circuit, and an output load circuit. The input stage circuit implements conversion from a single-ended signal to a differential signal, implements input impedance matching, and converts an inputted radio-frequency voltage signal into a radio-frequency current signal. The input stage circuit comprises a first three-coil transformer, consisting of a primary coil, a secondary coil, and a third coil. The common-gate stage circuit transmits the radio-frequency current signal outputted by the input stage circuit to the output load circuit, increases the withstand voltage and equivalent output impedance of the circuit, and implements gain control in at least two modes. The output load circuit converts the radio-frequency current signal from the common-gate stage circuit into a radio-frequency voltage signal, implements conversion from a differential signal to a single-ended signal, and outputs an amplified radio-frequency voltage signal. The present application provides a radio-frequency amplifier having a small size, broadband matching, high linearity, a large dynamic range, and low design complexity.

The invention discloses a radio frequency matching method, a radio frequency matcher and a storage medium, which are used for solving the problems of matching dead zone and overlong time. Load impedance is detected through a load state sensor, input impedance is adjusted through an impedance adjusting network, and the impedance adjusting network comprises adjustable capacitors C1 and C2; and constructing a loss function L based on the modulus square of the reflection coefficient gamma, calculating the gradient and iteratively adjusting the capacitance parameter. The main control module drives the vacuum capacitor to continuously adjust, dynamic optimization is carried out in combination with a gradient descent algorithm, discrete limitation and dead zones of a traditional table look-up method are eliminated, pulse mode microsecond-level rapid matching is adapted, and radio frequency overshoot is restrained. The method improves the matching precision and speed under a dynamic load (such as plasma), gives consideration to the stability of a complex process, and is suitable for the technical processes of semiconductor etching and the like.

The utility model provides a sampling circuit, an analog circuit and electronic equipment, and the sampling circuit comprises an input processing unit which is connected with the output end of a target circuit, and is used for collecting the common-mode output voltage of the target circuit, and carrying out the sampling input processing of the common-mode output voltage, and obtaining a first operational amplifier in-phase sampling signal and a first operational amplifier anti-phase sampling signal; the signal amplification unit is connected with the input processing unit and is used for respectively amplifying the first operational amplifier in-phase sampling signal and the first operational amplifier anti-phase sampling signal to obtain a second operational amplifier in-phase sampling signal and a second operational amplifier anti-phase sampling signal; and the signal stabilization unit is connected with the signal amplification unit and the control circuit, and is used for keeping the second operational amplifier in-phase sampling signal and the second operational amplifier anti-phase sampling signal, generating a feedback signal according to the second operational amplifier in-phase sampling signal and the second operational amplifier anti-phase sampling signal, and outputting the feedback signal to the control circuit. In this way, the input impedance and the sampling precision are improved.

The invention discloses an AFE analog front-end circuit applied to a multi-channel high-speed optical receiver. The circuit comprises an SF-TIA, a single-ended to differential circuit and a CLTE. The SF-TIA, the single-ended to differential circuit and the CLTE are connected in sequence; the SF-TIA is used for converting an input current signal into a voltage signal and transmitting the voltage signal to the single-ended to differential circuit; wherein the current signal is obtained by converting an input optical signal; the single-ended to differential circuit is used for converting the voltage signal into a differential voltage signal and transmitting the differential voltage signal to the CLTE; and the CLTE is used for compensating the high-frequency gain of the differential voltage signal to obtain a compensated voltage signal and outputting the compensated voltage signal. The amplifier has the advantages of being high in gain, low in power consumption, low in input impedance, low in noise, low in requirement for power supply voltage and simple in structure.

The invention discloses a power amplifier and circularly polarized antenna integrated structure which comprises a power amplifier and an antenna which are integrated together, and the antenna is a circularly polarized antenna. The input impedance of the antenna is directly matched with the output impedance of the power amplifier at the center frequency 1.9 GHz and the center frequency 2.6 GHz through the feed point position of the microstrip line in the antenna and the impedance of the microstrip line; the dual-frequency dual-band antenna has the advantages of being small in occupied size, high in integration level, small in transmission loss, high in transmission efficiency in high-frequency, broadband and high-power application scenes, capable of achieving dual-frequency work and capable of meeting the requirements of a wireless communication system for multi-frequency and high-quality transmission.

The present disclosure provides a plasma processing apparatus comprising: a plasma processing chamber; a substrate support; an electrode or an antenna; a radio frequency power supply; a power receiving coil electrically connected to the at least one power-consuming member; a power transmitting coil electromagnetically inductively coupled with the power receiving coil; a power transmitting unit electrically connected to the power transmitting coil to supply a power to the power transmitting coil; and a controller. The power transmitting unit includes a voltage detector and a current detector, and the controller is configured to determine a required power level corresponding to a parameter value including an input impedance obtained from the input voltage and the input current or a load resistance value of the at least one power-consuming member, and to control the power transmitting unit to output an output power having the required power level.

The invention discloses an optimization method of a butterfly-shaped UHF antenna, and the method comprises the following steps: determining a preset angle range of a semi-apex angle based on the matching relation between the characteristic impedance of the butterfly-shaped antenna and the working frequency band width, so as to achieve the stable change of the input impedance and the broadening of the frequency band; according to the wavelength of the low-frequency end of the working frequency band, a preset proportional relation between the arm length and the wavelength is established to determine the value of the arm length, so that the requirement of the antenna impedance bandwidth on low-frequency-band signal receiving is met; a butterfly antenna is arranged in a metal back cavity to form a back cavity type antenna, the height of the back cavity is determined according to the wavelength corresponding to the strongest frequency of a signal so as to suppress back radiation and enhance forward radiation gain, and systematic improvement of electromagnetic wave signal receiving performance is realized through collaborative optimization of structural parameters of the butterfly antenna and the back cavity.

The invention discloses a radio frequency power amplifier, a radio frequency power amplifier module and a radio frequency power amplifier module, and the radio frequency power amplifier comprises a four-stage power amplifier structure which is used for amplifying an input signal to preset output power; the inter-stage matching network is used for completing impedance matching between the output impedance of each stage of array and the output impedance of the rear-stage array and impedance matching between the input impedance of each stage of array and the output impedance of the front-stage array through an impedance matching technology; the protection circuit comprises a temperature protection unit and a standing-wave ratio protection unit. The temperature protection unit is used for monitoring the temperature of the GaN power amplifier unit in each array in real time and comparing the temperature with a preset temperature, and generating a logic instruction for cutting off the power supply of the corresponding array when the number of overtemperature units is judged to be greater than a preset number; the standing-wave ratio protection unit is used for detecting the output standing-wave ratio and generating a logic instruction for switching power supply when it is judged that the detected standing-wave ratio is larger than a preset ratio. According to the invention, high-performance communication requirements and simple and effective exception protection can be met.

The invention relates to a broadband impedance spectroscopy cable fault identification method and system and a storage medium, and the method comprises the steps: building a cable equivalent model according to any preset cable fault type; frequency sweep signals are input into the model, parameters of a cable core, a sheath and a steel armor under different frequency sweep signals are obtained, input impedance of the head end of the cable under different frequency sweep signals is calculated based on a cable modulus matrix and an input impedance formula, and a fault broadband impedance amplitude spectrum and a phase spectrum are drawn; repeating the steps to obtain a broadband impedance amplitude spectrum and a phase spectrum of the cable fault; the input impedance of an actual cable is collected in real time, a real-time broadband impedance amplitude spectrum and a real-time broadband impedance phase spectrum are drawn and compared with a cable fault broadband impedance amplitude spectrum and a cable fault phase spectrum, and the cable fault type and the distance between a fault point and the head end are recognized. Compared with the prior art, rapid cable fault identification and fault point determination are realized.

A method can include wireless circuits that, by operation of transmit switch circuits, include a transmit component in an output signal path between a transmit amplifier and an antenna port, the output signal path including a shared matching network. By operation of a transmit amplifier, an output signal can be generated for transmission over an output signal path to an antenna port. In a receive mode, by operation of the transmit switch circuits, an input impedance of the transmit component can be excluded from an input signal path between the antenna path and a receive amplifier. An input signal path can include the shared matching network. By operation of the receive amplifier, amplifying the received input signal. Corresponding devices and systems are also disclosed.

The invention discloses an underwater wireless transmission system multi-parameter online identification energy efficiency improvement method, which comprises the following steps: firstly, constructing a topological graph of an underwater wireless power transmission system, when the system works normally, acquiring voltage U1 and current I1 of a transmitting coil, and calculating input impedance; determining an equivalent circuit, and establishing an equation of a mutual inductor M, a bridging capacitor Ce and an equivalent load RLe through the voltage U1 and the current I1; and solving the mutual inductance M, the bridging capacitor Ce and the equivalent load RLe to realize multi-parameter identification. According to the technology, the driving frequency of a system does not need to be changed, a complex circuit does not need to be added, and the identification requirements of mutual inductance, bridging capacitance and load can be rapidly and accurately met. Afterwards, the working state of the system is judged according to the obtained bridging capacitance value, the method can accurately control the power and efficiency of the system, and the stability and reliability of the charging process are improved.

The invention relates to a multi-protocol communication interface chip receiver. The receiver comprises an RS232 receiver and an input switch resistance circuit, wherein the input end of the RS232 receiver is connected with the input switch resistance circuit; the input switch resistance circuit is used for enabling the input end of the RS232 receiver to be in a determined state voltage under the condition that the chip is turned off, and comprises a driving control circuit, a switch grid control and clamping circuit, a switch circuit and an input resistor; the design problem of a multi-protocol communication interface chip caused by incompatibility of the communication protocols of the RS232 receiver and the RS485 receiver in the aspects of common-mode input impedance and the like is solved, and the design of the multi-protocol communication interface chip can be realized.

The invention discloses a control method for power adaptive virtual impedance oscillation suppression of a cascaded dynamic voltage restorer, and relates to the technical field of power electronics. According to an instruction that a superior system outputs a three-phase voltage to the dynamic voltage restorer, a corresponding current instruction signal is obtained according to a voltage controller and coordinate transformation, and a direct-current bus oscillation component of a load converter parallel input virtual impedance in the equivalent cascade type dynamic voltage restorer is superposed to serve as a reference input signal of the current controller; therefore, the low-frequency-band negative real number input impedance of the load converter is weakened. Compared with the prior art, the input impedance can be adaptively adjusted according to the load power, the small signal stability of the cascade type dynamic voltage restorer under the condition that the load power changes is greatly improved, the influence of virtual impedance on the dynamic performance of the load converter can be avoided, the response speed to the load change is improved, and the stability of the load converter is improved. And meanwhile, the controller is low in order, few in control parameters and easy to digitally control.

The invention discloses a phased-array antenna control method and system based on impedance matching, a medium and a product, and relates to the technical field of antennas. In the method, before the phased-array antenna works, a target impedance matching parameter is calculated for active input impedance under each preset scanning angle point; establishing a target mapping relation table based on the plurality of preset scanning angle points and the corresponding target impedance matching parameters; during the working period of the phased-array antenna, receiving a target scanning angle, and calculating to obtain a corresponding beam pointing phase value for each antenna unit in the antenna array according to the target scanning angle; determining a real-time impedance matching parameter based on the target scanning angle and the target mapping relation table; and loading the beam pointing phase value to a phase shifter in the feed network, and applying a real-time impedance matching parameter to the dynamic impedance matching network, so that the input impedance of the antenna array is matched with the characteristic impedance of the feed network. By implementing the technical scheme provided by the invention, the radio frequency performance of the phased-array antenna is improved.

A DFIG wind power facility configured to be operated during grid faults is provided. The wind power facility includes a Doubly-Fed Induction Generator, a control system, an electric converter, a short-circuit controlled switch to selectively short-circuit the stator and a Stator Neutral Brake Chopper coupled to the stator. The DFIG includes a rotor and a stator, the stator including at least one three-phase winding. The electric converter includes a Machine Side Converter, a Grid Side Converter and a DC link connected therebetween. The SNBC includes a three-phase rectifier including three inputs, an impedance and an active high-frequency switch configured to vary the average value of the impedance by adjusting its duty cycle; each of the three inputs of the rectifier is connected to a phase of the at least one three-phase winding of the stator. Methods for operating a DFIG wind power facility during grid faults are also provided.

The invention provides a gain-reconfigurable active phase shifter with a low phase error, and relates to the technical field of phase shifters, and the phase shifter comprises a quadrature coupler which converts a radio frequency input signal into a shunt radio frequency signal; the input matching Balun converts the shunt radio frequency signal into a shunt differential signal; the digital control signal received by the phase inversion variable gain amplifier is used for controlling the on-off state of a differential pair in each differential group, and determining a differential combination current corresponding to a differential pair combination in a conduction state based on a shunt differential signal corresponding to each differential pair; the differential combination current is used for representing a gain state corresponding to the differential pair combination; the input impedance and the output impedance of the phase inversion variable gain amplifier in different gain states are kept unchanged; the vector synthesis module determines a phase shift differential signal based on the differential combined current; the output matching Balun converts the phase shift differential signal into a radio frequency output signal. The antenna has a wide gain adjustable range and a low phase error.

A power converter includes switching section, tuning section, and rectification section. The tuning section includes transformer with a primary inductance and a secondary inductance and a primary series capacitor connected in series with a primary winding and a secondary series capacitor connected in series with a secondary winding. The primary series capacitor is selected with a resonant frequency with the primary inductance and the secondary series capacitor is selected with the resonant frequency with the secondary inductance. The tuning section includes a resonant tank with a primary parallel capacitor connected in parallel with the primary series capacitor and the primary winding and a primary resonant inductor connected between the switching section and a connection to the primary parallel capacitor. An input impedance of the resonant tank at a switching frequency is below a frequency intersecting an open circuit input impedance and a short circuit input impedance of the resonant tank.

The invention is suitable for the technical field of radio frequency front ends, and particularly relates to a low-noise amplifier and a radio frequency chip. The low-noise amplifier provided by the invention comprises an input switching circuit, an amplifying circuit and an output matching circuit which are electrically connected in sequence, the input switching circuit comprises a plurality of input matching units, and the plurality of input matching units are used for receiving radio frequency signals of different frequency bands respectively; the amplifying circuit comprises a first amplifying unit, a first inductor and a plurality of second amplifying units connected in parallel, the input ends of the second amplifying units serve as the input end of the amplifying circuit, and the input ends of the second amplifying units are connected with the output ends of the input matching units in a one-to-one correspondence mode. Compared with the prior art, the low-noise amplifier disclosed by the invention can be used for independently optimizing the input impedance of each input port, so that not only can the noise coefficient be optimized, but also the optimal gain and linearity performance can be obtained.

This invention relates to the field of pulse circuit technology and discloses a high-efficiency AC power line zero-crossing detection chip, including a path selection module, a signal processing module, and a driving module. The path selection module switches the charging circuit according to the potential of the internal power supply capacitor. The signal processing module uses a feedback loop to adjust the switching level of the sampling branch and generate a zero-crossing trigger pulse signal. The driving module responds to the zero-crossing trigger pulse signal by segmentally turning on the internal power supply capacitor and the external energy supply capacitor in the initial and subsequent stages of the zero-crossing point. This invention solves the contradiction between the ultra-high input impedance sampling environment and the driving strength through a controlled hysteresis window and a segmented current injection mechanism, suppresses signal jitter, improves the timing accuracy of zero-crossing detection, and effectively reduces the static power consumption of the system.

The present application relates to a kind of broadband impedance spectrum cable fault identification method, system and storage medium, comprising: according to any preset cable fault type, establish cable equivalent model;Frequency-sweep signal is input to model, obtain the parameter of cable core, sheath and steel armor under different frequency-sweep signals, and the input impedance of cable head under different frequency-sweep signals is calculated based on cable modulus matrix and input impedance formula, draw fault broadband impedance amplitude spectrum and phase spectrum;Repeat the above steps, obtain cable fault broadband impedance amplitude spectrum and phase spectrum;Real-time acquisition actual cable input impedance and draw real-time broadband impedance amplitude spectrum and phase spectrum, compare with cable fault broadband impedance amplitude spectrum and phase spectrum, identify cable fault type and fault point distance from head end.Compared with prior art, the present application realizes the quick cable fault identification and fault point determination.

A Doherty amplifier according to the present disclosure comprises a main amplifier, an auxiliary amplifier, a distribution circuit that distributes signals to the main amplifier and the auxiliary amplifier, and a phase compensation circuit. The main amplifier has a first input matching circuit and a plurality of main amplification stages. The auxiliary amplifier has a second input matching circuit and a plurality of auxiliary amplification stages. The distribution circuit has a first line connected to the first input matching circuit and a second line connected to the second input matching circuit. The electrical length of the first line is such that the input impedance of the first line is higher than the characteristic impedance of the first line and the imaginary component is less than 10% of the real component when a small signal is input. The electrical length of the second line is such that the input impedance of the second line is higher than the characteristic impedance of the second line and the imaginary component is less than 10% of the real component when a small signal is input. The phase compensation circuit is provided in an inter-stage matching circuit of the plurality of main amplification stages or the plurality of auxiliary amplification stages.

The invention discloses a high-frequency electrotome negative plate impedance detection method and system and a high-frequency electrotome, and the detection method comprises the steps: an impedance detection signal preprocessing step: determining an acquisition time interval of an impedance detection signal according to a current working mode and a corresponding optimal acquisition time interval; only the impedance detection signals in the acquisition time interval are collected; the acquisition time interval is one or more carrier periods in which the signal-to-noise ratio of the impedance detection signal is higher than the average value of the signal-to-noise ratio in a unit modulation period T under the current working mode; and the optimized impedance detection signal is filtered and amplified and then is input into an impedance calculation module to calculate and obtain a real-time impedance value of the negative plate of the high-frequency electrotome. Interference is filtered out by monitoring information such as power and impedance intervals when the high-frequency electrotome works and combining noise waveform characteristics of different working modes.

The application discloses a kind of adjustable low-pass filter circuits based on self-bias pseudo resistance, the filter circuit includes: self-bias pseudo resistance circuit, differential source follower circuit and gain compensation circuit.The self-bias pseudo resistance circuit is made of back-to-back PMOS transistor, and its gate-source voltage is controlled by the direct current component of system input signal and output signal, so as to realize the function of adjustable large resistance;The differential source follower circuit uses common-drain amplifier, and converts passive amplifier into active amplifier with large input impedance and medium output impedance, while providing stable adjustable bias for the above-mentioned pseudo resistance;The gain compensation circuit is used to compensate for the gain loss of the common-drain amplifier due to the substrate effect.The low-pass filter circuit of the application can achieve considerable time constant with very small chip area and power consumption, and can be used in wearable physiological signal detection device, with the advantages of low power consumption, small area, high stability and the like.