351 results about "Output impedance" patented technology

The invention relates to the technical field of circuit board conductivity detection, and discloses a circuit board conductivity detection method and system based on deep learning, and the method comprises the steps: obtaining high-resolution image data and circuit design parameters of a to-be-detected circuit board, and generating a circuit board feature data set; calculating theoretical impedance distribution of each area of the circuit board by using a physical constraint neural network based on the circuit board feature data set, and outputting an impedance prediction parameter set; inputting the impedance prediction parameter set and the circuit symbol rule into a neural symbol inference device to generate a conductance fault diagnosis result; and obtaining diagnosis results of a plurality of detection sites, executing cross-site diagnosis fusion, and outputting a unified circuit board conductivity detection report. The method overcomes the limitation that a traditional visual detection method cannot identify electrical characteristic defects, and solves the detection problem of hidden faults such as discontinuous impedance of the high-frequency circuit board.

The invention discloses a network construction converter virtual impedance and power reference cooperative adjustment method and system, and relates to the technical field of power control, a virtual synchronous generator system introduces virtual impedance to increase equivalent output impedance of an inverter, and an internal voltage reference generated by a virtual synchronous generator algorithm of the inverter is monitored in real time; monitoring the local voltage measured by the common coupling point in real time; based on the vector difference between the internal voltage reference and the local voltage, the accurate amplitude of the virtual impedance is solved in real time by combining the maximum current limit value of the power electronic device; and determining a function relationship between an active power reference value and reactive power based on the accurate amplitude of the virtual impedance, monitoring the reactive power measured at the common coupling point in real time, and adjusting the active power reference value according to the function relationship to keep a stable balance point. And virtual impedance is dynamically calculated to accurately limit current, and active power reference is adaptively adjusted according to real-time reactive response, so that maximized power grid support and safe and stable operation of the converter are realized.

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 provides a stability margin calculation method of a new energy station grid-connected system, a terminal and a storage medium. The method comprises the following steps: acquiring inverter output impedance and power grid side equivalent impedance of an initial new energy station grid-connected system under multiple working conditions; taking the ratio of the output impedance of the inverter to the equivalent impedance of the power grid side under the same working condition as an open-loop transfer function, and determining a gain margin and a phase margin of the new energy station grid-connected system under each working condition based on the open-loop transfer function under each working condition; determining the weakest working condition of the new energy station grid-connected system based on the gain margin and the phase margin of the new energy station grid-connected system under each working condition; and under the weakest working condition, based on the gain margin and the phase margin of the new energy station grid-connected system under different numbers of inverters connected in parallel, the maximum capacity expansion number is determined. According to the method, accurate quantification of the capacity expansion limit is realized, the system stability is ensured, and the capacity expansion potential of the station is fully excavated.

The embodiment of the invention discloses a cable defect positioning and defect aging state detection method and equipment, belongs to the technical field of cable defect detection, and solves the problem that cable defects are difficult to reliably position during cable defect diagnosis in the prior art. Comprising the steps of constructing an integral transformation kernel function based on cable initial characteristic parameters; based on the integral transformation kernel function, constructing an integral transformation function corresponding to the cable head end impedance spectrum data, obtaining a cable defect diagnosis function, and determining cable defect positioning information through the cable defect diagnosis function; inputting the obtained cable defect positioning information into a cable impedance spectrum calculation model containing a local defect section, and outputting an impedance spectrum calculation value; optimizing a difference value objective function corresponding to the impedance spectrum calculation value and the impedance spectrum measurement value through a particle swarm algorithm to obtain characteristic parameters of the defect section of the cable; and determining the aging state of the local defect of the cable based on a preset cable aging characteristic parameter threshold and the characteristic parameters of the defect section of the cable.

Provided is a buffer circuit that can realize a wide dynamic range, a reduced area, and a reduced power consumption amount while maintaining low output impedance. The buffer circuit includes a first transistor, a current source, a second transistor, an output terminal, and first and second capacitors. The first transistor has a gate to which an input signal is input. The current source is connected to one terminal of the first transistor. The second transistor is connected to the other terminal of the first transistor. The output terminal is connected to the one terminal or the other terminal of the first transistor. The first and second capacitors are between the current source and the gate of the second transistor. The first transistor, the second transistor, and the first capacitor form a first feedback circuit. The first transistor, the current source, and the second capacitor form a second feedback circuit.

The invention provides a distributed photovoltaic grid-connected converter low-voltage ride-through control method based on sum-difference coordinate transformation, and solves the problems of insufficient synchronism, poor stability, insufficient reactive power support potential excavation and the like existing in collaborative response under power grid voltage drop during distributed photovoltaic grid connection. According to the method, impedance modeling and equivalent symmetry transformation are carried out on the distributed photovoltaic inverter, and a coupling multi-dimensional matrix equation is established; an original coupling system is decoupled into a sum current channel and a plurality of difference current channels, the control complexity is simplified, and an open-loop output impedance expression and a closed-loop output impedance expression are deduced; secondly, formulating a refined active / reactive current collaborative distribution strategy for different voltage drop depths, dynamically calculating the minimum reactive current during voltage drop, preferentially meeting the national standard, and maximizing active output or balancing loss under the limit of rated current; and finally, through sum-difference coordinate transformation, the total current demand and distribution are efficiently decoupled and issued to a current loop controller of each inverter, so that rapid, synchronous and stable cooperative operation of multiple inverters is realized.

The invention discloses a dual-frequency positive-sequence impedance modeling method for a network-building type energy storage converter considering frequency coupling. The method comprises the following steps: 1, injecting a dual-frequency positive-sequence disturbance voltage signal at a grid-connected point of the network-building type energy storage converter based on a virtual synchronous machine; 2, establishing a linearized small signal model for each control link of an active-frequency loop, a reactive-voltage loop, a virtual impedance-containing voltage and current double closed loop and the like to form a multi-frequency signal model; and 3, according to the multi-frequency coupling relationship between the current and the voltage, constructing a frequency coupling impedance matrix, and reducing a coupling term into output impedance to obtain the positive sequence output impedance and the negative sequence output impedance of the converter considering the frequency coupling, thereby simplifying the model stability analysis. According to the method, dual-frequency positive sequence disturbance is introduced, the coupling effect between different frequency components is effectively described, the defect that a traditional single-frequency modeling method cannot reflect the multi-frequency interaction characteristic is overcome, and the accuracy and applicability of the impedance model of the network construction type energy storage converter under the multi-frequency disturbance scene are remarkably improved.

The invention discloses an impedance-invariant vector synthesis phase shifter, an array element and a phased array, and relates to the technical field of phased array design. According to the impedance-invariant vector synthesis phase shifter provided by the invention, two capacitive compensation branches are arranged in each Gilbert unit of a variable gain amplifier, and the capacitive compensation branches are connected to a circuit only when bits are turned off, so that the output impedance of the unit is kept unchanged when the bits are turned on and turned off, and the output impedance of the unit is not changed when the bits are turned off. The phase shifting precision of the phase shifter is effectively improved, the root mean square phase error of the phase shifter is reduced to be within the acceptable range of the engineering field, phase shifting is directly carried out according to the most ideal condition based on IQ orthogonal signals, complicated calibration work is avoided, and the calibration problem of the vector synthesis phase shifter is solved. The invention further provides an array element which adopts the impedance-invariant vector synthesis phase shifter, the continuous time linear equalizer and the current mode attenuator and has the advantage of being convenient to deploy.

The invention discloses an automatic frequency modulation energy storage control method and system based on PCS power regulation, and belongs to the technical field of power system automation control, and the method comprises the steps: obtaining a voltage sampling sequence and a current sampling sequence of a PCS AC side port, and calculating a power grid side fundamental frequency equivalent impedance initial value; a preset high-frequency disturbance signal is injected into the PCS power output end, the fundamental frequency equivalent impedance initial value of the power grid side is corrected, and a real-time power grid impedance parameter is obtained; determining a target adaptive gain coefficient from a preset gain mapping table according to the combination of the real-time power grid impedance parameter and a preset virtual output impedance parameter; inputting the power grid frequency deviation value and the target adaptive gain coefficient into a frequency modulation power calculation function to obtain a PCS target active power regulation quantity; inputting the PCS target active power adjusting quantity into a PCS power control loop, and controlling the PCS to output AC side active power equal to the PCS target active power adjusting quantity; according to the invention, the frequency modulation response precision is improved.

An apparatus is provided that includes a memory array including non-volatile memory cells configured to store weights of an artificial neural network, a bit line coupled to a plurality of the non-volatile memory cells, and an interface circuit coupled to the bit line, the interface circuit configured to amplify an output impedance of the memory array.

A broadband Doherty power amplifier is provided, which includes a power divider, a carrier power amplifier circuit, a peak power amplifier circuit, and a load modulation network. The carrier power amplifier circuit includes a carrier input matching circuit, a carrier power amplifier, and a carrier output matching circuit. The peak power amplifier circuit includes a peak input matching circuit, a peak power amplifier and a peak output matching circuit. A resistance value of a system load is ZL. An output impedance of the carrier output matching circuit is Zm and meets Zm=ZL(n+1). An output impedance of the peak output matching circuit is Zp and meets Zp=ZL(n+1) / n. The load modulation network is configured to set an impedance of a combination point to be ZQ, whose resistance value is ZL. A method of implementing a broadband Doherty power amplifier is further 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 circuit arrangement for current limiting and an electrical system comprising such a circuit arrangement. An output terminal of a current limiting control circuit is connected to a control input of a semiconductor switch via a limiting resistor (RB). The current limiting control circuit is configured to change an output impedance of the current limiting control circuit at the output terminal. The semiconductor switch is configured to set a current (I) in a circuit between an electrical power source and a load. An inductor (L) is configured to be connected to the electrical power source and to a terminal of the load and an input of the current limiting control circuit is connected to the inductor (L). The current limiting control circuit is configured to detect an overcurrent-related voltage drop (VL) of the inductor (L) and reduce its output impedance to increase an output impedance of the semiconductor switch.

The invention relates to an audio decoding output stage circuit and audio equipment, the audio decoding output stage circuit comprises an I / V conversion module and a low-pass filtering module, and the I / V conversion module comprises a conversion circuit, a crossed diamond amplification circuit, an overcurrent protection circuit and a Roche network circuit; the conversion circuit comprises a JFET (Junction Field Effect Transistor) audio operational amplifier chip and an I / V (Input / Output) conversion resistor and is used for converting an input current into an analog voltage signal; the crossed diamond amplifying circuit can reduce the input offset voltage; the over-current protection circuit can carry out over-current protection; the rowbell network circuit can prevent high-frequency self-oscillation of the power output stage; and the low-pass filtering module comprises a filtering circuit and an ultrahigh frequency filtering circuit arranged at the output end of the audio decoding output stage circuit. The scheme can bring high-performance sound performance, and has the advantages of lower distortion, higher conversion rate, low output impedance and large pushing current.

The application discloses a kind of high-efficiency adaptive dynamic wireless power supply systems for wheel hub motor, battery is connected adaptive coupling transmission unit by vehicle-mounted power supply unit, the adaptive coupling transmission unit includes transmitting end and receiving end, the transmitting end dynamically adjusts output impedance according to control instruction, to match the load and coupling state of receiving end variation, the receiving end converts and outputs electric energy to wheel hub motor.The application completely cancels the physical high-voltage cable connection from the vehicle body to the rotating wheel, helps to improve the safety performance of vehicle, and improves the dynamic transmission performance and stability, can ensure the long-term reliable operation of power electronic elements in harsh environment, realizes prospective power regulation, avoids unnecessary energy waste, so as to improve the cruising range of whole vehicle.

Voltage ripple reduction in a power management circuit is disclosed. The power management circuit includes a power amplifier circuit configured to amplify a radio frequency (RF) signal based on a modulated voltage and an envelope tracking integrated circuit (ETIC) configured to provide the modulated voltage to the power amplifier circuit via a conductive path. Notably, an output impedance presenting at an input of the power amplifier circuit can interact with a modulated load current in the power amplifier circuit to create a voltage ripple in the modulated voltage to potentially cause an undesirable error in the RF signal. In this regard, a notch circuit is provided, preferably in the ETIC, to reduce the voltage ripple within a modulation bandwidth of the RF signal. As a result, it is possible to minimize the undesirable error, such as root-mean-square (RMS) error vector magnitude (EVM), within the modulation bandwidth of the RF signal.

The present application relates to the technical field of power system stability control, and particularly relates to a high-proportion wind power access system wide-frequency oscillation suppression method based on impedance shaping. The content comprises: constructing a frequency domain output impedance matrix, extracting a dominant wide-frequency oscillation coupling mode frequency band, introducing a mode suppression driven impedance shaping compensation mechanism, constructing a mode suppression driving quantity based on the mode direction in the dominant wide-frequency oscillation coupling mode, and performing local impedance shaping on the output impedance; based on the mode suppression driving quantity, quantifying the mode interference sensitivity between wind power converters, and introducing an impedance shaping gain correction mechanism based on the mode interference sensitivity, to correct the target output impedance after local shaping. The problems that the shaping process cannot effectively adjust dynamically according to the equipment capacity of the wind power converter and the frequency risk, resulting in no difference shaping and excessive compensation, and the problems that the interference coupling between the wind power converters cannot be effectively suppressed, resulting in excessive oscillation or suppression are solved.

The invention provides a high-precision voltage-stabilizing constant-current power supply for continuous discharge of a CO2 laser, which relates to the technical field of high-voltage voltage-stabilizing constant-current power supplies and comprises a high-voltage direct-current voltage-stabilizing power supply and a high-impedance amplification loop. The high-voltage direct-current voltage-stabilized power supply is boosted by a transformer, rectified by a rectifier bridge and stabilized by a filter capacitor, and continuously adjustable high-voltage output of 0-30kV is provided; the high-impedance amplification loop is composed of an operational amplifier, a three-stage triode amplification circuit and an electronic tube, the output impedance reaches up to 650 megohms, and the high-impedance amplification loop has the excellent constant-current characteristic. The power supply can accurately adjust the output current in the range of 0-30mA, the current fluctuation is less than one thousandth, the power supply can continuously and stably operate for more than 18 hours, and the power supply is suitable for laser discharge control in a high-temperature and high-density plasma environment. According to the invention, high-precision output is realized by adopting common performance devices, the advantages of voltage resistance, overload resistance and cost are considered, and the problems of poor current stability and inconvenient adjustment of a traditional laser power supply are solved.

The present invention provides an output circuit capable of lowering output impedance while using a diamond semiconductor, and an electronic device and a signal transmission system that include said output circuit. To that end, an output circuit (10) includes a field-effect transistor configured to be of the p-channel type and formed on a diamond substrate. The field-effect transistor comprises: a diamond transistor (Q5) that constitutes a drain ground circuit and outputs an output voltage (Vo2) from the source in accordance with an input voltage (Vi2) inputted to the gate; and a diamond transistor (Q6) that supplies a bias current to the diamond transistor (Q5). The diamond transistor (Q6) has normally-on characteristics and constitutes a current source due to the gate and the source being connected to each other.

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.

The utility model discloses a charging and downloading integrated cabinet and a seismic exploration system, and belongs to the field of seismic exploration. The charging and downloading integrated cabinet comprises a signal source assembly and a plurality of interface circuit boards. Each interface circuit board is provided with a voltage following circuit, and the voltage following circuits are connected between the signal interface end of the signal source assembly and the seismic exploration node instrument. The voltage follower circuit has the characteristics of high input impedance and low output impedance, so that under the action of the voltage follower circuit, the acquisition test signal sent by the signal source assembly can be normally transmitted to the seismic exploration node instrument through the voltage follower circuit; in addition, it can be ensured that the abnormal voltage of the circuit station does not affect the signal source assembly, so that the signal source assembly can send a normal acquisition test signal to perform acquisition index test on other normal seismic exploration node instruments.

An amplifier device, such as a Doherty amplifier device, may include an extra lead and decoupling capacitor coupled to radio frequency (RF) cold points of output impedance matching circuitry of multiple amplification paths, such as a carrier path and peaking path, of the amplifier device. The extra lead and the decoupling capacitor are configured to provide low frequency resonance decoupling for the multiple amplification paths. A drain bias voltage may be provided to the drain terminals of transistors of amplifiers of the amplifier device via the extra lead. An integrated passive device (IPD) including a wire fence and one or more conductive pads may be disposed between a carrier amplifier die and a peaking amplifier. The extra lead may be coupled to the RF cold points via the IPD. The wire fence may mitigate RF interference between the carrier amplifier die and the peaking amplifier die.

This invention provides an output impedance calculation device, which includes: a control unit, an adjustment unit, a LORA transmitting unit, a first impedance calculation unit, a second impedance calculation unit, a matching unit, and a transmitting antenna. The control unit is used to transmit wireless signals; the LORA transmitting unit is used to convert wireless signals into LORA signals; the first impedance calculation unit is used to calculate the input impedance based on the LORA signals; the second impedance calculation unit is used to calculate the output impedance based on the LORA signals; the control unit is used to calculate the reflection coefficient based on the input and output impedances, and to calculate the standing wave ratio based on the transmission coefficient; the adjustment unit is used to adjust the impedance in the circuit based on the standing wave ratio and the reflection coefficient, thereby achieving impedance matching and balance between the input and output terminals of the line, improving the output quality of radio signals, reducing the overall output power consumption, and reducing harmonic interference.

Provided are an impedance matching circuit and method, a radio frequency circuit, and an electronic device, and belong to the technical field of electronics. The impedance matching circuit comprises a transducer, a first adjustable circuit and a first switch circuit coupled between a first coil of the transducer and a first signal end, a second adjustable circuit and a second switch circuit coupled between a second coil of the transducer and a second signal end, and a control circuit coupled with the adjustable circuits and the switch circuits. The control circuit can adjust the working parameters of the adjustable circuits and the on-off states of the switch circuits based on the input impedance and the output impedance determined under different signal gain configurations, so as to achieve impedance matching. Therefore, the impedance matching circuit can achieve better impedance matching for different signal gain configurations, and has better flexibility in impedance matching.

Output impedance calibration and related apparatuses, systems, and methods are disclosed. An apparatus can include a plurality of drivers, where each driver of the plurality of drivers includes a plurality of transistors coupled to an output node. The apparatus can further include circuitry coupled to the plurality of drivers. The circuitry can configure at least one driver of the plurality of drivers in each of a plurality of configurations, where each of the plurality of configurations is associated with one calibration code of a plurality of calibration codes. Each configuration generates an associated channel performance response of a plurality of channel performance responses in response to a signal transmission via the output node. The circuitry can also store a calibration code of the at least one cell driver, where the calibration code generates a desired channel performance response of the plurality of channel performance responses.

The invention discloses a low noise amplifier and a wireless receiving system. The low-noise amplifier comprises an input matching circuit used for receiving a to-be-amplified signal output by a signal input end and matching impedance between the signal input end and an input end of a first amplifying circuit; the first amplification circuit is used for performing first-stage amplification processing on the signal to be amplified; the inter-stage matching circuit is used for matching the output impedance of the amplifying circuit with the input impedance of a second amplifying circuit; the second amplification circuit is used for performing second-stage amplification on the output signal of the inter-stage matching circuit; the output matching circuit is used for matching the output impedance of the second amplifying circuit with the impedance between a signal output end and outputting an amplified signal through the signal output end; and the bias adjusting circuit is used for adjusting the bias voltage of at least one of the first amplifying circuit and the second amplifying circuit. By adopting the scheme, the dynamic range of the low-noise amplifier can be improved.

A radio frequency module, a low-noise amplifier, and an electronic device. The radio frequency module includes: N first low-noise amplifiers coupled between a signal input port and a signal output port, where an input impedance and an output impedance of the first low-noise amplifier match a first frequency band; and M second low-noise amplifiers coupled between the signal input port and the signal output port, where the second low-noise amplifier includes an impedance adjustment network, and the impedance adjustment network can adjust an input impedance and an output impedance of the second low-noise amplifier, so that the input impedance and the output impedance of the second low-noise amplifier match different frequency bands. In this way, the second low-noise amplifier can be reused between different frequency bands such as an LB band and an MHB band, thereby increasing utilization of the low-noise amplifier.

The application discloses a kind of ultra-low voltage wideband low noise amplifiers, it is related to radio frequency signal transceiver technical field.Solve the high-frequency gain attenuation problem in the design of current low power supply voltage wideband low noise amplifier, including two-stage common-source amplifier connected in turn;The input stage amplifier is composed of input matching network, source sense asymmetric current sharing structure, cascaded matching network;The output stage amplifier is composed of MOS single-layer common-source structure, output matching network.The application improves the conventional source degeneration inductance structure, proposes a kind of source sense asymmetric current sharing structure, on the one hand, gain compensation of high frequency band is realized under the premise of not increasing power consumption, on the other hand, circuit uses peak inductance technology to realize wideband matching, gain compensation and reduce noise.In addition, the circuit uses active substrate noise reduction technology, adds high output impedance gate ground MOS tube to improve substrate resistance, reduce the noise change due to power consumption reduction.