62 results about "Signal Sensitivity" patented technology

The invention relates to the technical field of fault positioning, in particular to a power wire fault positioning system based on the Internet of Things, which comprises a data collection module, a fault analysis module and a data visualization module, firstly, a data collection module obtains wire data collected by a sensor on a wire in real time; secondly, the fault analysis module is used for carrying out data processing on the wire data to obtain fault data; according to the conductor data and the fault data, constructing a power conductor digital twinborn model; analyzing the fault features and the environmental parameters through a power conductor digital twinborn model to obtain an output result; analyzing the output result through a topology detection algorithm and signal sensitivity adjustment to obtain an optimized output result; obtaining a space-time propagation process formula of the fault signal through signal propagation simulation and space-time analysis according to the output result; evaluating the accuracy of an output result according to a space-time propagation process formula of the fault signal; and finally, the data visualization module generates a visualization chart and an analysis report.

The invention relates to the technical field of semiconductor chip preparation, in particular to a VCSEL chip and a manufacturing method thereof, and the VCSEL chip comprises a substrate, an epitaxial layer, an oxide layer, a passive film and a P-type electrode. During manufacturing, a groove and a mesa platform are formed on an epitaxial layer, a diffusion barrier layer is manufactured in the groove to prevent subsequent atoms from diffusing through an active region and an oxide layer, and then chemical vapor deposition is adopted to perform atom diffusion in the horizontal direction from the side surface through the groove, so that a diffusion region is formed at the top of the P-type DBR in the inner and peripheral regions of the groove, and the reflection capability is lost. The front edge of the diffusion area formed by side diffusion is a cylindrical surface, and the diffusion depth is easy to control; and through side surface atom diffusion, the non-destructive P-type DBR contact area between the front edge of the diffusion region and the vertical direction of the light outlet hole is greatly increased, so that the VCSEL chip can still work in a single transverse mode under the condition of relatively high output power, and the gas detection range or the signal sensitivity can be increased.

The invention relates to the technical field of sensitivity testing devices, in particular to a 5G communication module signal sensitivity testing device and a using method thereof.The 5G communication module signal sensitivity testing device comprises a display controller and a machine table assembly, one side of the display controller is fixedly connected with the machine table assembly, one end of the machine table assembly is fixedly connected with a position adjusting assembly, and the inner side of the position adjusting assembly is slidably connected with a clamping assembly; one side of the upper end of the machine table assembly is fixedly connected with a spacing adjusting assembly, the spacing adjusting assembly is provided with a detection assembly, the position adjusting assembly comprises a disc block, a rectangular groove is formed in the inner side of the disc block, the inner side of the rectangular groove formed in the disc block is fixedly connected with a first electromagnet, and the inner side of the rectangular groove formed in the disc block is fixedly connected with a guide rod; according to the 5G communication module testing device, the probe array can be flexibly adjusted according to the pin layout of a module circuit board, the 5G communication module testing device can adapt to 5G communication modules of different models and sizes, and the testing accuracy and effectiveness are ensured.

The invention relates to the technical field of nondestructive testing, in particular to an online detection system based on an eddy current technology and a detection method thereof, and the system comprises an array eddy current sensor module, a signal processing module, a data acquisition module, an algorithm processing system module, a control system module, a display module, a power supply module and a storage module. Through the effects of the array eddy current sensor module, the signal processing module and the control system module, the system has the advantages of good sensitivity and high display result precision; the problems that according to an existing on-line detection system, due to the fact that an eddy current sensor achieves displacement measurement by converting impedance changes of an inductive probe into voltage or current changes, the impedance output characteristics of the inductive probe are affected by environment temperature, an excitation source, a detected object and the like, the performance and signal transmission of the sensor in all aspects are affected, and displacement measurement is influenced are solved. Therefore, the signal sensitivity and the display result precision are reduced.

Methods and systems for measurement of wafer tilt and overlay are described herein. In some embodiments, the measurements are based on the value of an asymmetry response metric and known wafer statistics. Spectral measurements are performed at two different azimuth angles, preferably separated by one hundred eighty degrees. A sub-range of wavelengths is selected with significant signal sensitivity to wafer tilt or overlay. An asymmetry response metric is determined based on a difference between the spectral signals measured at the two different azimuth angles within the selected sub-range of wavelengths. The value of the asymmetry response metric is mapped to an estimated value of wafer tilt or overlay. In some other embodiments, the measurement of wafer tilt or overlay is based on a trained measurement model. Training data may be programmed or determined based on one or more asymmetry response metrics at two different azimuth angles.

The invention discloses a Raman-meter temperature and humidity laser radar detection system with three wavelengths and eight channels. The Raman-meter temperature and humidity laser radar detection system comprises a transmitting system, a receiving system, a data acquisition and processing system and a computer control system. Laser signals with the wavelengths of 355 nm and 532 nm are combined with a dynamic background light intensity adjusting mechanism, so that the signal sensitivity under the conditions of strong background light in the daytime and low background light at night is ensured. The light splitting module adopts a high-performance narrow-band optical filter and a multilayer medium coated dichroic mirror which are arranged at a preset inclination angle and cooperate with an achromatic lens group of the collimation system, so that efficient light beam transmission and accurate separation of multi-wavelength signals are realized, spectral crosstalk is remarkably reduced, and the system detection precision, the environment adaptability and the data processing reliability are improved; the method is suitable for all-weather and multi-scene atmosphere detection.

The present invention discloses a method for preparing a gain-adjustable MEMS pressure chip, which relates to the technical field of MEMS chip preparation. The method includes: forming an N+ buried layer area on the surface of a top silicon layer; bonding the top silicon layer to a double-polished silicon wafer, removing the SOI silicon wafer substrate layer and the buried oxide layer; forming a gain circuit area, an isolation area and a piezoresistive area on the top silicon layer; processing the double-polished silicon wafer layer to form a back cavity to obtain a MEMS chip; the collector area of ​​the gain circuit area is connected to the N+ buried layer area to reduce the series resistance and reduce the influence of parasitic transistors. The gain circuit area of ​​the present invention is located between the inner layer and the outer layer of the isolation area, the piezoresistive area is located within the range of the inner layer, and the gain circuit is integrated in the MEMS chip, which not only shortens the signal transmission path, but also effectively reduces the parasitic capacitance and signal loss in the traditional discrete design. The obtained MEMS pressure chip has the advantages of high integration, high signal sensitivity, high structural strength, and easy sensor integration.

The invention discloses a high-precision wide-range expiration detection device and method, which is applied to the technical field of expiration detection, and comprises an expiration sampling unit used for collecting an expiration sample; the gas analysis unit consists of a three-way valve, an analysis pump, an electrochemical sensor module and a filter; the control and calculation unit is used for controlling the three-way valve to perform quick switching of closing and opening according to the size of the real-time output signal when the ratio of the output signal to the saturation signal is greater than a preset threshold value, so that the expiration sample is mixed with the zero-point gas filtered by the filter before entering the electrochemical sensor module; the gas concentration in the expiration sample is calculated according to the proportion of the output signal, the sensitivity and the closing time of the three-way valve; the double clinical requirements for high precision and wide range of expiration detection are met.

The invention relates to the technical field of power system automation, and particularly discloses a power network fault early warning method based on a large model, and the method comprises the steps: directly mapping the data of a high-frequency power sensor into a time sequence soft prompt vector which can be understood by the large model through a lightweight encoder and a linear projection technology; deep alignment of continuous signals and discrete semantics is realized, and information loss and efficiency bottleneck caused by numerical textualization are avoided. And then, directionally retrieving an operation and maintenance knowledge base by using the soft prompt vector, introducing a cross-modal affinity matrix to construct a semantic gating mechanism, dynamically screening and enhancing retrieved key knowledge fragments according to real-time waveform characteristics, and automatically inhibiting redundant text noise irrelevant to the current working condition. And finally, deep attention interaction and reasoning are performed on a composite sequence formed by an instruction, enhanced knowledge and soft prompt through a large model, a control signal containing fault classification and disposal suggestions is output, and real-time accurate early warning considering high-frequency signal sensitivity and expert knowledge logicality is realized.

The application relates to the technical field of intelligent traffic control, and discloses a traffic signal lamp strategy dynamic regulation and control method based on space-time dimensions. The method captures multi-dimensional feature data of traffic flow, fuses weather and road topological information, constructs a dynamic traffic state tensor, carries out multi-scale space-time feature extraction on the tensor, generates a space-time mode atlas, analyzes the interaction strength between different traffic units based on the atlas through a graph neural network, divides a cooperative evolution area and a conflict frequent area, outputs a regional interaction label set, integrates signal lamp historical data and real-time delay, calculates a sensitivity coefficient of flow fluctuation on signal timing, forms a signal sensitivity analysis report, extracts conflict frequent area nodes with sensitivity exceeding an adaptive threshold, constructs a key interference node set, combines the space-time features of the set, uses a risk propagation model to evaluate a chain reaction probability, and generates a traffic signal optimization scheme containing a signal parameter optimization strategy and an emergency regulation and control instruction.

The present invention relates to the technical field of semiconductor chip preparation, and specifically to a VCSEL chip and a method for making the same. The VCSEL chip includes a substrate, an epitaxial layer, an oxide layer, a passivation film, and a P-type electrode. During the manufacturing process, a groove and a mesa platform are formed on the epitaxial layer, and a diffusion barrier layer is formed in the groove to prevent subsequent atomic diffusion through the active area and the oxide layer. Then, chemical vapor deposition is used to perform horizontal atomic diffusion from the side through the groove, so that a diffusion zone is formed at the top of the P-type DBR in the inner and outer areas of the groove, and the reflection capability is lost. The front edge of the diffusion zone formed by the side diffusion of the present invention is a cylindrical surface, and the diffusion depth is relatively easy to control; and through the side atomic diffusion, the contact area of ​​the non-destructive P-type DBR in the vertical direction of the light-emitting hole is greatly increased, which is conducive to the VCSEL chip still working in a single transverse mode under a large output power, and is conducive to increasing the gas detection range or increasing the sensitivity of the signal.

The application discloses a remote medical interactive method based on virtual reality, and particularly relates to the field of remote medical interaction, and comprises the following steps: through synchronous acquisition of patient end multi-modal tactile data and transmission state parameters, a joint feature vector is established, and transmission delay of each modal tactile signal is predicted in real time. Through real-time image extraction of the doctor end, the operation stage and the tactile signal sensitivity index are extracted, the reward value is calculated by combining the double-branch regression network, the mode transmission strategy is updated, and a dynamic priority allocation matrix is generated; based on the matrix, the real-time network state and the delay prediction are combined, the bandwidth slice strategy is optimized, and signal compensation is performed; in addition, the operation instrument switching and pathological mutation are detected, the priority allocation is dynamically adjusted, and efficient transmission and operation feedback of the tactile signal are ensured.

This application provides a radio frequency (RF) system and electronic equipment. The RF system includes an RF transceiver module, an RF front-end module, at least one antenna radiator, and at least one first low-noise amplifier module. The RF front-end module includes at least one transmit path and at least one receive path. One end of the transmit path is electrically connected to the RF transceiver module, and one end of the receive path is electrically connected to the RF transceiver module. The first low-noise amplifier module is connected between the antenna radiator and the receive path. When the first low-noise amplifier module is in a first operating state, it is conductive between the antenna radiator and the receive path. When the first low-noise amplifier module is in a first bypass state, it is short-circuited between the antenna radiator and the receive path. In the first operating state, by placing the first low-noise amplifier module close to the antenna radiator, the noise figure is reduced, and the signal sensitivity of the receive path is improved.

The invention provides a skeleton structure and a shell structure of a three-coil induction type oil chip sensor. The skeleton structure comprises a skeleton body and a shell body, the framework body is provided with a plurality of wiring channels, and the wiring channels are symmetrically distributed on the framework body and used for copper wires to penetrate out and be connected to an electric connector when the copper wires are wound. The shell body is provided with a fixed wire path matched with the wiring channel of the framework body, one end of the fixed wire path corresponds to the wiring channel of the framework body, and the other end of the fixed wire path is communicated to the wiring bin and used for fixing the wire wiring path to prevent the wire from passing through the induction area. And the wiring bin is used for connecting the lead which penetrates out with the sensor excitation circuit and the signal processing circuit through an aviation plug. According to the sensor, the plurality of wiring channels are formed in the framework and the shell, and the copper wire winding process is more tidy and symmetrical through the reasonable winding design, so that the signal quality of the sensor is effectively improved, and the signal sensitivity and stability are improved.

The utility model provides a high-gain high-sensitivity photon wireless signal transmitting and receiving shared device. The high-gain high-sensitivity photon wireless signal transmitting and receiving shared device comprises a metal shell, a silicon lens, a PCB circuit board, an optical fiber module, a PIN-PD integrated antenna chip, a planar antenna, a horn antenna and the like, wherein the silicon lens, the PCB circuit board, the optical fiber module, the PIN-PD integrated antenna chip and the planar antenna are fixed in the metal shell; the high-gain high-sensitivity photon wireless signal transmitting and receiving common device provided by the embodiment of the utility model not only can be used as a photon wireless signal receiving device, but also can be used as a photon wireless signal transmitting device; in addition, the photon wireless signal transmitting and receiving sharing device provided by the embodiment of the utility model can achieve the effects of improving the signal transmitting power and improving the signal receiving sensitivity. In addition, the purpose of continuously adjusting the transmitting frequency can be achieved.

The invention relates to a working electrode for detecting tetrahydrothiophene, a preparation method and an electrochemical sensor, and belongs to the technical field of electrochemical sensors. The preparation method of the working electrode for detecting tetrahydrothiophene comprises the following steps: mixing a metal catalyst, a conductive agent and a solvent, then adding a dispersant and a binder, mixing to obtain slurry, mixing the slurry with a diluent to obtain a suspension, spraying the suspension to a waterproof breathable film, drying, and pressing to obtain the working electrode. The signal sensitivity of the working electrode prepared by adopting the ultrasonic spraying method is higher than that of the working electrode prepared by adopting a silk-screen printing mode, the signal noise is low, the electrochemical sensor is more stable during working, a fluctuation signal of a base line is not easy to generate, and a false alarm is not generated.

The invention discloses a new energy motor shaft detection device which comprises a positioning mechanism, a driving mechanism and a detection mechanism. The positioning mechanism is used for fixing a to-be-tested motor shaft, and the driving mechanism drives the motor shaft to rotate. The detection mechanism comprises a signal transmitting assembly and a signal receiving assembly. One end of a signal lever of the signal transmitting assembly is provided with a signal transmitting unit, the other end is a contact end in contact with the shaft surface, and the lever structure amplifies infinitesimal displacement of the contact end into angular deflection of the transmitting unit. A receiving tube of the signal receiving assembly is internally provided with a multi-corner signal transmission channel, and each corner is provided with a signal receiving and reflecting unit with a reflecting layer and a sensor. When a defect exists on the surface of the shaft, displacement of the contact end causes change of the angle of the emitted light beam, so that the light beam is off-target in the channel, and signals received by one or more sensors are changed. Continuous deformation is converted into discrete optical path signals, and the method is high in sensitivity, visual in judgment, high in interference resistance and suitable for online rapid detection and sorting.

The utility model belongs to the field of air tightness detection devices, and discloses a simple device for detecting air tightness, which comprises a plurality of groups of whistles and a plurality of groups of connecting belts, the whistles are connected with snap rings, two ends of the connecting belts are respectively connected with buckles, the buckles are matched with the snap rings, the buckles are rotatably connected with sealing rods, and the buckles are connected with springs. The free end of the spring is connected with the sealing rod; the whistle is connected with a rubber backing ring; according to the technical scheme, the airtightness of the device is detected through the multiple groups of whistles, the multiple groups of whistles are connected in series through the connecting belts, operation is convenient, when leakage occurs to the device, leaked gas can make a sound for the whistles, detection personnel can rapidly determine leakage of the device and can rapidly determine leakage points, long-term concentration of the detection personnel is not needed, and the detection efficiency is improved. The detection signal sensitivity is improved; a corresponding number of whistles can be connected, and the distance between two adjacent groups of whistles can be adjusted, so that the applicability of the device is greatly improved, the device is convenient to disassemble and store, and the practicability is greatly improved.

The invention discloses a near-bit electromagnetic wave receiving structure based on a modular magnetic core antenna array, and belongs to the technical field of coal mine drilling measurement while drilling. Comprising a drill collar, a modular antenna unit and a signal processing circuit, an annular mounting groove is formed in the outer wall of the drill collar, and the multiple modular antenna units are distributed in the annular mounting groove in a circular array mode to jointly form a distributed receiving antenna array; and the signal processing circuit is arranged in the drill collar, is connected with the distributed receiving antenna array through a main interface, and is used for carrying out amplification, synthesis and noise suppression processing on array signals, so that the received signal-to-noise ratio is improved. The antenna is decomposed into a plurality of independent modular antenna units which are distributed in the annular mounting groove of the drill collar in a circular array mode, distributed array receiving is achieved, the units can be rapidly replaced, assembling is convenient, signal sensitivity is high, and the antenna is suitable for drilling of complex coal seams.

The invention provides a wireless receiving control circuit and signal transmission equipment. The wireless receiving control circuit comprises a signal amplification unit and a second resistor, the signal amplification unit is used for acquiring a wireless input signal, and a first resistor is arranged on the signal amplification unit; in a remote transmission state, the second resistor and the first resistor are connected in parallel, so that the signal amplification unit outputs a first amplification signal; in a short-range transmission state, the second resistor is disconnected with the first resistor, so that the signal amplification unit outputs a second amplification signal; the signal value of the first amplified signal is greater than that of the second amplified signal; by adjusting whether the second resistor is connected to the first resistor or not, the signal amplification unit outputs the first amplification signal and the second amplification signal with different signal values, the sensitivity of the output signal of the wireless receiving control circuit can be adjusted, signal transmission in different scenes can be adapted, and the signal transmission efficiency is improved. Therefore, the signal interference disorder is reduced.

The invention provides a preparation method of a monolithic MEMS pressure chip, and the method comprises the steps: preparing an N + buried layer and a shallow-cavity groove-shaped structure on top silicon of an SOI silicon wafer, bonding the SOI silicon wafer and a double-parabolic silicon wafer together, preparing a dielectric isolation structure, a collector region, a base region, a first injection region and a second injection region on the double-parabolic silicon wafer, arranging an emitter region on the base region, and arranging a second injection region on the emitter region. And sputtering metal leads correspondingly matched with the second injection region, the collector region, the base region and the emitter region, and upwards corroding the bottom of the double-parabolic silicon wafer to form a cavity. The preparation scheme provided by the invention has the advantages of clear steps, strong operability, batch manufacturing, high integration level, high signal sensitivity, high structural strength, easiness in sensor integration and the like.

Methods and systems for emulating a speed sensor with current output via a hardware-in-the-loop (HIL) system are described. In one example, the HIL system outputs a voltage signal that is converted into two current signals that may be interpreted into speed and direction information. The current output may decrease signal sensitivity to electrical noise.

This application discloses a bone conduction sensor and an electronic device. The bone conduction sensor includes: a first carrier plate with an electrical connector disposed on its lower surface, the electrical connector being configured to connect to an external device; a second carrier plate disposed above the first carrier plate, forming a vibration cavity together with the first carrier plate; a housing disposed above the second carrier plate, forming a microphone cavity together with the second carrier plate; a vibration system disposed within the vibration cavity; and a microphone assembly disposed within the microphone cavity. The bone conduction sensor of this application has a vibration system closer to the vibration source, enabling better sensing of vibration signals and higher sensitivity. Furthermore, the vibration system is disposed within the vibration cavity formed by the first and second carrier plates, allowing these components to be integrated into a subsystem, thereby simplifying the manufacturing process and improving reliability.

The invention discloses a shot blasting mass flow high-precision on-line monitoring device and a monitoring method thereof.The device comprises double spiral electrodes and double annular electrodes which are coaxially installed, the double annular electrodes are arranged in the axial direction of a pipeline at intervals, and the particle flow speed is calculated through a cross-correlation algorithm; the double-helix electrode adopts a coaxial reverse winding structure, and the RMS value of the particle charge quantity is obtained through signal summation and average processing, so that the shot blasting concentration is inverted. According to the invention, the time domain cross-correlation speed measurement of the annular electrode and the signal amplitude statistical measurement concentration of the spiral electrode are creatively combined, and the influence of the environment humidity is compensated through the dynamic calibration model, so that the high-precision online measurement of the shot blasting mass flow is realized. Besides, the coaxial winding design of the spiral electrodes avoids monitoring errors caused by non-uniform distribution of particles in the pipeline, signal sensitivity is enhanced, the embedded humidity sensor provides real-time environment compensation, and the device is suitable for high-speed industrial shot blasting monitoring.

An easy-to-carry flip-type antenna device according to the present invention comprises: a plate-shaped antenna portion which receives and transmits satellite signals in a beam steering manner; a plate-type base portion which is provided under the antenna portion and is capable of being linked to the antenna portion, and has a power supply module that supplies power necessary for driving the antenna portion; a rotation portion to which sides of the antenna portion and the base portion facing each other are respectively coupled and which allows the antenna portion to rotate according to the sensitivity of satellite signals so as to adjust an angle for efficiently transmitting / receiving satellite signals; and a grip portion which is provided at one side of the rotation portion to be gripped by a user, wherein, while the base portion is seated on the floor or a holder, the antenna portion is swung to be unfolded or folded with respect to the rotation portion as a reference axis, so that an unfolding angle can be adjusted during use.

This invention discloses a method and system for calculating the sensitivity of an electromagnetic environment monitoring system based on link configuration in low-temperature environments, belonging to the field of electromagnetic environment monitoring technology. The method includes: determining the monitoring scenario and link configuration of the electromagnetic environment monitoring system, and selecting a calculation method based on the determined monitoring scenario and link configuration; collecting parameters of each component of the electromagnetic environment monitoring system; if the monitoring scenario is an extreme environment, determining the correction coefficient kt corresponding to the ambient temperature and the actual operating temperature of each component of the electromagnetic environment monitoring system; and calculating the sensitivity of the electromagnetic environment monitoring system using the selected calculation method, the component parameters, the correction coefficient kt, and the actual operating temperature. This invention solves the problem that existing calculation methods do not distinguish between signal sensitivity and noise sensitivity calculation scenarios, leading to insufficient monitoring accuracy in special fields.

The embodiment of the application provides a communication system, a communication method and a computer storage medium, the communication system comprises at least two millimeter wave communication units, one of the millimeter wave communication units is a reference millimeter wave communication unit, a frequency synchronization channel is established between the reference millimeter wave communication unit and each of the other millimeter wave communication units, and the reference millimeter wave communication unit transmits a reference frequency to each of the other millimeter wave communication units through the frequency synchronization channel; each of the millimeter wave communication units demodulates the received millimeter wave signal through a corresponding radio frequency module based on the reference frequency, so that the frequency difference intermodulation caused by the reverse leakage is eliminated, the situation that the received millimeter wave signal cannot be correctly demodulated due to the frequency difference intermodulation is avoided, and then the signal frequency stability is improved, and the received signal sensitivity is improved.

The present invention belongs to the technical field of coal mining crack measurement, and specifically discloses a coal mining crack dynamic measurement and monitoring system, which includes a crack signal acquisition module, a crack signal processing module, a crack risk determination module, and a monitoring adjustment feedback terminal. By adopting a distributed high-frequency acoustic emission sensor array and combining a rupture event trigger threshold with time-domain / frequency-domain feature extraction technology, the present invention can capture the tiny energy release signals of rock burst precursors in real time, breaking through the limitation of traditional microseismic monitoring's insufficient sensitivity to tiny signals. By dynamically adjusting the frequency band division weights through wavelet packet decomposition technology, the present invention can effectively distinguish between noise and true crack expansion signals, preventing the tiny energy features from being submerged. At the same time, by dynamically adjusting the sampling frequency, sensor activation ratio, and data transmission frequency, the present invention ensures the integrity and real-time nature of the crack expansion signal, thus making up for the shortcomings of the traditional single data source.

The invention provides a transmitting and receiving sharing device for high-gain and high-sensitivity photon wireless signals and a preparation method of the transmitting and receiving sharing device for the high-gain and high-sensitivity photon wireless signals. Comprising a metal shell, and a silicon lens, a PCB circuit board, an optical fiber module, a PIN-PD integrated antenna chip and a planar antenna which are fixed in the metal shell, and a horn antenna interconnected with the metal shell. The high-gain and high-sensitivity receiving and transmitting shared device for the photon wireless signals provided by the embodiment of the invention not only can be used as a receiving device for the photon wireless signals, but also can be used as a transmitting device for the photon wireless signals; in addition, the photon wireless signal transmitting and receiving sharing device provided by the embodiment of the invention can achieve the effects of improving the signal transmitting power and improving the signal receiving sensitivity. In addition, the purpose of continuously adjusting the transmitting frequency can be achieved.

The utility model discloses a charge amplifier with high resolution and sensitivity setting. The charge amplifier comprises a charge conversion circuit, a high-pass filter circuit and a sensitivity setting circuit which are connected in sequence. The charge conversion circuit converts charge signals output by the piezoelectric sensor into voltage signals, the high-pass filter filters out low-frequency drift signals existing in the signals, and the sensitivity setting circuit comprises two digital potentiometers and an operational amplifier. The single-chip microcomputer controls the two digital potentiometers to set the resistance values of the digital potentiometers so as to realize matching of the piezoelectric sensors with different sensitivities. According to the utility model, the sensitivity setting is more accurate, the problem that the amplification factor of the sensitivity setting circuit cannot be accurately matched with the sensitivity of the piezoelectric sensor is solved, the sensitivity setting range of the charge amplifier is improved, and the charge amplifier can be matched with the piezoelectric sensor with lower sensitivity and the piezoelectric sensor with higher sensitivity; therefore, the charge amplifier has better universality, and the cost is greatly saved.