924 results about "Input impedance" patented technology

An impedance match housing is described. The impedance match housing includes an impedance matching circuit having an input that is coupled to a radio frequency (RF) generator. The impedance matching circuit has an output that is coupled to a first RF strap. The impedance match housing includes a uniformity control circuit coupled in parallel to a portion of the first RF strap to modify uniformity in a processing rate of a substrate when the substrate is processed within a plasma chamber.

A power transmission apparatus for wireless power transfer to a movable power receiving apparatus includes a power transmission resonator that includes a power transmission coil and a transmission resonance capacitor unit, and a power transmission circuit for supply of alternating-current power to the power transmission resonator. The power transmission apparatus includes a power-transfer request signal receiver configured to receive a power-transfer request signal transmitted from the power receiving apparatus, and a switching unit. The switching unit is configured to, when the power-transfer request signal receiver receives the power-transfer request signal, change an input impedance of the power transmission resonator to change a value of current flowing through the power transmission coil of the power transmission resonator to a controlled value enabled to transfer power from the power transmission coil to the power receiving apparatus.

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 wireless communication networks, and provides a low-channel electroencephalogram amplification circuit and brain-computer interface equipment oriented to an after-ear electroencephalogram signal, and the low-channel electroencephalogram amplification circuit comprises a dry electrode sensing module which is used for collecting an electroencephalogram signal; the front active amplification module comprises an operational amplifier circuit with high input impedance; the anti-aliasing filtering module is formed by cascading a multi-order passive filtering network and an active filtering circuit, is connected with the output end of the front active amplification module and is used for filtering high-frequency interference signals; the right leg driving feedback module comprises a programmable impedance adjusting circuit and a current limiting protection circuit, the right leg driving feedback module and the front active amplification module form a closed-loop feedback loop, and the output end of the right leg driving feedback module and the human body form a current loop through a protection resistor; the analog-to-digital conversion module adopts an integrated low-power-consumption analog front-end chip; a wireless transmission module; and the power supply management module provides independent power supply for the analog front-end chip, the operational amplifier circuit and the wireless transmission module.

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 embodiment of the invention provides a high-sensitivity vibration measurement and analysis instrument. In the embodiment of the invention, the signal buffering and driving sub-module in the signal conditioning module effectively isolates the sensor from a subsequent circuit by providing high input impedance and low output impedance, the load effect of a signal source is prevented, and the integrity and stability of the signal in the transmission process are ensured. Moreover, the driver part enhances the driving capability of the signal, so that the signal can overcome the impedance of a transmission line, and the attenuation of the signal in long-distance transmission is reduced, thereby guaranteeing the quality of the signal, and enabling the adaptive gain controller sub-module to automatically adjust the gain according to the intensity of the input signal. By means of the innovative design, the system can keep the best sensitivity when facing vibration signals of different amplitudes, signal saturation is avoided, it is guaranteed that weak vibration or strong vibration can be accurately measured, and the data accuracy in the digital signal processing stage is guaranteed.

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.

A radiofrequency calibration system for a direct-drive radiofrequency power supply includes a reference box that includes a reference circuit for converting a non-reference input impedance to a reference output impedance. The reference box has an input connector electrically connected to a radiofrequency output coupling of the direct-drive radiofrequency power supply. A radiofrequency power meter has a radiofrequency power input electrically connected to an output connector of the reference box. The radiofrequency power meter has an input impedance and an output impedance that substantially match the reference output impedance of the reference box. A cable has a first end electrically connected to a radiofrequency power output of the radiofrequency power meter and a second end connected to a test load that has an impedance that substantially matches the reference output impedance of the reference box. A controller is connected in data communication with a data interface of the radiofrequency power meter.

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.

The invention discloses a differential closed-loop negative feedback amplification circuit based on JFET geminate transistors, a low-noise amplifier is used for measuring weak voltage signals, discrete JFET field-effect transistors are used for forming an input stage of the low-noise amplifier, noise interference is reduced, meanwhile, extremely high input impedance can be provided by using the characteristic that the grid current of the JFET field-effect transistors is basically zero, and the differential closed-loop negative feedback amplification circuit based on the JFET geminate transistors is obtained. Mirror current is provided for a pair of JFET field effect transistors in the low-noise amplifier module through a current mirror of the low-noise amplifier, a closed-loop feedback structure of the low-noise amplifier can save one path of input for the JFET field effect transistors, so that the amplifying circuit can realize dual-channel input, and a dual-channel input structure can enable an accessed signal to be a differential signal, so that common-mode interference is effectively inhibited, and the reliability of the amplifying circuit is improved. Overall closed-loop negative feedback can achieve high gain stability, reduce nonlinear distortion, increase input impedance, reduce output impedance and improve the performance of the amplifier, and solves the problem of precise amplification and measurement of weak voltage signals in the aviation electromagnetic field.

Methods and apparatus for a signal isolator that mitigates the effects of CMTI strikes. In embodiments, a first die comprises a transmit module and the first die has a first voltage domain; and a second die comprises a receive module including a receive amplifier configured to receive from the transmit module a transmit signal that includes a differential signal and a common mode current. The second die may have a second voltage domain with the first and second die being separated by an isolation barrier. In embodiment, the receive amplifier includes a differential amplifier to receive the differential input signal from the transmit module; and a common mode module configured to sense the common mode current and sink or source the common mode current and minimize changes to an input impedance of the receive amplifier.

The invention discloses a fast self-adaptive impedance matching method and system and a wireless power transmission system, an MCU enables a pi-type impedance matching network to be in a short circuit state by controlling a relay switch, two groups of reflection coefficients of the system are obtained through measurement of an amplitude phase measurement circuit, and two groups of input impedance are calculated; and calculating to obtain a theoretical optimal capacitor combination corresponding to each input impedance. And actually measuring the reflection coefficients of the two input impedances in the corresponding theoretical optimal capacitor combination, wherein the capacitor combination with the smaller reflection coefficient is the actual optimal capacitor combination. Furthermore, according to the method, a local optimal solution is searched around an actual optimal capacitor combination, and re-impedance matching is completed. And dynamically monitoring the input impedance of the system under the given frequency, and repeating the steps when the change of the input impedance exceeds a set threshold value. According to the method, theoretical calculation is combined with hardware testing, the matching efficiency of the system is greatly improved, in addition, the influence of parasitic parameters on the matching precision of the system can be effectively avoided through a local optimization control algorithm, the transmission efficiency and stability of the system are further improved, and good practicability is achieved.

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.

A radio-frequency system including: a self-complementary antenna characterized by an input impedance substantially independent of signal frequency across an operational frequency band; a passive coupling device characterized by a characteristic impedance and configured to couple the self-complementary antenna to a signal generator and a set of signal processors; a resistive matching network electrically connected between the self-complementary antenna and the passive coupling device configured to match the characteristic impedance of the passive coupling device to the input impedance of the self-complementary antenna; and a back-coupling line characterized by a substantially constant group delay across the operational frequency band configured to electromagnetically couple the signal generator to the set of signal processors.

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 dual-frequency compatible constant-current constant-voltage wireless charging system and a parameter tuning method thereof.The whole wireless charging system comprises a transmitting end and a receiving end, and the transmitting end comprises a direct-current voltage source Vdc, a high-frequency full-bridge inverter circuit, a primary side resonance compensation network and a transmitting coil Lp which are sequentially connected; and the receiving end comprises a receiving coil Ls, a secondary side resonance compensation network, a full-bridge rectification filter circuit and a direct-current load Ro which are connected in sequence. According to the invention, the hybrid compensation network is constructed in the system and parameter tuning is carried out on the hybrid compensation network, so that the resonant operation conditions of the system under two different frequencies can be met under the condition that inherent parameters of the system are not changed or complex control and additional devices are not used; on the basis, constant-current and constant-voltage hybrid wireless charging and input impedance zero-phase-angle operation can be achieved only through switching control over the two resonant frequencies, and the technical advantages of being high in efficiency, low in cost and easy to achieve are achieved.

A substrate processing system includes a drive circuit, an RF reference measuring circuit, and a make-break connector. The drive circuit generates an RF drive signal at a first RF frequency. The RF reference measuring circuit includes an LC circuit having an input impedance and an output impedance. An output of the LC circuit connects to an RF power meter and a dummy load. The make-break connector connects the drive circuit to one of the RF reference measuring circuit and a processing chamber load including a component of the substrate processing system. An output impedance of the drive circuit matches an impedance of an input impedance of the LC circuit. The output impedance of the drive circuit does not match impedances of the RF power meter and the dummy load. The LC circuit matches the impedance of the drive circuit to the RF power meter and the dummy load.

The invention provides a radio frequency power division unit, a radio frequency power division module and a radio frequency receiving system. The radio frequency power division unit comprises a first low noise amplifier, a first single-pole single-throw radio frequency switch, a second single-pole single-throw radio frequency switch, a third single-pole single-throw radio frequency switch, a power divider, a fourth single-pole single-throw radio frequency switch and a fifth single-pole single-throw radio frequency switch; the input impedance of the input end of the power divider, the impedance of the first output end of the power divider and the impedance of the second output end of the power divider are all the same. According to the radio frequency power dividing unit in the embodiment, the impedance of the two output ends of the power divider can be completely matched with the input impedance of the transceiver connected with the rear stage of the power divider, so that the transmitted radio frequency energy cannot be reflected, and the maximum transmission of the radio frequency energy is realized.

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 aims to provide the testing device based on the arm model heat flow, which is low in cost, can meet uv-level voltage testing requirements, can realize voltage testing of a plurality of channels, and can improve the testing efficiency. The device comprises an arm model, a heat flux sensor, a temperature sensor, an operational amplifier, an instrumentation amplifier, an analog-to-digital converter and a main control board, the heat flux sensor and the temperature sensor are both mounted on the surface of the arm model, the temperature sensor is mounted on the surface of a product, the temperature sensor is connected with the main control board, and the operational amplifier is connected with the main control board. The heat flux sensor is connected with the input end of the operational amplifier, the operational amplifier increases input impedance, the output end of the operational amplifier is connected with the input end of the instrument amplifier and amplifies and converts signals into differential analog signals, the output end of the instrument amplifier is connected with the 24-bit analog-to-digital converter, and the analog-to-digital converter is connected into an external upper computer through the main control board. The device is applied to the technical field of heat flux testing.

The invention relates to a plasma process supply system (100), in particular for pulsed plasma processes, comprising an RF generator (2) which has at least one amplifier circuit (30), an impedance matching circuit (3), and a control device (1). The plasma process supply system (100) can be connected to a plasma chamber (4). The RF generator (2) is connected to the impedance matching circuit (3), the impedance matching circuit (3) being designed to set a target impedance (10) as an input impedance for the RF generator (2). The control device (1) is designed to set the target impedance (10) such that a trajectory (40), which describes an impedance curve for the input impedance in a settling period (41), runs from a starting impedance region (42) through an ignition impedance region (43) to a target impedance region (44), the RF generator (2) delivering, in the ignition impedance region (43), a power level which is higher than a target power level in the subsequent target impedance region (44).

The invention discloses a broadband reflection amplification circuit design method based on a real frequency matching method, which comprises the following steps: firstly designing a reflection amplification circuit, designing a real frequency matching network based on the real frequency matching method, and finally inserting the real frequency matching network into the input end of the reflection amplification circuit to construct the broadband reflection amplification circuit based on the real frequency matching method. According to the method, the input impedance of the reverse amplification circuit is tested through the load traction technology, then the parameter characteristics of the matching network are calculated through the optimization algorithm, and finally the structure and parameter values of the matching network are obtained through the circuit synthesis method, so that the method is not limited by a specific matching network architecture, the performance of the matching network can be greatly improved, and the reliability of the matching network is improved. The problem of broadband matching between the transmitting-receiving antenna and the reflection amplification circuit is solved, so that the reflection amplification circuit can realize high gain under different input powers and input frequencies, the working bandwidth of the reflection amplification circuit is expanded, and the purpose of expanding the application scene of the reflection amplification circuit is achieved.

The invention relates to the technical field of wireless communication, and provides a power synthesis circuit and a power amplifier. Comprising a first signal input end, a second signal input end, an input impedance matching circuit, a first harmonic suppression circuit, a second harmonic suppression circuit, a first high-pass filter circuit, a second high-pass filter circuit, a low-pass filter circuit and a signal synthesis output end, the low-pass filter circuit comprises a first inductor, a second inductor and a first capacitor; the first end of the first inductor serves as the first input end of the low-pass filter circuit, the first end of the second inductor serves as the second input end of the low-pass filter circuit, the second end of the first inductor is connected with the first end of the first capacitor and the second end of the second inductor and serves as the output end of the low-pass filter circuit, and the second end of the first capacitor is grounded. The power synthesis circuit has the impedance conversion characteristic, and has the advantages of low cost, high isolation, high integration and the like.

A power amplifier with improved stability, gain, flatness and return loss and reduced the size, which comprises a two-stage power amplifier in balanced cascode topology that consists of a first common-source stage feeding into a first common-gate stage; a second common-source stage feeding into a second common-gate stage; an input matching network for matching the input impedance of the a two-stage power amplifier to a desired signal source impedance; an output matching network for matching the output impedance of the a two-stage power amplifier to a desired load; a first positive feedback path between the gate of the first common-source stage and the drain of the second common-gate (CG) stage and a second positive feedback path between the gate of the second common-source stage and the drain of the first common-gate (CG) stage; a first negative feedback path between the drain of the first common-gate (CG) stage and the gate of the first common-source stage and a second negative feedback path between the drain of the second common-gate (CG) stage and the gate of the second common-source stage; a first inter-stage matching network between the first common-source (CS) stage and the first common-gate (CG) stage; and a second inter-stage matching network between the second common-source (CS) stage and the second common-gate (CG) stage.

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.

Embodiments are directed to methods, devices and systems for determining and applying a gain adjustment to sensed electrical signals. The methods can include operating a device to determine that a user is wearing the wearable electronic device and applying a test signal to a sensing electrode of the wearable device. An input impedance for the sensing electrode can be determined using the test signal. The input impedance and a baseline impedance can be used to determine a gain adjustment. An electrical signal of the user can be measured using the sensing electrode and the gain adjustment can be applied to the electrical signal. A physiological parameter of the user can be determined using the measured electrical signal having the gain adjustment applied.

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.