107 results about "Input impedance" patented technology

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

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

A device comprises an input stage, a signal distribution network comprising a plurality of passive elements, and a plurality of output stages coupled to the signal distribution network. The input stage is configured to drive a signal onto the signal distribution network. The signal distribution network is configured to distribute the signal to the plurality of output stages. Each output stage of the plurality of output stages comprises a variable resistance element and a variable reactance element, for tuning a complex input impedance of the output stage to obtain a signal transfer characteristic for transferring the signal from the input stage to the output stage over the signal distribution network.

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.

The application discloses a tracking lock type maximum power point tracking circuit and an implementation method thereof, which comprises a rectifier circuit, a control circuit, a step-down-step-up converter control circuit and a step-down-step-up converter. The rectifier circuit is used for converting input alternating current energy into direct current energy. The control circuit is used for judging the length of current inductance demagnetization time, adjusting the current inductance demagnetization time, realizing indirect detection of inductance current zero-crossing point, and generating a switch timing control signal. The step-down-step-up converter control circuit is used for generating a first switch tube driving signal and a second switch tube driving signal. The step-down-step-up converter is used for adjusting input impedance according to the first switch tube driving signal and the second switch tube driving signal, and realizing maximum power point tracking. The application can realize adaptive locking of the maximum power point under different vibration frequencies and different open circuit voltages, improve the tracking speed of the circuit when the input changes, and can be widely applied to the technical field of integrated circuits.

This invention discloses a millimeter-wave broadband high harmonic suppression tripler, comprising an input matching network, a time-domain shaping tripler unit, and a differential common-source output stage. The proposed time-domain shaping tripler unit employs transistor pairs with different gate widths and bias voltages to superimpose two sets of voltage signals of different amplitudes in the time domain, thereby enhancing the inherent harmonic suppression of the tripler unit. Furthermore, by connecting a common-mode impedance control in series at the center tap of the primary inductor coil of the output transformer of the tripler unit, the output power of the third harmonic is further improved. The input matching network achieves single-ended to differential conversion, with its primary and secondary coil center taps grounded and open-circuited respectively in a counterintuitive manner, improving differential-mode balance and common-mode stability. Simultaneously, by using a series-coupled inductor, the quality factor of the transistor input impedance is reduced, improving the bandwidth performance of the tripler.

This invention discloses an adaptive AC / CDC power supply control method and system based on neural networks, belonging to the field of power supply control technology. By deeply integrating neural network technology with wide voltage impedance matching control and overall dynamic control of the AC / CDC power supply, it divides voltage characteristic intervals and constructs nonlinear correlation models of input impedance, grid voltage, and output power within each interval using neural networks. This achieves adaptive impedance matching by dynamically generating impedance matching control parameters based on real-time operating conditions within each interval. A smooth switching mapping relationship of control parameters between adjacent voltage characteristic intervals is established, enabling seamless adjustment of control parameters when the input voltage switches between intervals. Using a power factor correction circuit as the core regulating component, its parameters are dynamically adjusted via neural networks to achieve real-time and accurate matching of input impedance with the grid side. Combined with output closed-loop regulation, this meets the output requirements of electrical equipment, completing the overall adaptive control of the AC / CDC power supply.

Disclosed is an aerosol-generating device. The aerosol-generating device includes an antenna configured to radiate microwaves to an insertion space accommodating an aerosol-generating article, a source unit configured to provide a radio-frequency (RF) signal to the antenna, and a printed circuit board connected to the source unit and the antenna. The printed circuit board includes a first part including a first insulating layer and a transmission line disposed on one surface of the first insulating layer and electrically connected to the source unit and the antenna, and a characteristic impedance of the first part corresponds to an input impedance of the antenna.

An impedance matching apparatus for providing impedance matching for an RF component. The apparatus includes a balun transformer circuit having a primary coil at an input side of the balun transformer circuit. The primary coil can be connected to a signal source to receive an input signal from the signal source. The balun transformer circuit further includes a secondary coil at an output side of the balun transformer circuit, the secondary coil being coupled to the primary coil to supply an output signal to the RF component and having a parasitic leakage inductance configured to match the output impedance of the signal source to the input impedance of the RF component

Wake-up receivers (WuRx) are provided including an antenna having a real input impedance different than 50Ω configured for receiving a radiofrequency (RF) signal, resonant circuitry configured to provide voltage gain to the received RF signal to produce a boosted RF signal, and a passive rectifier configured to at least one of recover a data signal from the boosted RF signal, or convert the boosted RF signal into a DC power signal.

This invention proposes a high-gain, high-linearity amplifier circuit, mainly comprising an input circuit and an output circuit. The input circuit has high gain, converting the received input voltage into current and amplifying it. The input circuit transmits the amplified current to the output circuit. The output circuit generates an output voltage and reduces the input impedance of the input circuit through its included feedback loop. The feedback loop in the output circuit also stabilizes the gain of the entire circuit system and optimizes the system linearity. This invention significantly improves the system gain through the amplifier circuit structure and the back-gate coupled circuit structure, and optimizes the system linearity by setting passive and active feedback loops. This invention achieves both high gain and high linearity.

This utility model discloses a signal acquisition and amplification circuit, relating to the field of signal acquisition and transmission. The circuit includes: a Wheatstone bridge module for feeding back a fixed voltage signal and a temperature change signal to a differential amplifier module; and a differential amplifier module for varying the output voltage when there is a difference between the input fixed voltage signal and the temperature change signal. The advantages of this utility model are: by setting a differential amplifier module, the small signal obtained from the sensor is linearly amplified, which is more conducive to acquisition and identification by subsequent circuits; the circuit makes the correspondence between the output voltage signal Vout and the NTC resistor value clear and easy for subsequent circuits to acquire; the signal input impedance is high and the output impedance is low, which is beneficial for impedance matching with subsequent circuits and reduces power consumption; the differential amplifier module provides filtering for high-frequency noise; and the NTC resistor has low self-heating, ensuring the accuracy and stability of temperature acquisition.

The application belongs to the technical field of audio power amplifier filtering, and particularly relates to a band-pass filter circuit for eliminating radio frequency interference of an audio power amplifier. The band-pass filter circuit comprises an operational amplifier AMP, a reference voltage BYP connected to a non-inverting input terminal of the operational amplifier AMP, an input impedance network connected between an audio input terminal IN grounded and an inverting input terminal of the operational amplifier AMP, and a feedback impedance network connected between an output terminal and the inverting input terminal of the operational amplifier AMP. The feedback impedance network is composed of two parallel feedback branches. A first feedback branch is composed of a resistor R2, and a second feedback branch is composed of a resistor R3 and a capacitor C2 connected in series. A zero point is introduced in a transfer function of the band-pass filter circuit, and a zero point frequency is determined by a resistance value of the resistor R3 and a capacitance value of the capacitor C2, so as to suppress a gain near the zero point frequency, thereby effectively suppressing interference of high-frequency noise.

Method for determining an operating frequency of an acoustic transmission system (ATS) comprising a primary element (PE) and a secondary element (SE) arranged on either side of a wall, the primary element comprising a first electro-acoustic transducer (T1) for generating and detecting acoustic waves (AO), the secondary element (SE) comprising a second electro-acoustic transducer (T2) and being configured to modify in a controlled manner an electrical impedance across said second transducer between an open circuit condition and a short circuit condition;characterized in that said operating frequency is determined from the frequency-dependent evolution of the phase difference between an input impedance, on the side of the primary element (PE), of an electrical quadrupole modeling the assembly formed by the first (T1) and second (T2) acoustically coupled transducers, with the second transducer (T2) in short circuit and open circuit. System for implementing such a method. Figure for the abstract: Fig. 2;

This application provides a radio frequency (RF) front-end module and an electronic device. The RF front-end module has a connection port for connecting to a signal port via a first inductor. The RF front-end module includes a substrate, a low-noise amplifier (LNA), and a microstrip line. The substrate has the connection port, and the LNA is mounted on the substrate. The LNA includes an input port. The microstrip line is mounted on the substrate, with a first end connected to the connection port and a second end connected to the input port of the LNA. The microstrip line has a characteristic impedance greater than 50 ohms. By connecting a microstrip line with a characteristic impedance greater than 50 ohms in series between the input port of the LNA and the connection port of the RF front-end module, the real part of the input impedance of the input port can be increased, improving the matching performance and thus increasing the gain of the LNA.

This utility model relates to the field of voltage acquisition technology, specifically a feedback voltage acquisition circuit based on a phase-shifted full-bridge converter. It includes an inverter circuit, a resonant circuit, and a rectifier circuit electrically connected together. A voltage acquisition circuit is electrically connected to the resonant circuit. The voltage acquisition circuit includes operational amplifiers U1A, U1B, and U1C arranged in series. A capacitor C1 and a resistor R1 are connected in parallel on pins 1 and 2 of operational amplifier U1A. One end of operational amplifier U1A is connected to the voltage signal of a current transformer through a resistor R3. This utility model promptly disconnects the system connection when overvoltage or undervoltage occurs in the power grid, protecting the power grid and electrical appliances. The operational amplifiers implement second-order filtering. As voltage followers, the operational amplifiers achieve isolation, improve input impedance, reduce output impedance, and improve the small-signal load-driving capability.

A method for determining an operating frequency of an acoustic transmission system includes a primary element and a secondary element arranged on either side of a wall, the primary element including a first electro-acoustic transducer for generating and detecting acoustic waves, the secondary element including a second electro-acoustic transducer and being configured to controllably change an electrical impedance across the terminals of the second transducer between an open-circuit state and a short-circuit state; wherein the operating frequency is determined from the change as a function of the frequency of the phase difference between an input impedance, on the primary element side, of an electric quadrupole modelling the assembly formed by the first and second acoustically coupled transducers, with the second transducer in a short circuit and in an open circuit. A system for carrying out such a method is also provided.

The application belongs to the technical field of new energy vehicle electrical detection and health diagnosis, and discloses a new energy vehicle wire harness aging state online evaluation method based on impedance spectrum analysis. When the target wire harness loop is turned on, a diagnosis excitation signal is injected, and the voltage and current responses of the excitation end and the other end measurement port, the switch state, the wire harness temperature, the loop current and the state of charge signal are synchronously collected. According to the switch state, the transient shielding interval is generated, and the effective sampling points are extracted. The input impedance spectrum and the transmission impedance spectrum are calculated, and the segmented mapping is carried out in combination with the wire harness topology parameters and the segmented propagation time delay parameters. Then, the working condition normalization is carried out based on the working condition reference library, and the segmented aging residual characteristics are obtained. The degradation evaluation model is input, and the segmented aging index, the aging grade and the evaluation confidence are output.

This invention provides an electrocardiogram (ECG) instrument amplifier circuit and an ECG signal acquisition system. In the ECG instrument amplifier circuit provided by this invention, a first terminal of a first capacitor scaling circuit is connected to the first output terminal of the instrument amplifier; a second terminal of the first capacitor scaling circuit is connected to the first terminal of a first neutralizing capacitor array; the second terminal of the first neutralizing capacitor array is connected to the first terminal of a first switch; and the second terminal of the first switch is connected to the first input terminal of the instrument amplifier. A second capacitor scaling circuit has its first terminal connected to the second output terminal of the instrument amplifier; its second terminal is connected to the first terminal of a second neutralizing capacitor array; the second terminal of the second neutralizing capacitor array is connected to the first terminal of a second switch; and the second terminal of the second switch is connected to the second input terminal of the instrument amplifier. A parasitic capacitance calibration circuit is connected to both the first and second input terminals of the instrument amplifier. This ECG instrument amplifier circuit can significantly improve the input impedance of the instrument amplifier.

A dual-frequency low-noise amplifier circuit includes an input impedance matching circuit, a radio-frequency signal amplifying circuit and an output impedance matching circuit. An input end of the input impedance matching circuit inputs a radio-frequency signal, and an output end is connected to an input end of the output impedance matching circuit by means of the radio-frequency signal amplifying circuit; an output end of the output impedance matching circuit outputs an amplified radio-frequency signal; a first band radio-frequency signal is amplified, input and output switches are in a first open and closed state, and input and output impedances are first input and output impedances; and a second band radio-frequency signal is amplified, the input and output switches are in a second open and closed state, and the input and output impedances are second input and output impedances. Adjusting the dual-frequency low-noise amplifier circuit can reduce signal reflection and improve signal quality.

This invention discloses a method for preparing a band-tunable CoFe@C / ZnO coral-structured lightweight microwave absorbing material, belonging to the field of electromagnetic functional materials. The invention first obtains a coral-like porous carbon matrix embedded with CoFe nanocrystals through solvothermal and high-temperature heat treatment. Subsequently, based on interface modulation, ZnO quantum dots rich in oxygen vacancies are in situ loaded on the matrix surface, ultimately obtaining a semiconductor quantum dot-modified CoFe@C / ZnO composite material. Based on a lightweight coral-like CoFe@C matrix, this invention introduces semiconductor quantum dot modification through interface modulation to optimize input impedance and improve electromagnetic wave incident rate. Simultaneously, relying on the constructed multiphase heterogeneous interface to enhance synergistic loss, the material achieves efficient and band-tunable electromagnetic wave absorption performance in the 2-18 GHz frequency band, while maintaining its overall lightweight advantage.

This invention discloses a sensor-based signal acquisition and processing circuit and a signal acquisition system. The circuit includes a power isolation protection circuit for isolating internal and external power supplies and filtering high-frequency and low-frequency DC signals from the analog signal X output by the sensor to obtain a low-frequency AC signal; an emitter follower circuit for filtering amplitude interference of the low-frequency AC signal caused by the input impedance of subsequent circuits to obtain an output signal X' to be output to the acquisition card; a signal amplification and absolute value circuit for amplifying and processing the output signal X' to obtain a comparison reference voltage for the output signal X'; and a signal trigger filtering circuit for outputting an acquisition trigger signal to the acquisition card based on the comparison reference voltage and a threshold voltage of the output signal X', so that the acquisition card acquires the output signal X' according to the acquisition duration of the acquisition trigger signal. This invention provides a high-quality input signal for the acquisition card signal acquisition, meeting the requirements for high-precision data acquisition.

The application belongs to the technical field of digital battery pack, and particularly relates to a digital battery pack intelligent equalization management system based on dynamic impedance matching, which comprises a plurality of battery monomers connected in series or in parallel to form a digital battery pack; wherein the dynamic internal resistance is obtained through online identification by means of a high-frequency excitation signal or a pulse response method; and the impedance matching type active equalization topology network enables the output impedance of the energy transmission path to be equal to the input impedance of the target battery monomer in the equalization process, so as to realize dynamic equalization with high efficiency, low reflection and low thermal loss; under dynamic working conditions such as high-rate charging and discharging and load mutation, the problems of energy reflection, low efficiency and local overheating caused by impedance mismatch in the traditional equalization technology are effectively solved, the equalization efficiency, system safety and service life of the battery pack are significantly improved, and the intelligent energy management with high efficiency, low loss and high reliability is realized.

The utility model provides a kind of impedance matching test circuit board suitable for crystal network analyzer, it is related to electronic component testing technical field, the circuit board includes: input impedance conversion network, the input end of input impedance conversion network is used to connect the first port of network analyzer, input impedance conversion network is used to convert the transmission line impedance of network analyzer into preset low impedance value;Output impedance conversion network, the output end of output impedance conversion network is used to connect the second port of network analyzer, output impedance conversion network is used to convert back transmission line impedance from preset low impedance value;Test interface, test interface includes first test probe and second test probe, first test probe connects the output end of input impedance conversion network, second test probe connects the input end of output impedance conversion network, and first test probe and second test probe are respectively used to connect the two functional pins of crystal resonator.

The application discloses a kind of cable health state evaluation method and system based on single-end open circuit impedance spectrum, belong to nondestructive testing and impedance spectrum analysis technical field.This method only needs to carry out frequency sweep test at one end of cable and keep open circuit at the end, after obtaining wideband input impedance spectrum, extract real part data and identify resonance extreme point;The upper and lower envelope lines are constructed by extreme point interpolation, and the high-frequency characteristic impedance and attenuation constant of the full frequency band are derived;Further, the distributed parameters of the cable are calculated by combining the phase constant.By comparing the characteristics of the distributed parameters, the health status of the cable can be accurately evaluated, and the physical mechanism can effectively distinguish between thermal aging and moisture damage.The application eliminates the cumbersome of double-end cooperation test, does not need to intercept samples, greatly saves the test time, has wide applicability and strong anti-interference ability.

The application provides a single-balanced mixer circuit based on a carbon nanotube Schottky diode, comprising the following structure: one end of the carbon nanotube Schottky diode is connected with a 180-degree hybrid junction structure, and one end is connected with a fan-shaped open circuit line structure; a radio frequency input impedance matching network is located between a radio frequency input port and the 180-degree hybrid junction; a local oscillator input impedance matching network is located between a local oscillator input port and the 180-degree hybrid junction; the fan-shaped open circuit line structure is located between the carbon nanotube Schottky diode device and a 1 / 4 wavelength high-impedance microstrip line; the 1 / 4 wavelength high-impedance microstrip line is located between the fan-shaped open circuit line structure and an air bridge; the air bridge is transversely arranged on the radio frequency input impedance matching network; a thin film resistor and a plate capacitor are connected on a intermediate frequency output line. The mixer circuit provided by the application can realize lower conversion loss in a high frequency band, and greatly reduces the parasitic capacitance of the Schottky diode device and the substrate loss of the passive device.

A receiver of a light detection and ranging system includes at least one silicon photomultiplier (SiPM) sensor. A SiPM output signal of the at least one SiPM sensor is processed by an active non-inverting differentiator. The differentiator outputs an output signal which is based at least in part on the SiPM output signal, and a signal-to-nose ration (SNR) of the output signal is equal to or greater than the SNR of the SiPM output signal as the differentiator is configured to differentiate in a portion of a frequency domain of the SiPM output signal. The input of the differentiator is an input with active input impedance.