11results about How to "Increase output impedance" patented technology

The invention discloses an active damping control system for improving the output impedance of a current source type inverter, which comprises a current loop control loop, an active damping branch and an improved phase-locked loop, and is characterized in that the difference value of reference current and feedback network access current passes through a current controller to form the current loop control loop; the voltage of the grid-side inductor is fed back to the output of the current loop through the virtual resistor link to form a damping branch, and the voltage of the common coupling point enters the traditional phase-locked loop link through the low-pass filter and forms an improved phase-locked loop through phase compensation. The optimal feedback coefficient of the damping branch is designed according to the optimal damping ratio, the low-pass filter parameters are designed according to the phase at the maximum resonant frequency, the reasonable proportional gain link is designed according to the improvement of the output impedance amplitude, the resonance of the current source type inverter can be effectively inhibited, the output impedance of the inverter is increased, and the output impedance of the inverter is improved. And the quality of the network access current of the current source type inverter and the stability margin of the current source type inverter in a weak power grid are improved, and the stability of the system is improved.

The invention discloses a K-band amplitude-limiting low-noise amplifier, and belongs to the technical field of radio frequency microelectronics. The circuit comprises an input matching module, a diode amplitude limiting module, an inter-stage matching module, a low-noise amplification module and an output matching module which are cascaded in sequence, the input matching module is used for realizing impedance matching between a radio frequency signal input end and the diode amplitude limiting module and transmitting a radio frequency signal; the diode amplitude limiting module is used for limiting the amplitude of the radio frequency signal and transmitting the radio frequency signal; the inter-stage matching module is used for realizing impedance matching between the diode amplitude limiting module and the low-noise amplification module; the low-noise amplification module is used for carrying out amplification processing on the radio frequency signal after amplitude limiting and transmitting the radio frequency signal; and the output matching module is used for realizing impedance matching between the low-noise amplification module and the radio frequency signal output end and outputting the amplified radio frequency signal. According to the invention, the amplitude of the input signal can be limited, so that the amplitude is kept in a bearable range of the low-noise amplification circuit, and the stability and reliability of the whole system are ensured.

The invention relates to the technical field of power management, and discloses an LDO circuit, which comprises an LDO main loop and a current limiting circuit, and is characterized in that the LDO main loop comprises a power tube and an error amplifier; the current limiting circuit comprises a power tube current acquisition circuit and a current limiting feedback circuit, the positive electrode of a current source of the current limiting feedback circuit is connected with the power supply end and used for providing reference current, the power tube current acquisition circuit acquires power tube current, and the current limiting feedback circuit limits the power tube current so that the power tube current is not larger than a current limiting threshold value. The current limiting threshold is configured to be related to the output end current of the error amplifier, the reference current and device parameters in the current limiting circuit; the dominant pole of the current limiting circuit is located at the output end of the current limiting circuit, the secondary pole of the current limiting circuit is located at the negative electrode of the current source, and the low-impedance unit is located between the power end and the secondary pole of the current limiting circuit and used for reducing the output impedance of the secondary pole of the current limiting circuit. According to the LDO circuit, the load regulation rate of the LDO circuit with the current limiting function is improved.

The invention provides a broadband gain positive slope amplitude-phase control multifunctional chip for a T / R assembly, which relates to the technical field of radio frequency integrated circuits and comprises a receiving channel, a transmitting channel, an equalization circuit, a numerical control attenuator, a numerical control phase shifter, a transmitting-receiving change-over switch module and a parallel control module. The parallel control module is used for outputting parallel control signals to the numerical control attenuator, the numerical control phase shifter and the transceiving change-over switch module; the equalization circuit is respectively connected with the receiving channel and the transmitting channel through the transmitting-receiving change-over switch module, so that a signal path of the receiving channel and a signal path of the transmitting channel multiplex the equalization circuit, the numerical control attenuator and the numerical control phase shifter; and the equalization circuit is of an on-chip integrated structure and is used for adjusting the gain of the receiving channel and the gain of the transmitting channel to present a positive slope characteristic relative to the frequency in a wide frequency band so as to compensate the frequency attenuation of an external device.

This application discloses a current calibration loop and method for current calibration of a current-controlled DAC. The current calibration loop includes: a selected reference current source and a selected current source to be calibrated; a clamping management module that clamps the output nodes of the two sources to the same fixed potential to discharge the static current of the two output nodes in different calibration modes, retaining only the current difference; an error comparison module that amplifies the current difference into a voltage difference and outputs the comparison result; a calibration control logic module that generates a calibration control signal based on the comparison result; and a calibration module that injects error compensation current into the output nodes according to the calibration control signal, so that the compensated output current of the selected current source to be calibrated is equal to the reference current provided by the selected reference current source. By discharging most of the static current and retaining only the current difference for comparison, it can respond promptly to a wide current range, significantly improve the current calibration accuracy, and adapt to various calibration modes.

The present invention discloses a radio frequency power amplifier for vehicle networking communication, comprising an input four-way differential phase shift distribution and bias network, a first differential double-stacked amplifier, a second differential double-stacked amplifier, a third differential double-stacked amplifier, a fourth differential double-stacked amplifier, an inter-stage four-way differential matching and bias network, and an output four-way differential phase shift synthesis and bias network. The core architecture of the present invention adopts the high power and high gain characteristics of the double-stacked amplification network composed of field effect tubes in the radio frequency microwave band, and at the same time utilizes the good parasitic parameter suppression of the differential amplifier in the microwave frequency band, combined with the good power back-off efficiency characteristics of the double-stage Doherty drive amplification structure, so that the entire power amplifier obtains good high gain, high back-off efficiency and high power output capability.

The invention discloses a preparation method of a high-gain photoelectric detector, and relates to the technical field of photoelectric detectors, and the method comprises the steps: S1, structural design: selecting a corresponding photoelectric material to manufacture an avalanche photodiode according to the application scene requirements and the working environment of the detector, the method comprises the following steps: S1, preparing a semiconductor wafer, S2, preparing the wafer, namely cleaning the semiconductor wafer by using an ultrasonic cleaning agent and a chemical solution, S3, treating the material, namely performing doping operation, and injecting ions containing phosphorus and boron elements into a semiconductor material by using an ion accelerator, S4, performing gain optimization, namely optimizing a circuit by using a Cascode technology, connecting circuits of two transistors, and performing gain optimization. S5, packaging and integrating: packaging the manufactured chip into a shell; according to the photoelectric detector, the circuit of the semiconductor is optimized by using a Cascode technology, the gain of the photoelectric detector can be improved by adjusting the bias voltage of the circuit, configuring the gain circuit and processing external signals, and meanwhile, the influence on output impedance is reduced, so that the high-frequency performance and the linearity of the whole circuit are improved.

The application discloses a kind of based on chopping operational amplifier circuit, the positive and negative input of operational amplifier circuit is connected to operational amplifier unit through a pair of differential pair input, then is output through output stage, operational amplifier unit includes two gain boost operational amplifier, operational amplifier circuit also includes offset voltage adjustment current circuit, chopping switch is equipped at the positive and negative input of operational amplifier circuit, the input of gain boost operational amplifier and inside, gain boost gain boost folded cascode operational amplifier with chopping technology is used, including common-mode voltage control, while improving the output impedance and gain of cascode stage, the offset, drift and 1 / f noise of itself can be eliminated, offset voltage adjustment current circuit reduces the offset voltage caused by transistor size variation in production and manufacture, output stage uses DC bias voltage control circuit, both ensure that output tube is slightly on, improve the output response speed of operational amplifier, and can be controlled at lower static power consumption level.The application realizes effective zero drift technology by independent chopping circuit.

The application claims a high-gain operational amplifier circuit for Sigma-Delta ADC. The circuit comprises a main operational amplifier, a gain-improving auxiliary operational amplifier, a bias circuit and a switched-capacitor common-mode negative feedback circuit. The main operational amplifier serves as the main body of the circuit, has a high gain and a wide bandwidth; the auxiliary operational amplifier improves the output impedance and effectively improves the DC gain of the operational amplifier; the bias circuit is used to provide appropriate DC bias voltage for the main operational amplifier and the auxiliary operational amplifier; the switched-capacitor common-mode negative feedback is used to stabilize the output common-mode voltage. The application uses the auxiliary operational amplifier to improve the gain, ensures a high input-output swing of the operational amplifier, improves the DC gain of the operational amplifier, adopts a symmetrical switched-capacitor common-mode negative feedback, ensures the bandwidth range and reduces the nonlinearity of the circuit.

The invention provides an unmanned aerial vehicle based on 5G communication and 3D technology and an operation method thereof.The unmanned aerial vehicle is characterized in that a top plate is fixedly installed at the upper end of an overall frame structure of the unmanned aerial vehicle, multiple sets of supporting frameworks are symmetrically fixed to the periphery of the top plate, and supporting legs making contact with the ground are symmetrically installed at the lower end of the overall frame structure; a plurality of support arms are symmetrically connected to the middle end of the integral frame structure, and positive paddles and negative paddles are mounted at the tail ends of the symmetrically arranged support arms; a chip of the unmanned aerial vehicle adopts a Raspberry Pi development chip, a built-in CMOS chip and a 5G millimeter wave reverse array extremely simple framework, and the unmanned aerial vehicle is built in a flight control mainboard and is connected with a first speed reduction stepping motor and a second speed reduction stepping motor through Dupont lines. And the WIFI chip in the connection interface connected with the VR glasses controls the unmanned aerial vehicle. The 5G communication technology and the 3D technology are combined, the flight stability of the unmanned aerial vehicle is improved, the flight safety is improved, and the unmanned aerial vehicle can well adapt to the complex and severe environment.

The invention discloses an operational amplifier based on a floating capacitor voltage source gain bootstrap inverter, and the operational amplifier is characterized in that the operational amplifier comprises an inverter circuit which is used for carrying out the cascode gain amplification of an input signal, and then outputting the signal; the dynamic bias current source capacitance circuit is used for separating grid voltage of the inverter circuit; the zeroing capacitor circuit is used for storing the stabilized voltage and completing establishment of a working point of the operational amplifier; and the noise and the offset voltage are stored, and zero setting is completed. The suspension voltage source capacitance circuit is used for alternately charging and discharging and providing current for the operational amplifier; the gain bootstrap auxiliary operational amplifier circuit is used for providing grid voltage for the phase inverter circuit; and the switching circuit is used for regulating and controlling the working state of the operational amplifier based on an external control signal. The operational amplifier overcomes the defects that a traditional phase inverter operational amplifier is low in direct-current gain, needs an additional common-mode feedback circuit, is poor in PVT stability and the like.