105 results about "Variable-gain amplifier" patented technology

The invention discloses an MEMS resonator low ripple error temperature measurement system based on voltage feedback compensation, and the system comprises a trans-impedance amplifier, an analog-to-digital converter, a frequency detection module, a PI controller, a variable gain amplifier, a Schmitt trigger, a first digital-to-analog converter, a biasing circuit, mode switches S1 and S2, and a voltage feedback compensation loop. The compensation loop comprises an amplitude detection module, a lookup table, a second digital-to-analog converter and an adder; the amplitude detection module receives the digital signal from the analog-to-digital converter and outputs a vibration amplitude signal in real time; the lookup table receives the vibration amplitude signal, inquires and outputs a corresponding digital compensation voltage, and converts the digital compensation voltage into an analog voltage through a second digital-to-analog converter; the adder adds the analog voltage and a fixed bias voltage to generate a dynamic bias voltage and applies the dynamic bias voltage to a drive electrode of the MEMS resonator. According to the system, an amplitude-driving end bias voltage feedback compensation loop is introduced, so that the periodic ripples of the resonant frequency are effectively suppressed.

Bidirectional variable gain amplifiers (VGAs) for radio frequency (RF) communication systems are provided. In certain embodiments, a bidirectional VGA includes a first amplifier having an input coupled to a transmit / receive port, a second amplifier having an output coupled to a transmit port, a third amplifier having an input coupled to a receive port, a fourth amplifier having an output coupled to the transmit / receive port and to the input of the first amplifier, and a switch circuit that connects an output of the first amplifier to an input of the second amplifier in a transmit mode, and that connects an output of the third amplifier to an input of the fourth amplifier in a receive mode.

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

The invention provides a gain-reconfigurable active phase shifter with a low phase error, and relates to the technical field of phase shifters, and the phase shifter comprises a quadrature coupler which converts a radio frequency input signal into a shunt radio frequency signal; the input matching Balun converts the shunt radio frequency signal into a shunt differential signal; the digital control signal received by the phase inversion variable gain amplifier is used for controlling the on-off state of a differential pair in each differential group, and determining a differential combination current corresponding to a differential pair combination in a conduction state based on a shunt differential signal corresponding to each differential pair; the differential combination current is used for representing a gain state corresponding to the differential pair combination; the input impedance and the output impedance of the phase inversion variable gain amplifier in different gain states are kept unchanged; the vector synthesis module determines a phase shift differential signal based on the differential combined current; the output matching Balun converts the phase shift differential signal into a radio frequency output signal. The antenna has a wide gain adjustable range and a low phase error.

The invention relates to the technical field of amplifiers, in particular to a variable gain amplifier with a wide linear gain range and a working method, and the variable gain amplifier comprises the steps that a linear gain generation circuit receives a differential input signal and provides gain-adjustable differential output based on linear control voltage; the linear gain generation circuit comprises at least one stage of variable gain unit which comprises differential input pair transistors MN1 and MN2. The load resistor elements R1 and R2 are connected between the power supply voltage VDD and the drain electrodes of the differential input pair transistors MN1 and MN2; the tail current source MN3 provides bias current for the differential input pair transistors MN1 and MN2; the active load network is connected between the drain electrodes of the differential input pair transistors MN1 and MN2 and the ground; the active load network comprises a control tube MN8, the control tube MN8 works in a sub-threshold region, a grid electrode receives linear control voltage, equivalent impedance of the active load network is enabled to be in exponential change along with the linear control voltage through exponential I-V characteristics, and dB linear gain adjustment of the variable gain unit is achieved.

The invention relates to the technical field of channelized receiver management, in particular to a dynamic range channelized receiver method and system based on a block floating point and AGC (Automatic Gain Control), in the system, an automatic gain control module is used for detecting the power of an obtained intermediate frequency analog signal, generating an AGC voltage corresponding to the intermediate frequency analog signal and feeding back the AGC voltage to an analog front end; and dynamically updating the gain of the variable gain amplifier in the radio frequency signal preprocessing process. According to the invention, each channel has independent block floating point gain control, and the channels do not interfere with each other, so that parallel signal-to-noise ratio processing is realized; meanwhile, a complete gain control history is constructed by jointly recording the AGC gain and block floating point processing, data support is provided for recovering the original absolute power value of the signal in each channel, and the contradiction between gain control and information reservation is solved to a certain extent.

The embodiment of the present disclosure provides a variable gain amplifier with high temperature stability, which is applied to the technical field of electronic circuit. The amplifier comprises a constant transconductance bias circuit, a first variable gain amplifier and a second variable gain amplifier; wherein the output end of the constant transconductance bias circuit is connected with the input common source transistor of the first variable gain amplifier and the second variable gain amplifier, and is used for providing a constant transconductance bias signal which is compensated according to temperature change; the input end of the first variable gain amplifier is used for receiving an externally input differential signal, and the output end is connected with the input end of the second variable gain amplifier, and is used for transmitting the differential signal after coarse adjustment attenuation to the second variable gain amplifier; and the output end of the second variable gain amplifier is used for outputting an attenuation differential signal with temperature stability. In this way, by restraining the influence of temperature change on the transconductance characteristic of the input common source transistor of the variable gain amplifier, the stable attenuation characteristic of the variable gain amplifier in a wide temperature range is ensured.

A variable gain amplifier and an automatic gain control circuit including the same are provided. The variable gain amplifier includes a gain amplification circuit configured to output an amplified signal by amplifying an input signal according to an amplifier control voltage, and a gain control circuit configured to determine the gain control voltage based on gain indication information from outside the variable gain amplifier, wherein the gain control voltage includes a fixed control voltage component based on a ratio of circuit element parameters and a variable control voltage component adjusted by the gain indication information, convert the gain control voltage into an exponential control voltage having an exponential relationship with the gain control voltage, and amplify and filter the exponential control voltage to obtain the amplifier control voltage to control a gain of the gain amplification circuit.

The invention provides a PAM4 signal equalizer based on automatic gain control, which comprises a continuous time linear equalizer CTLE, a variable gain amplifier VGA, a negative capacitor I, a negative capacitor II, a power detector, an encoder, an eye diagram parameter calculation module, a digital time converter, a pipelined analog-to-digital converter and a counter, the first input end of the continuous time linear equalizer CTLE is connected to an input signal DIN, the second input end VCTLE1 of the continuous time linear equalizer CTLE is connected to the first output end of the encoder, the third input end VCTLE2 of the continuous time linear equalizer CTLE is connected to the second output end of the encoder, and the output end N1 of the continuous time linear equalizer CTLE is connected to the input end of the first negative capacitor and the first input end of the VGA. According to the invention, optimization and real-time adaptive adjustment for PAM4 characteristics can be realized, the adaptability and the anti-noise capability can be improved, and the signal recovery capability and the signal integrity can be improved.

A variable gain amplifier for amplifying an input voltage and providing an amplified output voltage includes an input stage including two differential transistor pairs, the input stage coupled to an input of the amplifier. The variable gain amplifier also includes an output stage including a transistor quad and an additional transistor pair, the output stage coupled to an output of the amplifier, the transistor quad including a terminal for receiving a gain control. The variable gain amplifier also includes coupling outputs of the two differential transistor pairs of the input stage to inputs of the transistor quad and additional transistor pair of the output stage to provide a variable gain path and a fixed gain path, respectively. The variable gain amplifier exhibits improved dynamic range of gain variability, lower complexity, and better noise performance.

The invention discloses a variable gain amplification unit and a dual-mode variable gain amplifier, and relates to the technical field of radio frequency integrated circuits. The variable gain amplifier aims to solve the problem that an existing variable gain amplifier cannot meet existing control requirements. According to the variable gain amplification unit and the dual-mode variable gain amplifier, the reconstruction of the gain change range can be realized by adjusting the bias voltage and the number of the cascaded VGA arrays, and different design requirements are met; in the VGA mode, the gain of the amplifier is controlled by the analog voltage and is continuously adjustable in the gain change range. In the PGA mode, the gain of the amplifier is controlled by a digital signal, and the linearity of gain change is extremely high. The circuit is built based on the VGA units with simple structures, and has the advantages of being easy to implement and low in power consumption.

A system for controlling a phase array antenna comprising a plurality of compensation units (2) associated to corresponding radiating elements (30) of the phase array antenna. The compensating unit (2) comprises a phase slope control module (10) that controls the phase slope of a radio frequency (RF) signal and comprises a no-delay line with a first variable gain amplifier (11) and a delay line with a second variable gain amplifier (12) and a delay line element (13), wherein the gain of the first amplifier and the gain of the second amplifier are interrelated. The compensating unit (2) comprises a phase shifter (20) that controls the phase shifting of the RF signal, wherein the phase shifter (20) and the phase slope control module (10) are connected. A processing unit (3) can coordinate the compensation units (2).

The application discloses a microwave wideband differential variable gain amplifier and relates to the technical field of electronic circuits.The amplifier comprises a differential structure variable gain amplification circuit, an additional phase shift phase offset numerical control bias circuit and a power consumption control bias circuit.The application is applicable to BiCMOS and other processes, the differential variable gain amplification circuit adopts a current steering type Cascode amplifier structure to realize gain adjustment, two control voltages which make the phase change trends opposite when the VGA gain is reduced (increased) are designed, and a phase compensation resistor is designed to realize the low additional phase shift characteristic of the VGA.The two control voltages are generated by the additional phase shift phase offset numerical control bias circuit, and a plurality of digital control bits are set to select a target gain state from the two control voltages to reduce the gain error of the VGA.

This invention discloses a variable-step automatic gain control method based on an adaptive window, applicable to signal automatic gain control in data acquisition systems. The method preprocesses the input signal and samples it using an ADC to obtain a digital signal, which is then fed into an FPGA. A zero-crossing detection method based on a hysteresis comparator is used to estimate the signal frequency, and the window length is calculated based on this adaptive amplitude matching. The average signal amplitude within the window is then calculated and compared with a preset automatic gain threshold range. The gain step value is dynamically matched and updated to the variable gain amplifier to complete closed-loop control. Finally, the gain value is used to perform an amplitude inverse calculation to restore the signal. This invention improves the detection accuracy and dynamic response speed of the system over a wide bandwidth and dynamic range, eliminates the hardware resource consumption of floating-point division operations, and accurately outputs a distortion-free original proportional signal stream.

The headset includes an electro-acoustic transducer, at least one noise reduction processing chain including external and internal microphones, a processing filter including mounted in parallel between the external microphone and an adder, at least one elementary filter each including a recursive filter and an elementary variable gain amplifier, a control unit for the gain of each elementary amplifier according to a signal coming from the external microphone and an error signal coming from the internal microphone.The processing filter includes an open-loop main filter connected at the input to the external microphone and the output of which is connected, to the adder, and to the input of the or each elementary filter.

The embodiment of the invention provides a low-noise broadband SerDes receiver analog front end, method and equipment, and belongs to the field of integrated circuit design. The broadband SerDes receiver analog front end comprises an input terminal, a continuous time linear equalizer, a variable gain amplifier and a trans-impedance amplifier which are connected in sequence. The continuous time linear equalizer and / or the variable gain amplifier comprise / comprises at least one reverse coupling peaking inductance structure; the transimpedance amplifier comprises a low-impedance path noise shunting structure; the reverse coupling peaking inductance structure of the variable gain amplifier is mutually coupled with an inductor in the low-impedance path noise shunting structure of the trans-impedance amplifier to form a three-coupling inter-stage feedback structure. According to the invention, the problems of high noise, limited bandwidth and difficult consideration of gain and power consumption in the prior art are effectively solved, and the high-performance and low-power-consumption receiver analog front end supporting 100Gbps PAM4 signal transmission is realized.

The application relates to a reflection compensation circuit of a controller, a controller, a method and equipment. A differential amplifier module is used to differentially amplify a communication bus signal of the controller to generate a differential amplified signal. Then, a variable gain amplifier circuit module is used to gain amplify the differential amplified signal according to a control signal of the controller to generate a gain amplified signal. A feedback loop module can output a feedback signal according to the difference between the gain amplified signal and a preset reference signal of the controller, so that the control signal can be adjusted based on the feedback signal until the signal value of the feedback signal is within the system preset value range of the controller. In this way, signal distortion can be reduced to the greatest extent, CAN signal distortion and noise interference can be improved, CAN communication quality can be improved, and the poor CAN communication quality problem in the prior art is solved.

A system for controlling a phase array antenna comprising a plurality of compensation units (2) associated to corresponding radiating elements (30) of the phase array antenna. The compensating unit (2) comprises a phase slope control module (10) that controls the phase slope of a radio frequency (RF) signal and comprises a no-delay line with a first variable gain amplifier (11) and a delay line with a second variable gain amplifier (12) and a delay line element (13), wherein the gain of the first amplifier and the gain of the second amplifier are interrelated. The compensating unit (2) comprises a phase shifter (20) that controls the phase shifting of the RF signal, wherein the phase shifter (20) and the phase slope control module (10) are connected. A processing unit (3) can coordinate the compensation units (2).

Systems and methods for operating phased arrays are described. A circuit can receive an index associated with an antenna among a plurality of antennas in a phased array. The circuit can use the index to identify at least a phase value and a gain value of a known beam. The circuit can receive at least one static configuration of the antenna and at least one beam transformation parameter. The circuit can transform, based on the at least one beam transformation parameter and the at least one static configuration, the phase and gain values of the known beam into phase and gain values of a desired beam. The circuit can map the phase value of the desired beam to a phase shifter setting of the antenna and the gain value of the desired beam to a variable gain amplifier setting of the antenna to generate the desired beam.

The utility model relates to a composite flame detector capable of realizing adaptive variable gain, which comprises three infrared pyroelectric sensors, a variable gain amplification circuit, an ultraviolet photoelectric sensor, an ultraviolet control and feedback circuit, an MCU (Microprogrammed Control Unit) control module, a power supply module and a relay output module, the output end of each infrared pyroelectric sensor is connected with the variable gain amplification circuit, the output end of the variable gain amplification circuit is connected with the MCU control module, the output end of the MCU control module is connected with the relay output module, the ultraviolet control and feedback circuit is connected with the MCU control module, the ultraviolet photoelectric sensor is connected with the ultraviolet control and feedback circuit, and the relay output module is connected with the relay output module. And the output end of the power supply module is connected with the infrared pyroelectric sensor, the variable gain amplification circuit, the MCU control module and the relay output module. By adopting the composite flame detector capable of realizing the self-adaptive variable gain, the gain parameter can be adjusted through the MCU to adapt to the field environment, the detection distance is increased, and the anti-interference capability can also be improved at the same time.

The application provides a closed-loop control integral system with amplitude compensation function, mainly comprising a non-ideal integrator, a gain-variable amplifier and a control signal generator; the non-ideal integrator receives a Rogowski coil output signal and performs integral operation on the signal to suppress integral overflow caused by interference direct current; after receiving a control signal generated by the control signal generator, the gain-variable amplifier performs amplitude gain adjustment on the output signal of the non-ideal integrator based on the control signal to compensate amplitude gain error caused by temperature drift and time drift of the non-ideal integrator; the control signal generator collects various electrical parameters of the Rogowski coil output end and combines various electrical parameters of the output signal of the gain-variable amplifier to generate a control signal for gain adjustment control of the gain-variable amplifier. By implementing the application, errors caused by device temperature drift and aging can be compensated in real time, and the application has the advantages of high measurement accuracy, low cost and more stable performance.

The application discloses a variable gain amplifier applied to a high-speed optical receiver, comprising a high gain stage, a low gain stage and a common gain load; the high gain stage comprises a high differential input pair tube and a high gain adjusting tube group connected in sequence; the common gain load is connected to the output ends of the high gain stage and the low gain stage simultaneously and is used for synthesizing the output currents of the high gain stage and the low gain stage into an output voltage; the high gain adjusting tube group has a gain adjusting voltage V ctrl1 ; the low gain adjusting tube group has a gain adjusting voltage V ctrl2 ; by independently controlling V ctrl1 and V ctrl2 , the total gain and the linearity of the amplifier can be adjusted coordinately. The application adopts the high gain stage and the low gain stage to control the circuit gain, the high gain stage provides higher gain for the circuit, and the low gain stage provides better linearity for the circuit, so that the circuit can realize high gain, and the linearity and the gain change range of the circuit are improved.

This invention relates to a wideband, low-error 6-bit active vector synthesis phase shifter for phase control of radio frequency signals. It includes an orthogonal signal generator, a wideband input matching network for the I / Q branch, a variable gain amplifier for the I / Q branch, a wideband output matching network, and a shift register. The orthogonal signal generator employs an RL multiphase filter (RLPP) based on a transformer structure, reducing losses caused by capacitive loads, saving space, and implementing a two-stage cascaded structure to extend bandwidth. An electromagnetically coupled resonator is used as the input and output wideband matching network for the variable gain amplifier, effectively extending the circuit bandwidth. Furthermore, a variable gain amplifier with adjustable tail current is designed, connected to two current mirror arrays through the tail current node in a Gilbert cell structure, enabling coarse and fine phase shift control of the phase shifter, thereby improving the phase shift accuracy.

A variable gain amplifier includes first and second stage common-source (CS) amplifiers and a first transformer. The second stage CS amplifier includes a differential circuit and a current steering circuit. The differential circuit and the current steering circuit are coupled to a common connecting node, and the current steering circuit draws at least part of a current flowing through the differential circuit from the common connecting node. The first transformer includes primary and secondary sides. A first terminal of the primary side is coupled to an output terminal of the first stage CS amplifier, and a second terminal of the primary side is coupled to the common connecting node. A first terminal of the secondary side is coupled to a first differential input terminal of the differential circuit, and a second terminal of the secondary side is coupled to a second differential input terminal of the differential circuit.

The invention discloses an ORU radio frequency gain adjusting system suitable for ORAN equipment. The system comprises a hardware platform, field programmable gate array logic and gain control software running on a main controller. The hardware platform comprises a digital radio frequency unit which is integrated in field programmable gate array logic, comprises a digital up-conversion module, a rest factor reduction module, a digital pre-distortion module and a digital down-conversion module, and provides a digital gain adjustment point; the radio frequency transceiving link comprises a digital-to-analog converter, an analog gain controller and a driving amplifier of the transmitting link; the receiving link comprises a low noise amplifier, a variable gain amplifier and an analog-to-digital converter; and a feedback link ADC; and the power amplifier unit comprises a final power amplifier and a bias control circuit thereof. According to the invention, high-precision and self-adaptive control of downlink (DL) and uplink (UL) gains can be realized, so that performance fluctuation caused by frequency and temperature changes and device batch differences can be compensated.

Aspects include amplifiers having different cells for improved performance. An amplifier has: a first transistor having a first gate coupled to a control input, and a first drain coupled to a first terminal of an output; and a second transistor having a second gate coupled to the control input and a second drain coupled to the second terminal of the output. The amplifier has: a third transistor having a third drain coupled to the source of the first transistor and a third gate coupled to the first terminal of the input; and a fourth transistor having a fourth drain coupled to the second transistor source and a fourth source gate coupled to a second terminal of the input, where the first transistor source is not connected to the second transistor drain via the one or more transistors.

An example apparatus (108A) includes: variable gain amplifier (VGA) circuitry (204) having: an input terminal, an output terminal, and a control terminal; and peak detector circuitry (222) having: an input terminal coupled to the output terminal of the VGA circuitry; an output terminal coupled to the control terminal of the VGA circuitry; the peak detector circuitry configured to: compare a voltage on the output (VOUT(P) - VOUT(N)) of the VGA circuitry to an offset voltage; and adjust, responsive to the comparison, a gain of the VGA circuitry.

This invention discloses a transimpedance amplifier circuit for 50GPON. The main links of the transimpedance amplifier include a core amplifier, a burst switched-capacitor coupling module, a single-ended to differential variable gain amplifier, an output driver, a first automatic gain control module, a second automatic gain control module, a differential offset cancellation module, a differential amplifier, and a DC voltage operating point module. A current signal is input from the IN terminal, converted into a single-ended voltage signal by the core amplifier, and transmitted to the burst switched-capacitor coupling module. After processing, one end outputs a signal with a DC voltage boost, and the other end outputs the average signal voltage, which serves as the input common-mode level for the single-ended to differential variable gain amplifier. The single-ended to differential variable gain amplifier converts the single-ended signal voltage into a differential voltage. The output driver transmits this differential signal to the next stage chip, ensuring impedance matching during transmission.

An example apparatus (108A) includes: variable gain amplifier (VGA) circuitry (204) having: an input terminal, an output terminal, and a control terminal; and peak detector circuitry (222) having: an input terminal coupled to the output terminal of the VGA circuitry; an output terminal coupled to the control terminal of the VGA circuitry; the peak detector circuitry configured to: compare a voltage on the output (VOUT(P) - VOUT(N)) of the VGA circuitry to an offset voltage; and adjust, responsive to the comparison, a gain of the VGA circuitry.

An example apparatus includes: variable gain amplifier (VGA) circuitry having: an input terminal, an output terminal, and a control terminal; and peak detector circuitry having: an input terminal coupled to the output terminal of the VGA circuitry; an output terminal coupled to the control terminal of the VGA circuitry; the peak detector circuitry configured to: compare a voltage on the output of the VGA circuitry to an offset voltage; and adjust, responsive to the comparison, a gain of the VGA circuitry.