100results about "Limiting amplitude" patented technology

Disclosed in the present invention are a radio frequency front-end module with input clipping protection, and an electronic device. The radio frequency front-end module comprises at least one transmission path, which comprises at least one stage of a power amplifier circuit, and an output matching circuit. Each stage of amplifier circuit comprises at least one clipping circuit and a biasing circuit thereof, and an input matching circuit and a power amplifier, wherein the clipping circuit, the input matching circuit, the power amplifier and the output matching circuit are sequentially connected in series; and the clipping circuit is used for performing clipping processing on an input signal power and then outputting a signal having a relatively small power, and when the input power of the transmission path is greater than a set threshold value, the clipping circuit enables a clipping function, such that the power amplifier is protected by means of reducing the input power.

The invention belongs to the technical field of sensor signal amplification, and discloses a vibration cylinder pressure sensor signal amplification circuit and a vibration cylinder pressure sensor.The vibration cylinder pressure sensor signal amplification circuit comprises a filter circuit, a gain adjusting circuit, a phase adjusting circuit, an amplitude limiting circuit, a frequency detection circuit and a temperature detection circuit; amplitude adjustment of a certain gain is achieved through a gain adjusting circuit, a gain amplification signal VB is obtained and input to a phase adjusting circuit and a frequency detection circuit, the phase adjusting circuit outputs a square wave signal VC and inputs the square wave signal VC to an amplitude limiting circuit, and the amplitude limiting circuit outputs an amplitude limiting square wave signal VD and loads the amplitude limiting square wave signal VD to a vibration cylinder; a gain amplification signal VB output by the gain adjusting circuit passes through the frequency detection circuit, a square wave frequency signal VO is output, a closed-loop control system is formed to achieve driving and detection of the resonance cylinder pressure sensor, and the actual frequency of the vibration cylinder body depends on the sensed pressure.

Disclosed in the present invention are a power amplifier module for implementing average power protection, an electronic device, and a method. The power amplifier module comprises: a controller, configured to provide logic control and bias voltage for a radio frequency power amplifier; the radio frequency power amplifier, configured to amplify the power of a radio frequency signal and then output the amplified radio frequency signal to a filter; and a filter for frequency bands, configured to filter the amplified radio frequency signal to obtain a radio frequency signal of a required specific frequency band. When the detected power of the radio frequency power amplifier is greater than or equal to a first power threshold, and the time during which the detected power is greater than or equal to the first power threshold reaches a first time threshold, the power amplifier module enters an average power protection operating mode, and the controller adjusts the gain of a power amplification unit, so as to protect the filter in the power amplifier module from being burnt out.

The invention provides a segmented adaptive gain-based short-wave band amplitude and phase control device and method, and relates to the field of short-wave intelligent control. The method comprises the following steps: performing coupling detection processing on N paths of input short-wave signals to obtain coupled short-wave signals and power values of the coupled short-wave signals; based on the coupled short-wave signal and the power value of the coupled short-wave signal, calculating adjustment parameters through a preset adaptive segmented multi-target differential evolution algorithm, wherein the adjustment parameters comprise a frequency correction parameter, a phase adjustment parameter and an amplitude control voltage; adjusting the coupled short-wave signal based on the adjustment parameter to obtain a target short-wave signal; and detecting whether the target short wave signal meets a preset output condition, and if the target short wave signal meets the preset output condition, coupling the target short wave signal to output a radio frequency output signal. Through the scheme, the communication quality is improved.

The invention discloses a final-stage voltage tracking anti-clipping circuit for an audio power amplifier, and relates to the technical field of power amplifiers, and the circuit comprises a voltage division circuit which is used for receiving final-stage voltage from target power amplifier equipment and generating a combined voltage signal; the audio attenuation module is used for receiving an audio input signal and a final-stage voltage, and judging whether amplitude limiting modulation is carried out on the audio input signal or not to complete power amplifier output by judging whether a starting signal is received or not; and the starting judgment module is used for receiving the combined voltage signal and the first output signal, and comparing the combined voltage signal with the first output signal to generate a starting signal. According to the invention, the collected final-stage voltage of the target power amplifier is set as the dynamic amplitude limiting threshold, so that an over-high signal can be effectively suppressed to a safe range quickly when the power supply drops instantaneously, and the effects of avoiding hearing deterioration caused by power amplifier signal waveform truncation and avoiding potential safety hazards caused by amplitude limiting and topping to the loudspeaker are achieved.

The invention belongs to the technical field of integrated circuit signal processing, and discloses a temperature compensation circuit for a logarithmic detector and the logarithmic detector thereof, and the temperature compensation circuit for the logarithmic detector comprises a first temperature compensation module, a second temperature compensation module and a third temperature compensation module. The first temperature compensation module is used for performing temperature compensation on the current summation module, the second temperature compensation module is used for performing temperature compensation on bias voltage and current of the limiting amplifier module, and the third temperature compensation module is used for performing temperature compensation on bias voltage and current of the rectifier module. The logarithmic detector temperature compensation circuit is suitable for performing temperature compensation on the current summation module, the limiting amplifier module and the rectifier module of the logarithmic detector, and the output precision and consistency of the logarithmic detector are improved.

The invention discloses a self-adaption method and device for a clock and data recovery circuit, and relates to the technical field of communication, and the method comprises the following steps: judging the phase deviation and frequency deviation between a sending clock and a receiving clock, transmitting a phase error signal to a loop filter, and analyzing the frequency response of the loop filter; the method comprises the following steps: determining a parameter adjustment range and a relative relation, calculating statistical characteristics output by a loop filter in real time, judging the working state of a clock and data recovery circuit, realizing a clock and data recovery circuit state machine, and determining the state of the clock and data recovery circuit according to the statistical characteristics output by the loop filter and based on a threshold detection principle. And determining parameters and an output range for adjusting the loop filter. The working state of the clock and data recovery circuit is monitored, the design parameters of the loop filter are adjusted in real time according to the state change, the frequency capture range is guaranteed, meanwhile, the phase noise of the clock and data recovery circuit in the steady state is improved, and the stability of data collection is improved.

The invention discloses a ferrite amplitude limiting circuit and a high-power microwave front door amplitude limiting protection device composed of the ferrite amplitude limiting circuit, and belongs to the technical field of microwaves. The ferrite amplitude limiting circuit comprises a ferrite substrate, and a centrosymmetric microstrip circuit structure is arranged on the front face of the ferrite substrate; the micro-strip circuit structure comprises long transmission lines, short transmission lines and input and output micro-strip lines, and all the long transmission lines and the short transmission lines are of a periodic folding structure or a quasi-periodic folding structure as a whole; absorption type amplitude limiting is carried out on high-power microwaves in the band through the nonlinear loss effect of the ferrite, front door protection can be started in the HPM electromagnetic environment, the good amplitude limiting effect is achieved, the size of the device is small, and application in a microwave receiver is facilitated.

The signal amplitude limiting circuit comprises a first voltage division circuit, a signal amplification circuit and a second voltage division circuit, the second voltage division circuit comprises a first resistor R1 and a third triode PQ3, the base electrode of the third triode PQ3 is electrically connected with the output end of the signal amplification circuit, the emitter electrode of the third triode PQ3 is grounded, and the first resistor R1 is electrically connected with the output end of the signal amplification circuit. The collector electrode of the third triode PQ3 is electrically connected with the second end of the first resistor R1, and the first end of the first resistor R1 is electrically connected with the signal output end. By arranging a first voltage division circuit, a signal amplification circuit and a second voltage division circuit, when an input signal exceeds a normal range, the input signal can drive a third triode PQ3 of the second voltage division circuit to enter an amplification state after passing through the first voltage division circuit and being amplified, and at the moment, an output signal is influenced by voltage division of a first resistor R1 and the third triode PQ3; and the output signal is not increased along with the increase of the input signal, so that distortion or overhigh power is avoided.

The disclosed embodiment provides a logarithmic conversion circuit and chip, in which the chopper circuit receives a DC input signal, performs a DC-to-AC process on the DC input signal, and generates an AC input signal; the conversion circuit receives an AC input signal, and performs amplification and AC-to-DC process on the AC input signal, and generates a DC output signal; the conversion circuit includes N cascaded amplifier circuits, and the first-stage amplifier circuit receives an AC input signal; the feedback circuit is connected between the output end of the j-stage amplifier circuit and the input end of the i-stage amplifier circuit, and is used to input a feedback signal to the input end of the i-stage amplifier circuit, wherein the feedback signal includes a DC portion and / or a low-frequency portion in the output signal of the j-stage amplifier circuit. The disclosed embodiment can suppress the offset voltage generated inside the amplifier circuit, which is beneficial for the circuit to achieve a large dynamic range.

A headset communication system with improved functionality. The headset communication system may include hear-through limiter functionality. The headset communication system may include failsafe functionality. The headset communication system may include multichannel, mixing, passive push-to-talk functionality. The headset communication system may include near field magnetic induction functionality.

The invention discloses a P-band high-power filtering and amplitude limiting assembly, which belongs to the technical field of microwaves and comprises a filter, an amplitude limiter, a polarizer, a coupler and a metal cavity. The amplitude limiter is installed on the bottom layer of the metal cavity, the filter and the polarizer are installed on the top layer of the metal cavity, the coupler is installed on the side wall of the metal cavity, the filter, the low-pass filter and the polarizer are connected in a wall-penetrating welding mode through a 50-ohm metal connecting rod, and the polarizer is fixed to the metal cavity through a medium supporting column. The whole assembly belongs to an upper-lower layer structure. According to the assembly, the transmission path between devices is shortened, the emission loss of the assembly is reduced, the size of the filtering and amplitude limiting assembly is greatly reduced under the condition that composite multiple functions are met, and the purposes of high power and high integration are achieved.

A data slicer may include an input transistor configured to generate an internal output voltage based on an input voltage at an input node. An output node may be configured to output an output voltage based on the internal output voltage, and a feedback transistor may be configured to adjust the internal output voltage based on a correction voltage corresponding to output of the output node in a previous cycle.

A clipping detector circuit (12) is configured to detect clipping of a pulse-width modulated signal (PWMout ) and comprises a timer circuit (120) configured to monitor edges of the pulse-width modulated signal (PWMout ) and to monitor a time period elapsing since a last occurrence of an edge in the pulse-width modulated signal (PWMout ), assert a first signal (ClipDet) when said time period elapses, and de-assert the first signal (ClipDet) and reset said time period as a result of an edge occurring in the pulse-width modulated signal (PWMout ); and a counter circuit (122) configured to monitor the pulse-width modulated signal (PWMout ) and the first signal (ClipDet), determine the number of pulses in said pulse-width modulated signal (PWMout ) since the last de-assertion of the first signal (ClipDet), and assert a second signal (ClipOut) when the number of pulses in said pulse-width modulated signal (PWMout ) since the last de-assertion of the first signal (ClipDet) reaches a certain number m of pulses. The clipping detector circuit (12) is configured (124) for generating at output a clipping detection signal ( ClipDet' ) indicative of whether the pulse-width modulated signal ( PWMout ) is clipped or not as a function of the first signal ( ClipDet ) and the second signal ( ClipOut ).

The invention provides a special amplitude limiting circuit for a PLC (Programmable Logic Controller), relates to the technical field of power line carrier communication, and aims to solve the technical problems that an AGC (Automatic Gain Control) circuit in an existing PLC communication system is limited in adjusting range, signal identification fails and the circuit burning risk is high. The system comprises a micro-control unit MCU, a current-limiting resistor, an optocoupler, a PLC signal coupling circuit and a PLC chip, and compared with a conventional PLC communication PLC chip signal path and process, a PLC amplitude limiting circuit is additionally arranged in front of the receiving ends RX + and RX-of the PLC chip; through the function that receiving ends RX + and RX-of a PLC chip identify the signal to noise ratio, the PLC chip communicates with a micro-control unit MCU through serial ports TX and RX, and through two modes of controlling and accessing different resistance values of series resistors to limit current and controlling and accessing different resistance values of divider resistors, the amplitude of a PLC signal is limited, so that the size of the PLC signal is changed, and the signal to noise ratio of the PLC signal is adjusted.

The utility model provides an absorption type amplitude limiter, which relates to the technical field of absorption type amplitude limiters and comprises a mounting mechanism, an amplitude limiter main body is mounted at the top end of the mounting mechanism, the mounting mechanism comprises a base, a bottom plate is arranged at the top end of the base, an insertion groove is formed in the front surface of the base, an insertion rod is slidably connected in the insertion groove, and the insertion rod is fixedly connected with the base. The top end of the inserting rod is fixed to the front face of the bottom plate, built-in grooves are formed in the positions, close to the front face and the right side, of the interior of the base, fixing assemblies are installed in the built-in grooves, a rotary knob is rotated to be disengaged from a sliding rod, the sliding rod is pushed out of a circular groove through a spring, and fixing of the inserting rod is relieved; and finally, the amplitude limiter main body is pushed forwards, and the amplitude limiter main body, the bottom plate and the insertion rod are taken out together for maintenance, so that compared with a traditional fixing mode, the operation convenience is greatly improved, and the maintenance efficiency is effectively improved.

The present invention is applicable to the field of microwave communication technology, and provides a microwave limiter and a transceiver based on feedback. The limiter comprises: a bidirectional coupler, a first forward detection module, a second forward detection module, a first choke inductor, a second choke inductor, a PIN diode, a first capacitor, an antenna end and a power transmitting end; the bidirectional coupler, the first main branch end is connected to the antenna end, the second main branch end is respectively connected to the first end of the first choke inductor, the positive electrode of the PIN diode and the power transmitting end, the first coupling end is connected to the input end of the first forward detection module, and the second coupling end is connected to the input end of the second forward detection module; the output end of the first forward detection module is connected to the second end of the first choke inductor; based on the characteristics of the bidirectional coupler, when a high-power signal is injected, the two detection modules are superimposed on the two ends of the PIN diode to perform unidirectional limiting, thereby realizing unidirectional protection of the high-power signal.

The invention relates to the technical field of analog integrated circuits, and provides a linear limiting amplifier circuit which comprises a fixed reference current generation circuit module, a current-to-voltage module and a variable current generation module. When the input voltage is lower than the lower threshold voltage, the output voltage is maintained at a low level, when the input voltage is higher than the lower threshold voltage, the output voltage is maintained at a high level, and when the input voltage is between the upper threshold voltage and the lower threshold voltage, the output voltage linearly changes along with the input voltage. According to the circuit scheme of the linear limiting amplifier based on the addition of the fixed current and the variable current, the problems of simple structure, high power consumption, poor linearity and the like in the existing technical scheme are solved, and the linear limiting amplifier can be widely applied to power supply management circuits for motor driving, LED driving and the like; and the method can also be used in a linear amplification circuit for a specific signal amplitude range of an expected signal in a signal conditioning circuit.

The invention relates to the technical field of anti-interference receiving, and discloses a tunable high-temperature superconducting amplitude limiter based on voltage regulation. Comprising a radio-frequency signal input end P1, a first impedance conversion node assembly, a superconducting amplitude limiting node L4, a direct-current bias regulation and control circuit for introducing bias current to the superconducting amplitude limiting node L4, a second impedance conversion node assembly and a radio-frequency signal output end P2 which are electrically connected in sequence, the first impedance conversion node assembly and the second impedance conversion node assembly are the same in structure, and each of the first impedance conversion node assembly and the second impedance conversion node assembly comprises a superconducting microstrip transmission line, a blocking capacitor and an impedance conversion node, on the premise that geometric structure parameters of the high-temperature superconducting amplitude limiting section are not changed, the working current density of the high-temperature superconducting amplitude limiting section can be changed within the range close to or away from the critical current density of the superconducting material by adjusting the magnitude of the bias current, and therefore tuning of the amplitude limiting threshold value and the power bearing capacity of the amplitude limiter is achieved.

The present invention provides a digital audio processing device that can generate harmonic signals ideal for improving sound quality, even when the digital audio signal contains waveforms with multiple consecutive samples of the same value as a maximum or minimum sample. [Solution] The maximum / minimum sample detection unit 11 detects the maximum and minimum samples in a series of samples that constitute a digital audio signal. The maximum / minimum sample correction unit 12, when there are consecutive samples with the same value as the maximum or minimum sample, assigns a maximum sample tag or a minimum sample tag to samples that are different from the maximum or minimum sample among the consecutive samples. If no consecutive samples exist, the maximum / minimum sample correction unit 12 assigns a maximum sample tag to the maximum sample and a minimum sample tag to the minimum sample.

This application relates to methods and apparatus for clipping prevention. A driver apparatus for driving a load with an output signal has a switching driver with a switch network and a modulator configured to control the switch network to switch output nodes between different switching voltages with a controlled duty-cycle. A quantizer controller receives a quantizer input signal based on an input signal and a feedback signal and controls the duty-cycle of the switch network. A clipping prevention controller is configured to control a gain applied to the input signal so as to provide limiting of the input signal to avoid clipping, wherein the clipping prevention controller is configured to dynamically control at least one limiting threshold used to determine when to apply limiting of the input signal based on an indication of said quantizer input signal.

The invention discloses a broadband amplitude limiting module with low reflection after overvoltage. The broadband amplitude limiting module comprises an impedance matching circuit, a high-input impedance amplifying circuit and a low-frequency gain control circuit, wherein the impedance matching circuit is used for performing 50 omega termination matching between an input signal and the high input impedance amplification circuit, and in the high input impedance amplification circuit, a low and medium frequency signal fed back by the low frequency gain control circuit and a high frequency signal coupled by the high frequency coupling capacitor are synthesized and then input to the differential operation amplification circuit; therefore, the problem of reflection caused by overvoltage in the circuit is solved, and the waveform quality of a signal path is ensured.

A driver apparatus 100c for driving a load (Fig.1, 102) with an output signal has a switching driver 101 with a switch network (Fig.1, 105) and a modulator 106 configured to control the switch network

Novel tools and techniques are provided for implementing a novel integrated programmable gain amplifier "PGA" and protection circuit. In various embodiments, a circuit is provided that includes a PGA, an analog-to-digital converter "ADC", and a protection circuit, all disposed on the same semiconductor chip. The PGA is configured to receive a wireless signal received from an antenna as input, and to output an amplified wireless signal at its output based on amplifying the wireless signal by a programmable gain amount. The protection circuit is configured to, in response to detecting a spike in gain at the output of the PGA that exceeds a threshold magnitude, control a reduction in the programmable gain amount to bring the resulting signal at the output of the PGA below the threshold magnitude. A normally open switch can also be added at the differential output of the PGA to further clamp the PGA output.

The present invention provides a power adaptive link allocation front-end receiving component, which mainly includes a front-end radio frequency circuit module, a detection signal operation circuit module, a radio frequency signal amplification circuit module, and an output power adjustment circuit module. A large-dynamic detector is used to detect the signal of the radio frequency receiving front-end to obtain a power-related level signal, and then the level signal is amplified by an operational amplifier. Then, according to the reference level set for radio frequency signals with different powers, the control level of the single-pole triple-throw switch in the subsequent circuit is automatically converted, and then different back-end signal processing links are selected to complete the signal processing function of the front-end receiving component, and finally the adaptive allocation feature of the receiving front-end is realized. The present invention can realize adaptive link allocation according to the magnitude of the radio frequency input power, and has the advantages of adaptive implementation, large dynamic range, high detection sensitivity, etc.

The utility model discloses an amplitude limiting circuit and communication equipment, and the amplitude limiting circuit comprises an amplitude limiting module, a voltage control attenuation module and a voltage control module. The amplitude limiting module is used for reducing the signal amplitude of the received input radio frequency signal, outputting a first radio frequency signal and outputting a coupling signal according to the first radio frequency signal; the voltage-controlled attenuation module is connected with the amplitude limiting module; the voltage-controlled attenuation module is used for reducing the signal amplitude of the first radio frequency signal to be not greater than a target threshold value according to a target attenuation value and then outputting a second radio frequency signal; the voltage control module is respectively connected with the amplitude limiting module and the voltage control attenuation module; the voltage control module is used for outputting a voltage control voltage according to the size of the detection coupling signal and a preset threshold voltage so as to adjust the attenuation value of the voltage control attenuation module to a target attenuation value. According to the invention, the application requirement of the radio frequency agility device can be met, and the problem that the receiving sensitivity of the whole device is reduced due to system noise brought to the receiving link by the pi-type attenuator can be relieved.

The utility model discloses a miniaturized low-noise amplifier, which belongs to the technical field of signal processing, and comprises a shell, a PCB (printed circuit board) is arranged in the shell, and an amplitude limiter, a first amplifier, a first attenuator, a second amplifier and a second attenuator are arranged on the PCB, so that the technical problems of reducing the volume of the low-noise amplifier and improving the reliability are solved. According to the utility model, the size of the device is greatly reduced, the difficulty in mounting and dismounting the device is reduced, the use scene of the device is expanded, the amplitude limiter is added in the circuit, the device is protected, the deterioration of the noise coefficient can be controlled in an extremely low range, the limitation of indexes is not exceeded, two attenuator networks are reserved as debugging nodes, and the debugging efficiency is improved. The debugging difficulty of engineers is reduced, and the output rate of equipment is improved.