31 results about "Envelope detector" patented technology

Embodiments of a compensation circuit for a power amplifier (PA) and a method of PA compensation are disclosed. In an embodiment, a compensation circuit for a power amplifier (PA) includes an envelope detector configured to measure an input power of the PA and a bias offset generator configured to apply a voltage offset in response to the input power of the PA to generate bias voltages that are applied to back gates of transistor devices of the PA for distortion compensation and second harmonic (HD2) compensation of the PA.

A device and method for detecting faults in a shield of an electrosurgical instrument is described. The device has a relay configured to selectively interrupt power to the electrosurgical instrument, monitoring circuitry configured to monitor a shield in the electrosurgical instrument, control circuitry to control the relay, and a battery power source. The monitoring circuitry has an envelope detector and a detected average shield current detector. The monitoring circuitry is configured to compare a shield current peak value to a shield current peak threshold value, and to compare a detected average shield current value to a detected average shield current threshold value. The device is further configured to operatively couple an active electrode of an electrosurgical instrument and a return electrode to an electrosurgical generator.

The invention discloses an envelope extraction system and method for metal particle ultrasonic signals in a filter field circuit breaker. The system comprises an ultrasonic sensor, a broadband amplifier, an envelope detector and a data acquisition and processing unit. Firstly, an ultrasonic sensor captures a broadband ultrasonic signal generated by impact of metal particles in the filter field circuit breaker, then the broadband ultrasonic signal is transmitted to a broadband amplifier to be amplified, the amplified signal is subjected to full-wave rectification through an envelope detector, a smooth low-frequency envelope signal is obtained, the envelope signal is received by a data acquisition and processing unit, and the data acquisition and processing unit processes the envelope signal. And key parameters are extracted, and alarm is triggered or ultrasonic positioning is carried out according to needs. According to the method, redundant collection of high-frequency carrier signals is avoided, efficient real-time diagnosis of the activity intensity of the particles is achieved, and the method is particularly suitable for defect detection of the free metal particles in cavities such as a filter field circuit breaker.

An exemplary setup includes: a rectifier circuit arrangement comprising: a first resistor with one terminal; a second resistor with one terminal; a first transistor with a first terminal, a second terminal, and a control terminal; and a second transistor with a first terminal, a second terminal, and a control terminal;a reference circuit arrangement comprising a first input, a second input, a third input, a fourth input and an output, wherein the first input of the reference circuit arrangement is coupled to the control terminal of the first transistor, wherein the second input of the reference circuit arrangement is coupled to the terminal of the second resistor and the first terminal of the second transistor, wherein the third input of the reference circuit arrangement is coupled to the control terminal of the second transistor, and wherein the fourth input of the reference circuit arrangement is coupled to the terminal of the first resistor and the first terminal of the first transistor.

An ultrasound imaging system includes a transducer array configured to transmit a plurality of ultrasound signals, each at a different angle of insonation, receive, for each of the plurality of ultrasound signal, an echo signal, and generate an electrical signal indicative of each of the echo signals. A beamformer is configured to beamform the electrical signals and produce a radio frequency (RF) signal for each of the different angles of insonation. An envelope detector is configured to detect an envelope of each of the RF signals for each of the different angles of insonation. A compressor is configured to compress each of the envelopes to produce frames of data for each of the different angles of insonation. A compounder is configured to adaptively compound the frames of data for each of the different angles of insonation to generate a compounded image. A display is configured to display the compounded image.

Method (100) for operating a camera system comprising a camera head and a control unit connected to each other via a radio frequency channel, the method (100) comprising the following steps: detection (102) of at least one physical parameter in the camera head and output (103) as a first signal by means of a detector unit; conversion (104) of the first signal into a low-frequency signal within a carrier frequency range by means of a carrier frequency modulator; transmission (105) of the low-frequency signal to the control unit via a first passive coupler over the radio frequency channel; reception (106) of the low-frequency signal by means of a second passive coupler in the control unit; demodulation (107) of the low-frequency signal by means of an envelope detector; alignment (108) of the demodulated signal with at least one reference value by means of a threshold circuit to obtain an alignment result;and output (109) of a control signal depending on the adjustment result.;

The invention discloses a receiver, a digital isolator and a disconnection protection method thereof. The digital isolator includes a transmitter and a receiver connected via a differential line. The receiver comprises an amplifier, an envelope detector and a driver which are connected in sequence, and the envelope detector is configured to perform envelope detection on a differential input signal received by the receiver so as to generate a corresponding envelope signal; the switch module is configured to control the on-off state of an input signal path of the envelope detector; and the broken line protection module is used for detecting the line fault of the differential line according to the signal change of the envelope signal in different on-off states during the power-on reset period, and stopping providing the output signal when the line fault exists in the differential line.

A method for operating a camera system including a camera head and a control unit, which are connected to one another by means of a high-frequency channel. The method includes: detecting at least one physical parameter in the camera head and outputting it as a first signal using a detector unit; converting the first signal into a low-frequency signal within a carrier frequency range using a carrier frequency modulator; transmitting the low-frequency signal to the control unit by means of a first passive coupler via the high-frequency channel; receiving the low-frequency signal using a second passive coupler in the control unit; demodulating the low-frequency signal using an envelope detector; comparing the demodulated signal with at least one reference value using a threshold circuit in order to obtain a comparison result; and outputting a control signal according to the comparison result.

The invention relates to the technical field of measurement and testing, and discloses a pulse ultrasonic sensing device and method for fluid anomaly detection, and the method comprises the steps: a programmable pulse generator in an application-specific integrated circuit generates a short pulse sequence with preset parameters, and the short pulse sequence is amplified by a power amplifier and then is transmitted to a fluid medium by an ultrasonic transducer. In a transmitting gap, the transmitting-receiving switching circuit switches the system to a receiving mode, and echo signals are conditioned through the low-noise preamplifier, the programmable band-pass filter and the automatic gain control circuit in sequence. The conditioned signals are digitalized through an analog-to-digital converter array, pulse shaping, time sequence alignment, signal accumulation and digital filtering operation are carried out in a digital processing module, then signal envelopes are extracted by an envelope detector, feature vectors are calculated, and finally abnormity judgment is carried out by a judgment logic unit. According to the invention, rapid ultrasonic detection and accurate judgment of abnormal signals are effectively realized.

A phase reconfigurable circuit (100) for a dual input power amplifier is provided. The circuit (100) includes an envelope detector (120) configured to process an envelope of the RF input signal into an envelope signal. A first vector and phase shifter (140) and a second vector and phase shifter (145) process an in-phase version and a quadrature-phase version of the RF input signal and the envelope signal to produce a first differential output signal having a dynamically modulated phase difference from the second differential output signal.

In accordance with an embodiment, an envelope detector includes a first transistor having a first current conduction terminal coupled to a first connection node; a second current conduction terminal coupled to an intermediate node; and a control terminal coupled to the signal input node and to a biasing node; a second transistor having a first current conduction terminal coupled to the intermediate node; a second current conduction terminal coupled to a second connection node; and a control terminal coupled to the biasing node; and a first temperature compensating transistor that is diode-connected and coupled between a compensation output node and the biasing node. The second connection node is coupled to the compensation output node and the first connection node is coupled to a detector output.

The invention discloses a fully-integrated high-sensitivity wake-up receiver, and the receiver comprises a low-noise amplifier which is used for amplifying a radio-frequency signal received by an antenna; the down-conversion module comprises two same signal processing paths, each path is driven by an orthogonal four-phase local oscillator signal, and the amplified signal is down-converted into two paths of differential baseband signals; the combiner is used for combining the two paths of differential baseband signals into one path of differential baseband signal; the variable gain amplifier is used for amplifying the differential baseband signal output by the combiner; the band-pass filter is used for carrying out filtering processing on the amplified differential baseband signal; the envelope detector is used for carrying out envelope extraction on the filtered differential signal and outputting a demodulated differential baseband signal; the hysteresis comparator is used for comparing the demodulated differential baseband signals and outputting digital baseband signals; and the digital correlator is used for processing the digital baseband signal, comparing the digital baseband signal with a preset wake-up code and outputting a wake-up signal. The invention has the advantages of low power consumption and high sensitivity.

The invention relates to a discharge positioning device of discharge equipment, belongs to the technical field of discharge equipment detection, and solves the problems of high operation detection cost and low precision of the discharge equipment in the prior art. The discharge positioning device comprises a plurality of antennas; a plurality of envelope detectors, each of which is connected with one antenna and is used for demodulating the antenna signal and outputting a low-frequency detection signal; a plurality of shaping circuits, each of which is connected with one envelope detector and is used for processing the low-frequency detection signal and outputting a discharge pulse signal to the FPGA; the FPGA is used for counting each input discharge pulse signal according to a plurality of counting clocks to obtain the time when each antenna receives the original partial discharge signal; and the positioning module is used for positioning the discharge position of the discharge equipment according to the time when each antenna receives the original partial discharge signal and the position of each antenna. The low-cost detection of the safe operation of the discharge equipment is realized, and the precision is high.

In a digital envelope detector circuit, an input terminal receives a digital input signal and an output terminal produces a digital output signal. First and second digital processing circuitry between the input and output terminals each includes a memory element. The first processing circuitry applies low-pass filtering to the digital input signal. The second processing circuitry processes the digital input signal, stores in the memory element a value indicative of the processed digital input signal, and processes the output from the memory element so that the digital input signal is passed unaltered. A digital comparator circuit compares the digital input and output signals, asserts a control signal in response to the digital input signal being higher, and de-asserts the control signal in response to the digital input signal being lower. The first / second processing circuitry produces the digital output signal in response to the control signal being de-asserted / asserted.

An embodiment includes a forward data receiving device that demodulates and receives an Amplitude Shift Keying (ASK) modulation signal, and includes: an input module configured to receive the ASK modulation signal as an input; a resonance regulating rectifier module configured to regulate and rectify an input voltage of the ASK modulation signal on the basis of Pulse Width Modulation (PWM) according to a preset target voltage, and apply a regulated voltage through an output transistor; and a demodulation module configured to demodulate the ASK modulation signal according to a trend in a change of the input voltage compared to the regulated voltage, wherein the resonance regulating rectifier module includes a comparison unit configured to generate a gate signal for controlling on / off of the output transistor, and generate a sample signal for demodulating the ASK modulation signal.

A system for detecting a partial discharge in electric power equipment is disclosed. The has a sensor located so as to receive ultra-high frequency signals related to the partial discharge, which has antenna and two or more envelope detectors connected to the antenna through respective bandpass filters. A measurement hub is located so as to allow safe access and has a computational platform. The sensor and the measurement hub are interconnected by a cable. The antenna derives UHF signals in different frequency bands, and envelope detectors simultaneously detect respective baseband signals from the UHF signals. Cable transmits the baseband signals on corresponding signal lines of the cable from the sensor to the measurement hub. A corresponding method is also provided.

The invention discloses an all-optical terahertz envelope detection method, and relates to the technical field of optical terahertz technology and envelope detection, and the method comprises the steps: converting a received terahertz pilot frequency and a target electric signal into a single-side-band optical signal through an ultra-wideband electro-optical processing technology; the upper path adopts a laser injection locking technology to filter a target optical signal and amplify pilot frequency optical power, and the lower path retains the target optical signal through an optical filtering technology; the optical signals of the upper path and the lower path are coupled, the optical signals are converted into intermediate-frequency electric signals through the broadband electro-optical beat frequency technology, and then digital sampling is carried out to recover target communication or sensing information. The invention further discloses an all-optical terahertz envelope detection receiving system. According to the method, the terahertz signal envelope receiving bandwidth can be effectively improved, the problem that the bandwidth of an electronic envelope detector is limited is solved, and the detection sensitivity is improved; in addition, by using the homologous characteristic of the pilot frequency and the target signal, the frequency offset interference of the target signal can be eliminated, and the system complexity is reduced.

An ultrasonic echo ranging time delay estimation method is characterized in that a transmitting transducer, a transmitting circuit, a receiving transducer, a receiving circuit and a processor are included, the receiving circuit comprises a primary amplification circuit, a band-pass filter circuit, a secondary amplification circuit, an envelope detection circuit and an A / D sampling circuit, and the processor comprises a memory and a rectangular window. After the rectangular window completes sliding summation of the sampled signals, a sampling point corresponding to the maximum sum value of the sampled signals is screened out, a corresponding ultrasonic echo distance measurement time delay estimated value is calculated, and when the rectangular window carries out sliding summation on the sampled signals, the interval between the moment corresponding to the ultrasonic echo wavefront and the moment corresponding to the maximum sum value is fixed, and the time delay estimated value of the ultrasonic echo distance measurement is calculated. The difference of the time delay is from the difference of measurement distances, and the rectangular window calculates a time delay estimated value correction value according to the difference so as to realize distance measurement.

Embodiments of the present disclosure relate to envelope detector circuits, corresponding receiver circuits and current isolator devices. A rectifier stage includes a differential input transistor pair coupled between a reference voltage node and an intermediate node, and a load circuit coupled between the intermediate node and a supply voltage node. The differential input transistor pair receives a radio frequency amplitude modulated signal. A rectified signal representative of an envelope of the radio frequency amplitude modulated signal is generated at the intermediate node. An amplifier stage coupled to the intermediate node generates an amplified rectified signal indicative of the envelope of the radio frequency amplitude modulated signal at an output node. The rectifier stage includes a resistive element coupled in parallel with the load circuit between the intermediate node and the supply voltage node.

An electronic circuit (12) connected to a variable-excitation sensor (24) and comprising:a digital envelope detector (20) arranged to acquire signal that is produced by the sensor in response to an excitation signal, the detector comprising:an analog-to-digital converter (22) arranged to sample the measurement signal in such a manner as to produce sample points during successive observation windows of duration T that comprise a number NS of sample points, the sample points being spaced apart by a sampling period TS, the sampling period TS and the duration T being such that:TS=NP·T0+(NT / NS)·T0 and T=NS·TS,where T0 is one excitation period of the excitation signal, where NP, NT, and NS are non-zero natural integers, and where NT is not a multiple of NS.

The invention relates to a method (100) for operating a camera system and to a camera system comprising a camera and a control device which are connected to one another by means of a high-frequency channel, the method (100) comprising the following steps: detecting (102) at least one physical parameter in the camera by means of a detector unit and outputting (103) said physical parameter as a first signal; converting (104) the first signal into a low frequency signal in a carrier frequency range by means of a carrier frequency modulator; transmitting (105) the low-frequency signal to the control device via the high-frequency channel by means of the first passive coupler; receiving (106) the low frequency signal by means of a second passive coupler in the control device; demodulating (107) the low frequency signal by means of the envelope detector; comparing (108) the demodulated signal with at least one reference value by means of a threshold circuit in order to obtain a comparison result; and outputting (109) a control signal as a function of the comparison result.

The present application belongs to the field of digital-analog hybrid integrated circuits, and particularly relates to an asynchronous envelope detector based on zero-crossing events of an input signal. The asynchronous envelope detector based on zero-crossing events of the input signal can flexibly adapt to input signals of different frequencies, and the detection timing thereof is directly driven by zero-crossing events of the input signal, so that real-time envelope detection can be realized without an external clock. The design completely relies on dynamic characteristics of the input signal itself to realize asynchronous adaptive operation, so that the working frequency of the envelope detector can be automatically adjusted according to the change of the input signal frequency, thereby maintaining stable detection precision and rapid response capability under the condition of wide-band signals from low frequency to high frequency. The present application does not require complex clock distribution and control logic, significantly reduces system power consumption and design complexity, can realize high real-time and high energy efficiency envelope extraction in a high-speed signal environment, and is very suitable for integrated implementation and high-speed signal processing applications.

An oscillator circuit for a signal transmitter, the oscillator circuit including: a resonant circuit (12) including a resonant inductor (LR) and a resonant capacitor (CR) parallel to the resonant inductor (LR); a driving branch (14) including a pump driver bank (38) connected to the resonant circuit (12); a feedback branch (15) connected to the resonant circuit (12), and an amplitude regulation loop (28) connected to the resonant circuit (12) via the feedback branch (15) and operable to control the pump driver bank (38). The amplitude regulation loop (28) includes: an envelope detector (30) connected to the resonant circuit (12) via the feedback branch (15), a differential amplifier (32) connected to the feedback branch (15) via the envelope detector (30), and an analog to digital converter (ADC) (34) connected to an output of the differential amplifier (32) and operable to control the pump driver bank (38).

The present invention provides a method and circuit for estimating symbol timings within one or more received data frames of a given nominal envelope signal. [Solution] The circuit includes an envelope detector and a symbol timing estimator. The envelope detector generates an envelope detection output 212 of the received data frame 20. The envelope detection output has amplitude ripple related to the symbol timing in the received data frame. The symbol timing estimator receives the envelope detection output and generates a symbol timing estimate output 216 based on the amplitude ripple.

The invention provides an optimized matching digital isolator and an application circuit thereof. A first matching network and / or a second matching network in the digital isolator with a return function are / is an RF transformer; the RF transformer comprises a first winding, a second winding and a third winding; the first winding is connected with a corresponding signal amplifier, the second winding is connected with a corresponding antenna, and the third winding is connected with a corresponding envelope detector. The second matching network is preferably a second RF transformer; a first winding in the second RF transformer is connected with the second signal amplifier, a second winding is connected with the second coupling piece, and a third winding is connected with the second envelope detector. Aiming at a digital isolation circuit for realizing two-way communication based on a single-pair coupling transmission structure, the isolation circuit is provided with the RF transformer for network matching, so that impedance coordination, signal reflection elimination and maximum power transmission signal energy of a coupling piece, an envelope detector and a signal amplifier can be realized, and meanwhile, the system performance is improved.

An envelope detector comprises a first differential transistor pair that receives first and second input signals, a second differential transistor pair that receives third and fourth input signals, a resistor, a current source, and a comparator. The first and second differential pairs each comprise two transistors having first current terminals coupled together and second current terminals coupled together. The resistor is coupled between the second current terminals of the first and second differential pairs. The current source has a first terminal coupled to the second terminal of the resistor and to second current terminals of the second differential pair and a second terminal configured to receive a negative supply voltage. The comparator has a negative input coupled to first current terminals of the first differential pair and a positive input coupled to first current terminals of the second differential pair.

An example apparatus includes: rectifier circuitry including: a first resistor having a terminal; a second resistor having a terminal; a first transistor having a first terminal, a second terminal, and a control terminal; and a second transistor having a first terminal, a second terminal, and a control terminal; reference circuitry having a first input, a second input, a third input, a fourth input, and an output, the first input of the reference circuitry coupled to the control terminal of the first transistor, the second input of the reference circuitry coupled to the terminal of the second resistor and first terminal of the second transistor, the third input of the reference circuitry coupled to the control terminal of the second transistor, the fourth input of the reference circuitry coupled to the terminal of the first resistor and the first terminal of the first transistor.

Methods and systems for inter-path delay estimation. A method for inter-path delay estimation includes injecting, nearly simultaneously, a continuous wave tone at an input test point in a first communication path and at an input test point in a second communication path, combining output signals from the first communication path and the second communication path, measuring a magnitude of a combined output signal using an envelope detector, and adjusting a delay element in one of the first communication path and the second communication path until the magnitude of the combined output signal is maximized.

The application provides an environment backscattering communication system based on phase deviation reconstruction, which comprises a radio frequency signal source, a terminal device and a receiving device; the radio frequency signal source transmits radio frequency signals to the terminal device through a first path hst and transmits radio frequency signals to the receiving device through a second path hsr; the terminal device selects whether to reflect the radio frequency signals transmitted through the first path hst to the receiving device through a third path htr or not according to the binary data to be transmitted; the receiving device recovers the binary signal waveform by superimposing the radio frequency signals transmitted through the second path hsr and the radio frequency signals reflected by the terminal device through the third path htr and detecting through an envelope detector. The application solves the problem that the phase inconsistency between the radio frequency signals reflected by the terminal device and the radio frequency signals transmitted by the radio frequency signal source in the environment backscattering communication system leads to communication failure.