59 results about "Envelope detector" patented technology

A near-field transmitter includes a power amplifier, a resonant network, an envelope detector, and an antenna tuning circuit. The power amplifier has an input for receiving a communication signal, and an output for providing a differential output signal. The resonant network is coupled to the output of the power amplifier and has a tunable reactive element tuned by a tuning signal. The envelope detector is coupled to the output of the power amplifier for providing an envelope signal in response to the differential output signal. The antenna tuning circuit is for adjusting the tuning signal in response to the envelope signal.

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.

An ultrasound imaging system (302) includes a transducer array configured to transmit a plurality of ultrasound signals, each at a different sonication angle, receive an echo signal for each ultrasound signal of the plurality of ultrasound signals, and transmit the echo signal to the transducer array. And generating an electrical signal indicative of each of the echo signals. A beamformer (329) is configured to beamform the electrical signal and generate a radio frequency (RF) signal for each of the different acoustic wave action angles. An envelope detector (604) is configured to detect an envelope of each of the RF signals for each of the different acoustic wave action angles. A compressor (606) is configured to compress each of the envelopes for each of the different acoustic wave action angles to produce a data frame. A recombiner (326) is configured to adaptively recombine the data frames for each of the different acoustic action angles to generate a composite image. A display (330) is configured to display the composite image.

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 utility model provides a high-frequency millimeter wave digital isolator which comprises an emitter, a receiver and an integrated isolation device, the integrated isolation device comprises a first millimeter wave antenna and a second millimeter wave antenna, and the first millimeter wave antenna and the second millimeter wave antenna are arranged on the same horizontal plane. An isolation belt is arranged between the first millimeter wave antenna and the second millimeter wave antenna, the first millimeter wave antenna is connected with the transmitter, the second millimeter wave antenna is connected with the receiver, signals are transmitted between the transmitter and the receiver through an integrated isolation device, and the receiver comprises a second matching network, an envelope detector and an output buffer. And the second millimeter wave antenna, the second matching network, the envelope detector and the output buffer are connected in sequence. And the receiver adopts the design of replacing the existing amplifier and demodulator with an envelope detector, so that the power consumption is effectively reduced. The two millimeter wave antennas are arranged in parallel on the same horizontal plane, so that the risk of open circuit caused by collapse can be effectively avoided. And the isolation efficiency and the transmission efficiency are maintained.

A system includes an inverter including: a first galvanic isolator separating a low voltage area from a high voltage area, the first galvanic isolator having a first galvanic isolator output path; a second galvanic isolator having a second galvanic isolator output path; an amplifier connected to the first galvanic isolator via the first galvanic isolator output path, and connected to the second galvanic isolator via the second galvanic isolator output path, the amplifier having a first amplifier output path and a second amplifier output path; a comparator connected to the amplifier via the first amplifier output path and the second amplifier output path, the comparator having a first comparator output path and a second comparator output path; and a pulse reshape and envelope detector connected to the comparator via the first comparator output path and the second comparator output path.

The invention provides a digital isolator capable of passing back abnormity, an application circuit of the digital isolator and an isolation communication method. A first isolation circuit of the digital isolator comprises a first coupling piece, a first matching network, a first transmitter and an envelope detector; the second isolation circuit comprises a second coupling piece, a second matching network, a second transmitter and a second receiver; the first emitter and the envelope detector are respectively connected with the first matching network, and the first matching network is connected with the first coupling piece; the first coupling piece is connected with the second coupling piece; the second coupling piece is connected with the second matching network; the second receiver and the second transmitter are respectively connected with the second matching network; and the second transmitter is connected with a second isolated circuit corresponding to the second isolating circuit. According to the invention, the abnormity of the second isolated circuit can be transmitted back to the first isolated circuit only by using a single channel formed by a single pair of coupling pieces, so that the first isolated circuit is prompted to take protection measures.

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.

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.

The invention discloses a microwave sensing system for noninvasive blood glucose detection, and relates to the technical field of blood glucose detection, and the microwave sensing system comprises a voltage-controlled oscillator used for generating a frequency-adjustable radio frequency signal; the radio-frequency amplifier is used for improving radio-frequency signal power; the double-resonance unit differential detection structure comprises a test channel and a reference channel which are the same in structure and each comprise a split ring interdigital resonator and an envelope detector. The power divider / directional coupler is used for distributing the output signal of the radio frequency amplifier to the test channel and the reference channel according to the proportion of 1: 1; the test channel is used for outputting a direct-current voltage Vtest; the reference channel outputs direct-current voltage Vref; the differential processing module comprises a subtractor and is used for calculating the voltage difference delta V = Vtest-Vref in real time and eliminating common-mode interference. The method does not depend on a vector network analyzer, and the cost is reduced; the common-mode interference of environmental noise is effectively suppressed; the system volume is reduced and the power consumption is greatly reduced.

A method for providing a user equipment (20) main radio (21) to be activated by a wake up signal, performed by a wake up radio (10) provided to the user equipment (20) comprising the steps of detecting carrier signals having energy in a defined channel band from continuously listened carrier signals by an envelope detector (112), generating a chirp to modulate the detected signal, modulating the detected signal by a correlator (121) with defined chirp spreading factors (SF) according to the chirp, detecting peak amplitudes with a peak detector (122) to determine that the modulated signals are modulated according to a defined spreading factor, demodulating the carrier signal embedded in modulated frequency-shifted chirps with a synchronization mechanism (131), detecting the information carried by the demodulated signal using the fast fourier transform method, generating a trigger signal to wake up the main radio (21) if the information carried by the demodulated signal is found to be identical to a reference information, transmitting the trigger signal to the main radio (21).

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 application discloses a microwave photon technology-based radio frequency pulse width measuring device and method, belongs to the microwave photon technology field, and solves the problem that the envelope detector is used to measure radio frequency pulse parameters in the prior art, and it is difficult to realize the measurement requirement of the ultra-wideband radio frequency signal; the application utilizes the advantage of the microwave photon technology ultra-wideband signal processing, processes the ultra-wideband radio frequency pulse signal in the optical domain through two kinds of modulation modes, utilizes the beat frequency output of the photoelectric detector to output two low-frequency edge pulse signals, converts the to-be-measured radio frequency pulse signal in the ultra-wideband frequency range into a low-frequency signal range for collection and measurement, and the ultra-wideband, fast pulse width measurement of the ultra-wideband radio frequency signal can be realized without the collection and processing capacity of the high-speed ultra-wideband radio frequency signal.

A method of envelope detection operates by receiving a RF (radio frequency) signal having a first voltage at a first node and a second voltage at a second node; using a common-mode source-follower (CMSF) having a first source follower and a second source follower connected in parallel and configured to receive the first voltage and the second voltage, respectively, and jointly output a first current to a third node in accordance with a sum of a second current and a third current received via a fourth node; establishing a first negative feedback control loop by converting the first current into the third current using a current-controlled current source (CCCS); and establishing a second negative feedback control loop by converting a drain voltage at the third node into the second current using a voltage-controlled current source (VCCS).

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 present invention discloses a microwave sensing system for non-invasive blood glucose detection, which relates to the technical field of blood glucose detection. The system comprises: a voltage-controlled oscillator for generating a frequency-adjustable radio frequency signal; a radio frequency amplifier for boosting the radio frequency signal power; a dual-resonance unit differential detection structure comprising a test channel and a reference channel, both of which have identical structures, including a split-ring interdigital resonator and an envelope detector; a power divider / directional coupler for distributing the output signal of the radio frequency amplifier to the test channel and the reference channel in a 1:1 ratio; the test channel for outputting a DC voltage V_test; and the reference channel for outputting a DC voltage V_ref; and a differential processing module including a subtractor for calculating a voltage difference ΔV = V_test-V_ref in real time to eliminate common-mode interference. The system does not rely on a vector network analyzer, reducing costs; effectively suppresses common-mode interference from environmental noise; and reduces system size and power consumption.

A radio frequency (RF) voltage limiter for a radio frequency identification (RFID) transponder is provided. The RF voltage limiter includes an envelope detector configured to track an envelope of a signal received at the antenna. The envelope detector has an output for providing an envelope signal. A peak detector is included and has an input coupled to the output of the envelope detector. The peak detector includes a current mirror having an input coupled to the output of the envelope detector, and an output configured to provide a control signal. A shunt circuit is coupled to provide an impedance to the antenna in response to the control signal. The impedance decreases with an increasing voltage of the control signal to limit a maximum voltage at the antenna. In another embodiment, a method is provided for limiting a RF voltage at the antenna.

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.

An integrated circuit includes a demodulator to demodulate a signal simultaneously transmitted over an isolation communication channel and obtain gate information and configuration information. The demodulator includes a gate demodulation path and a configuration demodulation path. The received signal oscillates at a first frequency to represent a first state, oscillates at different frequencies to represent a seconds state, oscillates at a third frequency (or third and fourth frequencies), which are lower than the first frequency, to represent a third state, and the received signal is steady state to represent a fourth state. The gate demodulation path detects the first and second states. The configuration demodulation path includes first and second sub-demodulation paths. An envelope detector in the first sub-demodulation path detects the second state and the second sub-demodulation path detects the third state. The configuration demodulation paths uses an output of the gate demodulation path.

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.

An antenna tuning circuit is provided. The antenna tuning circuit includes an envelope detector, an operational amplifier, and a switch. The envelope detector is configured to track an envelope of a signal received at an antenna terminal. The operational amplifier includes a first input coupled to an output of the envelope detector to receive a first signal and a second input coupled to receive a second signal and is configured to generate an output signal at an output based on the first signal and the second signal. The switch includes a first terminal coupled to the output of the operational amplifier, a second terminal coupled to the second input of the operational amplifier, and a control terminal coupled to receive a first control signal. The operational amplifier is configured in a follower configuration when the first control signal is at a first voltage value.

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.

The application relates to the technical field of backscatter communication and discloses a ZigBee backscatter method and system based on environmental Bluetooth excitation. The method comprises the following steps: an excitation source sends a Bluetooth extended broadcast packet as an excitation signal, and an amplitude modulation signal carrying the channel number of the Bluetooth extended broadcast packet is sent before the excitation signal is sent; a tag demodulates the amplitude modulation signal through an envelope detector, acquires the channel number of the Bluetooth extended broadcast packet, calculates a frequency shift amount according to a dynamic difference value between the listening channel number of a ZigBee receiving end and the channel number of the Bluetooth extended broadcast packet, adjusts the center frequency of a generated backscatter signal through the frequency shift amount; and the ZigBee receiving end receives and demodulates the backscatter signal on a fixed listening channel to obtain tag data. The application uses a Bluetooth excitation signal with a longer duration, improves the data transmission amount of single backscatter, and thus improves the effective throughput.

The present invention relates to a differential envelope detector, which comprises: input terminals for separating cathode and anode components from a signal and receiving same; a first voltage output unit for outputting a first common mode voltage between the input terminals; a first amplification unit, which receives an input signal as a differential pair and amplifies same so as to output a first output signal; a second amplification unit, which receives the first common mode voltage so as to output a second output signal; and a second voltage output unit for outputting a second common mode voltage between a constant current source unit and an output terminal, wherein the output size of the detector is hardly affected by temperature changes, and an output DC voltage is also fixed so as to be effective with respect to input bias of the next stage amplifier.