18 results about "Linear amplifier" patented technology

The invention belongs to the technical field of radiation monitoring, and particularly relates to a design method of a wide-range NaI (T1) detector, which comprises the following steps of: 1, connecting all lines of the NaI (T1) detector, and opening a multi-channel analyzer; 2, a 137Cs radioactive source is adopted, different preamplifier electronic gains are adjusted, the relation between the high voltage and the channel position where the characteristic energy of the 137Cs radioactive source is located is established, and energy spectrum data are output; 3, according to the output energy spectrum data, preamplifier electronic gain and linear amplifier high voltage needed by the detector are determined; and 4, under the determined preamplifier electronic gain required by the detector and the high voltage condition of the linear amplifier, different radioactive sources are adopted to carry out energy calibration on the detector, and whether digital gain needs to be adjusted is determined according to the energy calibration. According to the method, the measuring range of the sodium iodide gamma-ray spectrometer can be expanded, so that the sodium iodide gamma-ray spectrometer can cover high-energy radiation monitoring of 3MeV-10MeV or above.

This invention discloses a relay-charge parallel envelope tracking power supply with multiplexed input sources, comprising: a stepped wave voltage generation circuit, an AB-class linear amplifier, a feedforward control circuit, and a pulse edge distribution unit. It improves upon conventional parallel envelope tracking power supplies by using a relay-charge switched-capacitor converter to generate a stepped wave voltage based on the modulated wave voltage output from the feedforward control circuit. By integrating a level providing unit and a level gating unit, it simultaneously reduces the switching frequency relative to the reference signal frequency l / k, thereby reducing switching losses. This facilitates further reducing the switching frequency while maintaining tracking bandwidth, simplifying the circuit structure. Multiplexing the input source of the stepped wave voltage generation circuit reduces linear amplifier losses and input power, further improving the overall circuit efficiency.

An envelope tracking power supply modulator (ETSM) and a wireless communication system are provided. A linear amplifier of the ETSM includes a pre-driver stage circuit and an output stage circuit. The pre-driver stage circuit receives an envelope input and generates a pre-driver output in accordance therewith. The output stage circuit generates an amplifier output of the linear amplifier in accordance with the pre-driver output, the amplifier output being used to set a modulated supply voltage for a power amplifier. A plurality of amplifiers of the output stage circuit includes first and second amplifiers. The first amplifier participates in setting the amplifier output when the power amplifier has a first output power level, and the second amplifier does not participate in setting the amplifier output. The first amplifier and the second amplifier participate in setting the amplifier output when the power amplifier has a second output power level that is different from the first output power level. Broad bandwidth envelope tracking is achieved with reduced quiescent current consumption, and efficiency of the power amplifier is improved.

The invention discloses an ultra-wideband high-harmonic suppression low-noise amplifier circuit, and relates to the technical field of integrated circuits. The circuit comprises an input predistortion low-noise amplifier, a waveform correction unit, an output high-linearity amplifier and a filtering unit which are connected in sequence. Through pre-distortion processing and waveform correction, secondary harmonic components generated by the two stages of inverting amplifiers are equivalent in amplitude, the phase difference is 180 degrees, mutual harmonic cancellation is achieved, high-frequency harmonics are filtered out through the filtering unit, and the problem that in-band secondary harmonics in an ultra-wideband amplifier are difficult to restrain is effectively solved. The amplifier has the advantages of ultra wide band, low noise, high gain, high linearity and high harmonic suppression ratio.

This application discloses a device and method for diagnosing the health status of a vibrating wire sensor, relating to the field of sensor status diagnosis technology. The device includes a main processor, a vibration signal generation module, a linear amplifier circuit, and a saturation amplifier circuit. The vibration signal generation module generates an excitation modulation signal to cause the vibrating wire of the vibrating wire sensor to vibrate. The vibration signal of the vibrating wire sensor is acquired by a signal processing unit. The linear amplifier circuit and the saturation amplifier circuit obtain a linear amplified signal and multiple harmonic signals. The main processor performs time-domain and frequency-domain signal processing on the linear amplified signal and multiple harmonic signals to obtain the signal-to-noise ratio (SNR) value and the duration of each harmonic signal. Based on the time-domain and frequency-domain signals, SNR value, and duration of each harmonic signal in the linear amplified signal and multiple harmonic signals, the health status of the vibrating wire sensor is determined and diagnosed. This application realizes automatic diagnosis of the health status of vibrating wire sensors.

An anti-clogging forced discharge valve for a tubular chain conveyor belongs to agricultural machinery. A C-shaped inner tube is rotatably installed within a fixed, inverted, grooved valve body. A C-shaped outer tube is fixedly fitted onto the outside of the inner tube. A C-shaped air passage is provided between the inner and outer tubes. A flexible air inlet pipe connects to the air passage via an air inlet nozzle. A rotating air nozzle is fitted at the lower part of the outer tube. A servo motor is connected to the rotating air nozzle. A stepper motor drives the inner tube to rotate via a drive gear and a driven gear. The automatic controller consists of a button module, a microcontroller, a servo motor drive module, a stepper motor drive module, a voltage linear amplifier, a D / A converter, and a display screen. The pneumatic transmission system includes a pressure sensor, an air compressor, an air tank, a filter, and an electro-proportional valve. This invention achieves air-assisted forced discharge and air-blowing anti-clogging at the discharge point of the tubular chain conveyor, featuring a reasonable structure, stable discharge, thorough discharge, and resistance to clogging.

An ultrasonic transmitter including a linear amplifier, an output stage, a switch, and a current compensation circuit. The linear amplifier includes first and second amplifier stages. The output stage has an input coupled to an output of the linear amplifier, and presents the transmitter output. The switch is coupled to the output of the linear amplifier. The current compensation circuit has an output coupled at the output of the first amplifier stage. Select circuitry is configured to couple the switch to a bias terminal when the switch is closed, and to couple one or more nodes of the switch to the control terminal of the current compensation circuit when the switch is open. The current compensation circuit generates a compensation current responsive to a sensed non-linear current conducted through the switch when open.

Radar signal processing device (14) comprising: a signal receiver (20) which is configured to receive received data in a polar coordinate system based on a received signal; a data storage device for previous data, designed to store previous correlated data in the polar coordinate system; a polar coordinate correlator (21) designed to generate correlating data by establishing a correlation in the polar coordinate system between the received data and the previous correlated data stored in the data memory of previous data, have been carried out; a trend curve calculation module (22) configured to calculate a trend curve of a distance-direction signal level of the received data in the polar coordinate system; and a target acquisition module (24) which is trained to identify a target based on the signal level of the received data and the trend curve, wherein the polar coordinate correlator (21) modifies the contents of the correlation of the received data based on the target acquisition result of the target acquisition module (24), characterized in that the signal receiver (20) has a log amplifier (26) and a linear amplifier (32) and wherein the signal receiver (20) outputs a log amplifier (26) to the trend curve calculation module (22) and the target acquisition module (24) and outputs a linear amplifier (32) to the polar coordinate correlator (21).

The application discloses a power supply of a broadband envelope tracking power amplifier, comprising a linear amplification circuit, a comparison circuit and a switching amplification circuit; the linear amplification circuit comprises a linear amplifier, a switching amplifier two and an envelope bandwidth processing unit, the input end of the envelope bandwidth processing unit is used for accessing an envelope, the output end of the envelope bandwidth processing unit is connected with the input end of the switching amplifier two, the output end of the switching amplifier two is used for providing a voltage signal to the linear amplifier, and the input end of the linear amplifier is used for accessing the envelope; the output end of the linear amplifier is connected with the input end of the comparison circuit, the output end of the comparison circuit is connected with the input end of the switching amplification circuit, and the output end of the linear amplifier and the output end of the switching amplification circuit are used for providing a power supply signal to the broadband envelope tracking power amplifier. The application changes the design of the linear power supply, improves the efficiency of the linear power supply at the peak envelope, and thus can improve the overall efficiency of the envelope tracking power supply without reducing the performance.

The application belongs to the technical field of laser, and relates to a high-energy ultrashort pulse laser. The laser comprises a mode-locked fiber laser oscillator, a nonlinear amplifier, a stretcher, a pulse selection module, a pre-amplification stage, a main amplification stage and a compressor. In the laser, the cavity dispersion of the mode-locked fiber laser oscillator is negative dispersion which is designed optimally, and the output pulse is injected into the nonlinear amplifier after pre-chirp management, so that a flat wide spectrum can be obtained; the stretcher, the pulse selection module, the pre-amplification stage, the main amplification stage and the compressor are combined to realize further efficient amplification of the injected pulse. The application can adopt a full polarization maintaining structure which has high stability and reliability, and realizes common use of nonlinear amplification and chirped pulse amplification technology, so that the gain narrowing problem in the traditional chirped pulse amplification process can be overcome, the single pulse energy amplification limit of the nonlinear amplification technology can be broken through, and finally the output of high-energy ultrashort laser pulse is realized.

The invention provides a low-voltage AGC (Automatic Gain Control) circuit for an inductance encoder. The device is characterized by comprising a sine channel PreAmp (1), a cosine channel PreAmp (2), a sine channel dB linear amplifier (3), a cosine channel dB linear amplifier (4), a phase difference circuit (5), a vector amplitude synthesis circuit (6), a quantization circuit (7), a digital algorithm circuit (8), a sine channel output buffer (9) and a cosine channel output buffer (10). According to the invention, an innovative full-simulation vector amplitude synthesis circuit is adopted to replace a traditional switched capacitor scheme, so that the technical bottleneck that the signal amplitude cannot be accurately detected in a low-voltage environment is successfully overcome, and the AGC system can stably work and accurately control the output amplitude at the low voltage of less than or equal to 3.3 V. In combination with a wide dynamic range brought by a dB linear amplifier and precise control of a digital intelligent algorithm, the circuit finally provides a complete low-voltage solution with high response speed, ultrahigh amplitude stability and excellent anti-interference capability for an inductance encoder, and is particularly suitable for low-power-consumption scenes such as portable equipment and the Internet of Things.

An envelope tracking system for a power amplifier (PA) is provided, which is configured to track the envelope component of a radio frequency (RF) signal over a wide bandwidth. The system comprises an auxiliary DC-to-DC converter, a main DC-to- DC converter, a fast switcher (in the form of a properly configured DC-to-DC converter) and a linear amplifier (LA). The auxiliary and main DC-to-DC converters are powered by a battery and generate output signals based on corresponding control signals. Each of the LA and the third DC-to-DC converter is fed with the output signal of the auxiliary DC-to-DC converter. The LA generates an output signal based on a modulation signal derived from the envelope component of the RF signal. The fast switcher generates an output signal based on a control signal, the modulation signal and a first error signal being a replica of the LA output signal. The main DC-to-DC converter further uses a second error signal to generate the second output signal, which is a replica of a combination of the output signal from the fast switcher and the LA output signal. The output signals from the main DC-to-DC converter, the fast switcher and the LA are combined into a PA supply at an output port of the ET system. The LA further uses a feedback signal to generate the LA output signal, which is defined based on the PA supply. There is a low-pass filter at the output of each of the DC-to-DC converters and the fast switcher, and each of the LA and the fast switcher is connected to the output port via a common or different AC coupling capacitor.

The embodiment of the utility model relates to an intelligent alternating-current voltage-stabilizing power supply system which is composed of an analog voltage detector, a digital voltage detector, a comparator, a linear amplifier, a switching amplifier, a linear regulator, a switching regulator, a controller and an analog quantity module. And the changes are counteracted by adjusting part of output voltage, so that rapid and accurate adjustment is realized, constant voltage output is provided, and sensitive electronic equipment is protected from being influenced by fluctuation of a power grid.

This invention discloses a power modulator and a high-speed envelope tracker based on multi-band current injection. The power modulator includes a linear amplifier, a first current detection circuit, a low-speed DC-DC converter, a second current detection circuit, and a high-speed DC-DC converter. The linear amplifier clamps the voltage at the power supply terminal to track the envelope signal; the low-speed DC-DC converter provides the DC and low-frequency components of the current required by the power amplifier; and the high-speed DC-DC converter provides the mid-to-high frequency transient components of the current required by the power amplifier, so that the real-time output current of the linear amplifier approaches zero. This invention constructs a low-speed, high-speed, and linear integrated current supply system, achieving seamless coordination of multiple power supplies. This brings the overall system efficiency close to the theoretical limit of switching power supplies, solving the problems of excessive linear amplifier load, limited overall system performance, and the contradiction between dynamic response accuracy and power consumption in existing architectures.

The present application belongs to the technical field of integrated circuits, and particularly relates to a digital control envelope tracking power modulator. The envelope tracking power modulator comprises a digital control current source array, a switching amplifier, a digital-to-analog converter, and an off-chip power inductor. One end of the power inductor is connected to the output of the digital control current source array and the feedback input end of the switching amplifier, and the other end is connected to the output of the switching amplifier. The output of the digital-to-analog converter is connected to the reference voltage input end of the switching amplifier. The present application provides high-frequency current to the load through the digital control current source array, provides low-frequency current to the load through the switching amplifier, and controls the switching amplifier through the digital-to-analog converter. The present application removes the linear amplifier in the traditional hybrid architecture envelope tracking power modulator, and relies on the digital control current source array to generate the high-bandwidth envelope power at a very high speed to power the power amplifier, thereby improving the overall efficiency of the system.

A multilevel linear amplifier with non-linear components, MLINC (1), for a radio frequency transmitter, the MLINC (1) comprising a first outphasing amplifier (2) adapted to receive a first set of input signals (S11, S12) and providing a first intermediate signal (S1) with a stepped envelope depending on a controlled portion (θc1) of a phase modulation in the first set of input signals (S11, S12); a second outphasing amplifier (3) adapted to receive a second set of input signals (S21, S22) and to provide a second intermediate signal (S2) with a stepped envelope depending on a controlled portion (0c2) of a phase modulation in the second set of input signals (S21, S22); and a combiner (6) adapted to combine the first and second intermediate signals (S2) into an output signal (Sout) having an envelope linearized due to a phase symmetry of the first and second intermediate signals (S1, S2).

A linear amplifier with correction circuit is provided. According to one aspect, a linear amplifier includes a high current output stage configured to produce an output voltage and current to deliver power to a load. An output correction circuit receives the output voltage from the high current output stage and produces an error current proportional to a voltage drop across the high current output stage. An input stage receives at least one input and produces a first input current. A current-to-voltage resistor receives produces a first voltage that depends on the first input current and the error current. A first unity gain voltage buffer receives the first voltage from the current-to-voltage resistor and outputs a second voltage that is input to the high current output stage. The first voltage is compensated by the error current to reduce the voltage drop across the high current output stage.

The present invention provides a linear laser driving circuit, comprising a primary linear amplifier, a linear branch, and a non-linear branch. The non-linear branch is used for receiving a differential voltage signal output by the primary linear amplifier, and outputting a non-linear compensation signal to compensate for a non-linear effect of a laser, and an output terminal of the non-linear branch is connected to an output terminal of the linear branch, such that the compensation signal output by the non-linear branch and a driving signal output by the linear branch are superposed, to form an output electrical signal. In this way, the non-linear effect of the laser can be compensated for, the linearity of the optical signal output by the laser can be enhanced, and the performance of an optical eye pattern can be optimized.