27 results about "Pulse front" patented technology

The application discloses an energy-saving control method of a CSR high-frequency PWM rectifier circuit. According to the value change of each line voltage of three-phase alternating current in a rectifier circuit and the characteristic that the rectifier circuit works at a high frequency, the two pulse wave edges of two phases of the three-phase alternating current are overlapped. The overlapping time of the overlapping of the two pulse wave edges is equal to the sum of the turn-on time and the turn-off time of a switching tube, so that the front edge or the rear edge of a pulse of a switching signal is in a soft switching state or in a cut-off low voltage state, thereby reducing the switching process loss of the switching tube. The application provides the energy-saving control method of the CSR high-frequency PWM rectifier circuit, which can reduce switching loss, reduce cost, save energy, prolong service life and is safe and reliable.

The invention relates to the technical field of pulse power, in particular to a time sequence synchronous trigger control method for a multi-path pulse switch of an LTD module, which comprises the following steps: S01, measuring the inherent delay time of each discharge branch in the LTD module from trigger signal input to gas switch conduction; and S02, inputting the measured inherent delay time value of each branch into a pulse time sequence controller as a compensation parameter, and setting the delay time of each output channel of the pulse time sequence controller. Through system calibration and programmable delay compensation of the pulse time sequence controller, in combination with high-precision time sequence control of the FPGA, the multi-way switch conduction time deviation can be controlled at the nanosecond level, the energy synthesis efficiency is greatly improved, inductance isolation transmission is achieved through magnetic ring coupling, traditional resistance isolation is replaced, pulse leading edge distortion is avoided, and the energy synthesis efficiency is improved. And meanwhile, high-voltage isolation safety is guaranteed, and trigger signal transmission quality is stable.

The application discloses a partial discharge signal detection and segmentation method and system based on a wavelet Bayesian threshold, and the method comprises the following steps: through the combination of a shift-invariant wavelet transform and a Bayesian adaptive threshold, adaptive noise reduction is performed on a collected first partial discharge signal to suppress white noise and electromagnetic interference and avoid a pseudo Gibbs effect; then, a cascaded fourth-order zero-phase Butterworth high-pass filter is used to eliminate a direct current component and low-frequency clutter and completely retain pulse front characteristics; then, square amplitude enhancement and adaptive threshold screening are sequentially performed on the filtered signal to highlight effective pulses and eliminate slight interference; finally, through sliding window energy analysis, the starting position of a pulse wave front and the ending position of a pulse are accurately identified, and a reserved expansion sampling interval is combined to automatically intercept a complete partial discharge waveform, so that the automatic segmentation of a partial discharge event can be realized without relying on manual operation, and the recognition and positioning accuracy of the partial discharge signal is improved.

The invention relates to a SiC DSRD structure for optimizing pulse output characteristics and a preparation method, the structure comprises a cathode, an N + substrate, an N-base region, a P-base region, a P + region and an anode from bottom to top, and the main body structure material is a 4H-SiC material; one side, close to the N + substrate, in the N-base region is provided with at least one minority carrier lifetime attenuation suspension island layer, the top of the uppermost minority carrier lifetime attenuation suspension island layer does not exceed the transverse center line position of the N-base region, the minority carrier lifetime attenuation suspension island layers are arranged at intervals, one layer comprises at least one minority carrier lifetime attenuation suspension island, and the minority carrier lifetime attenuation suspension islands are distributed at equal thickness at intervals; the minority carrier lifetime attenuation suspension island is formed by injecting heavy metal ions into the N-base region; the problem of carrier distribution is solved from the source, the turn-off process of the SiC DSRD is quicker, the output voltage peak value is higher, the pulse leading edge is quicker, the carrier mobility is met, and meanwhile it is guaranteed that breakdown voltage is not degraded.

The invention relates to the technical field of nuclear radiation detection, in particular to a quasi-hemispherical CdZnTe detector reading circuit and a working method thereof. The reading circuit comprises a pre-amplification circuit, a clamping protection circuit, a pole-zero cancellation circuit, an operational amplification circuit, a differentiating circuit, an adjustable gain amplification circuit, a high-precision operational amplification circuit, a first-order S-K filter circuit and an impedance matching circuit which are connected in sequence. Wherein the pole zero cancellation circuit is used for offsetting an exponential decay pole introduced by the pre-amplification circuit; the differentiating circuit is used for compressing the signal pulse width; the adjustable gain amplification circuit is connected with the DAC voltage feedback circuit and is used for realizing gain adjustability; the reading circuit provided by the invention is connected with the CdZnTe detector, a charge signal output by the CdZnTe detector is processed by the reading circuit, and the energy resolution of the CdZnTe detector is improved to be less than 1% (at) 662 keV by extremely reducing noise, inhibiting accumulation, stabilizing a base line and keeping pulse front edge integrity.

The invention provides a double-grating monochromator, a double-grating monochromatization method, a double-grating monochromatization device, a medium and equipment, a first optical system comprises a first plane line-distance-variable grating and an incident plane mirror, a monochromatic light slit is arranged at the image plane position of the first optical system, a second optical system comprises an emergent plane mirror and a second plane line-distance-variable grating, and a monochromatic light slit is arranged at the image plane position of the second optical system. The second plane variable-line-distance grating and the first plane variable-line-distance grating are matched in parameter and are symmetrically arranged, so that the forward inclination of the pulse introduced by the first plane variable-line-distance grating is counteracted by the opposite dispersion effect generated by the second plane variable-line-distance grating; wherein the incident plane mirror and the emergent plane mirror respectively adjust the angle of an incident light beam at a fixed spatial distance in an off-axis rotation mode, and the angle adjustment and the scanning angle of the corresponding grating are cooperatively changed so as to maintain a constant grating equation relationship. And the output pulse width is remarkably compressed, and collaborative optimization of high energy resolution and optimal pulse output is realized.

The application relates to the technical field of lighting control, and discloses a night running sensing energy-saving lighting control system based on three-dimensional comprehensive positioning, which comprises a cloud server for establishing an association mapping table containing a preferred light color parameter, a main control computer for positioning a physical rod interval according to a face image, generating a first judgment instruction, and issuing a linkage preparation signal to complete electrical preheating, a millimeter wave radar for calculating a transient motion speed value and outputting an auxiliary judgment trigger pulse, a front-end single-chip microcomputer for responding to the auxiliary judgment trigger pulse to obtain actual space coordinates, combining the transient motion speed value to generate a theoretical motion track for space distance difference comparison, and confirming a linkage output instruction. A sub-controller receives the confirmed linkage output instruction, combines a background environment illuminance value and the preferred light color parameter, and outputs a digital dimming signal to an RGB+W lamp for light emission adjustment. The application combines macro interval positioning and micro track verification to realize precise follow-up lighting, and dynamically adjusts output according to ambient light to reduce system energy consumption.

The application discloses a method for generating an IRIG-B direct current code synchronous second pulse front edge based on a single-chip microcomputer. max The application can realize the same second pulse 1PPS precision by using a domestic single-chip microcomputer, does not need to use a separate FPGA, and greatly reduces the cost. When the first N max code symbols are received, a timer TIMER2 is enabled to start counting. When the counting value of the timer TIMER2 reaches a maximum value, an overflow interrupt is entered, and the timer TIMER3 is configured as a single pulse mode and enabled after the timer TIMER2 enters the overflow interrupt. After the timer TIMER3 is triggered, a signal second pulse 1PPS output by the timer TIMER3 is synchronized with the rising edge of the frame start code symbol of the next frame after a fixed delay Δ and a programmable delay Delay.

The invention provides an optical fiber laser pulse string generation and amplification integrated module. The module sequentially comprises a pulse seed unit, a pulse frequency-selecting shaping unit and a pulse string amplification unit from an input end to an output end along a signal transmission light path, wherein the pulse seed unit is used for generating a MHz-magnitude high-repetition-frequency original pulse and pre-amplifying the MHz-magnitude high-repetition-frequency original pulse to obtain a first pulse string; the pulse frequency selection shaping unit is used for performing pulse frequency pickup and stepped intensity modulation processing on the first pulse string to obtain a second pulse string; the pulse string amplification unit is used for performing main amplification processing on the second pulse string so as to output a third pulse string with consistent sub-pulse intensity; the stable pulse source is provided through the pulse seed unit, meanwhile, by means of step-shaped modulation of the frequency selection shaping unit, reverse compensation of'front-strong and rear-weak 'of sub-pulses and flexible regulation and control of pulse parameters during main amplification are achieved at a stroke, then efficient power increasing of the pulse string amplification unit is guaranteed, and finally stable output of the uniform-strength high-repetition-frequency pulse string is achieved.

This invention discloses an extreme ultraviolet (EUV) time-delay compensated monochromator, processing method, and electronic device, relating to the field of EUV light processing technology. The monochromator includes: a first optical structure comprising a first planar blazed grating and a first ring mirror, wherein the first planar blazed grating is used to split and diffract the incident light, and the first ring mirror is used to focus and reflect the beam; a second optical structure comprising a second planar blazed grating and a second ring mirror, wherein the second planar blazed grating is used to compensate for the pulse forward tilt introduced by the first planar blazed grating, and the second ring mirror is used to focus and reflect the beam; and a slit plane, disposed between the first and second optical structures to ensure symmetry, for filtering the beam corresponding to the desired wavelength. This invention solves the technical problem in related technologies where monochromators cannot simultaneously achieve performance indicators such as energy transfer efficiency, spectral resolution, and pulse forward tilt compensation.

This invention discloses a detection system and method for cable fault location, relating to the field of cable fault location technology. It acquires nanosecond-level pulse propagation front-end change trajectory data and echo peak width change data to establish a high-frequency attenuation continuous-time distribution map; extracts pulse broadening growth segments and performs front-end compression control to form a compressed pulse front-end shape; rearranges the peak time position to separate low-amplitude reflection signals; tracks its amplitude trajectory and identifies local insulation anomaly segments by comparing with the peak width evolution trajectory; establishes a distance-back mapping and corrects the echo time coordinates to obtain the fault location interval. This invention improves the ability to identify early insulation defects by constructing a continuous-time distribution map and compressing pulse broadening segments, shortening the peak diffusion time, and separating low-amplitude reflection signals within the peak; simultaneously, it improves fault location accuracy and stability by establishing a distance-back mapping relationship and dynamically correcting the echo time coordinates.

The invention relates to a high-altitude electromagnetic pulse simulation device, in particular to an all-solid-state high-altitude electromagnetic pulse standard source based on a multi-tube series avalanche tube Marx circuit. The technical problem that due to inherent parasitic inductance existing in a discharge loop of an existing multi-tube series avalanche tube Marx circuit, output pulses cannot meet the requirements of high amplitude, fast leading edge and low jitter at the same time is solved. The standard source comprises a direct current charging power supply, a trigger unit, an avalanche transistor Marx circuit, a coaxial output cable, a radiating antenna and a waveform modulation structure. A multi-tube series avalanche tube Marx circuit topological structure is improved, an additional waveform modulation structure is introduced, the rising time of output pulses is effectively shortened, the technical problem that the pulse leading edge of a multi-tube series circuit is broadened due to parasitic inductance is solved, and the output pulse of the multi-tube series circuit is increased. And the high-altitude electromagnetic pulse waveform which is high in amplitude, fast in leading edge and low in jitter and meets the requirements of the international electrician committee standard can be generated.

The application discloses a pulse electronic switch based on an enhanced driving and voltage equalization network, which comprises an H-bridge driving circuit, the H-bridge driving circuit is connected with primary windings of a plurality of magnetic isolation modules; the secondary windings of the magnetic isolation modules are respectively connected with corresponding driving waveform optimization circuits; the driving waveform optimization circuits are connected with gates of series power MOSFETs; a voltage equalization network is connected in parallel between the drains and the sources of the series power MOSFETs; the steps of the design method are as follows: step one, the control chip driving signal is amplified to 200V / 12A through the H-bridge power circuit; step two, the isolation driving is realized by using a through primary winding and a plurality of secondary windings; step three, the deviation of the pulse front edge and the pulse trailing edge of the gate driving signal is controlled to be within 10ns by using an analog compensation technology in the post-stage driving waveform optimization circuit; step four, the voltage equalization network composed of the voltage equalization resistors Rm, the RCD buffer circuit and the transient suppression diode is connected in parallel on the series switch link, the dynamic voltage peak of the switch is absorbed, the dynamic and static voltage equalization of the switch is realized, and the dynamic and static voltage unequalization problem can be effectively solved.

The invention discloses a nuclear signal-noise discrimination method based on pulse width, relates to the technical field of discrimination of flicker signals and photomultiplier dark noise, and can effectively distinguish photomultiplier dark noise signals and flicker signals and discriminate electronic noise at the same time. The method comprises the following steps: obtaining a plurality of pulse signals which are automatically triggered without a threshold value; carrying out peak searching on the signal, and judging the time t0 corresponding to a peak value; carrying out leading edge timing on the peak value t0 of the pulse signal to obtain the time t1 of the pulse leading edge; carrying out trailing edge timing on the peak value t0 of the pulse signal, and setting a time threshold value of the trailing edge timing; judging the data of the trailing edge timing, judging whether a plurality of peak superposition events exist in the trailing edge timing, and determining the time t2 of the pulse trailing edge; performing pulse width calculation according to the difference between the leading edge timing t1 and the trailing edge timing t2 judged from the peak time t0; and judging the types of PMT dark noise and nuclear signals according to the calculated pulse width.

The application provides a pressure-bearing equipment thermal insulation layer undismounting type pulse eddy current thickness measurement system and method, and relates to the technical field of nondestructive testing. The system comprises a probe module and a control analysis module. The probe module emits a detection pulse to the pressure-bearing equipment and receives a secondary magnetic field signal. The control analysis module extracts a quantitative space fluctuation parameter of the decay slope at the initial stage of the off period of the secondary magnetic field signal in the preceding detection period, feeds forward and scales the set pulse width of the current detection period according to the parameter; extracts the late residual amplitude at the tail end of the preceding detection period, maps the decay slope at the initial stage of the off period to a space penetration compensation coefficient, and dynamically sets the source end excitation peak value of the reverse demagnetization level by using the product of the two; and injects the reverse demagnetization level with the excitation peak value before applying the current detection pulse. The application can dynamically compensate the energy penetration dissipation caused by the space fluctuation and block the residual eddy current head-tail aliasing interference, and improve the accuracy of the equipment wall thickness inversion calculation.

The application relates to a single-pulse forward-looking scanning imaging focus compensation method, and aims to solve the problem of imaging defocus caused by the angle measurement deviation of a nonlinear angle discrimination curve in the single-pulse angle measurement process of an existing single-pulse forward-looking scanning imaging result. The process comprises the following steps: 1, obtaining the pulse compression echo results of sum and difference channels, namely one-dimensional range images; 2, taking N pulse compression echoes of the center scanning angle of the sum channel, calculating the normalized amplitude variance, selecting a distance unit with the maximum amplitude of the one-dimensional range image and a normalized amplitude variance less than 0.12; 3, obtaining a time-frequency diagram, calculating an azimuth angle and recording the corresponding scanning angle; 4, in the distance unit, selecting each scanning angle respectively, repeating step 3 to obtain a curve, and fitting the curve with a polynomial; 5, obtaining a focused compensated image by using the corrected angle single-pulse projection. The application is used in the field of radar imaging.

The full solid-state parameter adjustable energy recovery excitation source comprises a charging circuit, a main power circuit and a load circuit. The coil current parameters can be flexibly regulated by the working time sequence of each stage switch. The number of discharge modules contained in the full solid-state parameter adjustable energy recovery excitation source is flexibly adjustable, the structure is simple and reliable, the corresponding module number can be matched according to the application requirement, and the cost is reduced. The full solid-state parameter adjustable energy recovery excitation source can feed back the load energy to each stage capacitor through the front-end commutation switch and the energy feedback diode, so that the system energy utilization efficiency is improved. The full solid-state parameter adjustable energy recovery excitation source can break through the limitation that the traditional topology can only adjust the pulse front edge or a single parameter by controlling the input time sequence of each module, and fine and multi-dimensional control of the whole pulse waveform is realized.

The application provides a nanosecond front edge high-voltage pulse trigger power supply, which comprises a power frequency voltage-boosting rectification unit, a primary discharge unit, a pulse transformer and a secondary high-voltage unit connected in sequence; the input end of the power frequency voltage-boosting rectification unit is connected with an external power supply, the output end of the power frequency voltage-boosting rectification unit is connected with the input end of the primary discharge unit, and the primary discharge unit is used for receiving direct-current high voltage output by the power frequency voltage-boosting rectification unit and storing energy; the output end of the primary discharge unit is connected with the input end of the pulse transformer, the output end of the pulse transformer is connected with the input end of the secondary high-voltage unit, the pulse transformer is used for generating a microsecond high-voltage pulse when the primary discharge unit discharges, and the secondary high-voltage unit receives and utilizes the microsecond high-voltage pulse to further generate a nanosecond high-voltage pulse, so that the nanosecond front edge high-voltage trigger power supply with the advantages of high output voltage, fast pulse front edge, repeatable frequency operation and convenient output polarity adjustment is realized.

A method for processing an analog signal comprising: - Detection of the analog signal, this detection including the generation of a first time reference signal, in particular a reference pulse, provided that an amplitude of the analog signal exceeds a predefined threshold; - Generation of a series of time windows, on several channels (V1, V2, V3, V4), from the first time reference signal, the time windows of the series being successive and / or of different durations; - Generation of signal shapes, on each of the channels (V1, V2, V3, V4), by multiplying each of these time windows by the analog signal as is or converted into a baseband signal; and, - A step of generating the parallel output signals. Figure for the abstract: Fig. 1

The application belongs to the technical field of radio frequency power amplifier overheat protection, in particular to a self-adaptive temperature sensing power amplifier tube protection method and system, wherein the method comprises: establishing a nonlinear time-varying thermal model of the power amplifier tube; before transmitting a pulse, calculating a heat consumption function of heat consumption changing with time according to the pulse input power and the pre-labeled power-heat consumption relationship; collecting the working temperature of the power amplifier tube in real time, and comparing it with the model predicted temperature to obtain a temperature error; correcting the thermal model parameters and the temperature rise function in real time according to the error through an adaptive filter; generating static bias compensation and dynamic baseband pre-distortion signals based on the corrected temperature rise function, and pre-distorting and compensating the input signal. The application overcomes the defects of large error of traditional linear thermal model and open-loop compensation without feedback, realizes high-precision and self-adaptive temperature protection and linearization, and is particularly suitable for magnetic resonance imaging and communication systems.

This invention relates to the field of laser communication technology and discloses a high-precision ranging method and system based on spaceborne laser communication. The method includes: when two terminals send communication signals, aligning the falling edge of the last bit of the frame synchronization header of the data frame with the leading edge of the local satellite clock's integer second pulse as a ranging identifier; modulating the baseband signal containing the ranging identifier into an optical signal and transmitting it into free space; receiving the downlink optical signal from the cooperating terminal and demodulating it into a baseband signal; performing multi-level time delay calibration to obtain the time delay parameters of the system's transceiver channel, and using a code synchronization loop in the communication link to recover the symbol clock phase; and calculating the distance and clock difference between the two terminals based on the arrival time of the ranging identifier and the time delay parameters using a bidirectional one-way ranging model. The above method integrates laser communication and ranging, ensuring high ranging accuracy while saving hardware resources, and is suitable for inter-satellite and satellite-to-ground high-precision laser ranging and high-speed data transmission integration scenarios.

The invention discloses a method for adjusting the output front edge of a multi-primary pulse modulator, and the method comprises the steps: controlling the conduction time sequence of each primary winding of the multi-primary pulse modulator, and adjusting the conduction time of each primary winding in real time, thereby adjusting the output pulse front edge through the influence of the conduction of the primary windings on the loop impedance. According to the scheme, software is adopted to control the conduction time sequence of the primary windings, that is, the conduction time of each group of primary windings can be adjusted through the software, the opening time of each path is adjusted in real time, loop impedance is affected through the method, and then the leading edge is affected to achieve the adjustment purpose.

The invention provides a nanosecond leading edge high-voltage pulse trigger power supply. The nanosecond leading edge high-voltage pulse trigger power supply comprises a power frequency boost rectification unit, a primary discharge unit, a pulse transformer and a secondary high-voltage unit which are connected in sequence, the input end of the power frequency boost rectification unit is connected with an external power supply, the output end of the power frequency boost rectification unit is connected with the input end of the primary discharge unit, and the primary discharge unit is used for receiving direct-current high voltage output by the power frequency boost rectification unit and storing energy; the output end of the primary discharge unit is connected with the input end of the pulse transformer, the output end of the pulse transformer is connected with the input end of the secondary high-voltage unit, and the pulse transformer is used for sensing and generating microsecond high-voltage pulses when the primary discharge unit discharges; and the secondary high-voltage unit receives and utilizes the microsecond high-voltage pulse to further generate a nanosecond high-voltage pulse, so that the nanosecond front-edge high-voltage trigger power supply which outputs high voltage, fast pulse front edge and repeatable frequency operation and outputs a convenient and adjustable polarity is realized.

The application provides a high-energy GHz femtosecond pulse train laser amplification system and an amplification method, and solves the technical problem of pulse narrowing effect caused by energy saturation effect in a fiber amplifier during high-energy pulse train amplification; after the pulse train is modulated, the amplitude of the front edge of the modulated pulse is much lower than the back edge, so the pulse train waveform will first experience the change process from exponential rise to gentle rise, then to relatively constant amplitude, and finally gradually evolve into the process of high front and low back and experience pulse narrowing, instead of pulse narrowing effect occurring at the beginning. Therefore, the pulse train modulation delays the occurrence of the pulse narrowing process, effectively suppresses the pulse narrowing effect, reduces the pulse peak power, and thus effectively avoids the accumulation of more nonlinear phase and fiber damage.

This invention relates to a method for generating terahertz radiation and a terahertz radiation source. In the method according to the invention, a pump beam (14) emitted from a pump beam source is incident on a block of a semiconductor nonlinear optical medium (10) having a planar parallel front boundary surface and a rear boundary surface (11, 12), wherein the pump beam (14) is decomposed into a set of sub-pump beams upon refraction on a periodic structure (13) formed by pairs of planar surfaces in the front boundary surface of the block. The sub-pump beams travel in angular directions required to satisfy velocity matching conditions. The envelope of the pump pulse leading edge segment propagating in the sub-pump beam segment propagates in a direction perpendicular to the rear boundary surface (12) (i.e., the exit surface of the optical medium (10)) at the propagation speed of terahertz radiation, and generates terahertz radiation in the semiconductor optical medium (10) by means of optical rectification to satisfy the velocity matching condition; here, is the group velocity of the pump beam (14), is the phase velocity of the generated terahertz radiation, and y is the angle between the envelope of the pulse leading edge of the pump beam (14) and the phase leading edge.

The invention provides an intermediate infrared femtosecond laser pulse spectrum measurement device. The intermediate infrared femtosecond laser pulse spectrum measurement device comprises a beam splitter, a nonlinear frequency up-converter, a quasi-monochromatic pulse generator, a sampler, a first spectrograph, a delay regulator, a focuser, a sum frequency device and a second spectrograph, after a laser pulse to be measured is split by the beam splitter, a first laser beam sequentially passes through the nonlinear frequency up-converter and the quasi-monochromatic pulse generator to form a quasi-monochromatic pulse; the quasi-monochromatic pulse is extracted and sliced by the sampler and enters a first spectrograph for calibrating the central wavelength; after the second laser beam passes through the delay regulator, the second laser beam and the quasi-monochromatic pulse pass through the focuser to generate nonlinear sum frequency in the sum frequency device, and a sum frequency pulse is generated; and the sum frequency pulse signal is received by the second spectrograph to obtain a copy spectrum of a near-infrared domain, and an original spectrum of the intermediate infrared femtosecond pulse to be detected is given after data processing. The device has the advantages of high measurement precision, high signal-to-noise ratio, real-time performance and more compactness.

The application discloses a pulse stable output control method and system of an ns-level high-repetition-frequency fast pulse power supply, and relates to the technical field of automatic control. The system is composed of a plurality of function modules, and comprises: an adaptive absorption module which acquires power supply parameters, including load impedance and switch tube parasitic parameters, through real-time sampling, and dynamically optimizes R, C parameters of an RCD absorption circuit and an active clamp circuit based on the power supply parameters; a feedforward prediction module which extracts derived state information according to the power supply parameters, acquires load current feedforward and resonant loop state based on the derived state information, models based on the load current feedforward and the resonant loop state, and predicts a switch tube drain-source voltage valley time; and a multi-section variable impedance transmission module which adopts a three-section variable impedance structure, performs wide-band impedance matching based on the optimized R, C parameters of the RCD absorption circuit and the active clamp circuit, suppresses pulse front edge reflection distortion, and outputs a distortion-free pulse signal.