16 results about "Pulse front" patented technology

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.

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 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.

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 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.