Picosecond high-voltage pulse generator with dynamic performance

Abstract

The invention discloses a picosecond high-voltage pulse generator with dynamic performance, and belongs to the field of high-voltage pulses. An STM32 main control chip and a magnetic reed relay are adopted to design an eight-channel high-voltage control circuit, and the eight-channel high-voltage control circuit is fused with a picosecond high-voltage pulse generator, so that V-shaped high-voltage pulse output with adjustable amplitude, pulse width and rising edge slope is realized. According to the generator, through a parallel control strategy, the pulse amplitude can be accurately adjusted within the range of-1.212 kV to-1.887 kV, the full width at half maximum is stabilized at 245-327 ps, and the slope of the rising edge is 3.61-10.01 V / ps. According to the multi-channel synchronous output pulse generator, the high-voltage isolation characteristic of the magnetic reed relay is utilized, accurate time sequence control of the STM32 is combined, inter-channel crosstalk and time sequence jitter are effectively reduced, and the problem of performance degradation of a traditional pulse generator during multi-channel synchronous output is solved. The device is suitable for high-precision high-voltage pulse application, and has the advantages of dynamic adjustability, high stability and multi-channel synchronous output.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-voltage pulse, in particular to a picosecond high-voltage pulse generator with dynamic performance. BACKGROUND

[0002] In the field of high-voltage pulse technology, the traditional pulse generator generally has the problem of fixed output parameters and insufficient dynamic adjustment capability. The existing technology mostly adopts fixed structure Marx circuit or solid-state switch scheme, which can realize picosecond pulse output, but it is difficult to dynamically adjust the key parameters such as pulse amplitude and pulse width during operation. Especially in the scene of multi-channel synchronous output, time sequence deviation and signal crosstalk are easily generated between channels, which seriously affects the consistency of pulse waveform.

[0003] The performance optimization of picosecond high-voltage pulse generator has always been a research difficulty in pulse power technology. The current mainstream scheme compresses the pulse width through cascaded LC filter network, but the output pulse rising slope adjustment range is limited due to the fixed parameters of inductance and capacitance elements. In addition, the mechanical relay has slow switching speed and short service life, and the semiconductor switch also faces the defect of insufficient high-voltage isolation, which makes it difficult for the system to meet the dual requirements of fast response and high-voltage resistance.

[0004] In frontier applications such as ultrafast diagnosis and laser driving, higher standards are put forward for the dynamic performance of the pulse generator. For example, inertial confinement fusion experiments require that the pulse amplitude can be accurately adjusted in the range of -1kV to -2kV, while maintaining a stable output with a half-width of <300ps. Due to the lack of intelligent real-time control mechanism, the existing technology often needs to adjust the parameters by physically replacing the elements, which seriously restricts the experimental efficiency. Therefore, developing a picosecond high-voltage pulse generator with wide-range dynamic adjustment capability and multi-channel synchronous output has become a key direction to break through the current technical bottleneck. SUMMARY

[0005] To solve the problems in the background art, the present application provides a picosecond high-voltage pulse generator with dynamic performance, which builds a multi-channel control system through a master control chip and a magnetic reed relay, combines a Marx circuit and an LC high-pass filter, and realizes dynamic adjustment of pulse amplitude, half-width and rising slope, meeting the diversified needs of ultrafast diagnostic equipment for high-voltage pulses.

[0006] The technical scheme of the present application is as follows:

[0007] The picosecond high-voltage pulse generator comprises a Marx pulse generation module, an LC filter shaping module and an STM32 control module.

[0008] The Marx circuit adopts a 3-stage synchronous trigger structure, each stage containing an avalanche transistor and an avalanche diode parallel component.

[0009] Preferably, the direct current power supply is 3.74kV, the trigger signal V2-V4 has an amplitude of 5.8kV and a frequency of 10Hz.

[0010] Preferably, the filter resistors R2-R4 in the Marx circuit are 100Ω, the resistors R5-R 10 150kΩ, the load R is 200Ω, the filter capacitors C1-C3 are 10μF, and the charging capacitors C4-C6 are 2nF. The capacitors C7-C9 are 2pf.

[0011] The LC high-pass filter adopts a multi-stage cascade structure, and the inductors L1-L3 are 725nH, 10nH and 10nH respectively.

[0012] The control module adopts an STM32H33VG master control chip and a magnetic reed relay to build an 8-channel switching system.

[0013] Preferably, the resistors R 101 / R 201 / R 301 port control triode drive relay to realize the dynamic combination of capacitors C A1 / C A2 , C B1 / C B2 , C C1 / C C2 .

[0014] Preferably, the capacitors C A1 , C B1 , C C1 , C A2 , C B2 and C C2 are 1pf and 2pf.

[0015] Compared with the prior art, the present application has the following advantages:

[0016] 1. In the prior art, the output performance of the picosecond high-voltage pulse is often fixed and difficult to adjust flexibly according to actual needs. The present application designs an 8-channel control circuit by using an STM32 master control chip and a magnetic reed relay, and integrates it with a picosecond high-voltage pulse generator. By sending control signals in parallel, the dynamic performance V-type picosecond high-voltage pulse output with an amplitude of-1.212-1.887kV, a half-width of 245-327ps and a rising slope of 3.61-10.01V / ps can be realized, meeting the diversified needs in different scenarios.

[0017] 2. By combining the 3-stage LC high-pass filter technology, the capacitors with different capacitance values are selected by the control circuit to change the filter cutoff frequency, and then the time width and rising edge characteristics of the pulse are adjusted. Compared with the traditional fixed parameter filter circuit, more pulse compression scenarios can be adapted.

[0018] 3. Utilize the high-speed processing capability of the STM32 chip, realize one-key switching and real-time monitoring of pulse parameters through program preset control logic, avoid manual adjustment error, and improve control precision and efficiency.

[0019] 4. A magnetic reed relay is used to build a high-voltage switch array, a strong electric pulse path is controlled through a weak electric signal, high-voltage isolation and rapid switching are realized, compared with a traditional mechanical switch or a transistor switch, the response time is shorter, and the reliability is higher. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a circuit schematic of a picosecond high-voltage pulse generator with dynamic performance of the application;

[0021] Figure 2 is an output pulse curve diagram of different channels of a picosecond high-voltage pulse generator with dynamic performance of the application;

[0022] Figure 3 is an output pulse amplitude diagram of different channels of a picosecond high-voltage pulse generator with dynamic performance of the application;

[0023] Figure 4 is an output pulse half-height width diagram of different channels of a picosecond high-voltage pulse generator with dynamic performance of the application;

[0024] Figure 5 is an output pulse rising edge slope diagram of different channels of a picosecond high-voltage pulse generator with dynamic performance of the application. DETAILED DESCRIPTION

[0025] In order to have a clearer understanding of the technical features, objectives and effects of the application, the accompanying drawings will be described below. Figure 1 to Figure 5 The application will be described in detail.

[0026] Figure 1 is a circuit schematic of a picosecond high-voltage pulse generator of the application.

[0027] Specifically, the picosecond high-voltage pulse generator is designed by using a 3-stage Marx circuit of series-parallel avalanche triodes, an LC high-pass filter pulse shaping circuit and a control circuit.

[0028] Specifically, the output of the Marx circuit is the input of the pulse shaping circuit, the A, B and C ends of the control circuit are respectively connected to the three-stage capacitor selection ends of the pulse shaping circuit, a controllable LC high-pass filter is formed, and the corresponding output pulses pulse 1-pulse 8 are obtained by gradually controlling the capacitance increase and decrease of the C end-B end-A end in turn.

[0029] Further, in the Marx circuit, each stage circuit is composed of a power supply, an avalanche transistor, an avalanche diode and a trigger circuit. Taking the first stage Marx circuit as an example, in the working process, first, the power supply VI charges the capacitor C4, and when the voltage across the capacitor C4 reaches VI, the charging is completed, V2 sends a trigger signal to make the transistor Q1 conduct, and the avalanche transistors Q2-Q8 are sequentially broken down by high voltage avalanche; then, after the avalanche transistors Q1-Q8 are all turned on, the left end of the capacitor C4 is short-circuited to the ground, and the relative potential is pulled to 0V. Due to the non-rupturable nature of the capacitor, the voltage of the lower plate of C4 becomes -VI; finally, by analogy, the three-stage Marx circuit outputs a nanosecond high-voltage pulse, and inputs an LC high-pass filter with a control function. By selecting the capacitor through the control circuit, a dynamic picosecond high-voltage pulse with multiple performances is realized.

[0030] Further, taking the A group channel as an example, in the working process, if channel A1 is selected, first, the STM32 sends a high-level signal to the R 101 port to make the transistor Q A cut off, and there is no potential difference across the relay; then, the power supply VEE supplies power to the relay RL A through the relay RL A1 , the relay RL A1 is closed, and the relay RL A2 is opened; finally, since the RL A1 is turned on, the capacitor CA1 is connected to the picosecond high-voltage pulse generator; if channel A2 is selected, first, the STM32 sends a low-level signal to the R 101 port to make the transistor Q A conduct, and the power supply VCC supplies power to the relay RL A ; then, the power supply VEE supplies power to the relay RL A through the relay RL A2 , the relay RL A2 is closed, and the relay RL A1 is opened; finally, since the RL A2 is turned on, the capacitor C A2 is connected to the picosecond high-voltage pulse generator.

[0031] Further, when the STM32 master control chip synchronously sends control signals to the R 101 , R 201 and R 301 ports of the three groups of channels, by controlling the devices finally connected to the picosecond high-voltage pulse generator in each channel, the gating of different channels can be realized. The specific channel gating condition and the related output identifier are shown in Table 1.

[0032] Table 1

[0033] Figure 2is the output pulse amplitude graph of different channels of the picosecond high-voltage pulse generator of the application.

[0034] Specifically, by comparing the complete output pulse waveforms under 8 control instructions, the system shows the dynamic adjustment capability, and the amplitude range of the output pulse is-1.212-1.887kV.

[0035] Figure 3 is the output pulse half-width graph of different channels of the picosecond high-voltage pulse generator of the application.

[0036] Specifically, by quantifying the influence of different control modes on the output amplitude, it can be concluded that the half-width of the output pulse is 245-327ps.

[0037] Figure 4 is the output pulse rising edge slope graph of different channels of the picosecond high-voltage pulse generator of the application.

[0038] Specifically, by quantifying the influence of different control modes on the rising edge slope, it can be concluded that the rising edge slope of the output pulse is 3.61-10.01V / ps.

[0039] In summary, the identification order of the output pulse (pulse 1-pulse 8) and its output performance are not a linear change relationship, but a random distribution state. The application adopts STM32 master chip and magnetic reed relay to design 8-channel control circuit, and combines with high-voltage pulse forming circuit designed by 3-stage Marx circuit and 3-stage LC high-pass filter to realize accurate control of pulse amplitude, half-width and rising edge slope. Through the control circuit, the dynamic performance picosecond high-voltage pulse output is realized, which provides a new way for the fusion of automatic control technology and high-power pulse.

[0040] The above examples are only for illustrating the technical solutions of the application, but the protection scope of the application is not limited thereto. Any equivalent replacement, parameter adjustment or structure optimization of the examples within the technical concept of the application, as long as the same technical principle is adopted and similar technical effects are achieved, should be included in the protection scope of the application.

Claims

1. A dynamic performance picosecond high voltage pulse generator, characterized by: The dynamic performance picosecond high-voltage pulse generator includes a multi-channel control circuit, a Marx pulse generation module, and an LC high-pass filter module. The dynamic adjustment of pulse parameters is achieved through the STM32 main control chip and the reed relay. The specific structure is as follows: Multi-channel control circuit: Using STM32 main control chip (model STM32H33VG) and 8 groups of reed relays (model 5504-05-1, voltage resistance 3.5kV) to form an 8-channel gating system, switching different filter capacitor combinations (C A1 / C A2 、C B1 / C B2 、C C1 / C C2 ), the capacitance of each group is 1pF / 2pF; Marx pulse generation module: adopts 3-level avalanche transistor series-parallel topology (avalanche transistor model 2N5551), DC power supply V1 = 3.74kV, trigger signal V2 ~ V4 = 5.8V / 10Hz, charging capacitor C4 ~ C6 = 2nF, current limiting resistor R5 ~ R 10 =150kΩ; LC high-pass filter module: adopts 3rd-order LC cascade structure, inductor L1 = 725nH, L2 = L3 = 10nH, capacitors C7 ~ C9 = 2pF, load resistance R = 200Ω; Output pulse parameters: amplitude range -1.212 to -1.887 kV, half-width 245 to 327 ps, rising slope 3.61 to 10.01 V / ps, dynamically adjustable through channel gating.

2. The dynamic performance picosecond high voltage pulse generator according to claim 1, characterized in that: The STM32 chip of the multi-channel control circuit outputs a TTL level signal through the GPIO port, which is amplified by the transistor S9012 and then drives the reed relay to realize the selection of 8 channel combinations, and each group of channels corresponds to a different filter capacitor configuration.

3. The dynamic performance picosecond high voltage pulse generator according to claim 1, characterized in that: The control circuit of the generator adopts differential signal transmission technology, outputting differential control signals to the reed relay drive circuit through the STM32 chip, effectively suppressing common-mode interference and making the control signal transmission delay ≤500ps, ensuring the timing synchronization accuracy during multi-channel switching.

4. The dynamic performance picosecond high voltage pulse generator according to claim 1, characterized in that: The generator has a built-in automatic calibration module. This module collects pulse waveforms by connecting a sampling resistor in parallel to the output terminal. The waveforms are then converted by a high-speed ADC and fed back to the STM32 chip. The STM32 chip performs real-time comparisons based on preset waveform templates. If an output parameter deviation exceeds ±5%, the chip automatically adjusts the trigger timing of the Marx circuit or the filter network parameters, achieving closed-loop calibration of the pulse parameters.

5. The dynamic performance picosecond high voltage pulse generator according to claim 1, characterized in that: The three-stage circuit of the Marx pulse generation module adopts a series-parallel hybrid architecture. Each stage includes a parallel protection network of an avalanche transistor and an avalanche diode (model 1N4007). The resistance ratio of the charging resistor to the discharging resistor is 15:1, ensuring that the pulse rise time fluctuation is ≤15ps and the half-height width error is ≤±5%.

6. The dynamic performance picosecond high voltage pulse generator according to claim 1, characterized in that: The LC high-pass filter module adopts a three-stage inductor and capacitor cascade design, and switches the capacitance value by channel gating, so that the cutoff frequency is adjustable in the range of 800MHz to 1.2GHz, thereby achieving nonlinear compression of the pulse width.

7. The dynamic performance picosecond high voltage pulse generator according to claim 1, characterized in that: The dynamic adjustment mechanism of the generator is achieved by: When the channel combination is A1B1C1, the output pulse amplitude is -1.734kV, the half-maximum width is 245ps, and the rising slope is 10.01V / ps; When the channel combination is A2B2C2, the output pulse amplitude is -1.511kV, the half-maximum width is 325ps, and the rising slope is 6.39V / ps; The relative error of each channel output parameter is ≤8%, meeting the pulse shaping requirements in dynamic scenarios.

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