High-voltage nanosecond pulse generator based on photoconductive switch and method for generating high-voltage pulse

Abstract

The application discloses a high-voltage nanosecond pulse generator based on a light guide switch and a high-voltage pulse generation method. The pulse generator comprises a high-voltage direct-current power supply, a trigger control module, N groups of capacitor charging and discharging modules, a voltage synthesis module and a load; the N groups of capacitor charging and discharging modules are connected in parallel between the high-voltage direct-current power supply and the voltage synthesis module; and the high-voltage direct-current power supply charges the capacitor charging and discharging modules. The trigger control module outputs N paths of pulsed laser to the capacitor charging and discharging modules, and the capacitor charging and discharging modules output N paths of pulsed voltage to the voltage synthesis module; and the voltage synthesis module synthesizes the N paths of pulsed voltage output by the capacitor charging and discharging modules to obtain high-voltage nanosecond pulses on the load. The application further provides a high-voltage pulse generation method using the pulse generator. The application realizes high-voltage pulse output and flexible adjustment of pulse parameters, and simultaneously solves the problems of system compactness, stability, long service life and high-voltage output.

Description

Technical Field

[0001] This invention relates to the field of pulse power technology, and in particular to a high-voltage nanosecond pulse generator and a high-voltage pulse generation method based on a photoconductive switch. Background Technology

[0002] Pulsed power technology stores electromagnetic field energy at a low power level and then releases it at a high power level to a specific load after pulse modulation; hence, it is also called high-power pulse technology. High-power nanosecond pulses have broad application prospects in many fields, such as high-voltage insulation technology, ultra-wideband signal generators, high-power microwaves, and Z-pinch driver technology. To meet different application needs, scholars both domestically and internationally have conducted extensive research. Constructing high-voltage nanosecond pulse generators with higher amplitude, flexible and adjustable waveform parameters, long lifespan, stable performance, and compact structure is currently the focus and challenge of research in this field.

[0003] Photoconductive switches possess characteristics such as high voltage withstand capability (several kV to tens of kV), ultrafast rise and fall times, trigger jitter on the order of picoseconds, immunity to electromagnetic interference, light weight, and small size. They are solid-state pulse power devices with broad application prospects and are suitable for constructing compact solid-state nanosecond pulse generators. Based on photoconductive switches, there are two main methods for generating nanosecond pulses:

[0004] (1) Combining photoconductive switches with solid-state pulse forming lines, nanosecond pulses are generated on the load by utilizing the process of the photoconductive switch turning off the wave formed on the transmission line. For example, "CN201410329680.1, A 300kV Nanosecond Pulse Generator" cross-stacks sixteen single-stage flat Blumlein pulse forming lines containing photoconductive switches, realizing the design of a high-voltage nanosecond pulse generator. This type of technology integrates high energy storage technology, transmission line technology, and switching technology, reducing the size and weight of pulse power devices, and to a certain extent realizing the miniaturization and compactness of pulse power systems. However, the shortcomings are: 1) The design parameters of the forming line determine the output pulse waveform parameters of the system (such as waveform type, pulse width, amplitude, etc.), making it difficult to flexibly adjust the waveform parameters; 2) The use of the forming line limits the further miniaturization and compactness of the system.

[0005] (2) An auxiliary switch is introduced to control the discharge process of the energy storage capacitor dominated by the photoconductive switch, thereby achieving artificial control of the nanosecond pulse voltage waveform on the load. For example, "CN201010105586.X, A High Voltage Square Wave Pulse Generator and a Method for Generating High Voltage Square Wave Pulses" uses a delay control device to turn on the photoconductive switch and the auxiliary switch (insulated gate bipolar transistor or spark gap switch) sequentially, so as to achieve the purpose of the auxiliary switch controlling the working state (turn-off time and turn-off speed) of the photoconductive switch, and obtains a square wave pulse with high voltage, adjustable pulse width and fast falling edge rate. This type of technology makes full use of the photoconductive switch's ability to enter avalanche working mode when the bias voltage meets the voltage threshold and the trigger light energy meets the trigger light energy threshold, maintaining circuit conduction, and directly outputting voltage pulses with pulse widths of several ns to hundreds of ns (voltage lockout characteristic), avoiding the use of forming lines and realizing system miniaturization. The disadvantages are: 1) The amplitude, peak size, pulse width, and other operating parameters of the obtained square wave pulse are strictly dependent on the performance indicators of the photoconductive switch in avalanche mode. However, the lifespan of the photoconductive switch when operating at several kV high voltage is generally only a few to several thousand cycles, making it difficult for this type of system to achieve long-term stable operation under high voltage output. 2) Currently, the pulses generated by this type of system are mainly square waves, and the system output waveform is difficult to adjust flexibly, limiting the applicability of the system.

[0006] Therefore, how to design a nanosecond pulse generator based on photoconductive switches that allows for flexible adjustment of output pulse waveform parameters while also featuring high voltage output, long lifespan, stable operation, and compact structure remains a technical issue of great interest to those skilled in the art. Summary of the Invention

[0007] The technical problem to be solved by this invention is that the output pulse waveform parameters of existing nanosecond pulse generators based on photoconductive switches are difficult to adjust flexibly, and cannot simultaneously achieve system compactness, stability, long life and high voltage output. This invention provides a high voltage nanosecond pulse generator based on photoconductive switches and a high voltage pulse generation method, which can achieve high voltage pulse output and flexible adjustment of pulse parameters while satisfying system compactness, and the system can operate stably for a long time.

[0008] To achieve the above-mentioned technical objectives, the technical solution of the present invention is as follows:

[0009] The high-voltage nanosecond pulse generator based on a photoconductive switch consists of a high-voltage DC power supply, a trigger control module, N (N is an even number greater than 0, and N≤16) sets of capacitor charging and discharging modules (let's call them the first capacitor charging and discharging module, the second capacitor charging and discharging module, ..., the nth capacitor charging and discharging module, ..., the Nth capacitor charging and discharging module), a voltage synthesis module, and a load. The N sets of capacitor charging and discharging modules are connected in parallel between the high-voltage DC power supply and the voltage synthesis module. The high-voltage DC power supply is connected to the N sets of capacitor charging and discharging modules to charge them. The trigger control module is connected to the N sets of capacitor charging and discharging modules and outputs N pulsed lasers to them, triggering each module to output N pulsed voltages to the voltage synthesis module. The voltage synthesis module is connected to the N sets of capacitor charging and discharging modules and the load, synthesizing the N pulsed voltages output from the modules and outputting the synthesized pulsed voltage to the load, thereby obtaining a high-voltage nanosecond pulse on the load.

[0010] The high-voltage DC power supply adopts a fully digital high-voltage power supply with an output DC voltage range of 0 to 40kV, and the output voltage is continuously adjustable within this range.

[0011] The trigger control module consists of a multi-channel digital delay trigger and N pulsed lasers. The multi-channel digital delay trigger can output N independent signals with adjustable delays, each controlling one of the N pulsed lasers (let's call them the first pulsed laser, the second pulsed laser, ..., the nth pulsed laser, ..., the Nth pulsed laser). The first, second, ..., nth pulsed lasers are LD (Laser Diode) nanosecond pulsed lasers, requiring an output pulsed laser wavelength greater than the intrinsic absorption limit of gallium arsenide (i.e., a wavelength greater than 873 nm), an output light energy greater than 2 μJ, and an output pulse width less than 20 ns. The first, second, ..., nth pulsed lasers transmit their pulsed laser light to the first, second, ..., nth capacitor charging / discharging modules, ..., Nth capacitor charging / discharging modules, respectively, via N optical fibers. That is, the first pulse laser transmits the pulse laser to the first capacitor charging and discharging module through an optical fiber, ..., the nth pulse laser transmits the pulse laser to the nth capacitor charging and discharging module through an optical fiber, ..., the Nth pulse laser transmits the pulse laser to the Nth capacitor charging and discharging module through an optical fiber.

[0012] The first capacitor charging / discharging module, the second capacitor charging / discharging module, ..., the nth capacitor charging / discharging module, ..., the Nth capacitor charging / discharging module have the same composition. The nth capacitor charging / discharging module consists of a charging isolation inductor, an energy storage capacitor, and a photoconductive switch. One end of the charging isolation inductor is connected to the high-voltage output terminal of the high-voltage DC power supply, and the other end is connected to the positive terminal of the energy storage capacitor and the anode of the photoconductive switch. The positive terminal of the energy storage capacitor is connected to the charging isolation inductor, and the negative terminal is grounded; the anode of the photoconductive switch is connected to the charging isolation inductor, and the cathode is connected to the input port of the voltage synthesis module. The laser output from the nth pulse laser is transmitted via optical fiber to the vicinity of the photoconductive switch in the nth capacitor charging / discharging module, and directly irradiates the area between the anode and cathode of the photoconductive switch.

[0013] The energy storage capacitor is a high-voltage ceramic capacitor with a maximum operating voltage greater than 40kV. The capacitance value C and the resistance value R of the load 5 are required to satisfy the relationship: RC < 20ns.

[0014] The charging isolation inductor is an impulse-resistant inductor with an inductance greater than 3μH and an instantaneous withstand voltage greater than 40kV.

[0015] The photoconductive switch electrode structure can be a bulk structure, a coplanar electrode structure, or a non-coplanar electrode structure; the substrate is selected with a resistivity greater than 10. 7 Ω·cm, mobility greater than 6000cm 2 A semi-insulating gallium arsenide material with a strength of / (V·s); the distance between the anode and cathode of the photoconductive switch is greater than 0.5 mm.

[0016] The voltage synthesis module is a pulse transformer. The coupling coefficient of the pulse transformer is required to be greater than 0.95, and the magnetic core must not be saturated during operation; the number of primary windings of the pulse transformer is equal to the number of windings N of the capacitor charging and discharging module; the number of secondary windings is 1.

[0017] The N primary windings of the voltage synthesis module (let's call them the first primary winding, the second primary winding, ..., the nth primary winding, ..., the Nth primary winding) have two layout configurations. If a high-voltage nanosecond square wave pulse or a high-voltage nanosecond unipolar pulse is required, the winding direction of the first primary winding, the second primary winding, ..., the nth primary winding, ..., the Nth primary winding on the magnetic core is the same as the winding direction of the secondary winding. If a high-voltage nanosecond bipolar pulse is required, the windings with odd numbers (i.e., in 1, 2, ..., n, ..., N) in the first primary winding, the second primary winding, ..., the nth primary winding, ..., the Nth primary windings have the same winding direction on the magnetic core as the secondary winding, and the windings with even numbers have the opposite winding direction on the magnetic core to the secondary winding.

[0018] The load is a resistor, and the resistance value R is required to satisfy RC < 20ns.

[0019] The maximum amplitude U of the high-voltage nanosecond pulse generated on the loadp The number N of the capacitor charging / discharging modules and the output voltage amplitude V of a single capacitor charging / discharging module determine the relationship U. p ∝NV, ∝ means proportional to.

[0020] The maximum pulse width W of the high-voltage nanosecond pulse generated on the load p The relative delay time t of the N pulsed lasers output by the trigger control module (2,1) , t (3,2) , ..., t (n,n -1), ...,t (N,N-1) The pulse width W of a single-channel pulse voltage s Decision, fulfillment relationship: W p =t (2,1) +t (3,2) +…t (n,n-1) …+t (N,N-1) +W s , and t (2,1) , t (3,2) , ..., t (n,n-1) , ..., t (N,N-1) <W s . t (n,n-1) This represents the delay of the nth pulsed laser relative to the (n-1)th pulsed laser.

[0021] A method for generating high-voltage nanosecond pulses using a photoconductive switch-based high-voltage nanosecond pulse generator includes the following steps:

[0022] The first step is to determine the pulse output requirement. If a high-voltage nanosecond square wave pulse is required, proceed to the second step. If a high-voltage nanosecond monopolar pulse is required, proceed to the ninth step. If a high-voltage nanosecond bipolar pulse is required, proceed to the sixteenth step.

[0023] The second step is to activate the multi-channel digital delay trigger and the N-channel pulsed laser, and set the relative delay of the N signals output by the multi-channel digital delay trigger to 0, i.e., set t... (2,1) , t (3,2) , ..., t (n,n-1) , ..., t (N,N-1) =0;

[0024] The third step involves starting the high-voltage DC power supply. The first capacitor charging / discharging module, the second capacitor charging / discharging module, ..., the nth capacitor charging / discharging module, ..., the Nth capacitor charging / discharging module operate in parallel. The output voltage U of the high-voltage DC power supply is adjusted to 0.1kV, allowing the high-voltage DC power supply to charge the energy storage capacitors to 0.1kV through the charging isolation inductors of the first capacitor charging / discharging module, the second capacitor charging / discharging module, ..., the nth capacitor charging / discharging module, ..., the Nth capacitor charging / discharging module.

[0025] Fourth step: Press the output button of the multi-channel digital delay trigger to trigger the N-channel pulsed laser to output N pulsed lasers. The N pulsed lasers are transmitted via optical fiber to the first capacitor charging / discharging module, the second capacitor charging / discharging module, ..., the nth capacitor charging / discharging module, ..., the Nth capacitor charging / discharging module, and then directly irradiate the area between the anode and cathode of the photoconductor switch in each of the modules, causing the photoconductor switch to conduct. Subsequently, the first capacitor charging / discharging module, the second capacitor charging / discharging module, ..., the nth capacitor charging / discharging module, ..., the Nth capacitor charging / discharging module output pulsed voltages to the voltage synthesis module.

[0026] The fifth step involves the voltage synthesis module synthesizing the N pulse voltages to obtain nanosecond pulses on the load.

[0027] Step 6: Use an oscilloscope to observe the high-voltage nanosecond pulse generated on the load; if the high-voltage nanosecond pulse obtained on the load is a high-voltage square wave pulse, proceed to step 8; if the high-voltage nanosecond pulse obtained on the load is not a high-voltage square wave pulse, proceed to step 7.

[0028] Step 7: Increase the output voltage U of the high-voltage DC power supply by 0.1kV, i.e., set U = U + 0.1kV, and then proceed to step 4;

[0029] Step 8: Turn off the high-voltage DC power supply, turn off the N-channel pulsed laser, turn off the multi-channel digital delay trigger, and go to step 24.

[0030] Step 9: Activate the multi-channel digital delay trigger and the N-channel pulsed laser, and set the relative delay of the N signals output by the multi-channel digital delay trigger to 0, i.e., set t... (2,1) , t (3,2) , ..., t (n,n-1) , ..., t (N,N-1) =0;

[0031] Step 10: Start the high-voltage DC power supply. The first capacitor charging / discharging module, the second capacitor charging / discharging module, ..., the nth capacitor charging / discharging module, ..., the Nth capacitor charging / discharging module operate in parallel. Adjust the output voltage U of the high-voltage DC power supply to 0.4kV, so that the high-voltage DC power supply charges the energy storage capacitor to 0.4kV through the charging isolation inductors of the first capacitor charging / discharging module, the second capacitor charging / discharging module, ..., the nth capacitor charging / discharging module, ..., the Nth capacitor charging / discharging module.

[0032] Step 11: Press the output button of the multi-channel digital delay trigger to trigger the N-channel pulsed laser to output N pulsed lasers. The N pulsed lasers are transmitted via optical fiber to the first capacitor charging / discharging module, the second capacitor charging / discharging module, ..., the nth capacitor charging / discharging module, ..., the Nth capacitor charging / discharging module, and then directly irradiate the area between the anode and cathode of the photoconductor switch in each of the modules, causing the photoconductor switch to conduct. Subsequently, each of the first capacitor charging / discharging module outputs N pulsed voltages to the voltage synthesis module.

[0033] Step 12: The voltage synthesis module synthesizes the N pulse voltages to obtain a high-voltage nanosecond pulse on the load;

[0034] Step 13: Use an oscilloscope to observe the high-voltage nanosecond pulse formed on the load. If the high-voltage nanosecond pulse obtained on the load is a high-voltage monopole pulse, proceed to step 15; if the high-voltage nanosecond pulse obtained on the load is not a high-voltage monopole pulse, proceed to step 14.

[0035] Step 14: Increase the output voltage U of high voltage DC power supply 1 by 0.1kV, that is, set U = U + 0.1kV, and go to step 11;

[0036] Step 15: Turn off the high-voltage DC power supply, turn off the N-channel pulsed laser, turn off the multi-channel digital delay trigger, and then proceed to step 24.

[0037] Step 16: Adjust the winding direction of the primary winding of the voltage synthesis module so that the winding direction of the odd-numbered windings in the N primary windings is the same as that of the secondary windings on the magnetic core, and the winding direction of the even-numbered windings on the magnetic core is opposite to that of the secondary windings.

[0038] Step 17: Adjust the relative delay between even-numbered signals output by the multi-channel digital delay trigger to 0, i.e., t (4,2) , t (6,4) , ..., t (m,m-2) , ..., t (N,N-2) All are 0. t (m,m-2) This represents the delay of the m-th signal relative to the (m-2)-th signal, where m is an even number and 4 ≤ m ≤ N; the relative delay between signals with odd-numbered outputs of the multi-channel digital delay trigger is adjusted to 0, i.e., t (3,1) , t (5,3) , ..., t (p,p-2) , ..., t (N-1,N-3) All are 0. t (p,p-2)Let represent the delay of the p-th signal relative to the (p-2)-th signal, where p is odd and 3 ≤ p ≤ N. Find the relative delay Δt between signals with odd indices and signals with even indices. (eo) Satisfying the relationship: Δt (eo) <W s .

[0039] Step 18: Start the high-voltage DC power supply. The first capacitor charging / discharging module, the second capacitor charging / discharging module, ..., the nth capacitor charging / discharging module, ..., the Nth capacitor charging / discharging module operate in parallel. Adjust the output voltage U of the high-voltage DC power supply to 0.1kV, so that the high-voltage DC power supply charges the energy storage capacitor to 0.1kV through the charging isolation inductors of the first capacitor charging / discharging module, the second capacitor charging / discharging module, ..., the nth capacitor charging / discharging module, ..., the Nth capacitor charging / discharging module.

[0040] Step 19: Press the output button of the multi-channel digital delay trigger to trigger the N-channel pulsed laser.

[0041] N pulsed laser beams are output to the capacitor charging / discharging module via optical fiber. After being transmitted to the capacitor charging / discharging module via optical fiber, the pulsed laser beams directly irradiate the region between the anode and cathode of the photoconductive switch in the first, second, ..., nth, ..., Nth capacitor charging / discharging modules, causing the photoconductive switch to conduct. Subsequently, the first, second, ..., nth, ..., Nth capacitor charging / discharging modules output N pulsed voltage beams to the voltage synthesis module.

[0042] Step 20: The voltage synthesis module synthesizes the N pulse voltages to obtain a high voltage nanometer on the load.

[0043] Second pulse;

[0044] Step 21: Observe the high-voltage nanosecond pulse generated on the load using an oscilloscope; if the high-voltage nanosecond pulse obtained on the load is a high-voltage bipolar pulse, proceed to step 23; if the high-voltage nanosecond pulse obtained on the load is...

[0045] A nanosecond pulse is not a high-voltage bipolar pulse. Proceed to step twenty-two.

[0046] Step 22: Increase the output voltage U of the high-voltage DC power supply by 0.1kV, that is, let U = U + 0.1kV.

[0047] Proceed to step nineteen;

[0048] Step 23: Turn off the high-voltage DC power supply, turn off the N-channel pulsed laser, and turn off the multi-channel digital...

[0049] Delayed trigger, proceed to step twenty-four.

[0050] Step 24, End.

[0051] Compared with the prior art, the present invention has the following advantages:

[0052] (1) The high voltage nanosecond pulse generator based on the photoconductive switch of the present invention utilizes the characteristics of rapid capacitor discharge and avalanche conduction and voltage lockout exhibited by gallium arsenide photoconductive switch in the time scale of several nanoseconds to tens of nanoseconds to directly output nanosecond pulses. It eliminates the pulse forming line and auxiliary switch commonly used in the prior art, simplifies the structure of the nanosecond pulse generator, and makes the system structure compact.

[0053] (2) The high-voltage nanosecond pulse generator based on the photoconductive switch of the present invention utilizes the characteristic that the gallium arsenide photoconductive switch can output nanosecond square wave pulses and nanosecond unipolar pulses under different bias voltages. By setting the trigger delay and utilizing the synthesis function of the voltage synthesis module, the effect of generating high-voltage nanosecond pulses including square wave, unipolar pulse and bipolar pulse based on a pulse generation system is realized. The type of high-voltage nanosecond pulse can be flexibly adjusted between square wave, unipolar pulse and bipolar pulse, and the adjustment method is simple.

[0054] (3) The high-voltage pulse generation method of the present invention obtains a high-voltage output by controlling the synchronous operation of N sets of capacitor charging and discharging modules and utilizing the synthesis effect of the voltage synthesis module. It has two significant advantages: 1) While keeping the system output voltage constant, this method can reduce the operating voltage of each gallium arsenide photoconductor switch, thereby increasing the overall system lifespan by one to two orders of magnitude and significantly improving system stability; 2) While ensuring that the operating voltage of each gallium arsenide photoconductor switch remains constant, this method can increase the amplitude of the system output voltage by multiple times, and this amplitude is positively correlated with the number N of capacitor charging and discharging modules connected to the system.

[0055] (4) The second, ninth and seventeenth steps of the high voltage pulse generation method of the present invention can adjust the leading edge, pulse width and amplitude of the pulse waveform on the load by changing the relative delay between the N trigger signals. Compared with the traditional technical solution, it has the advantages of flexible adjustment of waveform parameters and simple adjustment method. Attached Figure Description

[0056] Figure 1 This is the overall logic structure diagram of the high-voltage nanosecond pulse generator based on photoconductive switches of the present invention;

[0057] Figure 2 This is a schematic diagram showing the connection between the N-group capacitor charging and discharging modules and the voltage synthesis module in Embodiment 1 of the high-voltage nanosecond pulse generator based on photoconductive switches of the present invention.

[0058] Figure 3 This is a typical high-voltage nanosecond square wave pulse obtained on the load in Embodiment 1 of the high-voltage nanosecond pulse generator based on photoconductive switch of the present invention;

[0059] Figure 4 This is a typical high-voltage nanosecond monopole pulse obtained on the load in Embodiment 1 of the high-voltage nanosecond pulse generator based on photoconductive switch of the present invention;

[0060] Figure 5 This is a schematic diagram showing the connection between the N-group capacitor charging / discharging module and the voltage synthesis module in Embodiment 2 of the high-voltage nanosecond pulse generator based on a photoconductive switch of the present invention. Here, p is an odd number and m is an even number.

[0061] Figure 6 This is a typical high-voltage nanosecond bipolar pulse obtained on the load in Embodiment 2 of the present invention. Detailed Implementation

[0062] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0063] like Figure 1 As shown, the high-voltage nanosecond pulse generator based on a photoconductive switch consists of a high-voltage DC power supply 1, a trigger control module 2, N (N is an even number greater than 0, and N≤16) sets of capacitor charging and discharging modules 3 (let's call them the first capacitor charging and discharging module 31, the second capacitor charging and discharging module 32, ..., the nth capacitor charging and discharging module 3n, ..., the Nth capacitor charging and discharging module 3N), a voltage synthesis module 4, and a load 5. The N sets of capacitor charging and discharging modules 3 are connected in parallel between the high-voltage DC power supply 1 and the voltage synthesis module 4. The high-voltage DC power supply 1 is connected to the N sets of capacitor charging and discharging modules 3 to charge them. The trigger control module 2 is connected to the N sets of capacitor charging and discharging modules 3 and outputs N pulse lasers to them, triggering each module to output N pulse voltages to the voltage synthesis module 4. The voltage synthesis module 4 is connected to the N-group capacitor charging and discharging module 3 and the load 5. It synthesizes the N-channel pulse voltages output by the N-group capacitor charging and discharging module 3 and outputs the synthesized pulse voltage to the load 5, thereby obtaining a high-voltage nanosecond pulse on the load 5.

[0064] The high-voltage DC power supply 1 adopts a fully digital high-voltage power supply with an output DC voltage range of 0 to 40kV, and the output voltage is continuously adjustable within this range.

[0065] The trigger control module 2 consists of a multi-channel digital delay trigger 2D and N pulsed lasers 2L. The multi-channel digital delay trigger 2D can output N independent signals with adjustable delays, which control the operation of the N pulsed lasers 2L (let's call them the first pulsed laser 2L1, the second pulsed laser 2L2, ..., the nth pulsed laser 2Ln, ..., the Nth pulsed laser 2LN). The first pulsed laser 2L1, the second pulsed laser 2L2, ..., the nth pulsed laser 2Ln, ..., the Nth pulsed laser 2LN) are LD (Laser Diode) nanosecond pulsed lasers, requiring the output pulsed laser wavelength to be greater than the intrinsic absorption limit of gallium arsenide (i.e., the output pulsed laser wavelength to be greater than 873 nm), the output light energy to be greater than 2 μJ, and the output pulse width to be less than 20 ns. The first pulsed laser 2L1, the second pulsed laser 2L2, ..., the nth pulsed laser 2Ln, ..., the Nth pulsed laser 2LN transmit pulsed laser light to the first capacitor charging / discharging module 31, the second capacitor charging / discharging module 32, ..., the nth capacitor charging / discharging module 3n, ..., the Nth capacitor charging / discharging module 3N, respectively, via N optical fibers. That is, the first pulsed laser 2L1 transmits pulsed laser light to the first capacitor charging / discharging module 31 via optical fiber, the nth pulsed laser 2Ln transmits pulsed laser light to the nth capacitor charging / discharging module 3n via optical fiber, and the Nth pulsed laser 2LN transmits pulsed laser light to the Nth capacitor charging / discharging module 3N via optical fiber.

[0066] The first capacitor charging / discharging module 31, the second capacitor charging / discharging module 32, ..., the nth capacitor charging / discharging module 3n, ..., the Nth capacitor charging / discharging module 3N have the same composition. The nth capacitor charging / discharging module 3n consists of a charging isolation inductor 3L, an energy storage capacitor 3C, and a photoconductive switch 3P. One end of the charging isolation inductor 3L is connected to the high-voltage output terminal of the high-voltage DC power supply 1, and the other end is connected to the positive terminal of the energy storage capacitor 3C and the anode 3PA of the photoconductive switch 3P. The positive terminal of the energy storage capacitor 3C is connected to the charging isolation inductor 3L, and the negative terminal is grounded; the anode 3PA of the photoconductive switch 3P is connected to the charging isolation inductor 3L, and the cathode 3PC is connected to the input port of the voltage synthesis module 4. The laser output from the nth pulse laser 2Ln is transmitted via optical fiber to the vicinity of the photoconductive switch 3P in the nth capacitor charging / discharging module 3n, and directly irradiates the area between the anode 3PA and the cathode 3PC of the photoconductive switch 3P.

[0067] The energy storage capacitor 3C is a high-voltage ceramic capacitor with a maximum operating voltage greater than 40kV. The capacitance value C and the resistance value R of the load 5 are required to satisfy the relationship: RC < 20ns.

[0068] The charging isolation inductor 3L is an impulse inductor with an inductance greater than 3μH and an instantaneous withstand voltage greater than 40kV.

[0069] The photoconductive switch 3P electrode structure can be a bulk structure, a coplanar electrode structure, or a non-coplanar electrode structure; the substrate is selected with a resistivity greater than 10. 7 Ω·cm, mobility greater than 6000cm 2 The semi-insulating gallium arsenide material has a strength of / (V·s); the distance between the anode 3PA and the cathode 3PC of the photoconductive switch 3P is greater than 0.5 mm.

[0070] Voltage synthesis module 4 is a pulse transformer. The coupling coefficient of the pulse transformer is required to be greater than 0.95, and the magnetic core is required to remain unsaturated during operation; the number of primary windings 4A of the pulse transformer is equal to the number of windings N of capacitor charging and discharging module 3; the number of secondary windings 4B is 1.

[0071] The N primary windings 4A of the voltage synthesis module 4 (let's call them the first primary winding 4A1, the second primary winding 4A2, ..., the nth primary winding 4An, ..., the Nth primary winding 4AN) have two layout configurations. If a high-voltage nanosecond square wave pulse or a high-voltage nanosecond monopole pulse is required, the first primary winding 4A1, the second primary winding 4A2, ..., the nth primary winding 4An, ..., the Nth primary winding 4AN are wound on the magnetic core... The winding direction of the primary winding 4A1 is the same as that of the secondary winding 4B. If a high-voltage nanosecond bipolar pulse is required, the windings with odd numbers (i.e., 1, 2, ..., n, ..., N) in the first primary winding 4A1, the second primary winding 4A2, ..., the nth primary winding 4An, ..., the Nth primary winding 4AN have the same winding direction on the magnetic core as the secondary winding 4B, and the windings with even numbers have the opposite winding direction on the magnetic core as the secondary winding 4B.

[0072] Load 5 is a resistor, and the resistance value R is required to satisfy RC < 20ns.

[0073] The maximum amplitude U of the high-voltage nanosecond pulse formed on load 5 p The number N of capacitor charging / discharging modules 3 and the output voltage amplitude V of a single capacitor charging / discharging module 3 are determined by the relationship U. p ∝NV, ∝ means proportional to.

[0074] The maximum pulse width W of the high-voltage nanosecond pulse generated on load 5 p The relative delay time t of the N pulse lasers output by the trigger control module 2 (2,1) , t (3,2) , ..., t (n,n-1) , ..., t (N,N-1) The pulse width W of a single-channel pulse voltage s Decision, fulfillment relationship: W p =t (2,1) +t (3,2) +…t (n,n-1) …+t (N,N-1) +W s , and t(2,1) , t (3,2) , ..., t (n,n-1) , ..., t (N,N-1) <W s . t (n,n-1) This represents the delay of the nth pulsed laser relative to the (n-1)th pulsed laser.

[0075] A method for generating high-voltage nanosecond pulses using a photoconductive switch-based high-voltage nanosecond pulse generator includes the following steps:

[0076] The first step is to determine the pulse output requirement. If a high-voltage nanosecond square wave pulse is required, proceed to the second step. If a high-voltage nanosecond monopolar pulse is required, proceed to the ninth step. If a high-voltage nanosecond bipolar pulse is required, proceed to the sixteenth step.

[0077] The second step is to activate the multi-channel digital delay trigger 2D and the N-channel pulsed laser 2L, and set the relative delay of the N signals output by the multi-channel digital delay trigger 2D to 0, i.e., set t... (2,1) , t (3,2) , ..., t (n,n-1) , ..., t (N,N-1) =0;

[0078] The third step involves starting the high-voltage DC power supply 1, with the first capacitor charging / discharging module 31, the second capacitor charging / discharging module 32, ..., the nth capacitor charging / discharging module 3n, ..., the Nth capacitor charging / discharging module 3N operating in parallel. The output voltage U of the high-voltage DC power supply 1 is adjusted to 0.1kV, allowing the high-voltage DC power supply 1 to charge the energy storage capacitor 3C to 0.1kV via the charging isolation inductor 3L of the first capacitor charging / discharging module 31, the second capacitor charging / discharging module 32, ..., the nth capacitor charging / discharging module 3n, ..., the Nth capacitor charging / discharging module 3N.

[0079] Fourth step: Press the output button of the multi-channel digital delay trigger 2D to trigger the N-channel pulsed laser 2L to output N-channel pulsed lasers. The N-channel pulsed lasers are transmitted via optical fiber to the first capacitor charging / discharging module 31, the second capacitor charging / discharging module 32, ..., the nth capacitor charging / discharging module 3n, ..., the Nth capacitor charging / discharging module 3N, respectively, and then directly irradiate the area between the anode 3PA and the cathode 3PC of the photoconductor switch 3P in the first capacitor charging / discharging module 31, the second capacitor charging / discharging module 32, ..., the nth capacitor charging / discharging module 3n, ..., the Nth capacitor charging / discharging module 3N, causing the photoconductor switch 3P to conduct. Subsequently, the first capacitor charging / discharging module 31, the second capacitor charging / discharging module 32, ..., the nth capacitor charging / discharging module 3n, ..., the Nth capacitor charging / discharging module 3N respectively output pulsed voltages to the voltage synthesis module 4;

[0080] Fifth step, voltage synthesis module 4 synthesizes N pulse voltages to obtain nanosecond pulses on load 5;

[0081] Step 6: Use an oscilloscope to observe the high-voltage nanosecond pulse generated on load 5; if the high-voltage nanosecond pulse obtained on load 5 is a high-voltage square wave pulse, proceed to step 8; if the high-voltage nanosecond pulse obtained on load 5 is not a high-voltage square wave pulse, proceed to step 7.

[0082] Step 7: Increase the output voltage U of high-voltage DC power supply 1 by 0.1kV, that is, set U = U + 0.1kV, and then proceed to step 4;

[0083] Step 8: Turn off the high-voltage DC power supply 1, turn off the N-channel pulsed laser 2L, turn off the multi-channel digital delay trigger 2D, and go to step 24.

[0084] Step 9: Activate the multi-channel digital delay trigger 2D and the N-channel pulsed laser 2L, and set the relative delay of the N signals output by the multi-channel digital delay trigger 2D to 0, i.e., set t... (2,1) , t (3,2) , ..., t (n,n-1) , ..., t (N,N-1) =0;

[0085] Step 10: Start the high-voltage DC power supply 1, the first capacitor charging / discharging module 31, and the second capacitor charging / discharging module 31.

[0086] Modules 32, ..., nth capacitor charging / discharging module 3n, ..., Nth capacitor charging / discharging module 3N operate in parallel. The output voltage U of the high-voltage DC power supply 1 is adjusted to 0.4kV, causing the high-voltage DC power supply 1 to charge the energy storage capacitor 3C to 0.4kV through the charging isolation inductor 3L of the first capacitor charging / discharging module 31, the second capacitor charging / discharging module 32, ..., nth capacitor charging / discharging module 3n, ..., Nth capacitor charging / discharging module 3N.

[0087] Step 11: Press the output button of the multi-channel digital delay trigger 2D to trigger N pulses.

[0088] Laser 2L outputs N pulsed laser beams. These N pulsed laser beams are transmitted via optical fibers to the first capacitor charging / discharging module 31, the second capacitor charging / discharging module 32, ..., the nth capacitor charging / discharging module 3n, ..., the Nth capacitor charging / discharging module 3N, respectively. They then directly irradiate the area between the anode 3PA and cathode 3PC of the photoconductor switch 3P in each of these modules, causing the photoconductor switch 3P to conduct. Subsequently, each of the first capacitor charging / discharging module 31, the second capacitor charging / discharging module 32, ..., the nth capacitor charging / discharging module 3n, ..., the Nth capacitor charging / discharging module 3N outputs N pulsed voltage beams to the voltage synthesis module 4.

[0089] Step 12: Voltage synthesis module 4 synthesizes the N pulse voltages to obtain a high voltage on load 5.

[0090] Nanosecond pulse;

[0091] Step 13: Use an oscilloscope to observe the high-voltage nanosecond pulse formed on load 5. If a high-voltage nanosecond pulse is obtained on load 5...

[0092] The obtained high-voltage nanosecond pulse is a high-voltage monopole pulse; proceed to step 15. If the pulse obtained on load 5...

[0093] High-voltage nanosecond pulses are not high-voltage monopole pulses; proceed to step fourteen.

[0094] Step fourteen: Increase the output voltage U of high-voltage DC power supply 1 by 0.1kV, that is, let U = U + 0.1kV.

[0095] Proceed to step eleven;

[0096] Step 15: Turn off the high-voltage DC power supply 1, turn off the N-channel pulsed laser 2L, turn off the multi-channel digital delay trigger, and then proceed to step 24.

[0097] Step 16: Adjust the winding direction of the primary winding 4A of the voltage synthesis module 4 so that the winding direction of the odd-numbered windings in the N primary windings 4A on the magnetic core is the same as the winding direction of the secondary winding 4B, and the winding direction of the even-numbered windings on the magnetic core is opposite to the winding direction of the secondary winding 4B.

[0098] Step 17: Adjust the relative delay between even-numbered signals in the 2D output of the multi-channel digital delay trigger to 0, i.e., t (4,2) , t (6,4) , ..., t (m,m-2) , ..., t (N,N-2) All are 0. t (m,m-2) This represents the delay of the m-th signal relative to the (m-2)-th signal, where m is an even number and 4 ≤ m ≤ N; the relative delay between odd-numbered signals output by the multi-channel digital delay trigger 2D is adjusted to 0, i.e., t (3,1) , t (5,3) , ..., t (p,p-2) , ..., t (N-1,N-3) All are 0. t (p,p-2) Let represent the delay of the p-th signal relative to the (p-2)-th signal, where p is odd and 3 ≤ p ≤ N. Find the relative delay Δt between signals with odd indices and signals with even indices. (eo) Satisfying the relationship: Δt (eo) <W s .

[0099] Step 18: Start the high-voltage DC power supply 1. The first capacitor charging / discharging module 31, the second capacitor charging / discharging module 32, ..., the nth capacitor charging / discharging module 3n, ..., the Nth capacitor charging / discharging module 3N operate in parallel. Adjust the output voltage U of the high-voltage DC power supply 1 to 0.1kV, so that the high-voltage DC power supply 1 charges the energy storage capacitor 3C to 0.1kV through the charging isolation inductor 3L of the first capacitor charging / discharging module 31, the second capacitor charging / discharging module 32, ..., the nth capacitor charging / discharging module 3n, ..., the Nth capacitor charging / discharging module 3N.

[0100] Step 19: Press the output button of the multi-channel digital delay trigger 2D to trigger the N-channel pulsed laser 2L to output N-channel pulsed lasers to the capacitor charging and discharging module 3 via optical fiber. After the pulsed lasers are transmitted to the capacitor charging and discharging module 3 via optical fiber, they directly irradiate the area between the anode 3PA and cathode 3PC of the photoconductor switch 3P in the first capacitor charging and discharging module 31, the second capacitor charging and discharging module 32, ..., the nth capacitor charging and discharging module 3n, ..., the Nth capacitor charging and discharging module 3N, causing the photoconductor switch 3P to conduct. Subsequently, the first capacitor charging and discharging module 31, the second capacitor charging and discharging module 32, ..., the nth capacitor charging and discharging module 3n, ..., the Nth capacitor charging and discharging module 3N output N-channel pulsed lasers to the capacitor charging and discharging module 3N.

[0101] The compression synthesis module 4 outputs N pulse voltages;

[0102] Step 20: Voltage synthesis module 4 synthesizes the N pulse voltages to obtain a high voltage across load 5.

[0103] Nanosecond pulse;

[0104] Step 21: Use an oscilloscope to observe the high-voltage nanosecond pulse formed on load 5; if load 5...

[0105] The obtained high-voltage nanosecond pulse is a high-voltage bipolar pulse; proceed to step twenty-three. If load 5 receives...

[0106] The obtained high-voltage nanosecond pulse is not a high-voltage bipolar pulse. Proceed to step twenty-two.

[0107] Step 22: Increase the output voltage U of high-voltage DC power supply 1 by 0.1kV, that is, let U = U + 0.1kV.

[0108] Proceed to step nineteen;

[0109] Step 23: Turn off the high-voltage DC power supply 1, turn off the N-channel pulsed laser 2L, and turn off the multi-channel...

[0110] Digital delay trigger, proceed to step twenty-four.

[0111] Step 24, End.

[0112] Example 1

[0113] The high-voltage DC power supply is an adjustable DC high-voltage power supply from 0 to 40kV; the charging isolation inductor 3L has an inductance of 6.5mH; the energy storage capacitor 3C is a pulse capacitor with a withstand voltage greater than 40kV and a capacitance of 140pF; the gallium arsenide photoconductive switch 3P has a semi-insulating gallium arsenide chip material with a resistivity of 5×10⁻⁶. 7 Ω·cm, electron mobility 6000cm 2 / (V·s); The gallium arsenide photoconductive switch 3P has an out-of-plane structure with a horizontal distance of 1mm between the two electrodes; the trigger pulse laser wavelength is 1064nm, the light energy is greater than 2μJ, and the output pulse width is 2ns; the pulse transformer coupling coefficient is about 1; the load impedance is 50Ω.

[0114] Figure 2 This diagram illustrates the connection between the N-group capacitor charging / discharging module and the voltage synthesis module 4. The number of groups N = 2 for the primary winding 4A of the pulse transformer in the voltage synthesis module 4, with a relative delay t... 21 =0, the energy storage capacitor 3C charging voltage U>1.5kV. After triggering the conduction of the two photoconductive switches 3P, a high-voltage nanosecond square wave pulse can be obtained on the load 5, such as Figure 3 The image shows a typical high-voltage nanosecond square wave pulse obtained on the load. The amplitude of the high-voltage nanosecond square wave pulse is approximately 2200V, and the flat-top duration is approximately 10ns. Increasing the number of paths N involved in the synthesis will further increase the amplitude of the square wave pulse on load 5. When the charging voltage U of the energy storage capacitor 3C > 2.5kV, after triggering the conduction of the two photoconductive switches 3P, a high-voltage nanosecond unipolar pulse can be obtained on load 5, such as... Figure 4 This is a typical high-voltage nanosecond monopolar pulse obtained on the load. The amplitude of the high-voltage nanosecond monopolar pulse is approximately 4650V, and the pulse width is approximately 13ns. Similarly, increasing the number of paths N involved in the synthesis will further increase the amplitude of the monopolar pulse on load 5.

[0115] Example 2

[0116] Based on Example 1, the winding direction of the odd-numbered windings in the N groups of primary windings 4A is adjusted to be the same as that of the secondary windings, while the winding direction of the even-numbered windings is opposite to that of the secondary windings. For example... Figure 5 As shown, in the N groups of windings, the windings numbered 1, ..., p, ..., (N-1) have the same winding direction on the core as the secondary windings, while the windings numbered 2, ..., m, ..., N have the opposite winding direction on the core. Here, p is an odd number and m is an even number. Set N = 2, and the delay t... 21 =11ns; the energy storage capacitor 3C charging voltage U>2.5kV, after triggering the conduction of the two photoconductive switches 3P, a high-voltage nanosecond bipolar pulse can be obtained on the load 5, such as Figure 6The image shows a typical high-voltage nanosecond bipolar pulse obtained on the load. The amplitude of the high-voltage nanosecond bipolar pulse is approximately 2040V, and the peak-to-peak width is approximately 10ns.

[0117] The above content is only for illustrating the technical concept and typical embodiments of the present invention, and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A high-voltage nanosecond pulse generator based on a photoconductive switch, characterized in that... The high-voltage nanosecond pulse generator based on photoconductive switches consists of a high-voltage DC power supply (1), a trigger control module (2), N sets of capacitor charging and discharging modules (3), a voltage synthesis module (4), and a load (5). The N sets of capacitor charging and discharging modules (3) are named as follows: first capacitor charging and discharging module (31), second capacitor charging and discharging module (32), ..., nth capacitor charging and discharging module (3n), ..., Nth capacitor charging and discharging module (3N). The N sets of capacitor charging and discharging modules (3) are connected in parallel between the high-voltage DC power supply (1) and the voltage synthesis module (4). The high-voltage DC power supply (1) and the N sets of capacitor charging and discharging modules... The module (3) is connected to charge the N-group capacitor charging and discharging module (3); the trigger control module (2) is connected to the N-group capacitor charging and discharging module (3) and outputs N pulse lasers to the N-group capacitor charging and discharging module (3), which respectively trigger the N-group capacitor charging and discharging module (3) to output N pulse voltages to the voltage synthesis module (4); the voltage synthesis module (4) is connected to the N-group capacitor charging and discharging module (3) and the load (5), and synthesizes the N pulse voltages output by the N-group capacitor charging and discharging module (3), and outputs the synthesized pulse voltage to the load (5), thereby obtaining a high-voltage nanosecond pulse on the load (5); The high-voltage DC power supply (1) adopts a fully digital high-voltage power supply; The trigger control module (2) consists of a multi-channel digital delay trigger (2D) and N pulsed lasers (2L). The multi-channel digital delay trigger (2D) outputs N independent signals with adjustable delay, and controls the N pulsed lasers (2L) respectively, namely the first pulsed laser (2L1), the second pulsed laser (2L2), ..., the nth pulsed laser (2Ln), ..., the Nth pulsed laser (2LN). The first pulsed laser (2L1) transmits the pulsed laser to the first capacitor charging and discharging module (31) through an optical fiber, ..., the nth pulsed laser (2Ln) transmits the pulsed laser to the nth capacitor charging and discharging module (3n) through an optical fiber, ..., the Nth pulsed laser (2LN) transmits the pulsed laser to the Nth capacitor charging and discharging module (3N) through an optical fiber. The first capacitor charging / discharging module (31), the second capacitor charging / discharging module (32), ..., the nth capacitor charging / discharging module (3n), ..., the Nth capacitor charging / discharging module (3N) have the same composition; the nth capacitor charging / discharging module (3n) consists of a charging isolation inductor (3L), an energy storage capacitor (3C), and a photoconductive switch (3P); one end of the charging isolation inductor (3L) is connected to the high voltage output terminal of the high voltage DC power supply (1), and the other end is connected to the positive terminal of the energy storage capacitor (3C) and the anode (3P) of the photoconductive switch (3P). A) Connected; the positive terminal of the energy storage capacitor (3C) is connected to the charging isolation inductor (3L), and the negative terminal is grounded; the anode (3PA) of the photoconductor switch (3P) is connected to the charging isolation inductor (3L), and the cathode (3PC) is connected to the input port of the voltage synthesis module (4); the laser output by the nth pulse laser (2Ln) is transmitted through the optical fiber to the vicinity of the photoconductor switch (3P) of the nth capacitor charging and discharging module (3n), and directly irradiates the area between the anode (3PA) and cathode (3PC) of the photoconductor switch (3P); The photoconductive switch (3P) electrode structure is a bulk structure, a same-surface electrode structure, or a different-surface electrode structure; The voltage synthesis module (4) is a pulse transformer. The number of primary windings (4A) of the pulse transformer is equal to the number of windings N of the capacitor charging and discharging module (3); the number of secondary windings (4B) is 1. The N primary windings (4A) of the voltage synthesis module (4), namely the first primary winding (4A1), the second primary winding (4A2), ..., the nth primary winding (4An), ..., the Nth primary winding (4AN), have two layout forms. If it is necessary to generate a high-voltage nanosecond square wave pulse or a high-voltage nanosecond unipolar pulse, the first primary winding (4A1), the second primary winding (4A2), ..., the nth primary winding (4An), ..., the Nth primary winding (4AN) are in the magnetic core. The winding direction of the primary winding (4A1) is the same as that of the secondary winding (4B). If a high-voltage nanosecond bipolar pulse is required, the windings with odd numbers in the sequence 1, 2, ..., n, ..., N of the primary winding (4A1), primary winding (4A2), ..., nth primary winding (4An), ..., Nth primary winding (4AN) have the same winding direction on the magnetic core as the secondary winding (4B), while the windings with even numbers have the opposite winding direction on the magnetic core to the secondary winding (4B). The load (5) is a resistor.

2. The high-voltage nanosecond pulse generator based on a photoconductive switch as described in claim 1, characterized in that... The number of stages N of the capacitor charging and discharging module (3) is an even number greater than 0, and N≤16.

3. The high-voltage nanosecond pulse generator based on a photoconductive switch as described in claim 1, characterized in that... The high-voltage DC power supply (1) outputs a DC voltage range of 0 to 40 kV, and the output voltage is continuously adjustable within this range.

4. The high-voltage nanosecond pulse generator based on a photoconductive switch as described in claim 1, characterized in that... The first pulsed laser (2L1), the second pulsed laser (2L2), ..., the nth pulsed laser (2Ln), ..., the Nth pulsed laser (2LN) are LD nanosecond pulsed lasers, requiring the output pulsed laser wavelength to be greater than the intrinsic absorption limit of gallium arsenide, the output light energy to be greater than 2μJ, and the output pulse width to be less than 20ns.

5. The high-voltage nanosecond pulse generator based on a photoconductive switch as described in claim 1, characterized in that... The energy storage capacitor (3C) of the nth capacitor charging and discharging module (3n) is a high-voltage ceramic capacitor with a maximum operating voltage greater than 40kV, and the required capacitance value is... C Resistance value of load (5) R The relationship between them is satisfied: RC <20ns; the charging isolation inductor (3L) is an impulse inductor with an inductance greater than 3μH and an instantaneous withstand voltage greater than 40kV; the substrate of the photoconductive switch (3P) is selected with a resistivity greater than 10. 7 Ω·cm, mobility greater than 6000cm 2 The semi-insulating gallium arsenide material has a strength of / (V·s); the distance between the anode (3PA) and cathode (3PC) of the photoconductive switch (3P) is greater than 0.5 mm; the high voltage DC power supply is an adjustable DC high voltage power supply from 0 to 40 kV; the inductance of the charging isolation inductor (3L) is 6.5 mH; the energy storage capacitor (3C) is a pulse capacitor with a withstand voltage greater than 40 kV and a capacitance of 140 pF. The gallium arsenide photoconductive switch (3P) uses a semi-insulating gallium arsenide chip material as its substrate, with a resistivity of 5 × 10⁻⁶. 7 Ω·cm, electron mobility 6000 cm⁻¹ 2 / (V·s); the gallium arsenide photoconductive switch (3P) is a non-plane structure with a horizontal distance of 1mm between the two electrodes; the trigger pulse laser wavelength is 1064nm and the light energy is greater than 2μJ; the coupling coefficient of the pulse transformer is about 1; the load (5) impedance is 50Ω.

6. The high-voltage nanosecond pulse generator based on a photoconductive switch as described in claim 1, characterized in that... The coupling coefficient of the voltage synthesis module (4) is required to be greater than 0.95, and the magnetic core is required to remain unsaturated during operation.

7. The high-voltage nanosecond pulse generator based on a photoconductive switch as described in claim 1, characterized in that... The resistance value of the load (5) R satisfy RC <20ns; the maximum amplitude of the high-voltage nanosecond pulse formed on the load (5) U p The number N of the capacitor charging and discharging module (3) and the output voltage amplitude of a single capacitor charging and discharging module (3) are determined by... V Decision, fulfilling the relationship U p ∝ NV, ∝ indicates proportionality to; The maximum pulse width of the high-voltage nanosecond pulse formed on the load (5) W p Output by the trigger control module (2) N Relative delay time of pulsed laser t (2,1) , t (3,2) , ..., t (n,n-1) , ..., t (N,N-1) and the pulse width of a single-channel pulse voltage W s Decision, fulfillment of relationship: W p = t (2,1) + t (3,2) +…+ t (n,n-1) +…+ t (N,N-1) + W s ,and t (2,1) , t (3,2) , ..., t (n,n-1) , ..., t (N,N-1) < W s ; t (n,n-1) This represents the delay of the nth pulsed laser relative to the (n-1)th pulsed laser.

8. A method for generating high-voltage nanosecond pulses using a high-voltage nanosecond pulse generator based on a photoconductive switch as described in claim 1, characterized in that... Includes the following steps: The first step is to determine the pulse output requirement. If a high-voltage nanosecond square wave pulse is required, proceed to the second step. If you need to generate a high-voltage nanosecond monopolar pulse, proceed to step nine; if you need to generate a high-voltage nanosecond bipolar pulse, proceed to step sixteen. The second step is to activate the multi-channel digital delay trigger (2D) and the N-channel pulsed laser (2L), and set the relative delay of the N-channel signals output by the multi-channel digital delay trigger (2D) to 0, that is, set the output of the trigger control module (2) to... N Relative delay time of pulsed laser t (2,1) , t (3,2) , ..., t (n,n-1) , ..., t (N,N-1) =0, t (n,n-1) This represents the delay of the nth pulse laser relative to the (n-1)th pulse laser; The third step is to start the high-voltage DC power supply (1), and the first capacitor charging and discharging module (31), the second capacitor charging and discharging module (32), ..., the nth capacitor charging and discharging module (3n), ..., the Nth capacitor charging and discharging module (3N) work in parallel; adjust the output voltage of the high-voltage DC power supply (1). U The voltage is 0.1kV, so that the high voltage DC power supply (1) charges the energy storage capacitor (3C) to 0.1kV through the charging isolation inductor (3L) of the first capacitor charging and discharging module (31), the second capacitor charging and discharging module (32), ..., the nth capacitor charging and discharging module (3n), ..., the Nth capacitor charging and discharging module (3N). Fourth step, press the output button of the multi-channel digital delay trigger (2D) to trigger the N-channel pulse laser (2L) to output N-channel pulse lasers; N pulsed lasers are transmitted via optical fibers to the first capacitor charging / discharging module (31), the second capacitor charging / discharging module (32), ..., the nth capacitor charging / discharging module (3n), ..., the Nth capacitor charging / discharging module (3N), and then directly irradiate the area between the anode (3PA) and cathode (3PC) of the photoconductor switch (3P) of the first capacitor charging / discharging module (31), the second capacitor charging / discharging module (32), ..., the nth capacitor charging / discharging module (3n), ..., the Nth capacitor charging / discharging module (3N), making the photoconductor switch (3P) conduct; subsequently, the first capacitor charging / discharging module (31), the second capacitor charging / discharging module (32), ..., the nth capacitor charging / discharging module (3n), ..., the Nth capacitor charging / discharging module (3N) output pulsed voltages to the voltage synthesis module (4) respectively; Fifth step, the voltage synthesis module (4) synthesizes the N-channel pulse voltages to obtain nanosecond pulses on the load (5); Step 6: Use an oscilloscope to observe the high voltage nanosecond pulse formed on the load (5); if the high voltage nanosecond pulse obtained on the load (5) is a high voltage square wave pulse, proceed to step 8; if the high voltage nanosecond pulse obtained on the load (5) is not a high voltage square wave pulse, proceed to step 7. Step 7: Convert the output voltage of the high-voltage DC power supply (1) U Increase the voltage by 0.1kV, that is... U = U +0.1kV, proceed to step four; Step 8: Turn off the high-voltage DC power supply (1), turn off the N-channel pulsed laser (2L), turn off the multi-channel digital delay trigger (2D), and go to step 24; Step 9: Activate the multi-channel digital delay trigger (2D) and the N-channel pulsed laser (2L), and set the relative delay of the N signals output by the multi-channel digital delay trigger (2D) to 0, i.e., set... t (2,1) , t (3,2) , ..., t (n,n-1) , ..., t (N,N-1) =0; Step 10: Start the high-voltage DC power supply (1), and the first capacitor charging and discharging module (31), the second capacitor charging and discharging module (32), ..., the nth capacitor charging and discharging module (3n), ..., the Nth capacitor charging and discharging module (3N) work in parallel; adjust the output voltage of the high-voltage DC power supply (1). U The voltage is 0.4kV, so that the high voltage DC power supply (1) charges the energy storage capacitor (3C) to 0.4kV through the charging isolation inductor (3L) of the first capacitor charging and discharging module (31), the second capacitor charging and discharging module (32), ..., the nth capacitor charging and discharging module (3n), ..., the Nth capacitor charging and discharging module (3N). Step 11: Press the output button of the multi-channel digital delay trigger (2D) to trigger the N-channel pulsed laser (2L) to output N-channel pulsed lasers; N pulsed lasers are transmitted via optical fibers to the first capacitor charging / discharging module (31), the second capacitor charging / discharging module (32), ..., the nth capacitor charging / discharging module (3n), ..., the Nth capacitor charging / discharging module (3N), and then directly irradiate the area between the anode (3PA) and cathode (3PC) of the photoconductor switch (3P) of the first capacitor charging / discharging module (31), the second capacitor charging / discharging module (32), ..., the nth capacitor charging / discharging module (3n), ..., the Nth capacitor charging / discharging module (3N), making the photoconductor switch (3P) conduct; subsequently, the first capacitor charging / discharging module (31), the second capacitor charging / discharging module (32), ..., the nth capacitor charging / discharging module (3n), ..., the Nth capacitor charging / discharging module (3N) output N pulsed voltages to the voltage synthesis module (4); In the twelfth step, the voltage synthesis module (4) synthesizes the N-channel pulse voltages to obtain a high-voltage nanosecond pulse on the load (5); Step 13: Use an oscilloscope to observe the high voltage nanosecond pulse formed on the load (5). If the high voltage nanosecond pulse obtained on the load (5) is a high voltage monopole pulse, proceed to step 15; if the high voltage nanosecond pulse obtained on the load (5) is not a high voltage monopole pulse, proceed to step 14. Step fourteen, adjust the output voltage of the high-voltage DC power supply (1). U Increase the voltage by 0.1kV, that is... U = U +0.1kV, proceed to step eleven; Step 15: Turn off the high voltage DC power supply (1), turn off the N-channel pulsed laser (2L), turn off the multi-channel digital delay trigger, and go to step 24; Step 16: Adjust the winding direction of the primary winding (4A) of the voltage synthesis module (4) so ​​that the winding direction of the odd-numbered windings in the N primary windings (4A) is the same as the winding direction of the secondary winding (4B), and the winding direction of the even-numbered windings is opposite to the winding direction of the secondary winding (4B). Step 17: Adjust the relative delay between even-numbered signals output by the multi-channel digital delay trigger (2D) to 0, i.e. t (4,2) , t (6,4) , ..., t (m,m-2) , ..., t (N,N-2) All are 0; t (m,m-2) This represents the delay of the m-th signal relative to the (m-2)-th signal, where m is an even number and 4 ≤ m ≤ N; adjusting the relative delay between odd-numbered signals output by the multi-channel digital delay trigger (2D) to 0, i.e. t (3,1) , t (5,3) , ..., t (p,p-2) , ..., t (N-1,N-3) All are 0; t (p,p-2) Let Δ represent the delay of the p-th signal relative to the (p-2)-th signal, where p is an odd number and 3 ≤ p ≤ N; find the relative delay Δ between signals with odd numbers and signals with even numbers. t (eo) Satisfying the relation: Δ t (eo) < W s ; Step 18: Start the high-voltage DC power supply (1), and the first capacitor charging and discharging module (31), the second capacitor charging and discharging module (32), ..., the nth capacitor charging and discharging module (3n), ..., the Nth capacitor charging and discharging module (3N) work in parallel; adjust the output voltage of the high-voltage DC power supply (1). U The voltage is 0.1kV, so that the high voltage DC power supply (1) charges the energy storage capacitor (3C) to 0.1kV through the charging isolation inductor (3L) of the first capacitor charging and discharging module (31), the second capacitor charging and discharging module (32), ..., the nth capacitor charging and discharging module (3n), ..., the Nth capacitor charging and discharging module (3N). Step 19: Press the output button of the multi-channel digital delay trigger (2D) to trigger the N-channel pulse laser (2L) to output N-channel pulse laser to the capacitor charging and discharging module (3) through the optical fiber; after the pulse laser is transmitted to the capacitor charging and discharging module (3) through the optical fiber, it directly irradiates the area between the anode (3PA) and cathode (3PC) of the photoconductor switch (3P) of the first capacitor charging and discharging module (31), the second capacitor charging and discharging module (32), ..., the nth capacitor charging and discharging module (3n), ..., the Nth capacitor charging and discharging module (3N), so that the photoconductor switch (3P) is turned on; then, the first capacitor charging and discharging module (31), the second capacitor charging and discharging module (32), ..., the nth capacitor charging and discharging module (3n), ..., the Nth capacitor charging and discharging module (3N) output N-channel pulse voltage to the voltage synthesis module (4); Step 20: The voltage synthesis module (4) synthesizes the N-channel pulse voltages to obtain a high-voltage nanosecond pulse on the load (5); Step 21: Use an oscilloscope to observe the high voltage nanosecond pulse formed on the load (5); if the high voltage nanosecond pulse obtained on the load (5) is a high voltage bipolar pulse, proceed to step 23; if the high voltage nanosecond pulse obtained on the load (5) is not a high voltage bipolar pulse, proceed to step 22. Step 22: The output voltage of the high voltage DC power supply (1) U Increase the voltage by 0.1kV, that is... U = U +0.1kV, proceed to step nineteen; Step 23: Turn off the high voltage DC power supply (1), turn off the N-channel pulsed laser (2L), turn off the multi-channel digital delay trigger, and proceed to step 24; Step 24, End.

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