Blumlein-type pulse generating device

Abstract

This application provides a Blummlein-type pulse generator for use in the field of pulse power, comprising: a controller that, during the charging phase, controls a first switching unit to operate in a chopping mode, so that a boost converter charges a multi-stage transmission line using the increased input voltage; and a controller that, during the discharging phase, controls the first switching unit to conduct, so that the energy stored in the multi-stage transmission line is discharged to the load to generate an output pulse; and a coupling suppression module that includes at least one of a plurality of first magnetic elements sleeved on the load or a plurality of second magnetic elements sleeved on an impedance element connected in series with the load, configured to, during the discharging phase, increase the coupling impedance of the load to ground using at least one of the plurality of first magnetic elements or the plurality of second magnetic elements to suppress energy leakage.

Description

Technical Field

[0001] This application relates to the field of pulse power technology, specifically to a Blumlein-type pulse generator. Background Technology

[0002] With the widespread application of pulsed power in fields such as biomedicine and plasma physics, higher requirements have been placed on pulse parameters, including high repetition frequency, short pulses, and flexible adjustment of pulse parameters. Blumlein-type pulse generators, which are pulse generators with Blumlein lines forming pulses, are widely used due to their simple structure and ability to generate nanosecond-level short pulses.

[0003] Among related technologies, the superposition efficiency and voltage gain of Blumlein-type pulse generators are relatively low. Summary of the Invention

[0004] In view of the above problems, this application provides a Blumlein-type pulse generator.

[0005] According to one aspect of the embodiments of this application, a Blumein-type pulse generator is provided, comprising: a boost converter, the input terminal of which is connected to a DC power supply, the boost converter including a first switching unit and a multi-stage boost unit, the boost converter being configured to increase the input voltage provided by the DC power supply; a Blumein pulse forming line module, the input terminal of which is connected to the output terminal of the boost converter via the first switching unit, the output terminal of which is connected to a load, the Blumein pulse forming line module including a multi-stage transmission line; and a controller, the controller being connected to the first switching unit. The control terminal of the switching unit is connected and configured to control the first switching unit to operate in a chopping mode during the charging phase, so that the boost converter charges the multi-stage transmission line using the increased input voltage; and to control the first switching unit to conduct during the discharging phase, so that the energy stored in the multi-stage transmission line is discharged to the load to generate an output pulse; and a coupling suppression module, including at least one of a plurality of first magnetic elements sleeved on the load or a plurality of second magnetic elements sleeved on an impedance element connected in series with the load, is configured to increase the coupling impedance of the load to ground by using at least one of the plurality of first magnetic elements or a plurality of second magnetic elements during the discharging phase, so as to suppress energy leakage and compensate for the output pulse.

[0006] According to embodiments of this application, since the boost converter can increase the low input voltage provided by the DC power supply, a higher charging voltage is obtained from the source without relying on a high-voltage DC power supply, solving the problem of voltage gain being limited by the DC power supply capability. Due to the increased charging voltage, the number of transmission line stack-up stages in the Blummlein pulse forming line module can be reduced to achieve the same actual output voltage, thereby reducing the number of inter-stage energy leakage paths and lowering the pressure on the coupling suppression module to suppress energy leakage. The first switching unit is multiplexed as both the chopper switch of the boost converter and the trigger switch for pulse generation, reducing the number of components and simplifying the structure. The controller achieves timing separation of the charging and discharging stages by switching the operating state of the first switching unit, ensuring that the transmission line is charged before discharging. The multi-stage transmission lines employ parallel charging and series discharging to achieve voltage multiplication. A first magnetic element is fitted onto the load, or a second magnetic element is fitted onto an impedance element connected in series with the load, forming a common-mode inductor with the two conductors (the two terminals of the load or the two terminals of the impedance element). This common-mode inductor presents low impedance to normal current, reducing the impact on normal energy transmission, and high impedance to unexpected current, effectively suppressing interference and achieving selective suppression. Furthermore, the first or second magnetic element introduces common-mode inductance into the energy leakage path from the load to ground, making the inductive reactance dominant under high-frequency pulses, increasing the coupling impedance from the load to ground, effectively suppressing unexpected current, suppressing energy leakage, and thus improving superposition efficiency. In addition, during discharge, the current changes, generating a changing magnetic field. This changing magnetic field induces a current in the first or second magnetic element, which acts on the load or impedance element and superimposes with the normal current, achieving active compensation of the output voltage. The aforementioned boost converter increases the charging voltage, raising the theoretical upper limit of the actual output voltage. The Blumlein pulse forming line module further multiplies the voltage through multi-stage stacking. The controller separates the charging and discharging timing, ensuring stable system operation. The coupling suppression module suppresses energy leakage and compensates for output pulses, improving superposition efficiency and actual output voltage. The synergy of these four components enhances superposition efficiency and actual output voltage, thus achieving a balance between high voltage gain, high-level superposition efficiency, and nanosecond-level short pulses. Furthermore, by embedding the second magnetic element within an impedance element connected in series with the load, the problem of directly embedding the first magnetic element due to diverse load structures is solved. This indirectly suppresses energy leakage from the load to ground and compensates for the output voltage, improving versatility and feasibility. Attached Figure Description

[0007] The above-mentioned contents, other objects, features and advantages of the present application will become clearer from the following description of the embodiments of the present application with reference to the accompanying drawings.

[0008] Figure 1A block diagram of a Blumlein-type pulse generator according to an embodiment of this application is shown;

[0009] Figure 2 A circuit diagram of a boost converter according to an embodiment of this application is shown;

[0010] Figure 3A A circuit diagram of a single-stage Blumlein pulse forming line module is shown.

[0011] Figure 3B A schematic diagram illustrating the operation of a single-stage Blumlein pulse forming line module is shown.

[0012] Figure 4A A schematic diagram of a multi-level stacked Blumein pulse forming line module according to an embodiment of this application is shown;

[0013] Figure 4B An equivalent circuit diagram of a Blummlein pulse forming line module during the discharge phase, according to an embodiment of this application, is shown.

[0014] Figure 4C An equivalent circuit diagram of another Blummlein pulse forming line module during the discharge phase, according to an embodiment of this application, is shown.

[0015] Figure 5A The embodiments of this application are shown in Multiple impedance ratios In the case of superposition efficiency With cascaded series A diagram illustrating the relationship between them;

[0016] Figure 5B The embodiments of this application are shown in Multiple impedance ratios In the case of superposition efficiency With cascaded series A diagram illustrating the relationship between them;

[0017] Figure 6A A schematic diagram showing a plurality of first magnetic elements sleeved on a load according to an embodiment of the present application is shown;

[0018] Figure 6B A schematic diagram of a coupling impedance structure formed by sleeved multiple first magnetic elements on a load according to an embodiment of this application is shown.

[0019] Figure 7 A circuit diagram of a Blumlein-type pulse generator according to an embodiment of this application is shown;

[0020] Figure 8AThe simulation waveform of the Blumlein-type pulse generator with a repetition rate of 20 kHz, according to an embodiment of this application, is shown.

[0021] Figure 8B The embodiments of this application are shown in multiple A schematic diagram illustrating the relationship between pulse amplitude and superposition efficiency under certain conditions;

[0022] Figure 8C A schematic diagram of a simulated waveform of a pulse current flowing through a switching transistor according to an embodiment of this application is shown;

[0023] Figure 9 A schematic diagram of the experimental platform of the Blumlein-type pulse generator according to an embodiment of this application is shown;

[0024] Figure 10 A schematic diagram of a first magnetic ring and a third magnetic ring according to an embodiment of this application is shown;

[0025] Figure 11A The diagram shows the waveform of the positive polarity pulse output by the Blummlein-type pulse generator under multiple input voltages according to an embodiment of this application;

[0026] Figure 11B The diagram shows the waveform of the negative polarity pulse output by the Blumlein-type pulse generator under multiple input voltages according to an embodiment of this application;

[0027] Figure 12 The waveform of a 10kV positive pulse with a repetition frequency of 20kHz according to an embodiment of this application is shown.

[0028] Figure 13 The diagram shows the pulse current waveforms that the switching transistor withstands under corresponding pulse voltages according to embodiments of this application.

[0029] Figure 14 The diagram shows a bipolar pulse sequence waveform with a repetition frequency of 50 kHz and an amplitude of ±4 kV according to an embodiment of this application.

[0030] Figure 15A Pulse waveforms at repetition frequencies of 50 kHz and 100 kHz are shown according to embodiments of this application.

[0031] Figure 15B The following diagrams show pulse waveforms at repetition frequencies of 500 kHz and 1 MHz according to embodiments of this application.

[0032] Figure 16A schematic diagram showing a plurality of second magnetic rings fitted onto a resistor according to an embodiment of the present application is shown;

[0033] Figure 17 The diagram shows a comparison of pulse waveforms with and without the second magnetic ring, under a charging voltage of 800V for the transmission line, according to an embodiment of this application; and

[0034] Figure 18 A schematic diagram showing the theoretical and experimental results of the superposition efficiency of a 1-10 level stacked Blumlein-type pulse generator according to an embodiment of this application with and without the suppression of a second magnetic ring is presented. Detailed Implementation

[0035] The embodiments of this application will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of this application. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of this application for ease of explanation. However, it will be apparent that one or more embodiments may be implemented without these specific details. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of this application.

[0036] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0037] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0038] When using expressions such as "at least one of A, B or C", they should generally be interpreted in accordance with the meaning that is commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B or C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, or a system having A, B and C, etc.).

[0039] To facilitate understanding, some terms involved in the embodiments of this application will be explained below.

[0040] 1. Distributed parameter circuit

[0041] When the physical dimensions of a circuit are comparable to the wavelength of the electromagnetic wave propagating within it, the time required for the electromagnetic wave to propagate through the circuit cannot be ignored. Therefore, the voltage and current in the circuit are not only functions of time but also of spatial location; such circuits are called distributed parameter circuits. The parameters of a distributed parameter circuit are continuously distributed along the line, without clearly defined component boundaries. Components in a distributed parameter circuit can include distributed resistance, distributed inductance, distributed capacitance, or distributed conductance. Distributed parameter models can be mathematical tools used to describe and analyze distributed parameter circuits. For example, a distributed parameter model can include telegraph equations, fundamental parameters, and characteristic parameters.

[0042] Basic parameters can include resistance per unit length, inductance per unit length, capacitance per unit length, or conductance per unit length. Characteristic parameters can include characteristic impedance, wave velocity, or pulse width. Characteristic impedance can be the ratio between traveling wave voltage and traveling wave current. Characteristic impedance reflects the ratio of electric field energy to magnetic field energy in a traveling wave. As one implementation method, characteristic impedance can be determined based on inductance and capacitance per unit length.

[0043] 2. Transmission line

[0044] A transmission line can be a physical implementation of a distributed parameter circuit, a waveguide structure used to transmit electromagnetic energy (i.e., signal or power) from one point to another. In pulsed power technology, transmission lines can be used not only for energy transmission but also for energy storage and pulse generation. Transmission lines can take various forms, including coaxial lines (or coaxial transmission lines), striplines, microstrip lines, or parallel twin lines.

[0045] 3. Coupled transmission line

[0046] A coupled transmission line can refer to an equivalent transmission line formed by multiple transmission lines arranged closely in space, due to the electromagnetic interactions generated by interstage parasitic parameters (e.g., interstage parasitic capacitance and interstage parasitic inductance), used to describe energy coupling between lines. Coupled transmission lines allow energy to be transferred from one transmission line to another, resulting in unintended energy exchange. Interstage parasitic capacitance refers to the parasitic capacitance formed between adjacent transmission lines. Interstage parasitic inductance refers to the parasitic inductance formed by the loops of adjacent transmission lines.

[0047] 4. Voltage wave

[0048] Voltage waves can be the manifestation of voltage changes propagating along a transmission line. Voltage changes excite a changing electric field, which in turn excites a changing magnetic field. This mutual excitation of electromagnetic fields causes the voltage change to propagate along the transmission line in the form of a wave. Therefore, voltage waves are traveling waves. Based on their propagation behavior, they can be classified as incident waves, reflected waves, and transmitted waves.

[0049] An incident wave can be a traveling wave that propagates towards an impedance interface (e.g., the output of a load or transmission line). A reflected wave can be a traveling wave that, after being reflected from the impedance interface, propagates in the opposite direction along the original transmission line. A transmitted wave can be a traveling wave that passes through the impedance interface and continues to propagate in the forward direction into a subsequent transmission line. The sign of the voltage amplitude can be used to characterize the potential polarity of the traveling wave.

[0050] A reflected wave is the result of the interaction between the incident wave and the impedance interface. The reflection coefficient can represent the ratio between the reflected wave voltage and the incident wave voltage. The transmission coefficient can be the ratio between the transmitted wave voltage and the incident wave voltage. The magnitude and sign of the reflection coefficient can be determined based on the incident-side impedance and the load-side impedance. The incident-side impedance can refer to the characteristic impedance of the transmission line on the incident wave propagation path before reaching the impedance interface. The load-side impedance can refer to the equivalent impedance of the region entered by the incident wave after passing through the impedance interface. The equivalent impedance can include at least one of the characteristic impedance of the transmission line or the load impedance. The reflection coefficient can satisfy the following formula (1). The transmission coefficient can satisfy the following formula (2).

[0051] (1)

[0052] (2)

[0053] in, This represents the reflection coefficient. This represents the transmission coefficient. This indicates the incident impedance. This represents the load-side impedance.

[0054] According to formula (1) above, when the load-side impedance is equal to the incident impedance, the reflection coefficient is zero, and there is no reflection. When the load side is short-circuited, the load-side impedance is zero, the reflection coefficient is -1, total reflection occurs, and the polarity is reversed. When the load side is open-circuited, and the load-side impedance is infinite, the reflection coefficient is 1, total reflection occurs, and the polarities are the same.

[0055] The node voltage of a transmission line node can be determined based on the incident and reflected wave voltages of that node. Essentially, it reflects the effect of matching conditions on incident wave propagation in the reflected wave. For example, the node voltage of a transmission line node can be the sum of the incident and reflected wave voltages of that node.

[0056] 5. Matching conditions

[0057] Matching conditions refer to the constraints that must be met between the load-side impedance and the incident impedance to ensure that no reflected waves are generated at the impedance interface. When the load-side impedance and the incident impedance are equal, they are matched. When the load-side impedance and the incident impedance are not equal, they are mismatched.

[0058] As one implementation method, when the incident impedance is equal to the characteristic impedance of the transmission line and the load impedance is equal to the load impedance, if the load impedance matches the characteristic impedance of the transmission line, then no reflected wave is generated at the impedance interface.

[0059] 6. Pulse parameters

[0060] Pulse parameters can be parameters that describe the waveform characteristics of a pulse. Pulse parameters can include at least one of the following: pulse width, rise time, fall time, pulse time interval, pulse amplitude (or peak voltage), repetition frequency, or pulse duty cycle.

[0061] Pulse width refers to the duration of a single pulse. Rise time refers to the time required for the pulse leading edge (or rising edge of the pulse) to rise from a first predetermined amplitude to a second predetermined amplitude. Fall time refers to the time required for the pulse trailing edge (or falling edge of the pulse) to fall from a third predetermined amplitude to a fourth predetermined amplitude. Pulse interval refers to the time interval between two adjacent pulses. The pulse interval can be determined based on the charging time of the transmission line and the pulse width. Charging time refers to the duration of the charging phase of the transmission line. In a continuous pulse sequence, the pulse width needs to be less than or equal to the pulse interval to prevent pulse overlap. Repetition frequency refers to the number of pulses output by the pulse generator per unit time. The repetition frequency and pulse interval are reciprocals of each other. In laser processing, plasma physics, or biomedical fields, a high repetition frequency means higher processing speed and better processing quality. Pulse amplitude refers to the maximum voltage of the pulse during its duration. Pulse duty cycle refers to the ratio between the pulse width and the pulse interval.

[0062] 7. Pulse forming line module

[0063] A pulse forming line module can be a module that uses the distributed parameter characteristics of a transmission line and the phenomena of wave transmission and reflection to convert stored electric field energy into an output pulse with a target pulse width and target pulse amplitude.

[0064] 8. Coaxial cable

[0065] A coaxial cable can be a transmission line consisting of at least two coaxial cylindrical conductors and an insulating medium between them. For example, the at least two coaxial cylindrical conductors may include an inner conductor and an outer conductor. The inner conductor may be located on a central axis and is used to transmit signals or energy. The outer conductor may coaxially surround the inner conductor to provide a current loop and electromagnetic shielding. An insulating medium may be filled between the inner and outer conductors for isolation and support. This structure confines electromagnetic energy within the inner and outer conductors, reducing outward radiation. Coaxial cables possess characteristics such as high characteristic impedance, good impedance matching characteristics, good electromagnetic shielding performance, and good mechanical flexibility.

[0066] The charging phase of a coaxial cable refers to the stage where electrical energy is stored as electric field energy within the distributed capacitance between the inner and outer conductors. The discharging phase refers to the process of releasing the electric field energy stored in the distributed capacitance to form an output pulse. The charging and discharging phases of the coaxial cable are explained below.

[0067] During the charging phase of the coaxial line, when a DC voltage is applied to the input terminal, a potential difference is formed between the inner and outer conductors, establishing an electric field. Charge gradually accumulates on the surface of the inner conductor, and an equal amount of opposite charge is induced on the surface of the outer conductor. The electric field energy is stored in the electric field between the inner and outer conductors.

[0068] During charging, the incident wave propagates from the input to the output of the transmission line at wave speed. In the areas traversed by the incident wave, the coaxial line is charged to the target voltage. In areas not traversed by the incident wave, the transmission line remains uncharged. After the incident wave reaches the output and undergoes multiple reflections, the node voltages of the transmission line tend to become uniform, reaching the charging voltage.

[0069] Once charging is complete, the voltage between the inner and outer conductors of the coaxial line stabilizes at the charging voltage, and the node voltage is uniformly distributed along the transmission line. Energy is stored in the distributed capacitance in the form of electric field energy.

[0070] During the discharge phase of the coaxial cable, the discharge can be triggered by the conduction of a switching element. This switching element can be connected to either the input or output terminal of the coaxial cable. When the switching element is on, the terminal of the coaxial cable connected to it is short-circuited to ground, generating a voltage surge that triggers the discharge. Let's take an example where the switching element is connected to the input terminal of the coaxial cable, and the load impedance is equal to the characteristic impedance of the coaxial cable. When the switching element is on, the node voltage at the input terminal of the coaxial cable abruptly drops from the charging voltage to zero. This voltage surge generates a negative voltage incident wave, which propagates along the coaxial cable towards the output terminal at a wave speed. During the propagation of the incident wave, the voltage on the coaxial cable drops to zero in the area traversed by the incident wave. In the area not traversed by the incident wave, the voltage on the coaxial cable remains the charging voltage. When the incident wave reaches the output terminal of the coaxial cable, since the load impedance is equal to the characteristic impedance of the coaxial cable, the reflection coefficient is zero, and the incident wave is absorbed by the load, with no reflected wave generated. The output pulse formed on the load is a rectangular pulse. The amplitude of the output pulse is equal to the charging voltage. The pulse width of the output pulse can be the time required for the incident wave to travel from the input to the output.

[0071] 9. Blumlein line (or Blumlein pulse forming line)

[0072] Blumlein lines are pulse-forming lines that operate based on dual transmission line coupling. A Blumlein line can include two transmission lines (e.g., a first transmission line and a second transmission line), which, through the control of switching elements, enable parallel charging and series discharging. The matching condition for a Blumlein line can be that the load impedance is twice the characteristic impedance of the transmission line.

[0073] Blumlein lines can be implemented using various types of transmission lines. For example, the two transmission lines can be coaxial lines, striplines, microstrip lines, or parallel pairs. The form of the blumlein lines can be configured according to actual needs, as long as the characteristic impedances of the two transmission lines are the same; no specific limitation is imposed here.

[0074] As one implementation, when the transmission line is a coaxial line, two coaxial lines (e.g., a first coaxial line and a second coaxial line) can be integrated into a compact structure using a three-layer coaxial structure (i.e., an inner cylinder, a middle cylinder, and an outer cylinder). The outer surface of the inner cylinder and the inner surface of the middle cylinder form the first coaxial line, with the inner cylinder serving as the inner conductor of the first coaxial line and the middle cylinder as the outer conductor of the first transmission line. The inner surface of the outer cylinder and the outer surface of the middle cylinder form the second coaxial line, with the middle cylinder serving as the inner conductor of the second transmission line and the outer cylinder as the outer conductor of the second transmission line.

[0075] To further increase the output voltage, multiple Blumlein lines can be cascaded to form a multi-stage stacked Blumlein line. This multi-stage stacked Blumlein line uses parallel charging and series discharging. During charging, the multiple stages are charged in parallel to their respective charging voltages. During discharging, the multiple stages are discharged in series, and the output voltage obtained by the load is the sum of the charging voltages of each stage.

[0076] 10. Parasitic parameters

[0077] Parasitic parameters can refer to unintended stray electrical parameters in a circuit that are generated during the circuit design process.

[0078] Parasitic parameters may include at least one of basic parasitic parameters, derived parasitic parameters, or comprehensive parasitic parameters.

[0079] Basic parasitic parameters may include at least one of parasitic capacitance, parasitic inductance, or parasitic resistance. Derived parasitic parameters may include coupling capacitance. Combined parasitic parameters may include coupling impedance or short-circuit parasitic impedance.

[0080] Parasitic capacitance can include at least one of interstage parasitic capacitance, parasitic capacitance to ground, switching transistor parasitic capacitance, or wiring parasitic capacitance. Interstage parasitic capacitance can refer to the unintended capacitance formed between conductors of a multi-stage transmission line. Parasitic capacitance to ground can include at least one of the parasitic capacitance of a transmission line conductor to ground, the parasitic capacitance of a load to ground, or the parasitic capacitance of a switching transistor node to ground. Switching transistor parasitic capacitance can refer to the parasitic capacitance within a switching transistor. Wiring parasitic capacitance can include at least one of the parasitic capacitance between conductors or the parasitic capacitance between a conductor and ground.

[0081] Parasitic inductance can include at least one of interstage parasitic mutual inductance, lead parasitic inductance, loop parasitic inductance, or switching transistor parasitic inductance. Interstage parasitic mutual inductance can be the mutual inductance formed by the loops of two adjacent transmission lines.

[0082] Parasitic resistance can include at least one of conductor parasitic resistance, contact parasitic resistance, switching transistor on-resistance, or dielectric loss resistance. Conductor parasitic resistance can include at least one of inner conductor parasitic resistance or outer conductor parasitic resistance.

[0083] Coupling capacitance describes the parasitic capacitance between two circuit nodes through the interaction of electric fields; it is a derived form of parasitic capacitance. Coupling capacitance can refer to any parasitic capacitance used to describe a coupling relationship. Coupling capacitance can include interstage coupling capacitance (or interstage parasitic capacitance), ground coupling capacitance (or ground parasitic capacitance), or input-output coupling capacitance. Input-output coupling capacitance can refer to the parasitic capacitance between the input and output terminals.

[0084] Coupling impedance can refer to the equivalent impedance between two circuit nodes or between a node and ground. Coupling impedance can be used to describe the ease with which energy is transferred via electromagnetic coupling. For example, coupling impedance can include at least one of inter-stage coupling impedance, transmission line-to-ground coupling impedance, or load-to-ground coupling impedance. Inter-stage coupling impedance can refer to the equivalent impedance between the conductors of two adjacent transmission lines. Load-to-ground coupling impedance can refer to the equivalent impedance between the load resistor and ground. Transmission line-to-ground coupling impedance can refer to the equivalent impedance of the transmission line to ground.

[0085] Short-circuit parasitic impedance refers to the equivalent impedance formed by unexpected parasitic parameters in the short-circuit path when the switch is on. Short-circuit parasitic impedance can be determined based on the on-resistance of the switch, contact parasitic resistance, and parasitic inductance.

[0086] 11. Common mode inductor

[0087] A common-mode inductor can consist of two windings or two conductors wound on the same magnetic core, such that the magnetic flux generated by the differential-mode current cancels each other out, and the magnetic flux generated by the common-mode current is superimposed in the same direction, thus presenting an inductor element with low impedance to differential-mode current and high impedance to common-mode current.

[0088] 12. Energy leakage path

[0089] An energy leakage path can refer to a path where current that should flow to the load flows to ground or another level via an unexpected parasitic parameter. An energy leakage path can include its starting point, its carrier, and its ending point. The starting point can be the high potential of a high-voltage level or transmission line, serving as the source of energy leakage. The carrier can be parasitic parameters (e.g., inter-stage parasitic capacitance, ground parasitic capacitance, or inter-stage parasitic inductance), forming a channel for energy transfer. The ending point can be ground or another low-voltage level.

[0090] 13. Stacking efficiency (or layering efficiency or stacking efficiency)

[0091] Superposition efficiency refers to the ratio between the actual output voltage and the theoretical output voltage of a Blumblein-type pulse generator. Superposition efficiency reflects how closely the actual circuit approximates the theoretical circuit and is one of the indicators for evaluating the performance of a Blumblein-type pulse generator (e.g., output voltage and superposition efficiency). It determines at least one of the following: output voltage stability, energy utilization efficiency, component stress level, or waveform quality. It is crucial for achieving reliable operation of high-performance pulse power in practical applications.

[0092] 14. Voltage Gain

[0093] Voltage gain refers to the ratio between the actual output voltage and the input voltage, reflecting the circuit's ability to amplify voltage.

[0094] In this embodiment, the voltage gain may include the voltage gain of the boost converter, the voltage gain of the Blumlein pulse forming line module, or the total voltage gain.

[0095] The voltage gain of a boost converter can be defined as the ratio between the boosted input voltage (i.e., the charging voltage of the transmission line) and the input voltage, reflecting the factor by which the boost converter amplifies the input voltage provided by the DC power supply.

[0096] The voltage gain of the Blumlein pulse forming line module can be defined as the ratio between the actual output voltage and the charging voltage of the transmission line, reflecting the factor by which the Blumlein pulse forming line module amplifies the charging voltage of the transmission line.

[0097] Total voltage gain can be defined as the ratio between the actual output voltage and the input voltage supplied by the DC power supply. Total voltage gain can be the product of the voltage gain of the boost converter and the voltage gain of the Blumlein pulse-forming line module. The actual output voltage can be determined based on the voltage gain, input voltage, and superposition efficiency; that is, the actual output voltage can be determined based on the charging voltage, superposition efficiency, and the number of stack-up stages of the Blumlein pulse-forming line module.

[0098] 15. Magnetic components

[0099] Magnetic elements can refer to components made of magnetic materials that can interact with conductors to form inductance or common-mode inductance. In the embodiments of this application, magnetic elements can be used to form common-mode inductance to increase coupling impedance, thereby suppressing energy leakage. Magnetic elements may include magnetic cores. The form of the magnetic core may include a toroidal shape. A toroidal magnetic core may be called a magnetic ring.

[0100] Magnetic materials can include amorphous nanocrystals, ferrites, permalloy, or silicon steel sheets. Amorphous nanocrystals can include iron-based amorphous nanocrystals, cobalt-based amorphous nanocrystals, or iron-nickel-based amorphous nanocrystals, etc. Iron-based amorphous nanocrystals can include iron-based nanocrystals. Amorphous nanocrystals have the characteristics of high magnetic permeability, low loss, and temperature stability.

[0101] In the embodiments of this application, the magnetic element sleeved on the load can be referred to as the first magnetic element. The magnetic element sleeved on the impedance element connected in series with the load can be referred to as the second magnetic element. The magnetic element sleeved on the transmission line can be referred to as the third magnetic element.

[0102] 16. Impedance element

[0103] An impedance element can refer to a component in a circuit that has impedance characteristics. An impedance element can impede the flow of current. An impedance element can include at least one of a resistor, inductor, or capacitor. Resistors can include glaze film resistors, carbon film resistors, metal mold resistors, wire-wound resistors, planar resistors, chip resistors, or water resistors, etc. Glaze film resistors have advantages such as excellent high-frequency characteristics, pulse resistance, and stable resistance values. In the embodiments of this application, an impedance element can refer to an auxiliary component connected in series with the load and fitted with a second magnetic element, which can indirectly suppress energy leakage through the load-to-ground leakage path and compensate for the output voltage.

[0104] The inventive concept of the embodiments of this application will be described below.

[0105] In the field of pulsed power technology, Blumelin lines are widely used due to their simple structure and ability to generate nanosecond-level short pulses. To further increase the output voltage, multiple single-stage transmission lines can be stacked, allowing Blumelin pulse generators to achieve voltage multiplication using the principles of parallel charging and series discharging. For example, if the Blumelin pulse forming line module in a Blumelin pulse generator includes N stages of transmission lines, the theoretical output voltage can be N times that of a Blumelin pulse generator consisting of single-stage transmission lines. N can be an integer greater than 1.

[0106] However, in practical applications, the following problems have been found:

[0107] Since the voltage gain of the Blumelin pulse forming line module is the ratio between the actual output voltage of the Blumelin pulse forming line module and the input voltage provided by the DC power supply, and the actual output voltage of the Blumelin pulse forming line module is determined based on the charging voltage of the transmission line, the superposition efficiency, and the number of stacked stages of the Blumelin pulse forming line module, the voltage gain of the Blumelin pulse forming line module is positively correlated with the charging voltage of the transmission line, the superposition efficiency, and the number of stacked stages of the Blumelin pulse forming line module. Therefore, to improve the voltage gain, it can be achieved by increasing the charging voltage, increasing the number of stacked stages, or improving the superposition efficiency.

[0108] However, it was found that increasing the charging voltage is limited by the capability of the DC power supply, due to the large size, high cost, and safety hazards of high-voltage DC power supplies. It was also found that as the number of stacked stages increases, the actual output voltage of the Blumelin-type pulse generator is lower than the theoretical output voltage, resulting in a decrease in stacking efficiency. This limits the application of the Blumelin-type pulse generator. Achieving high voltage gain and high stacking efficiency has become a problem that needs to be solved for the Blumelin-type pulse generator. The following describes the inventive concept for improving stacking efficiency and voltage gain.

[0109] To improve the superposition efficiency of the Blumlein-type pulse generator, it was found that one of the reasons for the decrease in superposition efficiency is the unexpected electromagnetic interaction between the multi-stage transmission lines. That is, when the transmission line discharges, its energy flows not only to the load but also to the adjacent stage transmission line. The above-mentioned energy leakage causes the energy that should have flowed to the load to be diverted, thereby reducing the actual output voltage and decreasing the superposition efficiency.

[0110] Further investigation revealed that energy leakage occurred through unintended current paths formed by parasitic parameters, which can be termed energy leakage paths. Parasitic parameters can include the parasitic capacitance between the load and ground. Energy leakage paths can include load-to-ground leakage paths (i.e., energy leakage paths from the load to ground). Load-to-ground leakage paths can be paths formed by the parasitic capacitance between the load and ground.

[0111] Furthermore, parasitic parameters may also include at least one of the parasitic capacitance of the transmission line conductor to ground or interstage parasitic parameters. Interstage parasitic parameters may include at least one of interstage parasitic capacitance or interstage parasitic inductance. Interstage parasitic capacitance may be the capacitance formed between the conductors of two adjacent transmission lines. Interstage parasitic inductance may be the mutual inductance formed by the loops of two adjacent transmission lines. Energy leakage paths may also include at least one of the following: transmission line-to-ground leakage path formed by the parasitic capacitance of the transmission line conductor to ground, interstage capacitance leakage path (or electric field coupling path) formed by interstage parasitic capacitance, or interstage mutual inductance leakage path (or magnetic field coupling path) formed by interstage parasitic inductance.

[0112] Regarding the load-to-ground leakage path, during the discharge phase, high-frequency pulse energy can flow directly to ground through the parasitic capacitance between the load and ground, instead of being absorbed by the load, resulting in energy leakage.

[0113] Regarding the transmission line to ground leakage path, during the discharge stage, high-frequency pulse energy can flow directly to ground through the parasitic capacitance between the conductor of the transmission line and ground, resulting in energy leakage.

[0114] Regarding the interstage capacitance leakage path, adjacent conductors are equivalent to two plates of the interstage parasitic capacitance, with the insulating medium between them acting as the dielectric. During the discharge phase, the voltage of the high-potential conductor changes drastically. This voltage change is coupled to the low-potential conductor of the adjacent stage via the interstage parasitic capacitance, generating an unexpected induced current on that conductor. This induced current consumes energy that should flow to the load, leading to energy leakage.

[0115] Regarding the interstage mutual inductance leakage path, during the discharge phase, when the current in the transmission line changes rapidly, unexpected induced voltages can be induced in the transmission lines of adjacent stages through interstage parasitic mutual inductance, leading to energy leakage.

[0116] Further investigation revealed that the degree of energy leakage along a leakage path is determined by the impedance characteristics of that path, which can be termed coupling impedance. Coupling impedance can refer to the equivalent impedance between two circuit nodes or between a node and ground. It describes the ease with which energy is transferred via electromagnetic coupling. Coupling impedance can include the load-to-ground coupling impedance. The load-to-ground coupling impedance can refer to the equivalent impedance between the load and ground. Furthermore, coupling impedance can also include at least one of inter-stage coupling impedance or the conductor-to-ground coupling impedance of a transmission line. Inter-stage coupling impedance can be determined based on inter-stage parasitic capacitance and inter-stage parasitic mutual inductance. According to Ohm's law, leakage current is inversely proportional to coupling impedance. Therefore, the smaller the coupling impedance, the more severe the energy leakage; conversely, the larger the coupling impedance, the more suppressed the energy leakage. Thus, one way to suppress energy leakage is to increase the coupling impedance of the leakage path.

[0117] Having determined that energy leakage can be suppressed by increasing coupling impedance, it was found that increasing coupling impedance can be achieved by reducing parasitic capacitance (e.g., parasitic capacitance of the load to ground, parasitic capacitance of the transmission line conductor to ground, or interstage parasitic capacitance) or increasing inductance.

[0118] To reduce parasitic capacitance, it has been found that this can be achieved by increasing the distance between transmission lines or reducing the area of ​​the conductors facing each other. However, these methods increase the size of the Blumelin pulse generator and reduce the power density, which contradicts the miniaturization and compactness of the Blumelin pulse generator. Therefore, increasing the coupling impedance by reducing parasitic capacitance is not an ideal solution.

[0119] To increase inductance, it was found that coupling impedance can be increased by placing inductive components in the energy leakage path without changing the original structure. This method offers greater design freedom and lower volume cost.

[0120] Therefore, it was determined that using components with inductive properties in the energy leakage path would increase the coupling impedance. Furthermore, these inductive components must be able to withstand high-voltage pulse environments, minimizing their impact on normal energy transmission (i.e., the normal current path). It is understood that, due to energy conservation, suppressing energy leakage will result in more energy flowing to the load. To this end, components with inductive properties were further investigated, and it was found that using magnetic components with high permeability in the energy leakage path to form a common-mode inductor can meet the above requirements, for the following reasons.

[0121] The normal current in the normal current path is identified as differential-mode current, while the unexpected current in the energy leakage path is identified as common-mode current. This is determined by the operating principle of the Blumein line and the physical structure of the energy leakage path. Differential-mode current refers to current transmitted in a differential mode. Common-mode current refers to current transmitted in a common-mode mode. Differential-mode current can mean that the current flowing through the signal conductor and return conductor of the transmission line is equal in magnitude and opposite in direction. Common-mode current can mean that the current flowing through the signal conductor and return conductor of the transmission line is equal in magnitude and same in direction. As one implementation, the signal conductor can be the inner conductor of the transmission line, and the return conductor can be the outer conductor.

[0122] Since the normal current path is positive terminal of the power supply → signal conductor → load → return conductor → negative terminal of the power supply, the currents flowing through the signal conductor and return conductor are equal in magnitude and opposite in direction. Therefore, the normal current is differential-mode current. In the energy leakage path, because the unexpected current is superimposed on the return conductor, the current flowing through the return conductor is now superimposed on the normal current, while the current flowing through the signal conductor remains normal. In this case, the currents flowing through the signal conductor and return conductor no longer satisfy the equilibrium condition. Decomposing the unbalanced state reveals that the currents flowing through the signal conductor and return conductor are equal in magnitude and in the same direction. Therefore, the unexpected current is common-mode current.

[0123] Therefore, to suppress energy leakage and minimize its impact on normal energy transmission, components with inductive properties need to exhibit selective suppression characteristics when the coupling impedance is increased. That is, the magnetic flux generated by the differential-mode current cancels each other out in the inductive component, resulting in a total magnetic flux of zero. Therefore, it presents low impedance to the differential-mode current, reducing its impact on normal energy transmission. The magnetic flux generated by the common-mode current is superimposed in the inductive component. According to Faraday's law of electromagnetic induction, the changing magnetic field induces an electromotive force, which opposes the change in current. Therefore, it presents high impedance to the common-mode current, suppressing energy leakage. Furthermore, it has been found that when two conductors share the same magnetic component, a common-mode inductance is formed. Common-mode inductors have the following two characteristics:

[0124] First, it can increase coupling impedance. Common-mode inductors introduce inductance into the energy leakage path, causing inductive reactance to dominate under high-frequency pulses, thus increasing coupling impedance. Furthermore, since inductance is positively correlated with permeability, inductance can be increased by using magnetic components with higher permeability, thereby increasing coupling impedance.

[0125] Secondly, it has selective suppression characteristics. Common-mode inductors exhibit low impedance to differential-mode current and high impedance to common-mode current. Thus, common-mode inductors can distinguish between energy that needs to be transmitted and energy that needs to be suppressed, exhibiting low impedance to the former and high impedance to the latter.

[0126] These two characteristics make common-mode inductors an ideal choice, as they can suppress energy leakage by increasing coupling impedance and reduce the impact on normal energy transmission through selective suppression.

[0127] Based on the above concept, the implementation of common-mode inductors in the energy leakage path was studied, as follows:

[0128] To address the load-to-ground leakage path, a first magnetic element with high permeability can be fitted onto the load, forming a common-mode inductor with the two terminals of the load (or the load and ground). This common-mode inductor introduces inductance into the load-to-ground leakage path, causing inductive reactance to dominate at high frequencies and increasing the coupling impedance between the load and ground. Furthermore, since normal current (i.e., the current flowing through the load) is transmitted in differential mode (equal in magnitude and opposite in direction at both ends of the load), the magnetic flux generated by these two currents in the first magnetic element is opposite in direction, canceling each other out, and the total magnetic flux can be zero. Therefore, the first magnetic element presents low impedance to normal current, thereby reducing the impact on normal energy transmission. In the case of energy leakage, the unexpected current is transmitted in common mode (equal in magnitude and same in direction at both ends of the load). The magnetic flux generated by these two currents in the first magnetic element is in the same direction, superimposed, and the total magnetic flux is not zero. According to Faraday's law of electromagnetic induction, a changing magnetic field generates an induced electromotive force, which opposes the change in current. Therefore, the first magnetic element presents high impedance to unexpected current, thereby suppressing energy leakage. Furthermore, during the discharge phase, the current flowing through the load (i.e., the normal current or the load current) changes, and the changing current generates a changing magnetic field. The changing magnetic field can induce a current in the first magnetic element. The magnitude of the current can be proportional to the rate of change of the current. This current can act on the load and can be superimposed on the normal current, thereby increasing the total current and compensating for the output pulse (e.g., the output voltage).

[0129] Furthermore, it was found that the load structure is diverse; for example, the load can be a load resistor. The load resistor can include at least one of the following: glaze film resistor, carbon film resistor, metal mold resistor, wire-wound resistor, planar resistor, chip resistor, or water resistor. The load structure may be difficult to directly mount the first magnetic element on, or mounting the first magnetic element may not be effective, thus limiting the versatility and feasibility of the first magnetic element mounting load scheme.

[0130] Therefore, an alternative solution is proposed for the first magnetic element being fitted onto the load: an impedance element can be connected in series at the front end of the load, and the second magnetic element can be fitted onto this impedance element. The impedance value of the impedance element can be less than or equal to a predetermined impedance value. The impedance value of the impedance element can be less than the impedance value of the load.

[0131] Therefore, a second magnetic element is fitted onto an impedance element connected in series with the load, forming a common-mode inductor. Current flows first through the impedance element and then through the load. The second magnetic element introduces inductance into the load-to-ground leakage path (including the impedance element's leakage path), increasing the load-to-ground coupling impedance. Furthermore, since normal current (i.e., the current flowing through the impedance element) is transmitted in differential mode (equal in magnitude and opposite in direction across the impedance element), the magnetic flux generated by these two currents in the second magnetic element is opposite in direction and cancels each other out, resulting in zero total magnetic flux. Therefore, the second magnetic element presents low impedance to normal current, thus reducing the impact on normal energy transmission. In the event of energy leakage, unintended current is transmitted in common mode (equal in magnitude and same in direction across the impedance element). The magnetic flux generated by these two currents in the second magnetic element is in the same direction and superimposed, resulting in a non-zero total magnetic flux. According to Faraday's law of electromagnetic induction, a changing magnetic field induces an electromotive force, which opposes the change in current. Therefore, the second magnetic element presents high impedance to unintended current, thus suppressing energy leakage. Furthermore, during the discharge phase, the current flowing through the impedance element (i.e., the normal current or load current) changes. This changing current generates a changing magnetic field, which induces a current in the second magnetic element. The magnitude of this current is proportional to the rate of change of current. This current acts on the impedance element and can be superimposed on the normal current, increasing the total current and generating a compensation voltage on the impedance element. Since the impedance element is connected in series with the load, this compensation voltage is superimposed on the load voltage, compensating for the output pulse (e.g., the output voltage). Moreover, because the impedance value of the impedance element is less than the impedance value of the load, the impedance element has a smaller impact on the total impedance and a smaller impact on the matching conditions. Simultaneously, because the impedance value of the impedance element is small, the compensation voltage generated on the impedance element by the induced current, although small, can still provide compensation and has a minimal impact on the load.

[0132] The above alternative indirectly suppresses energy leakage from the load to ground leakage path and compensates for output pulses by using series impedance elements, while maintaining matching conditions, and has higher versatility and feasibility.

[0133] To address transmission line leakage paths to ground, interstage capacitance leakage paths, or interstage mutual inductance leakage paths, the transmission line can be wound around a third magnetic element with high permeability, or the third magnetic element can be fitted onto the transmission line, forming a common-mode inductor with the signal and return conductors. This common-mode inductor introduces inductance into these paths, causing inductive reactance to dominate at high frequencies, increasing interstage coupling impedance, and suppressing interstage energy leakage. Furthermore, normal currents in the signal and return conductors are equal in magnitude and opposite in direction, resulting in magnetic flux cancellation and low impedance, reducing the impact on normal energy transmission.

[0134] Furthermore, multi-stage transmission lines can each have an independent third magnetic element. An independent third magnetic element can isolate the multi-stage magnetic circuits from each other. Therefore, the magnetic flux generated by a given stage of transmission line is confined to its own third magnetic element, making it difficult to affect adjacent stages. This further suppresses energy leakage through transmission line-to-ground leakage paths, inter-stage capacitance leakage paths, or inter-stage mutual inductance leakage paths.

[0135] Thus, the problem of decreased stacking efficiency was solved, and increasing the number of stacking stages became a feasible way to improve voltage gain. With the problem of improving stacking efficiency resolved, the next step was to investigate how to improve voltage gain.

[0136] As mentioned above, voltage gain is positively correlated with the charging voltage of the transmission line, superposition efficiency, and the number of stacked stages. Although the problem of superposition efficiency has been solved, increasing voltage gain by increasing the charging voltage is still limited by the capabilities of the DC power supply. This is because in related technologies, the charging voltage is equal to the input voltage provided by the DC power supply. Therefore, to increase voltage gain, the number of stacked stages needs to be increased. However, increasing the number of stacked stages may increase the number of inter-stage energy leakage paths, thereby increasing energy leakage, reducing superposition efficiency, and also increasing the size of the Blummlein-type pulse generator. Therefore, it is worth considering whether it is possible to obtain a higher voltage gain with the same number of stacked stages by increasing the ratio between the charging voltage and the input voltage. In other words, is it possible to obtain a voltage higher than its input voltage from a low-voltage DC power supply as the charging voltage for the transmission line through a circuit?

[0137] Based on the above considerations, it is found that the boost converter meets the above requirements. A boost converter can be a circuit that can convert low-voltage DC voltage into high-voltage DC voltage. The voltage gain of the boost converter is determined according to the duty cycle and the number of stages, as shown in the following formula (3).

[0138] Therefore, while improving superposition efficiency by suppressing energy leakage, this paper proposes to address the problem of insufficient voltage gain at its source by using a boost converter to increase the DC power supply voltage as the charging voltage for the transmission lines. By increasing the charging voltage, the number of stacked stages is reduced while achieving the same actual output voltage, thereby reducing the number of inter-stage energy leakage paths and indirectly improving superposition efficiency.

[0139] Based on the above, this application proposes a Blumein-type pulse generator that uses magnetic elements to suppress electromagnetic coupling in transmission lines (i.e., uses magnetic elements to suppress energy leakage) to increase coupling impedance and improve superposition efficiency, and uses a boost converter to improve voltage gain.

[0140] The above describes the inventive concept of the embodiments of this application.

[0141] The Blumlein-type pulse generator proposed in this application will be described below with reference to the accompanying drawings. It is divided into three parts: Part One describes the Blumlein-type pulse generator; Part Two describes the simulation analysis of the Blumlein-type pulse generator; and Part Three describes the experimental verification of the Blumlein-type pulse generator. Regarding Part One, for ease of understanding, we will first refer to... Figure 1 The Blumlein-type pulse generator is described as a whole, followed by a description of each module in conjunction with the accompanying drawings. Figure 2 The boost converter is explained, in conjunction with the appendix. Figures 3A-3B ,as well as Figures 4A-4C This section explains the Blumlein pulse forming line module, in conjunction with... Figures 4B-4C , Figures 5A-5B and Figures 6A-6B The coupling suppression module is explained. Finally, it is combined with... Figure 7 The specific implementation of the Blumlein-type pulse generator, as well as the generation of the output pulse and the adjustment of the pulse parameters, are explained.

[0142] Figure 1 A block diagram of a Blummlein-type pulse generator according to an embodiment of this application is shown.

[0143] like Figure 1 As shown, a Blumlein-type pulse generator may include a boost converter, a Blumlein pulse forming line module, a controller, and a coupling suppression module.

[0144] The boost converter may include a first switching unit and at least one boost unit. The first switching unit may include at least one first switching transistor. The boost unit may include an energy storage subunit and a voltage multiplier subunit. Furthermore, the boost unit may also include a rectifier subunit. The energy storage subunit may include an energy storage element for storing electrical energy. For example, the energy storage element may include at least one of an energy storage inductor or an energy storage capacitor. The voltage multiplier subunit may include a voltage multiplier element for achieving voltage multiplication. For example, the voltage multiplier element may include a voltage multiplier capacitor. The rectifier subunit may be used for unidirectional conduction, suppressing energy backflow and ensuring correct current flow. For example, the rectifier subunit may include at least one of an interstage charging diode or an output coupling diode.

[0145] The Blumlein pulse forming line module may include multiple transmission lines. The form of the transmission lines can be configured according to actual business needs and is not limited here. For example, the transmission lines may be coaxial cables. The transmission lines may include a first transmission line and a second transmission line. Furthermore, the Blumlein pulse forming line module may also include at least one of a first switching unit or a second switching unit. The second switching unit may include at least one second switching transistor. The first and second switching transistors may be power switching transistors. Power switching transistors may include metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistors (IGBTs), or wide-bandgap power semiconductor devices. Wide-bandgap power semiconductor devices may include wide-bandgap power semiconductor devices represented by silicon carbide (SiC) and gallium nitride (GaN).

[0146] The coupling suppression module may include multiple first magnetic elements sleeved on the load. Optionally, the coupling suppression module may include multiple second magnetic elements sleeved on an impedance element connected in series with the load. Optionally, the coupling suppression module may include multiple first magnetic elements sleeved on the load and multiple second magnetic elements sleeved on an impedance element connected in series with the load.

[0147] The size and type of the first and second magnetic elements can be configured according to actual business needs and are not limited here. For example, the first magnetic element can be a first magnetic ring. Optionally, the second magnetic element can be a second magnetic ring. The first and second magnetic elements can be made of magnetic materials with high permeability to achieve a large inductance in a small volume, thereby facilitating the miniaturization and compactness of the Blumein-type pulse generator. For example, the magnetic materials of the first and second magnetic elements can be amorphous nanocrystalline. As one implementation, the first and second magnetic elements may include amorphous nanocrystalline magnetic rings.

[0148] An impedance element can refer to an auxiliary component that has impedance characteristics, is connected in series with the load, and is fitted with a second magnetic element. It indirectly suppresses energy leakage through the load-to-ground leakage path and compensates for the output voltage. An impedance element can include at least one of a resistor, inductor, or capacitor. The impedance value of the impedance element can be less than the impedance value of the load. For example, the impedance value of the impedance element may differ from the impedance value of the load by two orders of magnitude. As one implementation, the load can be a load resistor, and the impedance element can be a resistor. The resistance value of the resistor can be 10Ω. The resistance value of the load resistor can be 1kΩ. Because the impedance value of the impedance element is less than the impedance value of the load, its impact on the total impedance is smaller, and therefore, its impact on the matching conditions is smaller.

[0149] Furthermore, the impedance element and the second magnetic element can be designed as standard components, suitable for loads of various structures, improving versatility and feasibility, and reducing design and manufacturing costs. The current induced by the second magnetic element during energy leakage suppression generates heat, which is generated in the impedance element, reducing the additional thermal burden on the load and contributing to stable operation and extended service life.

[0150] The input terminal of the boost converter can be connected to the positive terminal of a DC power supply. The output terminal of the boost converter can be connected to the input terminal of the Blumlein pulse forming line module via a first switching unit. For example, the first terminal of the first switching unit can be connected to both the output terminal of the boost converter and the input terminal of the Blumlein pulse forming line module, and the second terminal of the first switching unit can be grounded or connected to the negative terminal of the DC power supply. The output terminal of the boost converter can be the output terminal of the voltage multiplier sub-unit. The input terminal of the Blumlein pulse forming line module can be the input terminal of a multi-stage sensing line. Therefore, the first switching unit can be connected in parallel between the output terminal of the boost converter and ground, and also in parallel between the input terminal of the transmission line and ground. The control terminal of the first switching unit can be connected to the output terminal of the controller. The output terminal of the Blumlein pulse forming line module can be connected to a load, an impedance element, and a second switching unit. This connection method makes the first switching unit a component of both the output circuit of the boost converter and the input circuit of the Blumlein pulse forming line module.

[0151] Therefore, the controller can coordinate the boost converter's boost function, the transmission line's charging (or energy storage) function, and the transmission line's pulse generation function by controlling the operating state of the first switching unit. For example, the controller can output corresponding control signals to cause the first switching unit to be in the corresponding operating state at the corresponding stage. The operating state of the first switching unit can include acting as a chopper switch for the boost converter during the charging stage and as a trigger switch for pulse generation during the discharging stage. The charging stage can refer to the period used to store energy in the transmission line, and the discharging stage can refer to the period during which the transmission line discharges to the load to generate output pulses. A detailed explanation follows.

[0152] During the charging phase of the multi-stage transmission line, the controller controls the first switching unit to operate in a chopping mode, enabling the boost converter to charge the multi-stage transmission line using the enhanced DC voltage. This results in the charging voltage of the multi-stage transmission line being the enhanced DC voltage, and the distributed capacitance of the transmission line stores electric field energy. During the discharging phase of the multi-stage transmission line, the controller controls the first switching unit to turn on, causing the energy stored in the multi-stage transmission line to discharge to the load, generating output pulses.

[0153] During the charging phase of the transmission line, the controller can control the first switching unit to operate in a chopping mode, that is, it can control the first switching unit to alternately turn on and off. Chopping mode refers to cutting a continuous DC voltage into a pulse sequence, and achieving voltage conversion through the synergistic effect of the energy storage inductor and voltage multiplier capacitor in the multi-stage boost unit. Chopping mode can include at least one chopping cycle. A chopping cycle can include a conduction phase where the first switching unit is in the on state and a turn-off phase where the first switching unit is in the off state.

[0154] During the conduction phase of the chopping cycle, the controller can output a control signal to the control terminal of the first switching unit to indicate conduction, thus enabling the first switching unit to conduct. Consequently, with the first switching unit conducting, the DC power supply can charge multiple energy storage inductors in parallel, causing the inductor current to rise linearly, and electrical energy to be converted into magnetic field energy and stored in the inductors. The voltage doubler capacitor can maintain the original voltage, and the output of the boost converter can be maintained by the voltage doubler capacitor.

[0155] During the turn-off phase of the chopping cycle, the controller can output a control signal to the control terminal of the first switching unit to indicate turn-off, thus turning off the first switching unit. When the first switching unit is off, since the inductor current of the energy storage inductor cannot change abruptly, a reverse induced electromotive force is generated. The energy storage inductor and the voltage doubler capacitor form a charging circuit. The inductor voltage of the energy storage inductor is superimposed on the DC power supply voltage, forming a DC voltage higher than the DC power supply voltage. This superimposed voltage charges the voltage doubler capacitor through the rectifier subunit, increasing its capacitor voltage. Multiple voltage doubler capacitors can be cascaded at the output terminal, allowing the boost converter's output voltage to be the sum of the capacitor voltages of the multiple voltage doubler capacitors. Furthermore, the distributed capacitance of the multi-stage transmission lines is charged by applying the output voltage to the multi-stage transmission lines through the first switching unit; the charging of the voltage doubler capacitors and the charging of the transmission lines are parallel processes. During the turn-on phase of the chopping cycle, the first switching unit turns on, grounding the boost converter's output terminal. Without the voltage doubler capacitor, the boost converter's output voltage would drop to zero, and the transmission lines would discharge accordingly. As a charged energy storage element, the voltage doubler capacitor maintains the voltage during the conduction phase. This is because the voltage across the voltage doubler capacitor cannot change abruptly. Even if the output of the boost converter is short-circuited, the voltage doubler capacitor can still maintain its voltage. The transmission line is connected to the voltage doubler capacitor through the first switching unit that is turned off; therefore, the charging voltage of the transmission line is also maintained. Furthermore, the voltage doubler capacitor can compensate for energy loss due to leakage current in the transmission line, thus stabilizing the charging voltage of the transmission line.

[0156] During the aforementioned chopping cycle, the output voltage of the boost converter increases, and the charging voltage of the transmission line also increases synchronously. Thus, the boost converter can increase the input voltage provided by the DC power supply. After multiple chopping cycles, the output voltage of the boost converter gradually increases to the target voltage (i.e., the increased input voltage), and the charging voltage of the transmission line also gradually increases to the target voltage. The voltage gain between the target voltage and the input voltage can be configured according to actual application requirements and is not limited here. The voltage gain between the target voltage and the input voltage can be determined based on the duty cycle of the first switching unit. The duty cycle can refer to the ratio between the on-time of the first switching unit and the switching cycle duration of the first switching unit.

[0157] Once the multi-stage transmission lines are fully charged, the controller can output a control signal to the control terminal of the first switching unit to indicate continuous conduction, ensuring the first switching unit remains on. With the first switching unit on, the input terminals of each of the multi-stage transmission lines are grounded. Consequently, the input voltage of the transmission lines abruptly changes from the target voltage (i.e., the charging voltage) to zero, generating an incident wave that propagates to the load. This wave, after reflection and transmission, forms an output pulse on the load.

[0158] A coupling suppression module can be used to suppress energy leakage and compensate for output pulses. The coupling suppression module may include at least one of a plurality of first magnetic elements sleeved on the load, or a plurality of second magnetic elements sleeved on an impedance element connected in series with the load. The first magnetic elements can form a common-mode inductance with the two terminals of the load. The second magnetic elements can form a common-mode inductance with the two terminals of the impedance element. Thus, for the load-to-ground leakage path, the coupling suppression module sleeves magnetic elements to form a common-mode inductance to increase the load-to-ground coupling impedance, thereby suppressing energy leakage to ground. Furthermore, the induced current can be used to actively compensate for output pulses. For an explanation of how to increase the coupling impedance, suppress energy leakage, and compensate for output pulses, please refer to the description of the inventive concept above, which will not be repeated here.

[0159] According to embodiments of this application, since the boost converter can increase the low input voltage provided by the DC power supply, a higher charging voltage is obtained from the source without relying on a high-voltage DC power supply, solving the problem of voltage gain being limited by the DC power supply capability. Due to the increased charging voltage, the number of transmission line stack-up stages in the Blummlein pulse forming line module can be reduced to achieve the same actual output voltage, thereby reducing the number of inter-stage energy leakage paths and lowering the pressure on the coupling suppression module to suppress energy leakage. The first switching unit is multiplexed as both the chopper switch of the boost converter and the trigger switch for pulse generation, reducing the number of components and simplifying the structure. The controller achieves timing separation of the charging and discharging stages by switching the operating state of the first switching unit, ensuring that the transmission line is charged before discharging. The multi-stage transmission lines employ parallel charging and series discharging to achieve voltage multiplication. A first magnetic element is fitted onto the load, or a second magnetic element is fitted onto an impedance element connected in series with the load, forming a common-mode inductor with the two conductors (the two terminals of the load or the two terminals of the impedance element). This common-mode inductor presents low impedance to normal current, reducing the impact on normal energy transmission, and high impedance to unexpected current, effectively suppressing interference and achieving selective suppression. Furthermore, the first or second magnetic element introduces common-mode inductance into the energy leakage path from the load to ground, making the inductive reactance dominant under high-frequency pulses, increasing the coupling impedance from the load to ground, effectively suppressing unexpected current, suppressing energy leakage, and thus improving superposition efficiency. In addition, during discharge, the current changes, generating a changing magnetic field. This changing magnetic field induces a current in the first or second magnetic element, which acts on the load or impedance element and superimposes with the normal current, achieving active compensation of the output voltage. The aforementioned boost converter increases the charging voltage, raising the theoretical upper limit of the actual output voltage. The Blumlein pulse forming line module further multiplies the voltage through multi-stage stacking. The controller separates the charging and discharging timing, ensuring stable system operation. The coupling suppression module suppresses energy leakage and compensates for output pulses, improving superposition efficiency and actual output voltage. The synergy of these four components enhances superposition efficiency and actual output voltage, thus achieving a balance between high voltage gain, high-level superposition efficiency, and nanosecond-level short pulses. Furthermore, by embedding the second magnetic element within an impedance element connected in series with the load, the problem of directly embedding the first magnetic element due to diverse load structures is solved. This indirectly suppresses energy leakage from the load to ground and compensates for the output voltage, improving versatility and feasibility.

[0160] The above provides an overall description of the Blumlein-type pulse generator. The following section will focus on... Figure 2 The boost converter described in the embodiments of this application will be further explained.

[0161] Figure 2A circuit diagram of a boost converter according to an embodiment of this application is shown.

[0162] like Figure 2 As shown, the boost converter may include a first switching unit and M boost units. The first switching unit may include a first switching transistor S1. The M boost units may include a first boost unit, a second boost unit, ..., a m-th boost unit, ..., a (M-1)-th boost unit, and an M-th boost unit. M may be an integer greater than or equal to 1. m may be an integer greater than or equal to 1 and less than or equal to M. m∈{1, 2, ..., M-1, M}.

[0163] The m-th stage boost unit may include the m-th stage energy storage sub-unit, the m-th stage voltage multiplier sub-unit, and the m-th stage rectifier sub-unit. The m-th stage energy storage sub-unit may include the m-th stage energy storage inductor L. m The m-th voltage multiplier subunit may include the m-th voltage multiplier capacitor C. m (or energy storage capacitor C) m The m-th stage rectifier subunit may include the m-th stage interstage charging diode D. m1 Coupled with the m-th stage output diode D m2 .

[0164] The first terminal of the first-stage energy storage inductor L1 (i.e., the input terminal of the boost converter) is connected to the DC power supply U. dc The positive terminal is connected. The second terminal of the first-stage energy storage inductor L1 can be connected to the first-stage interstage charging diode D. 11 The first electrode and the first stage are coupled to the output diode D. 12 The first pole connection.

[0165] m-th stage energy storage inductor L m The first terminal can be connected to the interstage charging diode D of the (m-1)th stage. （m-1）1 The second stage and the (m-1)th stage voltage multiplier capacitor C m-1 The first pole connection. The m-th stage energy storage inductor L. m The second terminal can be connected to the m-th stage interstage charging diode D. m1 The first stage and the m-th stage are coupled to the output diode D. m2 The first electrode connection. The m-th stage interstage charging diode D. m1 The second electrode can be connected to the m-th voltage multiplier capacitor C. m The first stage connection. The m-th stage coupling output diode D. m2 The second terminal (i.e., the output terminal of the boost converter) can be connected to the first terminal (i.e., the first terminal of the first switching unit) of the first switching transistor S1 and the input terminal (i.e., the input terminal of the multi-stage transmission line) of the Blumlein pulse forming line module.

[0166] The m-th voltage multiplier capacitor C mThe second pole can be connected to the DC power supply U dc The negative terminal is connected. The second terminal of the first switching transistor S1 (i.e., the second end of the first switching unit) can be connected to the DC power supply U. dc The negative terminal is connected. DC power supply U dc The negative terminal is grounded. The control terminal of the first switching transistor S1 (i.e., the control terminal of the first switching unit) can be connected to the control terminal of the controller. The first-stage coupling output diode D... 12 To the Mth stage coupling output diode D M2 It adopts a parallel output structure, with each of its second poles connected to the same output bus.

[0167] The m-th stage energy storage inductor L m The charging stage (or the m-th stage energy storage inductor L) m During the energy storage stage, the first switch S1 is turned on. This causes a near short circuit between the first and second terminals of the first switch S1, forcing the output bus potential to be pulled close to ground. Due to the m-th stage coupling output diode D... m2 The voltage at the first terminal is higher than the voltage at the second terminal; therefore, the m-th stage coupling output diode D... m2 Forward conduction. Due to the interstage charging diode D of the m-th stage. m1 The voltage at the first electrode is less than the voltage at the second electrode; therefore, the interstage charging diode D at the m-th stage... m1 Reverse cutoff.

[0168] When m=1, the charging current path of the first-stage energy storage inductor L1 is the DC power supply U. dc Positive terminal → First-stage energy storage inductor L1 → First-stage coupling output diode D 12 →DC power supply U dc The negative electrode.

[0169] When 1 < m ≤ M, the m-th energy storage inductor L m The charging current path is the (m-1)th stage voltage multiplier capacitor C. m-1 First pole → m-th energy storage inductor L m →m-th stage coupled output diode D m2 →The (m-1)th stage voltage multiplier capacitor C m-1 The second pole.

[0170] Therefore, the first-stage energy storage inductor L1 to the M-stage energy storage inductor L M Synchronous energy storage, with voltage multiplier capacitors C1 through C1 (stage 1) and C2 (stage M). M There is no energy exchange, and the capacitor voltage remains stable. This is due to the interstage charging diode D of the m-th stage. m1 Reverse cutoff, blocking the m-th stage energy storage inductor L m Interstage charging diode D of the m-th stage m1The connection between them, the m-th energy storage inductor L m The inductor current is coupled through the m-th stage output diode D. m2 The current flows to ground through the first switching transistor S1, but not to the m-th voltage multiplier capacitor C. m Therefore, the m-th voltage multiplier capacitor C m Without additional charging current, the capacitor voltage will not be increased. Furthermore, the m-th stage voltage multiplier capacitor C... m The second terminal is grounded, and the first terminal is connected via the m-th interstage charging diode D. m1 Connected to the outside, while the m-th stage interstage charging diode D m1 Reverse cutoff, m-th stage voltage multiplier capacitor C m With both ends open and no discharge path, its own charge is difficult to release. The capacitor voltage cannot change abruptly; without a charging / discharging path, the capacitor voltage remains constant. Therefore, whether in steady-state operation or a transient process, during the conduction of the first switch S1, the m-th voltage multiplier capacitor C... m This maintains the voltage charged into the first switching transistor S1 during the previous turn-off cycle, preventing voltage drop or boost, and providing stable voltage support for energy storage in the subsequent energy storage inductor. The first-stage voltage multiplier capacitor C1 to the Mth-stage voltage multiplier capacitor C... M Maintain capacitor voltage.

[0171] The m-th stage energy storage inductor L m The discharge stage (or the m-th stage voltage multiplier capacitor C) m During the charging stage, the m-th voltage multiplier capacitor C m The boost phase or load resistance R L During the power supply phase, the first switch S1 is turned off. This disconnects the current path during the charging phase, but the current path from the first-stage energy storage inductor L1 to the M-stage energy storage inductor L... M The inductor currents of each stage cannot change abruptly, and the induced electromotive force causes the first-stage energy storage inductor L1 to the M-stage energy storage inductor L... M The voltage at each of their second terminals increases. Consequently, the interstage charging diode D in the first stage... 11 To the Mth stage interstage charging diode D M1 Forward conduction, the first stage coupler output diode D 12 To the Mth stage coupling output diode D M2 Forward conduction forms the charging current path for the voltage multiplier capacitor and the charging current path for the multi-stage transmission line of the Blumlein pulse forming line module, realizing multi-stage voltage boost and energy output.

[0172] Therefore, for the m-th voltage multiplier capacitor C m The charging current path,

[0173] When m=1, the charging current path of the first-stage voltage multiplier capacitor C1 is the second terminal of the first-stage energy storage inductor L1 → the first-stage interstage charging diode D. 11 → The m-th voltage multiplier capacitor C m →m-th stage energy storage inductor L m The first end.

[0174] When 1 < m ≤ M, the m-th voltage multiplier capacitor C m The charging current path is the m-th stage energy storage inductor L m The second terminal → the m-th interstage charging diode D m1 → The m-th voltage multiplier capacitor C m →The (m-1)th stage voltage multiplier capacitor C m-1 →m-th stage energy storage inductor L m The first end.

[0175] For the charging current path of multi-stage transmission lines,

[0176] When m=1, the charging current path of the transmission line is the second terminal of the first-stage energy storage inductor L1 → the first-stage coupled output diode D. 12 →Output bus →Transmission line →First terminal of the first stage energy storage inductor L1.

[0177] When 1 < m ≤ M, the charging current path of the transmission line is the m-th energy storage inductor L. m The second end → the m-th stage coupling output diode D m2 →Output bus→Transmission line→M-1th stage voltage multiplier capacitor C m-1 →m-th stage energy storage inductor L m The first end.

[0178] Therefore, the first-stage energy storage inductor L1 to the M-stage energy storage inductor L M The stored energy is released synchronously when the first switch S1 is turned off: a portion of the energy is released via the m-th interstage charging diode D. m1 To the m-th voltage multiplier capacitor C m Charging increases the voltage multiplier capacitor C at the m-th stage. m The capacitor voltage. Another portion of the energy is coupled through the m-th stage output diode D. m2 The energy flows to the output bus. This is due to the first-stage energy storage inductor L1 to the Mth-stage energy storage inductor L... M Synchronous energy release occurs when multiple output branches simultaneously transfer energy to the output bus, and the amplitudes of the multi-stage output voltages are essentially equal. After multiple output branches are connected in parallel, the total output current is the sum of the individual output currents of each branch, achieving multi-stage voltage multiplication and superposition. This results in an output voltage on the output bus that is higher than the input voltage provided by the DC power supply. Based on the above, the first-stage energy storage inductor L1 to the M-stage energy storage inductor L... MEnergy is released to the voltage multiplier capacitors C1 through C1 (stage 1) and C2 (stage M). M Charging achieves a gradual increase in voltage. Multiple energy levels are connected in parallel and converged to the output bus to charge the multiple transmission lines.

[0179] As one implementation, the output voltage of the boost converter (i.e., the boosted input voltage) satisfies the following formulas (3) and (4).

[0180] (3)

[0181] (4)

[0182] in, This indicates the output voltage of the boost converter. Indicates DC power supply U DC The input voltage provided. This indicates the duty cycle during which the first switch S1 is turned on. This indicates the voltage gain of the boost converter. This indicates the number of stages in the boost converter.

[0183] The boost converter has been explained above. The following explanation uses a coaxial transmission line as an example, with reference to the accompanying diagram, to illustrate the Blumlein pulse forming line module. Figures 3A-3B For the case where the Blumlein pulse forming line module includes a single-stage coaxial line. Figures 4A-4C For Blumein pulse forming line modules that include multiple levels of coaxial cables, a Blumein pulse forming line module containing a single level of coaxial cable can be called a single-level Blumein pulse forming line module. A Blumein pulse forming line module containing multiple levels of coaxial cable can be called a multi-level stacked Blumein pulse forming line module.

[0184] Figure 3A A circuit diagram of a single-stage Blumlein pulse forming line module is shown.

[0185] like Figure 3A As shown, a single-stage Blumlein pulse forming line module may include a first-stage coaxial line, a first switching unit, and an isolation charging resistor R. C The first switching unit may include a first switching transistor S1. The first-stage coaxial line may include a first first-stage coaxial line T. 11 Second and first coaxial line T 12 First-order coaxial line T 11 This can refer to the first coaxial cable in a Class 1 coaxial cable series. The second Class 1 coaxial cable T 12 It can refer to the second coaxial line in the first-level coaxial line.

[0186] First-level coaxial cable T 11 The outer conductor can be coaxial with the second and first stages T. 12 The outer conductor is connected and grounded. Load resistance R L The first end can be coaxial with the first stage T 11 The inner conductor is connected, and the load resistance R L The second end can be coaxial with the second first stage T 12 The inner conductor is connected. Isolation charging resistor R C The first terminal can be connected to the output voltage of the boost converter. The positive terminal of the (i.e., the charging voltage of the Blumlein pulse forming line module) is connected. Isolation charging resistor R C The second end can be coaxial with the first pole and the first stage of the first switch S1. 11 The inner conductor is connected. The second terminal of the first switching transistor S1 can be coaxial with the first stage T. 11 The outer conductor and the output voltage of the boost converter The negative terminal connection.

[0187] exist Figure 3A Based on this, the following will combine Figure 3B The working process of a single-stage Blumlein pulse forming line module is explained.

[0188] Figure 3B A schematic diagram of the operation of a single-stage Blumlein pulse forming line module is shown.

[0189] like Figure 3B As shown, the first-order coaxial line T 11 Second and first coaxial line T 12 The lengths are all When the first switch S1 is turned on, a voltage wave is generated and propagated. The propagation speed of the voltage wave on the coaxial line is... DC power supply U DC The charging voltage is End A can refer to the first-level coaxial cable T. 11 The input terminal (i.e., the first terminal of the first switching transistor S1). Terminal B can refer to the second-stage coaxial line T. 12 The output terminal. Terminal B can be an open circuit terminal.

[0190] With the first switch S1 turned off, the first stage coaxial line T 11 Second and first coaxial line T 12 Charged to charging voltage In this state, the circuit is in a steady-state charging state, preparing for the generation of subsequent pulses.

[0191] When the first switch S1 is turned on

[0192] exist In the case of the first level coaxial line T 11 Second and first coaxial line T 12 The node voltage is .

[0193] exist In the case of the first level coaxial line T 11 The input terminal (i.e., terminal A) is grounded, generating a negative incident wave. Incident wave Incident wave voltage Incident wave From terminal A to the load resistor R L transmission.

[0194] Due to the incident wave First-order coaxial line T 11 Transmission has not yet reached the load resistance R. L Therefore, the second-order first-order coaxial line T 12 The node voltage is still Regarding the first-order coaxial line T... 11 , has been incident wave The node voltage of the covered nodes is The node voltage of the uncovered node remains the same. This forms a flow from terminal A to the load resistor R. L The voltage step that propels the movement.

[0195] exist In the case of incident wave Reaching the load resistance R L Incident wave Reflection and transmission occur. The reflection coefficient can be determined according to formula (1) mentioned above. The transmission coefficient is determined using formula (2). Therefore, the transmitted wave (i.e., the wave entering the second-first level coaxial line T) 12 (incident wave) incident wave voltage Reflected wave reflected wave voltage .

[0196] exist In the case of incident wave From the load resistor R L Transmitted to end B, second-level coaxial cable T 12 Incident wave The node voltage of the covered nodes is The node voltage of the uncovered node remains the same. , forming from the load resistance R L The voltage step that propels the voltage towards terminal B.

[0197] Reflected wave From the load resistor R L Transmission to end A, first-level coaxial cable T 11 The reflected wave The node voltage of the covered nodes is The node voltage of the uncovered node remains 0, forming a voltage drop from the load resistance R. L A voltage step that propels the voltage towards terminal A.

[0198] exist In the case of incident wave Upon reaching point B, the reflected wave Upon reaching point A, since points A and B are mismatched boundaries, the incident wave... Reflection occurs, generating a reflected wave. The reflection coefficient is determined according to the formula described above. Reflected wave Reflection occurs, generating a reflected wave. The reflection coefficient is determined according to the formula described above. Reflected wave From terminal B to the load resistor R L Transmission, reflection waves The reflected wave voltage is Reflected wave From terminal A to the load resistor R L Transmission, reflection waves The reflected wave voltage is .

[0199] exist In the case of reflected waves From terminal B to the load resistor R L Transmission, second-level first-stage coaxial cable T 12 The reflected wave The node voltage of the covered nodes is The node voltage of the uncovered node remains the same. This forms a flow from terminal B to the load resistor R. L The voltage step that propels the movement.

[0200] Reflected wave From terminal A to the load resistor R L Transmission, first-level coaxial cable T 11 The reflected wave The node voltage of the covered nodes is The node voltage of the uncovered node remains the same. This forms a flow from terminal A to the load resistor R. L The voltage step that propels the movement.

[0201] exist In the case of reflected waves Reaching the load resistance R L Reflected wave Reaching the load resistance R L Superimposed reflected waves voltage and reflected wave voltage, load resistance R L The voltage is zero. Therefore, the first stage coaxial line T... 11 Second and first coaxial line T 12 The node voltages are all zero.

[0202] Based on the above, in the load resistance R L The pulse width formed at the location is The pulse amplitude is The pulse is used to convert DC voltage to pulse voltage. Similarly, if the first switch S1 is set at terminal B, that is, if it is the second switch S2, then the load resistor R... L This generates pulses with opposite polarities and equal amplitudes. Furthermore, if the pulse width needs adjustment, it can be achieved by controlling the turn-on timing of the first switch S1 and the second switch S2.

[0203] The following is combined Figures 4A-4C The multi-level stacked Blumein pulse forming line module described in the embodiments of this application will be further explained.

[0204] Figure 4A A schematic diagram of a multi-level stacked Blummlein pulse forming line module according to an embodiment of this application is shown.

[0205] like Figure 4A As shown, the multi-stage stacked Blumlein pulse forming line module may include N-stage transmission lines. Additionally, it may include a first switching unit ( Figure 4A (Not shown). The nth-level transmission line may include the first nth-level transmission line T. n1 Second nth stage transmission line T n2 The first nth stage transmission line T n1 It can refer to the first transmission line in the nth-order transmission line. The second nth transmission line T n2 It can refer to the second transmission line in the nth stage transmission line. N can be an integer greater than 1. n can be an integer greater than or equal to 1 and less than or equal to N. n∈{1,2,...,N-1,N}.

[0206] When n=1, the first coaxial line T of the first level11 The inner conductor can be connected to the output terminal of the boost converter. First stage coaxial line T 11 The outer conductor can be grounded. The inner conductor T of the first-order coaxial line... 11 Can be coaxial with the second and first stages T 12 The inner conductor can be connected. Second-order first-stage coaxial line T 12 The outer conductor can be connected to the load (e.g., load resistance R). L The first end of the circuit is connected to the ground.

[0207] In the case that 1 < n ≤ N, the first and nth level coaxial line T n1 The inner conductor can be connected to the output terminal of the boost converter. First and nth stage coaxial line T n1 The inner conductor can be coaxial with the second nth stage T. n2 The inner conductor is connected. The first and nth coaxial lines T n1 The outer conductor can be grounded. The second and nth coaxial line T n2 The outer conductor can be coaxial with the first (n-1)th stage T. （n-1）1 The outer conductor is connected to ground. First and second level coaxial line T 21 Second and second level coaxial line T 22 The first and N-1th level coaxial line T （N-1）1 The second-N-1th coaxial line T （N-1）2 And the first and Nth level coaxial line T N1 Second Nth coaxial line T N2 For the connection relationships, see the first and nth level coaxial line T. n1 Second and nth coaxial line T n2 The explanation will not be repeated here.

[0208] The working process of the multi-level stacked Blumlein pulse forming line module is similar to that of the single-level Blumlein pulse forming line module, and will not be described in detail here.

[0209] Figure 4B An equivalent circuit diagram of a Blummlein pulse forming line module during the discharge phase, according to an embodiment of this application, is shown.

[0210] like Figure 4B As shown, a coaxial cable can employ a three-layer coaxial structure, including two transmission lines sharing a common intermediate conductor. During the charging phase, the two transmission lines are charged in parallel with the same polarity. During the discharging phase, due to structural constraints, the two transmission lines are connected in reverse series loops with opposite voltage polarities, and their voltage amplitudes are added together. Therefore, the equivalent voltage of a single-stage Blumein line is... .

[0211] The equivalent circuit diagram of the Blumlein pulse forming line module may include the equivalent voltage. Equivalent impedance The coupling impedance of the return conductor of the transmission line to ground (e.g., the coupling impedance of the outer conductor of a coaxial cable to ground). Coupling impedance between transmission lines and load resistance Coupling impedance to ground . . It can be an integer greater than 1. Equivalent impedance With the characteristic impedance of the transmission line Between . Figure 4B In this context, n represents N and g represents G.

[0212] The superposition efficiency of a single-switch Blumein pulse forming line module is affected by the coupling impedance of the return conductor of the transmission line to ground. and load resistance Coupling impedance to ground Therefore, the analysis of the embodiments in this application focuses on the coupling impedance of the return conductor of the transmission line to ground. and load resistance Coupling impedance to ground .

[0213] The superposition efficiency of the single-switch Blumein pulse forming line module is affected by the coupling impedance of the outer conductor of the coaxial line to ground. and load resistance Coupling impedance to ground Therefore, the analysis of the embodiments in this application focuses on the coupling impedance of the outer conductor of the coaxial cable to ground. and load resistance Coupling impedance to ground .

[0214] Assuming that the coupling impedance of each of the multi-stage coaxial cables to ground is the same, its coupling impedance value is... And neglecting other non-resistive losses. Therefore, according to Kirchhoff's laws, the node voltage is... nodes Current at It can satisfy the following formula (5).

[0215] (5)

[0216] in, Indicates the node voltage is nodes The current at that point. This represents the current flowing through the outer conductor on the coaxial line and to ground.

[0217] For the current involved in formula (5), it can be expressed by the corresponding node voltage and coupling impedance, which can satisfy the following formulas (6) and (7).

[0218] (6)

[0219] (7)

[0220] in, Represents a node The node voltage at that location. This indicates the output voltage of the boost converter (i.e., the charging voltage of the coaxial line).

[0221] Assume that the node voltages can satisfy a proportional relationship, i.e., the common ratio is... .if Meet the conditions and Then, the following formula (8) can be satisfied.

[0222] (8)

[0223] because For ease of calculation, we can assume that the following formulas (9) and (10) are satisfied.

[0224] (9)

[0225] (10)

[0226] Substituting formulas (9) and (10) into formula (8), we can satisfy the following formula (11).

[0227] (11)

[0228] public ratio The following formula (12) can be satisfied.

[0229] , (12)

[0230] because Therefore, node voltage It can satisfy the following formula (13).

[0231] (13)

[0232] in, and It can be a constant determined by boundary conditions. At node voltages... At node 0, and the node voltage is nodes At this point, the following formula (14) needs to be satisfied.

[0233] (14)

[0234] By solving formula (14), we obtain the following formula (15).

[0235] (15)

[0236] Will , , and Substituting into formula (8), we obtain the node voltage. The equivalent voltage magnitude satisfies the following formula (16).

[0237] (16)

[0238] Substituting the above formula (16) into formula (6), the correctness of formula (16) can be verified. Using the same method, the node current... The equivalent current magnitude satisfies the following formula (17) and the node impedance. The equivalent impedance satisfies the following formula (18).

[0239] (17)

[0240] (18)

[0241] thus, Figure 4B The equivalent circuit diagram can be further simplified to Figure 4C The equivalent circuit diagram is shown.

[0242] Figure 4C An equivalent circuit diagram of another Blummlein pulse forming line module during the discharge phase, according to an embodiment of this application, is shown.

[0243] like Figure 4C As shown, the equivalent circuit diagram of the Blumlein pulse forming line module can include node voltages. Node impedance Load resistance Coupling impedance to ground .

[0244] The following is combined Figures 4B-4C , Figures 5A-5B and Figures 6A-6BThe coupling suppression module described in the embodiments of this application will be further explained.

[0245] The output voltage of the Blumlein type pulse generator and superposition efficiency It can satisfy the following formula (19).

[0246] (19)

[0247] In an ideal situation, if and Then the following conditions are satisfied. , , Therefore, it can be determined that, under different impedance ratios, the stacking efficiency increases with the number of stacked stages. The general trend of increase. Superimposed efficiency. With cascaded series The relationship between them is as follows Figure 5A and Figure 5B As shown.

[0248] Figure 5A The embodiments of this application are shown in Multiple impedance ratios In the case of superposition efficiency With cascaded series A diagram illustrating the relationship between them.

[0249] Figure 5B The embodiments of this application are shown in Multiple impedance ratios In the case of superposition efficiency With cascaded series A diagram illustrating the relationship between them.

[0250] like Figure 5A and Figure 5B As shown, with the same number of stack-up stages, the stacking efficiency increases with the increase of the impedance ratio. With the same stacking efficiency, the number of stack-up stages increases with the increase of the impedance ratio.

[0251] As can be seen from the above, increasing the coupling impedance can improve the superposition efficiency. Therefore, the embodiments of this application propose to place multiple first magnetic elements on the load, or to place multiple first magnetic elements on an impedance element connected in series with the load, or to place multiple first magnetic elements on the load and multiple first magnetic elements on an impedance element, so as to increase the coupling impedance of the load to ground during the discharge stage of the transmission line, suppress energy leakage, and thereby improve the superposition efficiency.

[0252] During the discharge phase of the transmission line, the coupling control module can introduce a common-mode inductor in the energy leakage path from the load to ground using at least one of a plurality of first magnetic elements or a plurality of second magnetic elements, forming an impedance network with the parasitic capacitance in the energy leakage path to increase the coupling impedance and suppress energy leakage.

[0253] For example, a common-mode inductor is introduced into the energy leakage path from the load to ground. And the internal coupling capacitance between the load and the first magnetic element (or the impedance element and the second magnetic element). common mode inductor Parasitic capacitance of load to ground In series connection, under high-frequency pulse excitation, the total impedance of the energy leakage path is increased, thereby suppressing energy leakage and increasing the actual output voltage. Furthermore, the induced current can be applied to the load or impedance element to compensate for the output pulse. In the above case, the equivalent coupling impedance in parallel with the load can satisfy the following formula (20).

[0254] (20)

[0255] In the Blumlein pulse forming line module, the parasitic capacitance of the load to ground Approximately 10pF. Under high-frequency pulse excitation, the parasitic capacitance of the load to ground... The capacitive reactance reaches several thousand ohms. To suppress energy leakage through the aforementioned energy leakage paths, a common-mode inductor is used. Parasitic capacitance of load to ground The impedance of the resulting series LC branch needs to be configured to be at least a first predetermined multiple of the load resistance. This first predetermined multiple can be greater than 1. For example, the first predetermined multiple can be 20.

[0256] The following is combined Figure 6A and Figure 6B Explain the above formula (20).

[0257] Figure 6A A schematic diagram showing a plurality of first magnetic elements sleeved on a load according to an embodiment of the present application is shown.

[0258] like Figure 6A As shown, the first magnetic element can be a first magnetic ring.

[0259] Figure 6B A schematic diagram of a coupling impedance structure formed by sleeved multiple first magnetic elements on a load according to an embodiment of this application is shown.

[0260] like Figure 6B As shown, the coupling impedance structure may include a common-mode inductor. The load and the internal coupling capacitor of the first magnetic element Parasitic capacitance of load to ground .

[0261] One implementation method is to determine the inductance of the common-mode inductor based on the pulse width of the output pulse and a predetermined inductive reactance. For example, the inductance of the common-mode inductor can be determined based on the equivalent angular frequency of the output pulse and a predetermined inductive reactance. The equivalent angular frequency of the output pulse can be determined based on the equivalent frequency of the output pulse. The equivalent frequency of the output pulse can be determined based on the pulse width of the output pulse.

[0262] For example, the equivalent frequency of the output pulse and equivalent angular frequency It satisfies the following formula (21).

[0263] (twenty one)

[0264] in, This indicates the pulse width of the output pulse.

[0265] For example, it can be based on a predetermined resistance. Determine the required common mode inductance Required common-mode inductor The following formula (22) can be satisfied.

[0266] (twenty two)

[0267] In one implementation, the first magnetic element can be a first magnetic ring. The number of first magnetic rings can be determined based on the ratio between the inductance of the common-mode inductor and the inductance of the first magnetic ring. The inductance of the first magnetic ring can be determined based on the permeability and dimensional parameters of the first magnetic ring. For example, the permeability of the first magnetic ring can include the free permeability of the first magnetic ring and the effective relative permeability of the first magnetic ring at high frequencies. The dimensional parameters of the first magnetic ring can include the effective cross-sectional area and the effective magnetic path length of the first magnetic ring. The effective cross-sectional area of ​​the first magnetic ring can be determined based on the outer diameter, the inner diameter, and the height of the first magnetic ring. The effective magnetic path length of the first magnetic ring can be determined based on the outer diameter and the inner diameter of the first magnetic ring.

[0268] In one implementation, the second magnetic element can be a second magnetic ring. The number of second magnetic rings can be determined based on the ratio between the inductance of the common-mode inductor and the inductance of the second magnetic rings. The inductance of the second magnetic ring can be determined based on the permeability of the second magnetic ring and its dimensional parameters. For example, the permeability of the second magnetic ring can include the free permeability of the second magnetic ring and the effective relative permeability of the second magnetic ring at high frequencies. The dimensional parameters of the second magnetic ring can include its effective cross-sectional area and effective magnetic path length. The effective cross-sectional area of ​​the second magnetic ring can be determined based on its outer diameter, inner diameter, and height. The effective magnetic path length of the second magnetic ring can be determined based on its outer diameter and inner diameter.

[0269] For example, the inductance of a magnetic ring The following formula (23) can be satisfied.

[0270] (twenty three)

[0271] in, It can represent the number of turns in a winding. This represents the vacuum permeability of the magnetic ring. This represents the effective relative permeability of the magnetic ring at high frequencies. This represents the effective cross-sectional area of ​​the magnetic ring. This indicates the effective magnetic path length of the magnetic ring.

[0272] For example, the effective cross-sectional area of ​​a magnetic ring and the effective magnetic circuit length of the magnetic ring The following formula (24) can be satisfied.

[0273] (twenty four)

[0274] in, This indicates the outer diameter of the magnetic ring. This indicates the inner diameter of the magnetic ring. This indicates the height of the magnetic ring.

[0275] For example, the number of magnetic rings The following formula (25) can be satisfied.

[0276] (25)

[0277] Therefore, the number of the first magnetic ring and the number of the second magnetic ring can be determined according to the above formulas (23) to (25).

[0278] To ensure a high safety margin in the suppression effect, the number of magnetic rings can be configured to be a second predetermined multiple of the value determined by formula (25). The second predetermined multiple can be greater than 1. For example, the second predetermined multiple can be 1.2 to 1.5 times, which conforms to the target impedance specification for parasitic leakage current suppression.

[0279] As one implementation method, multiple first magnetic elements can be coaxially sleeved on the first magnetic element to form a magnetic shielding cylinder.

[0280] In one implementation, multiple second magnetic elements can be coaxially sleeved on the second magnetic element connected in series with the load to form a magnetic shielding cylinder.

[0281] As one implementation, the coupling suppression module may also include multiple third magnetic elements sleeved on the transmission line. Furthermore, during the discharge phase, the coupling suppression module may utilize multiple third magnetic elements to increase the suppression of energy leakage paths caused by inter-electrode parasitic parameters.

[0282] For example, the third magnetic element can be a third magnetic ring. The magnetic material of the third magnetic element can be amorphous nanocrystalline. As one implementation, the third magnetic element may include an amorphous nanocrystalline magnetic ring.

[0283] For an explanation of how the third magnetic element suppresses the energy leakage path caused by interstage parasitic parameters, please refer to the section on the inventive concept above, which will not be repeated here.

[0284] Furthermore, due to the relatively long length of coaxial cables, a spiral winding method can be used to achieve a compact structure. Since spiral winding increases the distance between transmission lines, it increases the coupling impedance. Moreover, the spiral structure makes the coaxial cables more compact, facilitating multi-stage stacking. Therefore, spiral winding is a way to achieve structural compactness and improve coupling impedance. The flat-top and trailing-edge distortion of wound pulse forming lines is also relatively small. Therefore, using a spiral winding method for coaxial cables not only makes the structure compact and facilitates stacking, but also increases the impedance of the coupled transmission lines, improving stacking efficiency and waveform quality.

[0285] In addition, the first magnetic element fitted onto the load, the second magnetic element fitted onto the impedance element connected in series with the load, and the third magnetic element fitted onto the transmission line all need to satisfy the volt-second product in order to reduce core saturation during pulse excitation.

[0286] Because of the high equivalent frequency of a single pulse, magnetic components in pulse-excited environments operate at high magnetization rates and high equivalent frequencies. Iron-based nanocrystals, as a balanced core material, possess characteristics such as high saturation induction, low coercivity, fast pulse response speed, and high and stable permeability. Therefore, iron-based nanocrystals are suitable for high-frequency power conversion applications. Furthermore, due to the structure and inherent hysteresis characteristics of magnetic components, iron-based nanocrystals exhibit lower high-frequency losses compared to other magnetic materials. A comparison of the magnetic material parameters of iron-based nanocrystals and manganese-zinc ferrites is shown in Table 1 below.

[0287]

[0288] Table 1

[0289] As shown in Table 1, iron-based nanocrystals outperform manganese-zinc ferrites in terms of magnetic saturation strength, coercivity, resistivity, initial relative permeability, and Curie temperature. Therefore, the magnetic material of the first, second, or third magnetic element can be iron-based nanocrystals.

[0290] The coupling suppression module has been explained above. The following section will discuss this in conjunction with... Figure 7 The specific implementation of the Blummlein-type pulse generator in the embodiments of this application, as well as the generation of the output pulse and the adjustment of the pulse parameters, are described.

[0291] Figure 7 A circuit diagram of a Blummlein-type pulse generator according to an embodiment of this application is shown.

[0292] like Figure 7 As shown, a Blumlein-type pulse generator may include a boost converter, a Blumlein pulse forming line module, a controller, and a coupling suppression module.

[0293] For details on boost converters, please refer to the documentation for [link to documentation]. Figure 2 For details regarding the Blumlein pulse forming line module, please refer to the documentation for... Figures 4A-4B For details regarding the coupling suppression module, please refer to the documentation for [specific details]. Figures 4B-4C , Figures 5A-5B and Figures 6A-6B The explanation will not be repeated here.

[0294] In addition, the Blummlein pulse forming line module may also include a second switching unit. The second switching unit may include a second switching transistor S2. A description of the second switching unit is provided below.

[0295] The following is combined Figure 7 The generation of the output pulse and the adjustment of the pulse parameters are further explained.

[0296] As one implementation, the Blummlein pulse forming line module may also include a second switching unit. The second switching unit can be connected to the output of the Blummlein pulse forming line module, i.e., it can be connected between the Blummlein pulse forming line module and the load. Specifically, the first end of the second switching unit can be connected to the output of the multi-stage transmission line, and the second end of the second switching unit can be connected to the first end of the load, which can be grounded. The control end of the second switching unit can be connected to the output of the controller. The second switching unit and the first switching unit are located at opposite ends of the transmission line, forming a symmetrical structure, providing the hardware foundation for achieving bipolar pulse output.

[0297] Therefore, the controller can turn on the second switching unit to generate a unipolar pulse on the load with the opposite polarity to that generated when the first switching unit is on. That is, the controller can turn on the second switching unit and turn off the first switching unit. When the second switching unit is on, the output terminals of each of the multi-stage transmission lines are grounded. Consequently, the output voltage of the transmission lines abruptly drops from the target voltage to zero, generating an incident wave towards the load. After reflection and transmission, this wave forms a unipolar pulse on the load with the opposite polarity to the output pulse generated when the first switching unit is on. A unipolar pulse can refer to a pulse with the same polarity. For example, all pulses may be positive or all pulses may be negative.

[0298] Furthermore, during the charging phase of the transmission line, the controller can control the first switching unit to operate in a chopping mode and control the second switching unit to turn off. During the discharging phase of the transmission line, depending on the polarity of the required unipolar pulse, the controller can control the first switching unit to turn on and the second switching unit to turn off, or vice versa.

[0299] According to embodiments of this application, by independently controlling the second switching unit to turn on, a unipolar pulse with the opposite polarity to that when the first switching unit is on can be formed on the load without changing the circuit connection. Furthermore, the dual-switching unit design eliminates the need for an additional polarity conversion circuit; polarity switching can be achieved simply by controlling the on / off state of different switching units, thereby simplifying the circuit structure. The second and first switching units can operate independently, improving reliability. Moreover, since the pulse width is determined based on the transmission line length and wave velocity, unipolar pulses with opposite polarities can have the same pulse width.

[0300] As one implementation method, the controller can also alternately control the second switching unit and the first switching unit to conduct in order to generate a bipolar pulse sequence on the load.

[0301] A bipolar pulse sequence refers to a pulse sequence in which positive and negative pulses alternate. Unlike unipolar pulses (where the pulses have the same polarity), the polarity of pulses in a bipolar pulse sequence changes alternately, forming a sequence of alternating positive and negative pulses. In a bipolar pulse sequence, the amplitude and width of the pulses can be the same, with only the polarity changing. This symmetrical bipolar pulse sequence can provide a balanced positive and negative electric field, reduce charge accumulation, and improve processing performance.

[0302] The first switching unit is connected to the input terminal of the Blummlein pulse forming line module (i.e., the input terminal of the transmission line), and the second switching unit is connected to the output terminal of the Blummlein pulse forming line module (i.e., the output terminal of the transmission line). This symmetrical configuration makes it possible to trigger discharge from either end. Specifically, when the first switching unit is on and the second switching unit is off, the discharge begins at the input terminal of the transmission line, forming a first polarity pulse (e.g., a positive pulse) on the load. When the first switching unit is off and the second switching unit is on, the discharge begins at the output terminal of the transmission line, forming a second polarity pulse (e.g., a negative pulse) on the load.

[0303] A bipolar pulse sequence (i.e., a sequence formed by a first polarity pulse and a second polarity pulse) can be formed in the following way:

[0304] During the discharge phase of the transmission line, the controller can turn on the first switching unit and turn off the second switching unit, with the node voltage of the multi-stage transmission line being the target voltage (i.e., the charging voltage). When the first switching unit is on, the input terminals of each of the multi-stage transmission lines are grounded. Consequently, the input terminal voltage of the transmission line abruptly changes from the target voltage (i.e., the charging voltage) to zero, generating an incident wave transmitted to the load. After reflection and transmission, this wave forms a first polarity pulse on the load. When the first polarity pulse ends, the controller can turn off the first switching unit, awaiting the next charging phase.

[0305] Upon the end of the first polarity pulse, the energy stored in the multi-stage transmission line has been fully released. The controller can then control the first switching unit to operate in chopping mode, while the second switching unit is turned off, allowing the boost converter to recharge the multi-stage transmission line. After several chopping cycles, the charging voltage of the transmission line gradually increases to the target voltage. For details on how the boost converter charges the multi-stage transmission line, please refer to the relevant section above; it will not be repeated here. Once the transmission line charging is complete, the controller can control the first switching unit to pause its chopping operation, awaiting the start of the transmission line charging phase to form the next pulse (i.e., the second polarity pulse).

[0306] During the discharge phase of the transmission line, the controller can turn on the second switching unit and turn off the first switching unit, with the node voltage of the multi-stage transmission line reaching the target voltage (i.e., the charging voltage). With the second switching unit on, the output terminals of each stage of the transmission line are grounded. Consequently, the output voltage of the transmission line abruptly drops from the target voltage (i.e., the charging voltage) to zero, generating an incident wave transmitted to the load. This wave, after reflection and transmission, forms a second polarity pulse on the load. The second polarity pulse has the same pulse width and amplitude as the first polarity pulse, but with opposite polarity. Upon the end of the second polarity pulse, the controller can turn off the second switching unit, awaiting the next charging phase.

[0307] Upon the end of the second polarity pulse, the energy stored in the multi-stage transmission line has been fully released. The controller can then control the first switching unit to operate in chopping mode again, while the second switching unit is turned off, allowing the boost converter to recharge the multi-stage transmission line. After several chopping cycles, the charging voltage of the transmission line gradually increases to the target voltage.

[0308] Repeating the above process, the controller can alternately control the first and second switching units to conduct, recharging the transmission line after the pulse ends, and then forming alternating polarity pulses on the load. In the bipolar pulse sequence, the amplitudes and pulse widths of the first and second polarity pulses are equal, thus balancing the positive and negative energy.

[0309] According to embodiments of this application, by alternately controlling the first and second switching units to conduct, a bipolar pulse sequence alternating between positive and negative pulses is formed on the load, expanding the application range of the Blumlein pulse forming device. Since the amplitude and pulse width of the first and second polarity pulses in the bipolar pulse sequence are equal, symmetry of the bipolar pulse sequence is achieved, reducing uneven processing results caused by inconsistent positive and negative pulse parameters. Because the charging process for generating pulses of opposite polarity is the same, there is no need to change the operating state of the boost converter, simplifying the control logic. In applications such as plasma processing, the bipolar pulse sequence can reduce charge accumulation caused by unipolar pulses, improving processing performance.

[0310] The time interval between adjacent pulses can be determined based on the charging duration of the first switching unit. Therefore, the charging speed can be changed by adjusting the charging power of the boost converter, thereby adjusting the time interval between adjacent pulses.

[0311] To further improve the performance of the Blumlein-type pulse generator and expand its output pulse adjustment capability, embodiments of this application provide an extended configuration scheme for the first switching unit and the second switching unit.

[0312] In one implementation, the first switching unit may include multiple first switching transistors. These multiple first switching transistors may be connected to the input of a Blummlein pulse forming line module; for example, they may be connected to the input of a multi-stage transmission line.

[0313] Therefore, the controller can control the conduction timing of multiple first switching transistors to adjust at least one of the repetition frequency or pulse width of the output pulse. The adjustment of repetition frequency and pulse width is explained below.

[0314] The pulse frequency can be adjusted in the following way.

[0315] One implementation method is to adjust the repetition frequency by interleaving the conduction of multiple first switches. For example, the controller can interleave the conduction of K first switches, thereby doubling the repetition frequency of the output pulses of the N-stage transmission lines. K can be an integer greater than or equal to 1 and less than or equal to N. Each first switch can be connected to at least one stage of the transmission line. The controller can control the k-th first switch to conduct, discharging the transmission line corresponding to the k-th first switch and generating the k-th pulse on the load. By interleaving the conduction of K first switches and determining the transmission lines participating in the discharge, multiple stages of transmission lines can generate their own pulses. The time interval between two pulses can be less than the charging time of the transmission line. This method allows the pulse period to generate K pulses, making the repetition frequency of the output pulse K times the original repetition frequency, thus achieving a doubling of the repetition frequency. K can be an integer greater than 1.

[0316] Pulse width adjustment can be achieved in the following way.

[0317] One implementation method is to adjust the pulse width by controlling the turn-on timing of the switching transistors that generate positive and negative pulses.

[0318] As another implementation method, pulse width adjustment can be achieved by determining the transmission lines of different lengths participating in the discharge. That is, the controller can control the conduction combination of multiple first switching transistors to determine the transmission lines participating in the discharge, thereby adjusting the pulse width of the output pulse.

[0319] Since the pulse width of a transmission line is proportional to its length, output pulses with different pulse widths can be generated by selecting transmission lines of different lengths to participate in the discharge. The lengths of the multi-stage transmission lines can be the same or different. Based on the pulse width, the transmission lines that need to participate in the discharge are determined, and the controller can then control the first switch corresponding to that transmission line to turn on.

[0320] According to embodiments of this application, by interleaving the conduction of multiple switching transistors (e.g., multiple first switching transistors or multiple second switching transistors), the repetition frequency of the output pulse is multiplied, achieving high repetition rate output. By controlling the conduction time interval of the multiple switching transistors (e.g., multiple first switching transistors or multiple second switching transistors), the pulse width of the output pulse is adjusted, achieving continuous adjustment of the pulse width. Therefore, the adjustable repetition frequency and pulse width enable the Blummlein-type pulse generator to meet the pulse parameter requirements of various application scenarios.

[0321] In one implementation, the second switching unit may include multiple second switching transistors. These multiple second switching transistors can be connected to the input terminals of the Blumlein pulse forming line module; for example, they can be connected to the input terminals of a multi-stage transmission line.

[0322] Therefore, the controller can control the turn-on timing of multiple second switching transistors to adjust at least one of the repetition frequency or pulse width of the output pulse.

[0323] As one implementation method, the controller can interleave the conduction of multiple second switches, thereby multiplying the repetition frequency of the output pulse.

[0324] In one implementation, the controller can control the conduction combination of multiple second switching transistors to determine the transmission line involved in the discharge, thereby adjusting the pulse width of the output pulse.

[0325] For instructions on how to adjust the repetition frequency or pulse width of the output pulse by controlling the second switching unit, please refer to the above explanation on how to achieve adjustment by controlling the first switching unit, which will not be repeated here.

[0326] In addition, the first and second switching units can cooperate to generate output pulses with a pulse width smaller than the pulse width of the transmission line.

[0327] As one implementation method, the controller can control the conduction time interval between the first switching unit and the second switching unit to generate an output pulse with a pulse width smaller than the pulse width of the transmission line.

[0328] The controller can trigger the second switching unit to conduct after a configured conduction time interval, starting with the first switching unit's conduction trigger pulse, thereby obtaining an output pulse with a pulse width smaller than the transmission line's pulse width. The transmission line's pulse width refers to the pulse width formed after a complete voltage wave process. The transmission line's pulse width can be determined based on the transmission line's length and the voltage wave's propagation speed.

[0329] When the transmission line is fully charged, the controller can turn on the first switching unit and turn off the second switching unit. The first switching unit grounds the input terminal of the transmission line, generating an incident wave that is transmitted to the load. The load voltage begins to rise, and an output pulse begins to form. During the configured on-time interval, the first switching unit remains on, and the pulse is continuously output. When the configured on-time interval is reached from the moment the first switching unit is turned on, the controller can turn on the second switching unit, turn off the first switching unit, and ground the input terminal of the transmission line, causing the load voltage to drop to zero and the output pulse to be forcibly truncated. Thus, the pulse width of the output pulse is equal to the on-time interval. When the on-time interval is less than the pulse width of the transmission line, the pulse width of the output pulse is less than the pulse width of the transmission line. Therefore, the pulse width can be continuously adjusted by adjusting the on-time interval.

[0330] According to an embodiment of this application, by adjusting the conduction time interval, a pulse width ranging from a narrower pulse width to the pulse width of the transmission line can be obtained, with a large pulse width adjustment range, thus achieving continuous adjustment of the pulse width.

[0331] The first part has been explained above. The second part will be explained below with reference to the accompanying drawings.

[0332] To verify the feasibility of integrating a Blumelein pulse forming line module into a multi-stage boost converter, a simulation model of a Blumelein-type pulse generator based on a 2-stage boost converter and a 10-stage stacked Blumelein pulse forming line module is constructed using simulation software (e.g., PSpice) according to the circuit diagram described above. The first and second switching transistors can be SiC MOSFETs. A coaxial cable can be used as the transmission line. This coaxial cable has the following characteristics: a withstand voltage of 1500V, a unit inductance of 250nH / m, a potential capacitance of 100pF / m, a characteristic impedance of 50Ω, polyethylene as the insulating medium, and a propagation delay of 10ns per meter. The energy storage inductor in the boost converter can be a nanocrystalline iron core inductor.

[0333] One of the conditions for establishing a traveling wave process is that, with the first switch turned on, the equivalent inductance of the boost converter is considered an open circuit, which requires the equivalent resistance to... The absolute value is much greater than the characteristic impedance of the transmission line. The order of magnitude needs to be greater than 10 times, that is Load resistance The impedance matching condition must be met, i.e. . The number of stacked levels is shown in Table 2 below. The component parameters used in the simulation model of the Blumlein-type pulse generator are shown in Table 2 below.

[0334]

[0335] Table 2

[0336] The following is combined Figures 8A-8C Explain the simulation results of the simulation model of the Blumlein-type pulse generator.

[0337] Figure 8A The simulation waveform of the Blumlein-type pulse generator with a repetition rate of 20 kHz, according to an embodiment of this application, is shown.

[0338] like Figure 8A As shown, with an input voltage of 390V and a duty cycle of 0.4, the charging voltage of the transmission line is approximately 1.03kV, which is about 2.64 times the input voltage. The simulation model of the Blumlein-type pulse generator produces a narrow pulse with an amplitude of approximately 10.3kV, a pulse width of 100ns, and a rise time of 32ns on the matched load resistor.

[0339] Figure 8B The embodiments of this application are shown in multiple The diagram illustrates the relationship between pulse amplitude and superposition efficiency under certain conditions.

[0340] like Figure 8B As shown, considering only the coupling impedance of the load to ground, multiple The pulse amplitude waveform. With As the efficiency decreases, the superposition efficiency decreases accordingly, and the lost energy is dissipated and leaked through the parasitic coupling path. Figure 8B middle It can represent .

[0341] Figure 8C A schematic diagram of a simulated waveform of a pulse current flowing through a switching transistor according to an embodiment of this application is shown.

[0342] like Figure 8C As shown, the simulated waveform of the pulse current of the first switching transistor can provide a reference for evaluating whether the switch can withstand instantaneous pulse current in subsequent switch selection.

[0343] The above explains Part Two; the following section, in conjunction with the accompanying diagram, explains Part Three.

[0344] To verify the feasibility of the Blumlein-type pulse generator proposed in the embodiments of this application, a method such as... was also developed. Figure 9 The experimental platform of the Blumlein-type pulse generator is shown.

[0345] Figure 9A schematic diagram of the experimental platform of the Blummlein-type pulse generator according to an embodiment of this application is shown.

[0346] like Figure 9 As shown, the oscilloscope (e.g., KEYSIGHTS MSO-X 3054A) has a bandwidth of 1 GHz and a sampling rate of 4 GS / s. The signal generator (e.g., SDG1062X) has a bandwidth of 60 MHz. Output voltage measurements are performed using a high-voltage probe (e.g., Tektronix P6015A) and a differential probe (e.g., TOKOY 701926). The DC power supply provides a maximum input voltage of 3 kV and a maximum input current of 5 A.

[0347] The choice of switch is crucial for pulse quality; ultra-fast turn-on speed and high-frequency stability are beneficial for the formation of fast leading edges, high repetition rates, and short pulses. Although GaN switches offer advantages such as fast turn-on and high repetition rates, their relatively low voltage and current ratings limit their power handling capabilities. Therefore, a SiC MOSFET (e.g., C2M0025120D) was selected as the fixed switch, with a rated voltage of 1.2kV, a continuous drain current of 72A, a pulsed drain current greater than 250A, and an on-resistance of 34mΩ. The gate driver used is the IXYS IXDN630. The load resistor is a high-power, non-inductive glaze film resistor with a resistance of 1kΩ and a rated power of 500W.

[0348] To reduce parasitic signal interference and achieve high-voltage isolation between the main circuit and the drive circuit, a fiber optic isolation scheme is adopted. The signal from the signal generator undergoes electro-optic-photoelectric conversion and is transmitted to the gate of the switching transistor, thereby achieving precise switching control. To support the high-frequency operation of the pulse generator, a heat sink is installed on the switching transistor, and air cooling is implemented. Furthermore, the printed circuit board layout design needs to minimize parasitic inductance in the discharge circuit to maintain pulse waveform quality even at higher frequencies.

[0349] To improve superposition efficiency, the transmission line can employ a reverse-stacked helical winding configuration. For example, the transmission line can be wound with a third magnetic ring with multiple turns (e.g., 8 turns). The dimensions of the third magnetic ring can be 40mm × 25mm × 10mm. Furthermore, according to the common-mode inductor design method described above, approximately 16 first magnetic rings are needed to achieve the predetermined impedance for suppressing energy leakage. The dimensions of the first magnetic ring can be 64mm × 40mm × 20mm. The load can be a glazed film resistor. The first magnetic ring is fitted onto the glazed film resistor. The length of the glazed film resistor can be 40cm, and the radius can be 30mm. Additionally, a fourth magnetic ring can be fitted onto the DC-DC (Direct Current-Direct Current) converter. The dimensions of the fourth magnetic ring can be 120mm × 70mm × 60mm. See also... Figure 10 . Figure 10 A schematic diagram of a first magnetic ring and a third magnetic ring according to an embodiment of this application is shown.

[0350] To evaluate the conversion performance of the multi-stage boost converter, the output parameters of the first to fourth stages of the boost converter were measured under the conditions of an input voltage of 160V and a duty cycle of 0.4, as shown in Table 3 below.

[0351]

[0352] Table 3

[0353] As shown in Table 3, increasing the number of stages in the boost converter leads to a corresponding increase in the number of required components. The voltage gains of both the single-stage and two-stage boost converters are slightly higher than theoretical values, and the charging current remains within the safe operating range of the components. For the three-stage boost converter, the voltage gain begins to fall below the theoretical value, and the charging current reaches 40A, resulting in significant current stress on the components. The voltage gain of the four-stage boost converter is significantly lower than the theoretical value, and the peak current is relatively high; therefore, it is not suitable for practical applications. Considering both the number of components and operational reliability, a two-stage boost converter is selected as the input stage of the Blummlein-type pulse generator.

[0354] The following is combined Figure 11A and Figure 11B This section explains the unipolar pulse output of a Blumelin-type pulse generator under multiple input voltage conditions. (In conjunction with...) Figure 12 A 10kV positive pulse with a repetition frequency of 20kHz is described.

[0355] Figure 11A The diagram shows the waveform of the positive pulse output by the Blumullein-type pulse generator under multiple input voltages according to an embodiment of this application.

[0356] like Figure 11A As shown, with an input voltage of 30–403V and a duty cycle of 0.5, the two-stage boost converter provides a charging voltage of 100–1050V to the transmission line, thereby generating a positive pulse output voltage of 1–10kV. The 10kV pulse has a pulse width of approximately 118ns, a rise time of 49ns, and a superposition efficiency of 94.3%. Despite DC-DC conversion and superposition efficiency losses, the combination of the two-stage boost converter and the 10-stage stacked Blumlein pulse forming line module achieves a voltage gain of approximately 25 times.

[0357] Figure 11B The diagram shows the waveform of the negative polarity pulse output by the Blumullein-type pulse generator under multiple input voltages according to an embodiment of this application.

[0358] like Figure 11B As shown, with an input voltage of 30~293V and a duty cycle of 0.5, the two-stage boost converter provides a charging voltage of 100~1050V to the transmission line, thereby generating a positive pulse output voltage of -1~-8kV.

[0359] Figure 12 The waveform of a 10kV positive pulse with a repetition frequency of 20kHz is shown according to an embodiment of this application.

[0360] like Figure 12 As shown, The charging voltage for the transmission line. The pulse amplitude represents the load resistance.

[0361] Figure 13 The diagram shows the pulse current waveform of the switching transistor under the corresponding pulse voltage according to an embodiment of this application.

[0362] like Figure 13 As shown, in the Blummlein-type pulse generator, the first switching transistor simultaneously charges and discharges multiple transmission lines. This method is simple, convenient, and highly synchronized, but it causes the first switching transistor to withstand a large current. Since the pulse rise time is determined by the conduction speed of the first switching transistor, a high current will slightly reduce the conduction speed, thus affecting wave formation. Therefore, the pulse width of a 10kV pulse is 118ns, and the pulse rise time is 49ns. Figure 13 Middle I S1 This represents the pulse current flowing through the first switching transistor.

[0363] Figure 14 The diagram shows a bipolar pulse sequence waveform with a repetition frequency of 50 kHz and a pulse amplitude of ±4 kV according to an embodiment of this application. Figure 15APulse waveforms at repetition frequencies of 50 kHz and 100 kHz are shown according to embodiments of this application. Figure 15B Pulse waveforms at repetition frequencies of 500 kHz and 1 MHz are shown according to embodiments of this application.

[0364] like Figure 14 , Figure 15A and Figure 15B As shown, due to the parasitic inductance in the circuit, local oscillations will occur after the pulse is generated at high frequencies.

[0365] Because load resistors come in various structural forms, it is difficult to fit magnetic rings onto them. To solve this problem, embodiments of this application propose connecting a 10Ω resistor in series with the front end of a 1kΩ load resistor and fitting multiple second magnetic rings onto this resistor. See also... Figure 16 , Figure 16 A schematic diagram showing a plurality of second magnetic rings fitted onto a resistor according to an embodiment of the present application is shown.

[0366] To further verify the validity of the finding that suppressing pulse coupling with magnetic rings can improve superposition efficiency, experimental studies were conducted on Blumein pulse forming line modules with different stack-up levels. The transmission line was charged to 800V, and the output voltage and superposition efficiency were measured with and without multiple second magnetic rings placed across a 10Ω resistor. The experimental results for both cases are shown in Table 4 below. Figure 17 .

[0367]

[0368] Table 4

[0369] Figure 17 The diagram shows a comparison of pulse waveforms with and without a second magnetic ring on the resistor, under a charging voltage of 800V for the transmission line, according to an embodiment of this application.

[0370] like Figure 17 As shown in Table 4, with a transmission line charging voltage of 800V, the output voltage of the 10-stage stacked Blumlein pulse forming line module without a second magnetic ring around the resistor is 5708V, with a superposition efficiency of 71.4%. With a transmission line charging voltage of 800V, the output voltage of the 10-stage stacked Blumlein pulse forming line module with multiple second magnetic rings around the resistor is 7667V, with a superposition efficiency of 95.8%. Compared to the case without coupling suppression, the superposition efficiency is improved by 24.4%.

[0371] Experimental results show that even if it is difficult to directly mount the first magnetic ring onto the load resistor, connecting a small-value resistor in series with the front end of the load resistor can suppress parasitic coupling and improve superposition efficiency with minimal impact on pulse formation.

[0372] To verify the accuracy of the theoretical analysis in this application, the actual impedance ratio of the Blumlein-type pulse generator was estimated and substituted into formulas (9), (10), (16), and (19) to determine the stacking efficiency from a single-stage Blumlein-type pulse generator to a 10-stage stacked Blumlein-type pulse generator. The theoretical derivation results were compared with experimental results under conditions of having and not having a second magnetic ring. See [reference needed]. Figure 18 .

[0373] Figure 18 A schematic diagram showing the theoretical and experimental results of the superposition efficiency of a 1-10 level stacked Blumlein-type pulse generator according to an embodiment of this application with and without the suppression of a second magnetic ring is presented.

[0374] like Figure 18 As shown, the theoretical derivation of the superposition efficiency as a function of the number of stacking stages is in high agreement with the experimental results, which verifies the accuracy of the proposed theoretical derivation. The difference between the theoretical derivation and the experimental results stems from residual parasitic coupling between transmission lines, experimental measurement uncertainties, and small estimation deviations of key circuit parameters in the theoretical derivation.

[0375] The theoretical derivation, simulation results, and experimental results of the 10-stage stacked Blumlein-type pulse generator using a magnetic ring coupling suppression scheme are shown in Table 5 below. The experiment was conducted with a transmission line charging voltage of 1.06 kV to achieve an output voltage of approximately 10 kV. The experimental results for pulse amplitude and superposition efficiency agree well with the simulation results. Due to the inherent characteristics of the switching devices, the switching transistors experience a large current during operation, affecting their turn-on speed. Therefore, compared to the simulation results, the pulse rise time is slower in the experimental results.

[0376]

[0377] Table 5

[0378] To achieve the output voltage for high-power pulsed power applications, two design strategies for Blumlein-type pulse generators were compared: increasing the number of stacked stages and integrating a nanocrystalline magnetic ring to suppress parasitic coupling.

[0379] Without magnetic ring coupling suppression, inter-stage parasitic energy leakage intensifies and stacking efficiency decreases with increasing stacking number. For a 10-stage stacked Blumlein-type pulse generator, the stacking efficiency without magnetic rings (e.g., a second or first magnetic ring) drops to approximately 71%, while the stacking efficiency with magnetic rings (e.g., a second or first magnetic ring) remains between 94% and 95%, demonstrating the effectiveness of the proposed technical solution.

[0380] In contrast, if a 10kV output voltage is achieved by increasing the number of stacking stages without implementing magnetic ring coupling suppression, the stacking efficiency continuously decreases with increasing stacking stages. The theoretical stacking efficiency of a 15-stage stacked Blumlein-type pulse generator without a magnetic ring (e.g., a second or first magnetic ring) is approximately 63%. The theoretical stacking efficiency of a 20-stage stacked Blumlein-type pulse generator without a magnetic ring (e.g., a second or first magnetic ring) is approximately 52%. These stacking efficiencies are estimates without optimization or processing.

[0381] The following evaluation compares a 10-stage stacked Blumlein-type pulse generator with 16 magnetic rings (e.g., the second or first magnetic ring) used in the embodiments of this application with an output voltage of approximately 10kV, and a 15-stage stacked Blumlein-type pulse generator without magnetic rings (e.g., the second or first magnetic ring). The evaluation results are shown in Table 6 below.

[0382]

[0383] Table 6

[0384] As shown in Table 6, simply increasing the number of stack-up stages leads to the following results: reduced stack-up efficiency, increased component voltage stress, increased size, increased weight, and increased cost. In contrast, the magnetic ring suppression strategy achieves approximately 24% improvement in stack-up efficiency on a 10-stage stack-up Blumlein-type pulse generator, while only slightly increasing size and cost, making it a more compact and cost-effective solution.

[0385] Therefore, magnetic ring coupling suppression is an effective way to improve superposition efficiency. However, the suppression effect of magnetic rings is not unlimited; once a threshold is reached, it is difficult to further improve the superposition efficiency by increasing the number of magnetic rings. When the number of magnetic rings is small, the superposition efficiency can be improved due to the change in impedance ratio. When the impedance ratio becomes sufficiently high, the improvement in superposition efficiency brought about by increasing the number of magnetic rings is limited.

[0386] Therefore, for a predetermined number of stacking stages, the number of magnetic rings required to achieve a predetermined impedance ratio can be determined, thereby keeping the stacking efficiency within the range of 80% to 90%. The above method not only reduces the number of magnetic rings, thereby reducing the overall volume and mass, but also achieves superior overall performance for the Blumlein-type pulse generator.

[0387] The magnetic ring suppression method proposed in this application is flexible and configurable. Excessively increasing the number of stacking stages or magnetic rings is neither necessary nor advisable. It can be optimized according to actual business needs, taking into account factors such as total volume, total mass, cost, and waveform quality.

[0388] The experimental results of the embodiment of this application, which combines a boost converter and a Blumlein-type pulse generator with magnetic ring coupling suppression, demonstrate the advantages of the Blumlein-type pulse generator in terms of high gain, high superposition efficiency, high repetition frequency, and short pulse width, thus meeting the requirements of high-power, solid-state, and modular pulse power supplies.

[0389] This application proposes a Blumlein-type pulse generator based on a multi-stage boost converter and magnetic ring coupling suppression. Through theoretical derivation, simulation analysis, and experimental verification, the following conclusions are drawn:

[0390] This application proposes a stacked Blumlein-type pulse generator, analyzes the theoretical voltage gain, and investigates the factors affecting superposition efficiency in single-switch and multi-switch configurations. Pulse output and superposition efficiency were evaluated under transmission line-to-ground, inter-stage, and load-to-ground coupling conditions. The results show that increasing the coupling impedance can improve the superposition efficiency.

[0391] A Blumelin-type pulse generator was designed and experimentally tested, which combines a two-stage boost converter and a ten-stage stacked Blumelin pulse forming line module. With an input voltage range of 30–400V, the transmission line is charged to 100–1050V. After ten stages of stacking, the output voltage is 1–10kV, with a pulse width of 118ns, a rise time of 49ns, and a stacking efficiency of 94.3%. The output frequency is adjustable between 20kHz and 1MHz, and it can generate positive, negative, and bipolar pulses.

[0392] By connecting a low resistance in series with the load resistor and incorporating multiple second magnetic rings, parasitic coupling is effectively suppressed, thereby improving the superposition efficiency. With a transmission line charging voltage of 800V, the output voltage of the 10-stage stacked Blumlein-type pulse generator increases from 5708V (without magnetic ring coupling suppression) to 7667V (with magnetic ring coupling suppression), resulting in a 24.4% improvement in superposition efficiency.

[0393] Therefore, the Blummlein-type pulse generator proposed in this application promotes the development of nanosecond pulse generators. It is characterized by high voltage gain, improved superposition effect and wide adjustable repetition frequency range, providing a compact and reliable solution for high-performance solid-state pulse power systems.

[0394] Those skilled in the art will understand that the features described in the various embodiments of this application can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this application. In particular, the features described in the various embodiments of this application can be combined and / or combined in various ways without departing from the spirit and teachings of this application. All such combinations and / or combinations fall within the scope of this application.

[0395] The embodiments of this application have been described above. However, these embodiments are merely illustrative and not intended to limit the scope of this application. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Without departing from the scope of this application, those skilled in the art can make various substitutions and modifications, all of which should fall within the scope of this application.

Claims

1. A Blumlein-type pulse generator, comprising: A boost converter, wherein the input terminal of the boost converter is connected to a DC power supply, the boost converter includes a first switching unit and a multi-stage boost unit, and the boost converter is configured to increase the input voltage provided by the DC power supply; The Blumlein pulse forming line module has its input terminal connected to the output terminal of the boost converter via the first switching unit, and its output terminal connected to the load. The Blumlein pulse forming line module includes multiple transmission lines. The controller is connected to the control terminal of the first switching unit and is configured to control the first switching unit to operate in a chopping mode during the charging phase, so that the boost converter charges the multi-stage transmission lines using the increased input voltage; and to control the first switching unit to turn on during the discharging phase, so that the energy stored in the multi-stage transmission lines discharges to the load to generate an output pulse. as well as The coupling suppression module includes at least one of a plurality of first magnetic elements sleeved on the load or a plurality of second magnetic elements sleeved on an impedance element connected in series with the load, configured to increase the coupling impedance of the load to ground by utilizing at least one of the plurality of first magnetic elements or the plurality of second magnetic elements during the discharge phase, so as to suppress energy leakage and compensate for the output pulse.

2. The Blumlein-type pulse generator according to claim 1, wherein, The coupling suppression module is configured to, during the discharge phase, introduce a common-mode inductance in the energy leakage path from the load to ground using at least one of the first magnetic elements or the second magnetic elements, forming an impedance network with the parasitic capacitance in the energy leakage path to increase the coupling impedance and apply the induced current to the load to compensate for the output pulse.

3. The Blumlein-type pulse generator according to claim 2, wherein, The first magnetic element is a first magnetic ring. The number of the first magnetic rings is determined based on the ratio between the inductance of the common-mode inductor and the inductance of the first magnetic ring. The inductance of the first magnetic ring is determined based on the permeability and size parameters of the first magnetic ring; and / or The second magnetic element is a second magnetic ring. The number of the second magnetic rings is determined based on the ratio between the inductance of the common-mode inductor and the inductance of the second magnetic ring. The inductance of the second magnetic ring is determined based on the permeability of the second magnetic ring and the size parameters of the second magnetic ring. The inductance of the common-mode inductor is determined based on the pulse width of the output pulse and a predetermined inductive reactance.

4. The Blumlein-type pulse generator according to any one of claims 1 to 3, wherein, The coupling suppression module further includes multiple third magnetic elements sleeved on the transmission line, configured to utilize the multiple third magnetic elements during the discharge phase to increase the suppression of energy leakage paths formed by interstage parasitic parameters.

5. The Blumlein-type pulse generator according to any one of claims 1 to 4, wherein, The Blumlein pulse forming line module further includes a second switching unit, which is connected to the output terminal of the Blumlein pulse forming line module. The controller, connected to the control terminal of the second switching unit, is further configured to control the second switching unit to conduct, thereby generating a unipolar pulse on the load with the opposite polarity to that of the first switching unit when it is conducted; or The controller is further configured to alternately control the second switching unit and the first switching unit to conduct in order to generate a bipolar pulse sequence on the load.

6. The Blumlein-type pulse generator according to claim 5, wherein, The first switching unit includes a plurality of first switching transistors, which are connected to the input terminal of the Blumlein pulse forming line module; the controller is further configured to control the turn-on timing of the plurality of first switching transistors to adjust at least one of the repetition frequency or pulse width of the output pulse; or The second switching unit includes a plurality of second switching transistors, which are connected to the output terminal of the Blumlein pulse forming line module; the controller is further configured to control the on-time of the plurality of second switching transistors to adjust at least one of the repetition frequency or pulse width of the output pulse.

7. The Blumlein-type pulse generator according to claim 6, wherein, The controller is configured to interleave the conduction of multiple first switches or multiple second switches, thereby doubling the repetition frequency of the output pulse; or The controller is configured to control the conduction combination of a plurality of the first switching transistors or a plurality of the second switching transistors to determine the transmission line participating in the discharge, thereby adjusting the pulse width of the output pulse; or The controller is configured to control the conduction time interval between the first switching unit and the second switching unit to generate an output pulse with a pulse width smaller than the pulse width of the transmission line.

8. The Blumlein-type pulse generating device according to any one of claims 1 to 7, wherein The transmission line is a coaxial line, and the multi-stage transmission line includes N stages, where N is an integer greater than 1; When n=1, the first-order coaxial lines include: A first-stage coaxial line, wherein the inner conductor of the first-stage coaxial line is connected to the output terminal of the boost converter, and the outer conductor of the first-stage coaxial line is grounded; and The second first-level transmission line has its inner conductor connected to the inner conductor of the first first-level coaxial line, and its outer conductor connected to the first end of the load and ground. In the case that 1 < n ≤ N, the nth level coaxial line includes: The first nth stage coaxial line has its inner conductor connected to the output terminal of the boost converter, and its outer conductor grounded. The second nth level transmission line has its inner conductor connected to the inner conductor of the first nth level coaxial line, and its outer conductor connected to the outer conductor of the first (n-1)th level coaxial line and ground. Where n is an integer greater than or equal to 1 and less than or equal to N.

9. The Blumlein-type pulse generating device according to any one of claims 1 to 8, wherein The multi-stage boost unit is an M-stage boost unit, where M is an integer greater than 1, and the first switching unit includes a first switching transistor; With m=1, the first-stage boost unit includes: The first stage energy storage inductor, wherein the first terminal of the first stage energy storage inductor is connected to the positive terminal of the DC voltage; The first stage interstage charging diode, wherein the first terminal of the first stage interstage charging diode is connected to the second terminal of the first stage energy storage inductor; The first-stage coupling output diode, wherein the first terminal of the first-stage coupling output diode is connected to the second terminal of the first-stage energy storage inductor and the first terminal of the first-stage interstage charging diode, and the second terminal of the first-stage coupling output diode is connected to the first terminal of the first switching transistor; and The first stage voltage multiplier capacitor has its first terminal connected to the second terminal of the first stage interstage charging diode, and its second terminal connected to the negative terminal of the DC power supply and the second terminal of the first switching transistor. When 1 < m ≤ M, the m-th boost unit includes: The first terminal of the m-th stage energy storage inductor is connected to the second terminal of the (m-1)-th stage interstage charging diode and the first terminal of the (m-1)-th stage voltage multiplier capacitor. The m-th stage interstage charging diode, wherein the first terminal of the m-th stage interstage charging diode is connected to the second terminal of the m-th stage energy storage inductor; The m-th stage coupling output diode, wherein the first terminal of the m-th stage coupling output diode is connected to the second terminal of the m-th stage energy storage inductor and the first terminal of the m-th stage interstage charging diode, and the second terminal of the m-th stage coupling output diode is connected to the first terminal of the first switching transistor; and The m-th stage voltage multiplier capacitor has its first terminal connected to the second terminal of the m-th stage interstage charging diode, and its second terminal connected to the negative terminal of the DC power supply and the second terminal of the first switching transistor. Where m is an integer greater than or equal to 1 and less than or equal to M, the first terminal of the first stage energy storage inductor is the input terminal of the boost converter, the first pole of the first switch terminal is the first terminal of the first switch unit, the second pole of the first switch terminal is the second terminal of the first switch unit, and the second pole of the m-th stage coupled output terminals is the output terminal of the boost converter.

10. The Blumlein-type pulse generating device according to any one of claims 1 to 9, wherein The first magnetic element or the second magnetic element comprises an amorphous nanocrystalline magnetic ring; and / or The impedance value of the impedance element is less than the impedance value of the load.

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