Single wire folded pulse generator with long output line

Abstract

The application discloses a single-line folded pulse generator with a long output line and belongs to the technical field of pulse power devices, and solves the technical problems of a Tesla type pulse generator, such as long length and poor output waveform quality, and the pulse generator comprises an upper conductor, a middle conductor, a lower conductor, a switch and a load. The upper conductor, the middle conductor and the lower conductor are metal conductors. The upper conductor and the middle conductor form a pulse forming line, and the middle conductor and the lower conductor form a pulse transmission line. The switch and the load are respectively located at two ends of the pulse forming line, the upper conductor and the lower conductor are connected through the switch, the characteristic impedances of the pulse forming line and the pulse transmission line are equal, and the pulse generator is gas insulated. The application is used for a pulse generating device.

Description

Technical Field

[0001] This invention belongs to the field of pulse power device technology, specifically relating to a single-wire folded pulse generator with a long output line. Background Technology

[0002] The Tesla-type pulse generator is a pulse generating device that integrates the Tesla transformer 10 within the pulse forming line 4. (See...) Figure 1 The concept was first proposed by Russian scientists (SD Korovin, et al, Repetitive nanosecond high-voltage generator based on spiral forming line. Proc. 13th IEEE Int. Pulsed Power Conf., 2001). Due to its simple structure, convenient voltage boosting, and ability to operate at high frequencies, the Tesla-type pulse generator is widely used as a high-power microwave drive source.

[0003] The main components of a Tesla-type pulse generator include a pulse forming line 4 with a built-in Tesla transformer, a pulse transmission line 5, a switch 6, and a load 7. (See...) Figure 1 (a). The pulse transmission line 5 is used to output the nanosecond square wave pulse generated by the pulse forming line 4 to the load 7 in a high-fidelity manner. Typically, the pulse transmission line 5 and the pulse forming line 4 are designed with equal impedance and length. This characteristic results in Tesla-type pulse generators being "thin and long," which is detrimental to the compactness and miniaturization of the entire device.

[0004] To address this problem, Chinese scientists proposed a technical approach of replacing long-pulse transmission lines with short-pulse transmission lines (JC Su, et al, “A Long-Pulse Generator Based on Tesla Transformer and Pulse-Forming Network,” IEEE Trans. Plasma Sci., vol. 37, no. 10, pp. 1954-1958, 2009.). See [link to relevant article]. Figure 1 (b) This method can shorten the axial length of the entire device by 1 / 3, but because the switch is closer to the load and the short pulse transmission line cannot fully isolate the main pulse and the reflected pulse, the output waveform is distorted and the quality is degraded.

[0005] This invention is an improvement on a Tesla-type pulse generator with a single-tube wire and a short output line. Summary of the Invention

[0006] To overcome the drawback of excessively long Tesla-type pulse generators with long output lines, this invention proposes a single-wire folded pulse generator with a long output line.

[0007] The technical solution adopted by the present invention to solve its technical problem is: while retaining the long output line, the axial length is reduced by folding the entire pulse generator, which can obtain better waveform quality and shorten the overall size of the machine.

[0008] A single-wire folded pulse generator with a long output line includes an upper conductor, a middle conductor, a lower conductor, a switch, and a load.

[0009] The upper conductor, middle conductor, and lower conductor are metallic conductors. The upper conductor and middle conductor form a pulse forming line, and the middle conductor and lower conductor form a pulse transmission line.

[0010] The switch and load are located at opposite ends of the pulse transmission line. The upper and lower conductors are connected by the switch.

[0011] The characteristic impedances of the pulse forming line and the pulse transmission line are equal.

[0012] The aforementioned single-wire folded pulse generator with a long output line also includes an isolation inductor.

[0013] The upper, middle, and lower conductors are rectangular flat plates placed parallel to each other. The upper conductor is located directly above the middle conductor, and the lower conductor is located directly below the middle conductor.

[0014] The middle conductor and the lower conductor are connected by a load.

[0015] The upper conductor, middle conductor, and lower conductor have equal widths, and the lengths of the pulse forming line and pulse transmission line are both equal to the length of the middle conductor.

[0016] The pulse forming line is open at the left end, and the pulse transmission line is connected in series with the load.

[0017] The two ends of the isolation inductor are connected to the middle conductor and the lower conductor, respectively, to isolate the pre-pulse.

[0018] The lower conductor is grounded via a grounding wire.

[0019] The single-wire folded pulse generator with a long output line can also generate two coaxial forms by rotation, characterized in that it includes a Tesla transformer;

[0020] The first type of coaxial configuration: the pulse forming line is the outer line; the pulse transmission line is the inner line, used to transmit the ns pulse to the load;

[0021] The middle conductor, lower conductor, switch, load, Tesla transformer, and isolation inductor are located inside the upper conductor;

[0022] The upper conductor is a hollow cylinder; the middle conductor is a cylinder with an opening at the right end; the lower conductor is a cylinder inserted into the middle conductor; the central axes of the upper, middle, and lower conductors are collinear; the upper conductor is grounded through a grounding wire.

[0023] The Tesla transformer is connected to the upper conductor and the middle conductor at both ends, and the isolation inductor is connected to the middle conductor and the lower conductor at both ends; the load is connected to the middle conductor and the lower conductor at both ends.

[0024] The second type of coaxial configuration: the pulse forming line is the inner line; the pulse transmission line is the outer line, used to transmit the ns pulse to the load;

[0025] The middle conductor, upper conductor, switch, load, Tesla transformer, and isolation inductor are located inside the lower conductor;

[0026] The upper conductor is cylindrical; the middle conductor is a cylinder with an opening at the right end; the lower conductor is a hollow cylinder, inside which the middle conductor is placed; the central axes of the upper, middle, and lower conductors are collinear; the lower conductor is grounded through a grounding wire.

[0027] The Tesla transformer is connected to the upper conductor and the middle conductor at both ends, and the isolation inductor is connected to the middle conductor and the lower conductor at both ends; the load is connected to the middle conductor and the lower conductor at both ends.

[0028] The beneficial effects of this invention are:

[0029] A single-wire folded pulse generator with a long output line shortens the axial length of the entire pulse generator to half of its original length while retaining the long pulse transmission line. This ensures both the quality of the output pulse and the overall size of the device, achieving the goal of "good waveform and short size". Attached Figure Description

[0030] Figure 1 These are schematic diagrams of existing Tesla-type pulse generators: (a) is a schematic diagram of a structure with a long pulse transmission line; (b) is a schematic diagram of a structure with a short pulse transmission line.

[0031] Figure 2 This is a schematic diagram of the structure of a Tesla-type pulse generator with an output line in Embodiment 1;

[0032] Figure 3 This is a schematic diagram of the folding process of the Tesla-type pulse generator with output line in Embodiment 1;

[0033] Figure 4 This is a schematic diagram of the single-wire folded pulse generator with a long output line in Embodiment 1;

[0034] Figure 5This is a schematic diagram of the structure of the flat-plate type single-wire folded pulse generator with a long output line in Embodiment 2;

[0035] Figure 6 This is a comparison diagram of the output waveform of the flat-plate single-wire folded pulse generator with a long output line in Example 2 and the output waveform when it is not folded.

[0036] Figure 7 This is the implementation process of the coaxial single-wire folded pulse generator with a long output line in Example 3, (a) load-in-built structure; (b) load-out structure;

[0037] Figure 8 This is a schematic diagram of charging a single-wire folded pulse generator with a long output line in the coaxial type of Embodiment 3, (a) load-in-built structure; (b) load-out structure;

[0038] Figure 9 The three-dimensional cross-sectional structure of the coaxial single-wire folded pulse generator with a long output line in Embodiment 3 is shown in (a) the load-in-built structure and (b) the load-out structure.

[0039] Figure 10 The output waveforms of the coaxial single-wire folded pulse generator with output line in Example 3 are: (a) output waveform with built-in load; (b) output waveform with external load.

[0040] The attached figures are labeled as follows:

[0041] 1. Upper conductor; 2. Middle conductor; 3. Lower conductor; 4. Pulse forming line; 5. Pulse transmission line; 6. Switch; 7. Load; 8. Grounding wire; 9. Isolation inductor; 10. Tesla transformer. Detailed Implementation

[0042] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0043] Example 1

[0044] A single-wire folded pulse generator with a long output line is proposed. This method "folds" a single-tube Tesla-type pulse generator with a long output line along its length while retaining the pulse transmission line. This significantly reduces the overall length of the pulse generator while ensuring waveform quality.

[0045] Figure 2 A schematic diagram of a Tesla-type pulse generator with a single-tube wire and a long output line is given. Considering that the pulse transmission line and the pulse forming line are of equal length, although the vertical dimension doubles after folding, the horizontal dimension is halved, thus significantly reducing the axial length of the entire pulse generator. The folded generator is a single-tube folded pulse generator with a long output line, such as... Figure 3 , Figure 4As shown in the diagram, the length of the middle conductor 2 is halved, and it becomes the common conductor for both the pulse forming line 4 and the pulse transmission line 5. During the folding process, the pulse transmission line 5 and the pulse forming line 4 are of equal length and impedance. This allows the designer to maintain the length of the pulse transmission line without increasing the axial length of the pulse generator, thereby isolating the generated pulse and improving waveform quality.

[0046] A single-wire folded pulse generator with a long output line includes a planar type single-wire folded pulse generator with a long output line and a coaxial type single-wire folded pulse generator with a long output line.

[0047] Example 2

[0048] Figure 5 A schematic diagram of a planar single-wire folded pulse generator with a long output line is given, relative to... Figure 4 , Figure 5 The middle conductor is positively charged, and an isolation inductor 9 is added between the two conductors of the pulse transmission line 5. The isolation inductor 9 serves to isolate the pre-pulse.

[0049] To perform the simulation, Figure 5 The parameters assigned to each component are as follows: 1) Line width: w=600 mm; 2) Line spacing: d=60 mm; 3) Line length: l=3000 mm; 4) Insulation method: gas insulation.

[0050] That is: the width of the upper conductor 1, the middle conductor 2, and the lower conductor 3 is w=600mm; the distance between the upper conductor 1 and the middle conductor 2 is equal to the distance between the middle conductor 2 and the lower conductor 3, both being d=60mm; the length of the pulse forming line 4 and the pulse transmission line 5 is l=3000mm.

[0051] Based on the above parameters, the characteristic impedance Z1 of pulse forming line 4 and the characteristic impedance Z2 of pulse transmission line 5 can be calculated to be 37.7 Ω, using the following formula:

[0052]

[0053] In the formula, Z is the characteristic impedance of the pulse forming line or pulse transmission line; d is the distance between the upper and lower conductors of the line; and w is the conductor width.

[0054] The electrical length τ of each line can also be calculated, and it is 10 ns, using the following formula:

[0055]

[0056] Where l is the length of the line; c is the speed of light, with a value of 3 × 10⁻⁶. 8 m / s.

[0057] Models of flat-plate pulse generators with long output lines, both folded and non-folded, were established, and field-circuit co-simulation was performed. In the simulation, both lines were charged to 1V, and the load impedance was set to 37.7Ω. Simulation results are shown below. Figure 6 As shown in the figure, the voltage pulse amplitude on the load is 0.5V, half of the charging voltage V0, which matches the theory; the pulse width is 20.9ns, approximately twice the length of a single wire (10ns), also matching the theory. This demonstrates the correctness of the simulation results. Furthermore, from... Figure 6 It can be seen that the waveform after folding is basically the same as the waveform without folding, which shows that the scheme of folding the output single line is feasible.

[0058] Example 3

[0059] By rotating a flat-plate single-wire folded pulse generator with a long output line around a horizontal axis, a coaxial single-wire folded pulse generator with a long output line can be obtained. See [link to details of the rotation process] for more information. Figure 7 Depending on whether the rotating axis is closer to the upper conductor 1 or the lower conductor 3, the final coaxial type has two subtypes: load-embedded type, see Figure 8 (a), and external load type, see Figure 8 (b).

[0060] For a single-wire folded pulse generator with a long output line and a coaxial cable built into the load, the upper conductor 1 is the outer conductor, and the lower conductor 3 is the inner conductor; the pulse forming line 4 is the outer line, and the pulse transmission line 5 is the inner line. The Tesla transformer 10 charges the outer line 4; the inner line 5 is used to transmit the ns pulse to the load 7 through the isolation inductor 9. An inherent drawback of this type of pulse generator is that the high voltage on the load is difficult to extract during discharge.

[0061] For a coaxial single-wire folded pulse generator with an external load and a long output line, the upper conductor 1 is the inner conductor, and the lower conductor 3 is the outer conductor; the pulse forming line 5 is the outer line, and the pulse transmission line 4 is the inner line. The Tesla transformer 10 charges the inner line 4; the outer line 5 is used to transmit the ns pulse to the load 7 through the isolation inductor 9. An inherent drawback of this type of pulse generator is that it is difficult to introduce high voltage into the inner conductor during charging.

[0062] Nevertheless, two coaxial single-wire folded pulse generator models with long output lines were still established, see [link to model]. Figure 9 (a) and (b) were used, and field-path coordination simulation was performed. The model parameters are as follows:

[0063] Diameter of the inner surface of the outer conductor: d out =544 mm;

[0064] Diameter of the outer surface of the middle conductor: d mid2 =200 mm;

[0065] Diameter of the inner surface of the middle conductor: d mid1 =195 mm;

[0066] Diameter of the outer surface of the inner conductor: d in =72 mm;

[0067] Length of inner and outer coaxial lines: l1 = 3300 mm;

[0068] Transmission line length: l2 = 600mm;

[0069] Both coaxial cables are gas-insulated.

[0070] According to the following formula, the characteristic impedance, Z, of both the inner and outer coaxial lines is 60 Ω:

[0071]

[0072] Where d out d mid2 d mid1 d in The definition is as before; ε r is the dielectric constant of the gas, with a value of 1.

[0073] According to the following formula, the electric length, τ, of both the inner and outer coaxial lines is 11 ns:

[0074]

[0075] Where c is the speed of light, and its value is 3 × 10⁻⁶. 8 m / s.

[0076] In the simulation, the pulse forming line was charged to 1V, and the load impedance R was set to a matched value of 60Ω. Simulation results are shown below. Figure 10 .from Figure 10 It can be seen that the voltage pulse amplitude on the load is approximately 0.5V, which is half of the charging voltage, consistent with the theoretical value. Simultaneously, the voltage pulse width is 25.85 ns, approximately twice the length of a single wire (11 ns), also consistent with the theory. Furthermore, it can be seen that... Figure 10 (a) or Figure 10 (b) The output waveforms of the two coaxial single-wire folded pulse generators with long output lines are very similar to those of the non-folded generator. This indicates that the waveform distortion caused by folding can be ignored and the transmission line plays a role in isolating reflected pulses. Therefore, the folding technology route is usable.

[0077] Example 4

[0078] A single-wire folded pulse generator with a long output line includes an upper conductor 1, a middle conductor 2, a lower conductor 3, a switch 6, a load 7, and an isolation inductor 9.

[0079] The upper conductor 1 and the middle conductor 2 constitute a pulse forming line 4, and the middle conductor 2 and the lower conductor 3 constitute a pulse transmission line 5. The pulse forming line 4 and the pulse transmission line 5 are of equal length.

[0080] The pulse forming line 4 and the pulse transmission line 5 share the middle conductor 2, and the switch 6 and the load 7 are located at both ends of the pulse forming line 4, respectively.

[0081] The upper conductor 1, middle conductor 2, and lower conductor 3 are metallic conductors.

[0082] The characteristic impedances of the pulse forming line 4 and the pulse transmission line 5 are equal.

[0083] The upper conductor 1, middle conductor 2, and lower conductor 3 are rectangular flat plates placed in parallel. The upper conductor 1 is located directly above the middle conductor 2, and the lower conductor 3 is located directly below the middle conductor 2.

[0084] The upper conductor 1 and the lower conductor 3 are connected by a switch 6, and the middle conductor 2 and the lower conductor 3 are connected by a load 7.

[0085] The upper conductor 1, middle conductor 2, and lower conductor 3 have equal widths, and the width directions of the upper conductor 1, middle conductor 2, and lower conductor 3 are perpendicular to the plane of the paper. The lengths of the pulse forming line 4 and the pulse transmission line 5 are both equal to the length of the middle conductor 2.

[0086] The pulse forming line 4 is open at its left end, and the pulse transmission line 5 is connected in series with the load 7.

[0087] The two ends of the isolation inductor 9 are connected to the middle conductor 2 and the lower conductor 3 respectively, and are used to isolate the pre-pulse.

[0088] The lower conductor 3 is grounded through the grounding wire 8.

[0089] Preferably, the single-wire folded pulse generator with a long output line can also generate two coaxial forms by rotation, characterized in that it includes a Tesla transformer 10.

[0090] The first coaxial configuration: the pulse forming line 4 is the outer line; the pulse transmission line 5 is the inner line, used to transmit ns pulses to the load 7; the middle conductor 2, the lower conductor 3, the switch 6, the load 7, the Tesla transformer 10, and the isolation inductor 9 are located inside the upper conductor 1; the upper conductor 1 is a hollow cylinder; the middle conductor 2 is a cylinder with an opening at the right end; the lower conductor 3 is a cylinder inserted into the middle conductor 2; the central axes of the upper conductor 1, the middle conductor 2, and the lower conductor 3 are collinear; the upper conductor 1 is grounded through the grounding wire (8); the two ends of the Tesla transformer 10 are connected to the upper conductor 1 and the middle conductor 2 respectively, and the two ends of the isolation inductor 9 are connected to the middle conductor 2 and the lower conductor 3 respectively; the two ends of the load 7 are connected to the middle conductor 2 and the lower conductor 3 respectively.

[0091] The second coaxial configuration: Pulse forming line 4 is the inner line; pulse transmission line 5 is the outer line, used to transmit ns pulses to load 7; the middle conductor 2, upper conductor 1, switch 6, load 7, Tesla transformer 10, and isolation inductor 9 are located inside the lower conductor 3; the upper conductor 1 is cylindrical; the middle conductor 2 is cylindrical with an opening at the right end; the lower conductor 3 is a hollow cylinder, with the middle conductor 2 placed inside it; the central axes of the upper conductor 1, middle conductor 2, and lower conductor 3 are collinear; the lower conductor 3 is grounded through grounding wire 8; the two ends of the Tesla transformer 10 are connected to the upper conductor 1 and the middle conductor 2 respectively, and the two ends of the isolation inductor 9 are connected to the middle conductor 2 and the lower conductor 3 respectively; the two ends of the load 7 are connected to the middle conductor 2 and the lower conductor 3 respectively.

Claims

1. A single-wire folded pulse generator with a long output line, characterized in that, Includes upper conductor (1), middle conductor (2), lower conductor (3), switch (6), and load (7); The upper conductor (1), middle conductor (2), and lower conductor (3) are metallic conductors; the upper conductor (1) and middle conductor (2) constitute a pulse forming line (4), and the middle conductor (2) and lower conductor (3) constitute a pulse transmission line (5); The switch (6) and the load (7) are located at both ends of the pulse forming line (5); the upper conductor (1) and the lower conductor (3) are connected through the switch (6); The characteristic impedances of the pulse forming line (4) and the pulse transmission line (5) are equal.

2. The single-wire folded pulse generator with a long output line according to claim 1, characterized in that, It also includes a grounding wire (8) and an isolation inductor (9); The upper conductor (1), middle conductor (2), and lower conductor (3) are rectangular flat plates placed in parallel; the upper conductor (1) is located directly above the middle conductor (2), and the lower conductor (3) is located directly below the middle conductor (2); The middle conductor (2) and the lower conductor (3) are connected by a load (7); The upper conductor (1), middle conductor (2), and lower conductor (3) have equal widths, and the lengths of the pulse forming line (4) and pulse transmission line (5) are equal to the length of the middle conductor (2). The pulse forming line (4) is open at the left end, and the pulse transmission line (5) is connected in series with the load (7). The charger (8) is connected to the lower conductor (3) for grounding the entire device; The isolation inductor (9) is connected at both ends to the middle conductor (2) and the lower conductor (3) respectively, and is used to isolate the pre-pulse.

3. The single-wire folded pulse generator with a long output line according to claim 1 can also generate two coaxial forms by rotation, characterized in that, Including Tesla transformers (10); The first type of coaxial configuration: the pulse forming line (4) is the outer line; the pulse transmission line (5) is the inner line, used to transmit the ns pulse to the load (7). The middle conductor (2), lower conductor (3), switch (6), load (7), Tesla transformer (10), and isolation inductor (9) are located inside the upper conductor (1); The upper conductor (1) is a hollow cylinder; the middle conductor (2) is a cylinder with an opening at the right end; the lower conductor (3) is a cylinder inserted into the middle conductor (2); the central axes of the upper conductor (1), the middle conductor (2), and the lower conductor (3) are collinear; the upper conductor (1) is grounded through a grounding wire (8); The Tesla transformer (10) is connected to the upper conductor (1) and the middle conductor (2) at both ends, and the isolation inductor (9) is connected to the middle conductor (2) and the lower conductor (3) at both ends; the load (7) is connected to the middle conductor (2) and the lower conductor (3) at both ends. The second type of coaxial configuration: the pulse forming line (4) is the inner line; the pulse transmission line (5) is the outer line, used to transmit the ns pulse to the load (7). The middle conductor (2), upper conductor (1), switch (6), load (7), Tesla transformer (10), and isolation inductor (9) are located inside the lower conductor (3); The upper conductor (1) is cylindrical; the middle conductor (2) is cylindrical with an opening at the right end; the lower conductor (3) is a hollow cylinder, inside which the middle conductor (2) is placed; the central axes of the upper conductor (1), the middle conductor (2), and the lower conductor (3) are collinear; the lower conductor (3) is grounded through a grounding wire (8); The Tesla transformer (10) is connected to the upper conductor (1) and the middle conductor (2) at both ends respectively, and the isolation inductor (9) is connected to the middle conductor (2) and the lower conductor (3) at both ends respectively; the load (7) is connected to the middle conductor (2) and the lower conductor (3) at both ends respectively.

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