Balanced transformation power directional coupler for short-pulse power linear superposition

Abstract

A balanced transformation power directional coupler for short-pulse power linear superposition, comprising a first coaxial transmission line, a second coaxial transmission line and a magnetic ring. The present invention can solve the problem of power saturation in existing short-pulse power synthesis methods, and achieves power linear superposition; the present invention can achieve conversion of two unbalanced pulses to one balanced pulse, and the pulse has relatively good anti-interference performance in a transmission process; the present invention has a small spatial volume, and can reduce the volume of a pulse generator when applied to inductive energy storage-pulse forming line (IES-PFL)-based power synthesis, thereby implementing a compact design; and components used in the present invention have low manufacturing costs and thus achieve high economical efficiency.

Description

A balanced power directional coupler for linear superposition of short pulse power Technical Field

[0001] The present invention relates to the technical field of all-solid-state pulse power sources, in particular to a balanced conversion power directional coupler for linear superposition of short pulse power. Background Art

[0002] Modular pulse superposition has been a major trend in the recent development of all-solid-state pulsed power source technology. This approach combines the "low-power pulses" generated by modules to achieve high-voltage, short pulse formation. Its advantages include relieving pressure on module insulation, the withstand voltage and power capacity of switching devices, and structural complexity. This facilitates standardization and mass production, improves versatility, and reduces costs and maintenance.

[0003] Currently, modular pulse superposition methods include Marx voltage superposition, LTD inductive superposition, and pulse forming line (PFL) stacking. The Marx circuit utilizes parallel charging and series discharging. During boosting, the low-voltage terminal of each module is connected to the high-voltage terminal of the previous stage. Using a three-terminal fully controlled switch, a square wave can be generated. However, as the number of stages increases, the output current increases, leading to a slowing of the leading edge and output power saturation, resulting in nonlinear superposition. Each module in the LTD has the same potential, and the voltage is superimposed at the output terminal through electromagnetic induction of the magnetic core. Therefore, LTD can achieve good linear power superposition, but it also suffers from the low magnetization efficiency of the core for fast-leading short pulses. The broadband characteristics of the forming line are advantageous for shaping fast-leading short pulses, but when stacking PFLs, linear power superposition cannot be achieved due to voltage reflection at the output port.

[0004] In summary, while existing pulse superposition methods can achieve modular power synthesis, power superposition exhibits nonlinear characteristics. From a circuit perspective, voltage is essentially the potential difference between two nodes, or potential imbalance. High-voltage output is an unbalanced state. When the potential is unbalanced, electromagnetic energy transfers from high to low potential, resulting in nonlinear power superposition and saturation.

[0005] Summary of the Invention

[0006] In view of the "nonlinear" characteristics of the stacked power synthesis in the existing short power synthesis method and the occurrence of power superposition saturation phenomenon, the present invention proposes a balanced conversion power directional coupler for linear superposition of short pulse power, which has good practical value and application prospects in the field of solid-state high-voltage short pulse sources.

[0007] The technical solution adopted to achieve the purpose of the present invention is as follows: a balanced conversion power directional coupler for linear superposition of short pulse power, including: a first coaxial transmission line, a second coaxial transmission line and a magnetic ring.

[0008] The first coaxial transmission line and the second coaxial transmission line include an inner conductor and an outer conductor covering the inner conductor.

[0009] One end of the first coaxial transmission line is recorded as a positive pulse input terminal, and the other end is recorded as a first pulse output terminal.

[0010] The positive pulse input terminal includes a first input terminal and a second input terminal.

[0011] The first input terminal is an inner conductor of the first pulse input end, and the second input terminal is an outer conductor of the first pulse input end.

[0012] The first input terminal and the second input terminal are electrically connected to the output end of the external positive pulse generator respectively.

[0013] An inner conductor of the first pulse output terminal is connected to a load.

[0014] One end of the second coaxial transmission line is recorded as a negative pulse input terminal, and the other end is recorded as a second pulse output terminal.

[0015] The negative pulse input terminal includes a third input terminal and a fourth input terminal.

[0016] The third input terminal is an inner conductor of the second pulse input terminal, and the fourth input terminal is an outer conductor of the second pulse input terminal.

[0017] The third input terminal and the fourth input terminal are electrically connected to the output end of the external negative pulse generator respectively.

[0018] The outer conductor of the second pulse output terminal is electrically connected to the outer conductor of the first pulse output terminal.

[0019] An inner conductor of the second pulse output terminal is connected to a load.

[0020] The first coaxial transmission line and the second coaxial transmission line are symmetrically wound on both sides of the magnetic ring.

[0021] During operation, the first pulse output terminal and the second pulse output terminal are respectively connected to the two ends of the load, the first input terminal and the second input terminal are connected to a pulse generator that generates positive pulses, and the first coaxial transmission line receives the positive pulses transmitted by the external positive pulse generator. The third input terminal and the fourth input terminal are connected to a pulse generator that generates negative pulses, and the second coaxial transmission line receives the negative pulses transmitted by the external negative pulse generator.

[0022] The first coaxial transmission line and the second coaxial transmission line work together to convert two unbalanced positive pulses and negative pulses into one positive and negative balanced pulse, and apply the positive and negative balanced pulse to the load to achieve linear voltage multiplication.

[0023] Furthermore, there is no electrical connection between the coaxial transmission line and the magnetic ring.

[0024] Furthermore, the magnetic ring includes an annular ferrite core.

[0025] The technical effects of the present invention are undoubted, and the beneficial effects of the present invention include:

[0026] 1. The present invention can solve the problem of power saturation in existing short pulse power synthesis methods and achieve linear power superposition;

[0027] 2. The present invention can realize the conversion of two unbalanced pulses into one balanced pulse, and the pulse has strong anti-interference performance during the transmission process;

[0028] 3. The present invention has a small space and can reduce the size of the pulse generator when used in inductive energy storage pulse forming line (IES-PFL) power synthesis, achieving a compact design.

[0029] 4. The components used in the present invention have low production costs and good economic efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a balanced conversion power directional coupler;

[0031] Figure 2 shows the balanced conversion power synthesis of the inductive energy storage pulse forming line;

[0032] Figure 3 is a physical diagram of a balanced conversion power directional coupler;

[0033] Figure 4 is an experimental prototype of an inductive energy storage pulse forming line balanced conversion power synthesis;

[0034] Figure 5 is the positive pulse voltage waveform of the inductive energy storage pulse forming line;

[0035] Figure 6 is the negative pulse voltage waveform of the inductive energy storage pulse forming line;

[0036] Figure 7 is the power linear superposition pulse voltage waveform;

[0037] In the figure: first input terminal 1, second input terminal 2, third input terminal 3, fourth input terminal 4, first pulse output terminal 5, second pulse output terminal 6, first coaxial transmission line 7, second coaxial transmission line 8, magnetic ring 9. DETAILED DESCRIPTION

[0038] The present invention will be further described below with reference to the following examples, but it should not be understood that the scope of the present invention is limited to the following examples. Without departing from the above technical ideas of the present invention, various substitutions and modifications can be made according to common technical knowledge and customary means in the art, and all should be included in the scope of protection of the present invention.

[0039] Example 1:

[0040] 1 to 7 , a balanced conversion power directional coupler for linear superposition of short pulse power includes: a first coaxial transmission line 7 , a second coaxial transmission line 8 and a magnetic ring 9 .

[0041] The first coaxial transmission line 7 and the second coaxial transmission line 8 include an inner conductor and an outer conductor covering the inner conductor. The coaxial line includes a transmission line with a characteristic impedance of 50 ohms.

[0042] One end of the first coaxial transmission line 7 is marked as a positive pulse input terminal, and the other end is marked as a first pulse output terminal 5 .

[0043] The positive pulse input end includes a first input terminal 1 and a second input terminal 2 .

[0044] The first input terminal 1 is an inner conductor of the first pulse input end, and the second input terminal 2 is an outer conductor of the first pulse input end.

[0045] The first input terminal 1 and the second input terminal 2 are electrically connected to the output end of an external positive pulse generator respectively.

[0046] The inner conductor of the first pulse output terminal 5 is connected to a load.

[0047] One end of the second coaxial transmission line 8 is marked as a negative pulse input terminal, and the other end is marked as a second pulse output terminal 6 .

[0048] The negative pulse input terminal includes a third input terminal 3 and a fourth input terminal 4 .

[0049] The third input terminal 3 is an inner conductor of the second pulse input terminal, and the fourth input terminal 4 is an outer conductor of the second pulse input terminal.

[0050] The third input terminal 3 and the fourth input terminal 4 are electrically connected to the output end of the external negative pulse generator respectively.

[0051] The outer conductor of the second pulse output terminal 6 is electrically connected to the outer conductor of the first pulse output terminal 5. The outer conductors of the two coaxial transmission lines are electrically connected, and the two inner copper cores serve as two terminals of the pulse output end connected to the load.

[0052] An inner conductor of the second pulse output terminal 6 is connected to a load.

[0053] The first coaxial transmission line 7 and the second coaxial transmission line 8 are symmetrically wound on both sides of the magnetic ring 9 .

[0054] During operation, the first pulse output terminal 5 and the second pulse output terminal 6 are respectively connected to the two ends of the load, and the output end of the balanced conversion power directional coupler is connected to a 100-ohm thick-film non-inductive resistor. The circuit connection principle diagram and the prototype are shown in Figures 2 and 4 respectively. The first input terminal 1 and the second input terminal 2 are connected to a pulse generator that generates positive pulses, and the first coaxial transmission line 7 receives the positive pulse transmitted by the external positive pulse generator. The third input terminal 3 and the fourth input terminal 4 are connected to a pulse generator that generates negative pulses, and the second coaxial transmission line 8 receives the negative pulse transmitted by the external negative pulse generator. The first coaxial transmission line 7 and the second coaxial transmission line 8 work together to convert the two unbalanced positive pulses and negative pulses into one positive and negative balanced pulse, and apply the positive and negative balanced pulses to the load to achieve linear voltage multiplication.

[0055] There is no electrical connection between the coaxial transmission line and the magnetic ring 9 .

[0056] The magnetic ring 9 comprises an annular ferrite core. The magnetic ring is selected from an annular ferrite core with high magnetic permeability to ensure that the device of the invention has a high bandwidth.

[0057] Example 2:

[0058] 1 to 7 , a balanced conversion power directional coupler for linear superposition of short pulse power includes: a first coaxial transmission line 7 , a second coaxial transmission line 8 and a magnetic ring 9 .

[0059] The first coaxial transmission line 7 and the second coaxial transmission line 8 include an inner conductor and an outer conductor covering the inner conductor. The coaxial line includes a transmission line with a characteristic impedance of 50 ohms.

[0060] One end of the first coaxial transmission line 7 is marked as a positive pulse input terminal, and the other end is marked as a first pulse output terminal 5 .

[0061] The positive pulse input end includes a first input terminal 1 and a second input terminal 2 .

[0062] The first input terminal 1 is an inner conductor of the first pulse input end, and the second input terminal 2 is an outer conductor of the first pulse input end.

[0063] The first input terminal 1 and the second input terminal 2 are electrically connected to the output end of an external positive pulse generator respectively.

[0064] The inner conductor of the first pulse output terminal 5 is connected to a load.

[0065] One end of the second coaxial transmission line 8 is marked as a negative pulse input terminal, and the other end is marked as a second pulse output terminal 6 .

[0066] The negative pulse input terminal includes a third input terminal 3 and a fourth input terminal 4 .

[0067] The third input terminal 3 is an inner conductor of the second pulse input end, and the fourth input terminal 4 is an outer conductor of the second pulse input end.

[0068] The third input terminal 3 and the fourth input terminal 4 are electrically connected to the output end of the external negative pulse generator respectively.

[0069] The outer conductor of the second pulse output terminal 6 is electrically connected to the outer conductor of the first pulse output terminal 5. The outer conductors of the two coaxial transmission lines are electrically connected, and the two inner copper cores serve as two terminals of the pulse output end connected to the load.

[0070] An inner conductor of the second pulse output terminal 6 is connected to a load.

[0071] The first coaxial transmission line 7 and the second coaxial transmission line 8 are symmetrically wound on both sides of the magnetic ring 9 .

[0072] During operation, the first pulse output terminal 5 and the second pulse output terminal 6 are respectively connected to the two ends of the load, and the output end of the balanced conversion power directional coupler is connected to a 100-ohm thick-film non-inductive resistor. The circuit connection principle diagram and the prototype are shown in Figures 2 and 4 respectively. The first input terminal 1 and the second input terminal 2 are connected to a pulse generator that generates positive pulses, and the first coaxial transmission line 7 receives the positive pulse transmitted by the external positive pulse generator. The third input terminal 3 and the fourth input terminal 4 are connected to a pulse generator that generates negative pulses, and the second coaxial transmission line 8 receives the negative pulse transmitted by the external negative pulse generator. The first coaxial transmission line 7 and the second coaxial transmission line 8 work together to convert the two unbalanced positive pulses and negative pulses into one positive and negative balanced pulse, and apply the positive and negative balanced pulses to the load to achieve linear voltage multiplication.

[0073] Example 3:

[0074] A balanced conversion power directional coupler for linear superposition of short pulse power, the main structure of which is shown in Example 2, wherein there is no electrical connection between the coaxial transmission line and the magnetic ring 9.

[0075] Example 4:

[0076] A balanced power directional coupler for linear superposition of short pulse power, the main structure of which is shown in Example 2, wherein the magnetic ring 9 comprises a ring-shaped ferrite core. The magnetic ring is selected from a ring-shaped ferrite core with high magnetic permeability to ensure that the device has a high bandwidth.

[0077] Example 5:

[0078] The principle diagram and actual device of the balanced power directional coupler proposed in this invention are shown in Figures 1 and 3, respectively. Ports 1 and 2 constitute the positive pulse input, ports 3 and 4 constitute the negative pulse input, and ports 5 and 6 constitute the pulse output. This directional coupler can linearly combine the power of two inductive energy storage pulse forming lines (pulse generators) generating positive and negative pulses. The following describes a specific embodiment.

[0079] The pulse output port of an inductive energy storage type pulse forming line that generates positive pulses is electrically connected to the positive pulse input terminal (ports 1 and 2) of the balanced conversion power directional coupler, and the pulse output port of another inductive energy storage type pulse forming line that generates negative pulses is electrically connected to the negative pulse input terminal (ports 1 and 2) of the balanced conversion power directional coupler. The output terminal of the balanced conversion power directional coupler is connected to a 100-ohm thick-film non-inductive resistor. The circuit connection schematic diagram and prototype are shown in Figures 2 and 4 respectively.

[0080] In the experiment, a PPE5kV (LeCroy, 6kV, 400MHz) high-voltage passive probe was used to measure the output voltage pulses. The probe was connected via a grounded spring pin to minimize parasitic inductance in the measurement loop. A Tektronix AFG31000 arbitrary / function generator was used as the control signal generator, and a WavePro 760Zi-A (LeCroy, 6GHz) oscilloscope was used to record the waveforms. The control signal generator simultaneously provided trigger signals to two inductive energy storage pulse generators, generating two synchronized positive and negative pulses, respectively. Ports 1 and 2 provided positive pulses, while ports 3 and 4 provided negative pulses. The voltage pulse waveforms are shown in Figures 5 and 6, respectively. The pulse amplitudes were +1kV and -1kV, respectively, and the pulse width was 20ns.

[0081] A voltage probe was used to measure the voltage across a 100-ohm load at the output of the balun (ports 5 and 6). The voltage waveform is shown in Figure 7. The voltage amplitude is 2 kV, twice the amplitude of the voltage pulse at the front end, and the pulse width is 20 ns. Therefore, the balun can achieve linear power combining of short pulses (tens of ns).

[0082] The present invention aims to overcome the shortcomings of the prior art and proposes a balanced power directional coupler for linear superposition of short pulse power. The invention includes the following parts:

[0083] 1. The present invention is characterized in that it includes two pulse input terminals, one pulse output terminal, one magnetic ring, and two coaxial transmission lines; wherein the two coaxial transmission lines are symmetrically wound on both sides of the magnetic ring, and there is no electrical connection between the coaxial transmission lines and the magnetic ring.

[0084] 2. The two pulse input ends of the balanced conversion power directional coupler are terminals on the same side of two coaxial transmission lines, one terminal is electrically connected to the output end of the pulse generator that generates positive pulses, and the other terminal is electrically connected to the output end of the pulse generator that generates negative pulses.

[0085] 3. The pulse output terminal of the balanced conversion power directional coupler is constructed as follows: the outer conductors of two coaxial transmission lines are electrically connected, and the two inner copper cores serve as the two terminals of the pulse output terminal and are connected to the load;

[0086] 4. The magnetic ring is made of a ring-shaped ferrite core with high magnetic permeability to ensure that the device has a high bandwidth;

[0087] 5. The coaxial transmission line is a transmission line with a characteristic impedance of 50 ohms;

[0088] 6. The two coaxial transmission lines transmit positive and negative pulses respectively, realizing the conversion of two unbalanced positive pulses and negative pulses into one positive and negative balanced pulse. The positive and negative balanced pulses have strong anti-interference ability during the transmission process, and finally act on the load to realize linear multiplication of the voltage.

Claims

1. A balanced conversion power directional coupler for short pulse power linear superposition, characterized in that: include: A first coaxial transmission line (7), a second coaxial transmission line (8) and a magnetic ring (9); The first coaxial transmission line (7) and the second coaxial transmission line (8) comprise an inner conductor and an outer conductor wrapping the inner conductor; One end of the first coaxial transmission line (7) is recorded as a positive pulse input terminal, and the other end is recorded as a first pulse output terminal (5); The positive pulse input terminal comprises a first input terminal (1) and a second input terminal (2). The first input terminal (1) is an inner conductor of the first pulse input end, and the second input terminal (2) is an outer conductor of the first pulse input end; The first input terminal (1) and the second input terminal (2) are electrically connected to the output end of the external positive pulse generator respectively; The internal conductor of the first pulse output terminal (5) is connected to a load; One end of the second coaxial transmission line (8) is recorded as a negative pulse input terminal, and the other end is recorded as a second pulse output terminal (6); The negative pulse input terminal comprises a third input terminal (3) and a fourth input terminal (4). The third input terminal (3) is an inner conductor of the second pulse input end, and the fourth input terminal (4) is an outer conductor of the second pulse input end; The third input terminal (3) and the fourth input terminal (4) are electrically connected to the output end of the external negative pulse generator respectively; The outer conductor of the second pulse output terminal (6) is electrically connected to the outer conductor of the first pulse output terminal (5); The internal conductor of the second pulse output terminal (6) is connected to a load; The first coaxial transmission line (7) and the second coaxial transmission line (8) are symmetrically wound on two sides of the magnetic ring (9); When in operation, the first pulse output terminal (5) and the second pulse output terminal (6) are respectively connected to two ends of a load, the first input terminal (1) and the second input terminal (2) are connected to a pulse generator that generates a positive pulse, and the first coaxial transmission line (7) receives a positive pulse transmitted by the external positive pulse generator; the third input terminal (3) and the fourth input terminal (4) are connected to a pulse generator that generates a negative pulse, and the second coaxial transmission line (8) receives a negative pulse transmitted by the external negative pulse generator; The first coaxial transmission line (7) and the second coaxial transmission line (8) work together to convert two unbalanced positive pulses and negative pulses into one positive and negative balanced pulse, and apply the positive and negative balanced pulses to the load to achieve linear voltage multiplication.

2. A balanced conversion power directional coupler for short pulse power linear superposition according to claim 1, characterized in that: There is no electrical connection between the coaxial transmission line and the magnetic ring (9).

3. A balanced conversion power directional coupler for short pulse power linear superposition according to claim 1, characterized in that: The magnetic ring (9) comprises an annular ferrite core.

Images