A method for suppressing oscillation in a traveling wave tube

Abstract

This application discloses a method for suppressing oscillations in a traveling wave tube (TWT), relating to the field of vacuum electronics technology. It obtains the gradually changing period length and the gradually changing width length by synchronously changing the strategy, and verifies the TWT formed by the gradually changing period length and the gradually changing width length using constraint verification and performance verification. This allows for continuous change of the cutoff frequency of the slow-wave structure. Unlike traditional methods that change the phase velocity by altering the size of the slow-wave structure, thereby disrupting phase velocity synchronization, this method achieves more fundamental and thorough suppression of oscillations without significantly increasing circuit losses, sacrificing electron beam throughput, or excessively increasing the tube length.

Description

Technical Field

[0001] This application relates to the field of vacuum electronics technology, specifically to a method for suppressing oscillations in a traveling wave tube. Background Technology

[0002] Traveling wave tubes (TWTs), as core microwave power amplification devices, play an irreplaceable role in radar, communication, and electronic warfare systems. With the ever-increasing power capacity requirements of systems, vacuum electronic devices have once again become a research focus due to their excellent stability and heat dissipation capabilities under high power and harsh environments. To obtain continuous wave or pulsed power at the kilowatt level or above, employing large-size waveguide-type slow-wave structures and driving high-current strip electron beams has become the mainstream technical approach. However, the high-gain and high-current operating conditions also significantly increase the risk of various parasitic oscillations within the TWT, such as back-wave oscillations and band-edge oscillations. These oscillations not only lead to output signal distortion and noise degradation, but in severe cases, they can also damage circuits or cause devices to malfunction. Therefore, oscillation suppression is a key technical challenge in ensuring the performance and reliability of high-power TWTs.

[0003] Traditional oscillation suppression techniques mainly revolve around disrupting the phase synchronization condition of the oscillation or increasing losses to absorb oscillation energy. Common methods include:

[0004] Centralized attenuator method: Attenuating material is inserted in the middle or at a specific location in the slow-wave circuit. While effective, this method blocks the electron beam path, increases circuit discontinuity, and leads to electron beam disturbances and energy loss. At high power and high duty cycle operation, the attenuator experiences extremely high local heat load, making heat dissipation design extremely difficult and becoming a bottleneck limiting power increases.

[0005] Phase velocity jump method: By changing the period or size of the slow-wave structure, the phase velocity is abruptly or gradually changed, thereby disrupting the synchronization condition between the electron beam and the returned wave. Although this method does not directly block the electron beam, to achieve a sufficient jump effect, the overall length of the structure usually needs to be increased. This not only increases the processing burden but also places more stringent requirements on the stable focusing of the strip electron beam throughout its entire lifespan. Furthermore, the complex gradual design is extremely sensitive to machining precision, resulting in high manufacturing costs and risks.

[0006] It is evident that while existing mainstream methods suppress oscillations, they often inevitably introduce negative effects such as additional losses, structural complexity, thermal management challenges, or decreased electron beam quality. These side effects are further amplified in high-power applications. Summary of the Invention

[0007] The purpose of this application is to provide a method for suppressing oscillations in traveling wave tubes, which solves the problem that existing technologies, while suppressing oscillations, often inevitably introduce negative effects such as additional losses, structural complexity, thermal management difficulties, or decreased electron beam quality.

[0008] This application is achieved through the following technical solution:

[0009] A method for suppressing traveling wave tube oscillations includes:

[0010] Determine the initial period length and initial width length of the target traveling wave tube to be oscillated and suppressed, and determine the period range and the width range based on the initial period length and the initial width length, respectively.

[0011] Based on the period range and the width range, determine the gradient period length and gradient width length corresponding to the target traveling wave tube;

[0012] Based on the gradient period length and gradient width length of the target traveling wave tube, the target traveling wave tube is simulated to obtain the simulation model of the target traveling wave tube.

[0013] Based on the simulation model corresponding to the target traveling wave tube, the constraints are verified by using pre-constructed phase velocity matching constraints, maintaining coupling impedance constraints, and passband transmission characteristic constraints, and the constraint verification results are obtained.

[0014] Based on the simulation model corresponding to the target traveling wave tube, the target traveling wave tube is subjected to oscillation suppression verification and comprehensive performance verification, and the performance verification results are obtained.

[0015] Based on the constraint verification results and the performance verification results, the oscillation suppression optimization progress is determined; wherein, the oscillation suppression optimization progress includes whether the oscillation suppression optimization is completed or not.

[0016] Based on the completion of the oscillation suppression optimization, the final gradient period length and final gradient width length of the target traveling wave tube are determined according to the period range and the width range, and the oscillation suppression optimization result is obtained and output.

[0017] If the oscillation suppression optimization progress is incomplete, a synchronous change strategy is adopted to change the period range and the width range, and the process returns to the step of obtaining the gradual period length and the gradual width length to enter the next iteration process.

[0018] In one possible implementation, determining the period range based on the initial period length and determining the width range based on the initial width length includes:

[0019] The initial cycle length is used as the starting value and the final value of the cycle length, respectively, and adjusted using a synchronous change strategy to obtain the cycle range;

[0020] The initial width length is used as the starting value and the final value of the width length, respectively, and adjusted using a synchronous change strategy to obtain the width range.

[0021] In one possible implementation, the gradient period length and gradient width length corresponding to the target traveling wave tube are determined based on the period range and the width range as follows:

[0022] Based on the period range and the width range, determine the period length and width length corresponding to each period unit in the target traveling wave tube;

[0023] p_n=p_start+(p_end−p_start)·(n−1) / (N−1);

[0024] l_n=l_start+(l_end−l_start)·(n−1) / (N−1);

[0025] In the formula, p_n is the period length corresponding to the nth periodic unit in the target traveling wave tube, n=1,2,…,N, N is the total number of periodic units, p_start is the starting value of the period length in the period range, p_end is the final value of the period length in the period range, l_n is the width length corresponding to the nth periodic unit in the target traveling wave tube, l_start is the starting value of the width length in the width range, and l_end is the final value of the width length in the width range;

[0026] The gradual period length is formed by the period lengths corresponding to all periodic units, and the gradual wide side length is formed by the wide side lengths corresponding to all periodic units.

[0027] In one possible implementation, the target traveling wave tube is simulated based on its gradient period length and gradient width length to obtain a simulation model of the target traveling wave tube, including:

[0028] Based on the gradually changing period length and gradually changing width length corresponding to the target traveling wave tube, the size of each period unit is continuously changed along the electron beam travel direction and simulated to obtain the simulation model corresponding to the target traveling wave tube.

[0029] In one possible implementation, the pre-built phase velocity matching constraint, preserving coupling impedance constraint, and passband transmission characteristic constraint include:

[0030] The phase velocity matching constraint is: the fluctuation range of the fundamental phase velocity along the axial direction at the target center frequency shall not exceed ±0.5%;

[0031] The coupling impedance constraint is maintained as follows: the variation of the coupling impedance along the axis of the slow-wave structure does not exceed ±15%.

[0032] The passband transmission characteristic constraint is: the passband of the simulation model corresponding to the target traveling wave tube completely covers the target operating frequency band corresponding to the target traveling wave tube.

[0033] In one possible implementation, based on the simulation model corresponding to the target traveling wave tube, the constraint verification is performed using pre-constructed phase velocity matching constraints, preserving coupling impedance constraints, and passband transmission characteristic constraints, to obtain the constraint verification results, including:

[0034] Based on the simulation model corresponding to the target traveling wave tube, verify whether the phase velocity matching constraint, the maintaining coupling impedance constraint, and the passband transmission characteristic constraint are all valid simultaneously. If so, the constraint verification result is determined to be a successful verification; otherwise, the constraint verification result is determined to be a failed verification.

[0035] In one possible implementation, based on the simulation model corresponding to the target traveling wave tube, the target traveling wave tube is subjected to oscillation suppression verification and comprehensive performance verification to obtain performance verification results, including:

[0036] Based on the simulation model corresponding to the target traveling wave tube, verify whether the signal oscillation of the target traveling wave tube meets the preset oscillation requirements and whether the performance meets the corresponding design target. If so, the performance verification result is determined to be verified as passed; otherwise, the performance verification result is determined to be verified as failed.

[0037] In one possible implementation, determining the oscillation suppression optimization progress based on the constraint verification results and the performance verification results includes:

[0038] If both the constraint verification result and the performance verification result are passed, the oscillation suppression optimization progress is determined to be completed; otherwise, the oscillation suppression optimization is determined to be incomplete.

[0039] In one possible implementation, a synchronous change strategy is used to change the period range and the width range, including:

[0040] Based on a preset change amount, the final value of the period length in the period range and the final value of the width length in the width range are increased simultaneously to obtain the changed period range and the changed width range.

[0041] Alternatively, based on a preset change amount, the starting value of the period length in the period range and the starting value of the width length in the width range are simultaneously reduced to obtain the changed period range and the changed width range.

[0042] In one possible implementation, the process of executing the synchronous change strategy further includes:

[0043] When the synchronization change strategy is executed for the first time, an increment process is performed;

[0044] When the synchronization change strategy is executed during the iteration process, the execution action of the previous execution of the synchronization change strategy is obtained; wherein, the execution action is to increase processing or decrease processing;

[0045] If the previous synchronous change strategy action was to increase processing, the current synchronous change strategy will use to decrease processing.

[0046] If the previous synchronous change strategy action was to reduce processing, the current synchronous change strategy will use to increase processing.

[0047] Compared with the prior art, this application has the following advantages and beneficial effects:

[0048] This application provides a method for suppressing oscillations in a traveling wave tube (TWT). By synchronously changing the strategy to obtain the gradually changing period length and the gradually changing width length, and by using constraint verification and performance verification, the TWT formed by the gradually changing period length and the gradually changing width length is verified. This allows for continuous change of the cutoff frequency of the slow wave structure. Unlike the traditional method of changing the size of the slow wave structure to change the phase velocity and thus destroying the phase velocity synchronization condition, this method can achieve more fundamental and thorough suppression of oscillations without significantly increasing circuit losses, sacrificing electron beam throughput, or excessively increasing the tube length. Attached Figure Description

[0049] To more clearly illustrate the technical solutions of the exemplary embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0050] Figure 1 A flowchart of a traveling wave tube oscillation suppression method provided in this application embodiment;

[0051] Figure 2 A schematic diagram of the interleaved dual-grid slow-wave structure provided in the embodiments of this application;

[0052] Figure 3 This is a schematic diagram of a folded waveguide slow wave structure provided in an embodiment of this application. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this application are only for explaining this application and are not intended to limit this application.

[0054] like Figure 1 As shown, this application provides a method for suppressing traveling wave tube oscillations, including:

[0055] S101. Determine the initial period length and initial width length of the target traveling wave tube to be oscillated and suppressed, and determine the period range and the width range based on the initial period length and the initial width length.

[0056] S102. Determine the gradient period length and gradient width length corresponding to the target traveling wave tube based on the period range and the width range.

[0057] S103. Based on the gradient period length and gradient width length corresponding to the target traveling wave tube, the target traveling wave tube is simulated to obtain the simulation model corresponding to the target traveling wave tube.

[0058] S104. Based on the simulation model corresponding to the target traveling wave tube, the constraint verification is performed using pre-constructed phase velocity matching constraints, maintaining coupling impedance constraints, and passband transmission characteristic constraints to obtain the constraint verification results.

[0059] S105. Based on the simulation model corresponding to the target traveling wave tube, the target traveling wave tube is subjected to oscillation suppression verification and comprehensive performance verification to obtain the performance verification results.

[0060] S106. Based on the constraint verification results and the performance verification results, determine the oscillation suppression optimization progress; wherein, the oscillation suppression optimization progress includes whether the oscillation suppression optimization is completed or not.

[0061] S107. Based on the completion of the oscillation suppression optimization, determine the final gradient period length and final gradient width length corresponding to the target traveling wave tube according to the period range and the width range, obtain the oscillation suppression optimization result, and output it.

[0062] S108. Based on the condition that the oscillation suppression optimization progress is incomplete, a synchronous change strategy is adopted to change the period range and the width range, and the process returns to the step of obtaining the gradual period length and the gradual width length to enter the next iteration process.

[0063] This method should be able to achieve more fundamental and thorough suppression of oscillations without significantly increasing circuit losses, sacrificing electron beam throughput, or excessively increasing tube length. Based on the innovative approach of continuously changing the cutoff frequency of the slow-wave structure, this application differs from the traditional method of altering the phase velocity by changing the size of the slow-wave structure, thereby disrupting phase velocity synchronization. By systematically designing the dispersion relation of the slow-wave structure, it provides a method for suppressing band-side and back-wave oscillations in high-power waveguide-type slow-wave traveling-wave tubes.

[0064] In one possible implementation, determining the period range based on the initial period length and determining the width range based on the initial width length includes:

[0065] The initial cycle length is used as the starting value and the final value of the cycle length, respectively, and adjusted using a synchronous change strategy to obtain the cycle range;

[0066] The initial width length is used as the starting value and the final value of the width length, respectively, and adjusted using a synchronous change strategy to obtain the width range.

[0067] For a selected waveguide-type slow-wave structure (such as an interlaced double-grating or folded waveguide) that meets the design objectives (e.g., operating in the Ka band, with a bandwidth of 5 GHz, an output power of 5 kW, and a gain of 25 dB), a dispersion model is established to obtain the dispersion characteristics of the periodic structure corresponding to the initial period length p and the width length l. Then, the period range and the width range can be determined based on the initial period length and the initial width length, respectively. Executing a synchronous change strategy is equivalent to simultaneously increasing both the period range and the width range by a certain amount (e.g., 5% or 10%).

[0068] In one possible implementation, the gradient period length and gradient width length corresponding to the target traveling wave tube are determined based on the period range and the width range as follows:

[0069] Based on the period range and the width range, determine the period length and width length corresponding to each period unit in the target traveling wave tube;

[0070] p_n=p_start+(p_end−p_start)·(n−1) / (N−1);

[0071] l_n=l_start+(l_end−l_start)·(n−1) / (N−1);

[0072] In the formula, p_n is the period length corresponding to the nth periodic unit in the target traveling wave tube, n=1,2,…,N, N is the total number of periodic units, p_start is the starting value of the period length in the period range, p_end is the final value of the period length in the period range, l_n is the width length corresponding to the nth periodic unit in the target traveling wave tube, l_start is the starting value of the width length in the width range, and l_end is the final value of the width length in the width range;

[0073] The gradual period length is formed by the period lengths corresponding to all periodic units, and the gradual wide side length is formed by the wide side lengths corresponding to all periodic units.

[0074] Continuous cutoff frequency adjustment: Based on waveguide theory, the cutoff frequency f c It is closely related to the period length l of the slow-wave structure. By continuously and monotonically changing l along the direction of electron beam propagation, the cutoff frequency can be continuously varied, thus disrupting the conditions that may lead to standing wave or back wave resonance.

[0075] Maintaining phase velocity synchronization of the fundamental wave: Observing the changes in the dispersion characteristics of the periodic structure after changing l, it can be found that simultaneously increasing or decreasing the period length p can compensate for the change in phase velocity caused by the change in l, ensuring that the phase velocity at the center frequency of different periodic structures is consistent. Throughout the gradient region, the electron beam and the fundamental wave always maintain phase synchronization, avoiding gain loss and maintaining phase velocity synchronization of the fundamental wave.

[0076] Gradient function design: The linear function described above is used to describe the relationship between p(z) and l(z) along the axial position z.

[0077] In one possible implementation, the target traveling wave tube is simulated based on its gradient period length and gradient width length to obtain a simulation model of the target traveling wave tube, including:

[0078] Based on the gradually changing period length and gradually changing width length corresponding to the target traveling wave tube, the size of each period unit is continuously changed along the electron beam travel direction and simulated to obtain the simulation model corresponding to the target traveling wave tube.

[0079] For example, macros in CST can be used to achieve rapid automatic modeling, or software such as Matlab can be used in conjunction with CST for joint modeling and simulation to transform the optimized parameters into a specific three-dimensional slow-wave structure model. A pre-designed gradient function is used to continuously change the size of each periodic unit along the electron beam propagation direction.

[0080] In one possible implementation, the pre-built phase velocity matching constraint, preserving coupling impedance constraint, and passband transmission characteristic constraint include:

[0081] The phase velocity matching constraint is: the fluctuation range of the fundamental phase velocity along the axial direction at the target center frequency shall not exceed ±0.5%;

[0082] The coupling impedance constraint is maintained as follows: the variation of the coupling impedance along the axis of the slow-wave structure does not exceed ±15%.

[0083] The passband transmission characteristic constraint is: the passband of the simulation model corresponding to the target traveling wave tube completely covers the target operating frequency band corresponding to the target traveling wave tube.

[0084] In this embodiment, the values ​​of p and l are determined with the goal of maintaining phase velocity matching, preserving coupling impedance, and passband transmission characteristics.

[0085] 1. Strict phase velocity synchronization maintenance. The fundamental phase velocity v is set. p The axial fluctuation range at the target center frequency should not exceed ±0.5%, ensuring efficient energy exchange throughout the entire interaction length and avoiding gain reduction or efficiency loss.

[0086] 2. Stability of coupling impedance. The variation of coupling impedance along the axis of the slow-wave structure should be controlled within ±15% to ensure the uniformity and stability of power extraction.

[0087] 3. Preservation of passband characteristics. The passband of the gradually changed slow-wave structure should completely cover the target operating frequency band (e.g., Ka-band 31-36 GHz). Select a suitable range of p and l variation: Based on the initial p and l values, increase or decrease p and l simultaneously by 10%, while simultaneously satisfying the above three target conditions to obtain new p and l values, forming a variation range with the initial p and l values.

[0088] In one possible implementation, based on the simulation model corresponding to the target traveling wave tube, the constraint verification is performed using pre-constructed phase velocity matching constraints, preserving coupling impedance constraints, and passband transmission characteristic constraints, to obtain the constraint verification results, including:

[0089] Based on the simulation model corresponding to the target traveling wave tube, verify whether the phase velocity matching constraint, the maintaining coupling impedance constraint, and the passband transmission characteristic constraint are all valid simultaneously. If so, the constraint verification result is determined to be a successful verification; otherwise, the constraint verification result is determined to be a failed verification.

[0090] In one possible implementation, based on the simulation model corresponding to the target traveling wave tube, the target traveling wave tube is subjected to oscillation suppression verification and comprehensive performance verification to obtain performance verification results, including:

[0091] Based on the simulation model corresponding to the target traveling wave tube, verify whether the signal oscillation of the target traveling wave tube meets the preset oscillation requirements and whether the performance meets the corresponding design target. If so, the performance verification result is determined to be verified as passed; otherwise, the performance verification result is determined to be verified as failed.

[0092] For example, oscillation suppression verification involves performing large-signal simulations within the target frequency band and observing whether non-harmonic frequency components appear in the output spectrum, especially near band-edge frequencies and the back-wave resonant frequency. The output spectrum should not contain obvious isolated peaks other than the fundamental frequency (operating frequency) and its reasonable harmonic components. Special attention should be paid to the vicinity of band-edge frequencies (such as the upper and lower band-edge frequencies of the passband) and the back-wave resonant frequency (usually located within the passband or near low frequencies); these locations should not have sharp peaks. The second and third harmonic powers should be significantly lower than the fundamental power (typically more than 20 dB lower), and their power levels should be consistent with theoretical or design expectations.

[0093] Overall performance evaluation: Output power, gain, bandwidth, and other indicators still meet the design goals. For example, a high-power interleaved dual-grid traveling wave tube operating in the Ka band has a working bandwidth of 5 GHz, an output power of 5 kW, and a gain of 25 dB.

[0094] In one possible implementation, determining the oscillation suppression optimization progress based on the constraint verification results and the performance verification results includes:

[0095] If both the constraint verification result and the performance verification result are passed, the oscillation suppression optimization progress is determined to be completed; otherwise, the oscillation suppression optimization is determined to be incomplete.

[0096] In one possible implementation, a synchronous change strategy is used to change the period range and the width range, including:

[0097] Based on a preset change amount, the final value of the period length in the period range and the final value of the width length in the width range are increased simultaneously to obtain the changed period range and the changed width range.

[0098] Alternatively, based on a preset change amount, the starting value of the period length in the period range and the starting value of the width length in the width range are simultaneously reduced to obtain the changed period range and the changed width range.

[0099] In one possible implementation, the process of executing the synchronous change strategy further includes:

[0100] When the synchronization change strategy is executed for the first time, an increment process is performed;

[0101] When the synchronization change strategy is executed during the iteration process, the execution action of the previous execution of the synchronization change strategy is obtained; wherein, the execution action is to increase processing or decrease processing;

[0102] If the previous synchronous change strategy action was to increase processing, the current synchronous change strategy will use to decrease processing.

[0103] If the previous synchronous change strategy action was to reduce processing, the current synchronous change strategy will use to increase processing.

[0104] For example, if the simulation results do not meet the standards, the change amount is increased by 10% or decreased by 10%, and the range of change of the gradual parameters is adjusted until all performance and stability requirements are met.

[0105] The method provided by this invention is applicable to various traveling wave tubes with waveguide-type slow wave structures, such as interleaved dual-grid slow wave circuits and folded waveguide slow wave circuits, and is especially suitable for high-power devices that drive high-current strip electron beams.

[0106] like Figure 2 As shown, a Ka-band (center frequency 34GHz) high-power interleaved dual-grid traveling wave tube is used as an example.

[0107] 1. Collaborative gradual design and optimization of key parameters.

[0108] Determine the dominant parameters: For the interleaved double-gate structure, the width length l is identified as the parameter most sensitive to the cutoff frequency, while the period length p is the most effective parameter for adjusting the fundamental phase velocity.

[0109] Establish a cooperative gradient model: Determine the ranges of p and l that can satisfy the constraints: 2.9mm≤p≤3.3mm, 4.9mm≤l≤6mm, and ensure the cutoff frequency f. c While continuously changing, maintain the fundamental phase velocity synchronization V pc =0.2445c.

[0110] 2. Implementation and performance verification of gradient structure.

[0111] The optimized gradient parameters are converted into a specific three-dimensional structural model, which consists of 25 periodic units, and the p and l dimensions of each unit are linearly varied according to the above range.

[0112] Oscillation suppression effect: Large signal simulation was performed across the entire operating frequency band (31.5-36.5 GHz), and the output signal spectrum was clean, with no oscillation characteristic frequency components observed.

[0113] like Figure 3As shown, a Ka-band (center frequency 34GHz) high-power folded waveguide traveling wave tube is used as an example.

[0114] 1. Collaborative gradual design and optimization of key parameters.

[0115] For a folded waveguide slow-wave structure, the ranges of p and l that satisfy the constraints are determined as follows: 2.7mm ≤ p ≤ 3.2mm, 5.2mm ≤ l ≤ 6mm, ensuring the cutoff frequency f. c While continuously changing, maintain the fundamental phase velocity synchronization V pc =0.243c. And ensure that the coupling impedance and passband characteristics meet the requirements for high-efficiency transmission.

[0116] 2. Implementation and performance verification of gradient structure.

[0117] The optimized gradient parameters were mapped to a three-dimensional folded waveguide model, and the geometry of each periodic unit was continuously adjusted along the direction of electron beam motion. A slow-wave circuit containing approximately 30 periodic units was constructed, and a full three-dimensional beam-wave interaction analysis was performed using simulation tools. Under large-signal operating conditions, its output power, gain, efficiency, and spectral purity in the 31–36 GHz band were evaluated. Simulation results show that the gradient structure can effectively suppress band-side oscillations and back-wave oscillations, and no abnormal spectral components appear in the output signal, verifying the feasibility and stability of the proposed method.

[0118] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0119] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1A device that provides the functions specified in one or more boxes.

[0120] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0121] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0122] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0123] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for suppressing oscillations in a traveling wave tube, characterized in that, include: Determine the initial period length and initial width length of the target traveling wave tube to be oscillated and suppressed, and determine the period range and the width range based on the initial period length and the initial width length, respectively. Based on the period range and the width range, determine the gradient period length and gradient width length corresponding to the target traveling wave tube; Based on the gradient period length and gradient width length of the target traveling wave tube, the target traveling wave tube is simulated to obtain the simulation model of the target traveling wave tube. Based on the simulation model corresponding to the target traveling wave tube, the constraints are verified by using pre-constructed phase velocity matching constraints, maintaining coupling impedance constraints, and passband transmission characteristic constraints, and the constraint verification results are obtained. Based on the simulation model corresponding to the target traveling wave tube, the target traveling wave tube is subjected to oscillation suppression verification and comprehensive performance verification, and the performance verification results are obtained. Based on the constraint verification results and the performance verification results, the oscillation suppression optimization progress is determined; wherein, the oscillation suppression optimization progress includes whether the oscillation suppression optimization is completed or not. Based on the completion of the oscillation suppression optimization, the final gradient period length and final gradient width length of the target traveling wave tube are determined according to the period range and the width range, and the oscillation suppression optimization result is obtained and output. If the oscillation suppression optimization progress is incomplete, a synchronous change strategy is adopted to change the period range and the width range, and the process returns to the step of obtaining the gradual period length and the gradual width length to enter the next iteration process.

2. The method for suppressing oscillations in a traveling wave tube according to claim 1, characterized in that, Determining the period range based on the initial period length and determining the width range based on the initial width length include: The initial cycle length is used as the starting value and the final value of the cycle length, respectively, and adjusted using a synchronous change strategy to obtain the cycle range; The initial width length is used as the starting value and the final value of the width length, respectively, and adjusted using a synchronous change strategy to obtain the width range.

3. The method for suppressing oscillations in a traveling wave tube according to claim 1, characterized in that, Based on the period range and the width range, the gradient period length and gradient width length corresponding to the target traveling wave tube are determined as follows: Based on the period range and the width range, determine the period length and width length corresponding to each period unit in the target traveling wave tube; p_n=p_start+(p_end−p_start)·(n−1) / (N−1); l_n=l_start+(l_end−l_start)·(n−1) / (N−1); In the formula, p_n is the period length corresponding to the nth periodic unit in the target traveling wave tube, n=1,2,…,N, N is the total number of periodic units, p_start is the starting value of the period length in the period range, p_end is the final value of the period length in the period range, l_n is the width length corresponding to the nth periodic unit in the target traveling wave tube, l_start is the starting value of the width length in the width range, and l_end is the final value of the width length in the width range; The gradual period length is formed by the period lengths corresponding to all periodic units, and the gradual wide side length is formed by the wide side lengths corresponding to all periodic units.

4. The method for suppressing oscillations in a traveling wave tube according to claim 1, characterized in that, Based on the gradient period length and gradient width length corresponding to the target traveling wave tube, a simulation of the target traveling wave tube is performed to obtain a simulation model of the target traveling wave tube, including: Based on the gradually changing period length and gradually changing width length corresponding to the target traveling wave tube, the size of each period unit is continuously changed along the electron beam travel direction and simulated to obtain the simulation model corresponding to the target traveling wave tube.

5. The method for suppressing oscillations in a traveling wave tube according to claim 1, characterized in that, The pre-built phase velocity matching constraints, preserving coupling impedance constraints, and passband transmission characteristic constraints include: The phase velocity matching constraint is: the fluctuation range of the fundamental phase velocity along the axial direction at the target center frequency shall not exceed ±0.5%; The coupling impedance constraint is maintained as follows: the variation of the coupling impedance along the axis of the slow-wave structure does not exceed ±15%. The passband transmission characteristic constraint is: the passband of the simulation model corresponding to the target traveling wave tube completely covers the target operating frequency band corresponding to the target traveling wave tube.

6. The method for suppressing oscillations in a traveling wave tube according to claim 1, characterized in that, Based on the simulation model corresponding to the target traveling wave tube, the constraint verification is performed using pre-constructed phase velocity matching constraints, preserving coupling impedance constraints, and passband transmission characteristic constraints, and the constraint verification results are obtained, including: Based on the simulation model corresponding to the target traveling wave tube, verify whether the phase velocity matching constraint, the maintaining coupling impedance constraint, and the passband transmission characteristic constraint are all valid simultaneously. If so, the constraint verification result is determined to be a successful verification; otherwise, the constraint verification result is determined to be a failed verification.

7. The method for suppressing oscillations in a traveling wave tube according to claim 1, characterized in that, Based on the simulation model corresponding to the target traveling wave tube, the oscillation suppression and comprehensive performance verification of the target traveling wave tube are performed to obtain the performance verification results, including: Based on the simulation model corresponding to the target traveling wave tube, verify whether the signal oscillation of the target traveling wave tube meets the preset oscillation requirements and whether the performance meets the corresponding design target. If so, the performance verification result is determined to be verified as passed; otherwise, the performance verification result is determined to be verified as failed.

8. The method for suppressing oscillations in a traveling wave tube according to claim 1, characterized in that, Based on the constraint verification results and the performance verification results, the progress of oscillation suppression optimization is determined, including: If both the constraint verification result and the performance verification result are passed, the oscillation suppression optimization progress is determined to be completed; otherwise, the oscillation suppression optimization is determined to be incomplete.

9. The method for suppressing oscillations in a traveling wave tube according to claim 1, characterized in that, A synchronous change strategy is employed to modify the period range and the width range, including: Based on a preset change amount, the final value of the period length in the period range and the final value of the width length in the width range are increased simultaneously to obtain the changed period range and the changed width range. Alternatively, based on a preset change amount, the starting value of the period length in the period range and the starting value of the width length in the width range are simultaneously reduced to obtain the changed period range and the changed width range.

10. The method for suppressing oscillations in a traveling wave tube according to claim 9, characterized in that, The process of executing the aforementioned synchronous change strategy also includes: When the synchronization change strategy is executed for the first time, an increment process is performed; When the synchronization change strategy is executed during the iteration process, the execution action of the previous execution of the synchronization change strategy is obtained; wherein, the execution action is to increase processing or decrease processing; If the previous synchronous change strategy action was to increase processing, the current synchronous change strategy will use to decrease processing. If the previous synchronous change strategy action was to reduce processing, the current synchronous change strategy will use to increase processing.

Images