High-power millimeter wave waveguide beam splitting method

Abstract

The invention provides a high-power millimeter wave waveguide beam splitting method, which comprises the following steps of: acquiring a high-order waveguide mode of a gyrotron cavity input radiator and geometric parameters of the radiator; setting target electromagnetic field distribution of the radiator, calculating deformation quantity of the inner wall of the radiator, and calculating output electromagnetic field distribution according to the deformation quantity; and the deformation quantity of the inner wall of the radiator is updated by using an iterative algorithm until the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution, so that the electromagnetic field distribution with a complex waveguide mode is converted into a low-loss space wave beam, and meanwhile, by setting the target electromagnetic field distribution, the low-loss space wave beam can be obtained. Multiple beams of electromagnetic waves are generated by continuously iteratively approaching target electromagnetic field distribution, the beam splitting function is achieved, the transmission power of each path of electromagnetic waves passing through a dielectric window area can be remarkably reduced, and the single-tube output power of the gyrotron is improved.

Description

Technical Field

[0001] The present invention relates to the field of high-power millimeter wave transmission, and in particular to a high-power millimeter wave waveguide beam splitting method. Background Art

[0002] Gyrotron is a fast-wave device that uses electron cyclotron resonance stimulated emission as its mechanism, overcoming the physical size limitations of the resonance region of traditional microwave devices. In the millimeter-wave frequency band, gyrotron is the only device that can produce high-efficiency and high-power continuous wave output, and is therefore widely used in plasma heating and plasma diagnosis. In order to obtain the highest possible power capacity, the gyrotron usually operates in the following mode: or Mode, the above modes have serious polarization and diffraction losses when propagating in free space, and the radiation is in the shape of a hollow cone, which is not conducive to electromagnetic wave transmission and application. In order to facilitate the transmission and control of the output beam, the high-order mode is generally converted into a fundamental mode Gaussian beam suitable for propagation in free space. At present, gyrotrons generally use quasi-optical mode converters to realize the working mode. mode to fundamental mode Gaussian beam conversion.

[0003] The quasi-optical mode converter consists of an open waveguide antenna (radiator) and a mirror system. The radiator converts the gyrotron generated or The mode is pre-bunched and mode-transformed, and the high-order waveguide mode is converted into a paraxial beam, which is then radiated to the subsequent mirror system through the incision. The subsequent mirror system further corrects the beam propagation direction and phase, and finally corrects it to a Gaussian beam output.

[0004] Existing radiators primarily focus on efficiently transforming the complex electromagnetic field distribution of high-order waveguide modes into a spatial paraxial beam. The primary research focus is on improving the conversion efficiency of a single beam. With the continued development of fusion devices, the demand for the output power of future gyrotrons is also increasing. Currently, theoretical calculations indicate that the output power of a gyrotron cavity can reach 4MW / CW. However, due to the power capacity limitations of a single dielectric window, the output power of a single tube is far less than 4MW / CW. Even with the use of a diamond window, the theoretical power capacity is only 2MW / CW.

[0005] At the same time, existing beam splitting methods are often gratings or dielectric plates, neither of which is suitable for high-order waveguide modes, and their efficiency and power capacity are also relatively limited.

[0006] Therefore, the existing technology needs to be further developed. Summary of the Invention

[0007] The purpose of the present invention is to overcome the above technical deficiencies and provide a high-power millimeter-wave waveguide splitting method to solve the problems existing in the prior art.

[0008] To achieve the above technical objectives, according to a first aspect of the present invention, the present invention provides a high-power millimeter-wave waveguide beam splitting method, comprising: S100, obtaining high-order waveguide modes of the gyrotron cavity input radiator and geometric parameters of the radiator; S200, setting a target electromagnetic field distribution of a radiator, calculating a deformation of an inner wall of the radiator, and calculating an output electromagnetic field distribution based on the deformation; S300: Using an iterative algorithm to update the deformation of the inner wall of the radiator until the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution.

[0009] Specifically, the geometric parameters of the radiator include: The length of the radiator, the initial radius of the radiator.

[0010] Specifically, setting the target electromagnetic field distribution of the radiator includes: The target electromagnetic field distribution is set to have at least two concentrated electromagnetic field distributions in a Brillouin zone before the radiation aperture.

[0011] Specifically, the method for calculating the deformation amount of the inner wall of the radiator includes: The deformation of the inner wall of the radiator is calculated using the following formula: : ; in, Indicates the location The deformation of the inner wall of the radiator at It represents the phase difference between the forward propagation and reverse propagation of the electromagnetic field distribution of the high-order waveguide mode in the inner wall of the radiator, k represents the free space wave number, Represents the angle factor, which is used to describe the propagation direction of electromagnetic waves in the radiator.

[0012] Specifically, the method for calculating the output electromagnetic field distribution according to the deformation variable includes: The output electromagnetic field distribution is calculated using the following formula: ; Where i represents the number of iterations, Indicates the +1 output electromagnetic field distribution after iteration, represents the output electromagnetic field distribution after the i-th iteration, Indicates the location The deformation of the inner wall of the radiator at represents the length of the radiator, R0 represents the initial radius of the radiator, k represents the free space wave number, represents the Green's function, which is used to describe the source point of the propagation of high-order waveguide modes To the target point The electromagnetic field contribution, represents the normal vector of the inner wall of the radiator, the symbol - represents the forward propagation of the high-order waveguide mode, and the symbol + represents the reverse propagation of the high-order waveguide mode.

[0013] Specifically, the Green's function The calculation method is as follows: ; ; in, Indicates the source point of the propagation of higher-order waveguide modes To the destination distance.

[0014] Specifically, the angle factor The calculation method is as follows: = ; in, Indicates the The derivative of the Bessel function of order, Indicates the mode parameters, represents the free space wave number, Indicates the initial radius of the radiator.

[0015] Specifically, the method of updating the deformation amount of the inner wall of the radiator using an iterative algorithm includes: The output electromagnetic field distribution of the high-order waveguide mode during forward propagation and the output electromagnetic field distribution of the target electromagnetic field distribution during reverse propagation are calculated, and then the phase difference between the forward propagation of the high-order waveguide mode and the reverse propagation electromagnetic field distribution of the target electromagnetic field distribution is calculated, and the deformation of the inner wall of the radiator is updated according to the phase difference.

[0016] Specifically, the output electromagnetic field distribution of the high-order waveguide mode during forward propagation is: the electromagnetic field distribution when the high-order waveguide mode propagates from the entrance of the radiator to the exit of the radiator; The output electromagnetic field distribution of the target electromagnetic field distribution during reverse propagation is: the electromagnetic field distribution when the target electromagnetic field distribution propagates from the outlet of the radiator to the entrance of the radiator.

[0017] Specifically, the method of using an iterative algorithm to update the deformation of the inner wall of the radiator until the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution includes: Determine whether the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution. If so, stop using the iterative algorithm to update the deformation of the inner wall of the radiator and output the current multi-path spatial beam; If not, the deformation of the inner wall of the radiator is continuously updated using the iterative algorithm until the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution.

[0018] Beneficial effects: The present invention provides a high-power millimeter-wave waveguide beam splitting method. The method obtains the high-order waveguide mode of the gyrotron cavity input radiator and the geometric parameters of the radiator, sets the target electromagnetic field distribution of the radiator, calculates the deformation of the inner wall of the radiator, and calculates the output electromagnetic field distribution according to the deformation; uses an iterative algorithm to update the deformation of the inner wall of the radiator until the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution, thereby realizing the conversion of the complex electromagnetic field distribution of the waveguide mode into a low-loss spatial beam. At the same time, multiple beams of electromagnetic waves can be generated by setting the target electromagnetic field distribution and continuously iteratively approximating the target electromagnetic field distribution to realize the beam splitting function. The method can significantly reduce the transmission power of each electromagnetic wave through the dielectric window area and improve the output power of a single gyrotron tube. Compared with existing gratings and dielectric beam splitters, the method has high efficiency, only diffraction loss and ohmic loss of the waveguide wall, and no dielectric loss. At the same time, it has high power capacity, can realize high-power millimeter-wave mode conversion and beam splitting of several megawatts of continuous waves, and has good universality and can be used for most high-order waveguide modes. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a flow chart of a high-power millimeter-wave waveguide beam splitting method provided in a specific embodiment of the present invention; Figure 2 is a flowchart of an iterative algorithm provided in a specific embodiment of the present invention; Figure 3 It is a schematic diagram of the target electromagnetic field distribution provided in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the drawings of the present invention. Based on the embodiments in this application, other similar embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of this application. In addition, the directional words mentioned in the following embodiments, such as "up", "down", "left", "right", etc., are only reference to the directions of the drawings. Therefore, the directional words used are used to illustrate rather than limit the invention.

[0021] The present invention will be further described below with reference to the accompanying drawings and preferred embodiments.

[0022] See also Figure 1 This embodiment provides a high-power millimeter-wave waveguide beam splitting method, including: obtaining high-order waveguide modes of a gyrotron cavity input radiator and geometric parameters of the radiator; setting a target electromagnetic field distribution of the radiator, calculating the deformation of the inner wall of the radiator, and calculating the output electromagnetic field distribution based on the deformation; and using an iterative algorithm to update the deformation of the inner wall of the radiator until the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution.

[0023] It can be understood that the present invention sets the target electromagnetic field distribution and uses an iterative algorithm to update the deformation of the inner wall of the radiator, thereby controlling and converting the incoming high-order waveguide modes, thereby achieving efficient splitting of the high-power millimeter waves generated in the gyrotron cavity, reducing the transmission power of a single beam and generating multiple beams through multiple dielectric window areas on the tube body, greatly improving the output power of a single gyrotron tube, and solving the technical problems in the prior art that the output power of the gyrotron cavity is limited by the power capacity of a single dielectric window, and that the existing grating splitting method or dielectric sheet splitting cannot be applied to high-order waveguide modes.

[0024] See also Figure 1 In the high-power millimeter-wave waveguide splitting method of this embodiment, the specific method includes: S100: Acquire high-order waveguide modes of a gyrotron cavity input radiator and geometric parameters of the radiator, where the geometric parameters of the radiator include: The length of the radiator, the initial radius of the radiator.

[0025] It is understood that higher-order waveguide modes include or Mode is generated by the gyrotron cavity. Currently, gyrotrons generally use quasi-optical mode converters to achieve working mode. The quasi-optical mode converter consists of an open waveguide antenna (radiator) and a mirror system. The radiator converts the gyrotron-generated Gaussian beam into a fundamental mode. or The mode is pre-bunched and mode transformed. The geometric parameters of the radiator include length and initial radius, which are the basis for calculating the electromagnetic field distribution inside the radiator.

[0026] S200 , setting a target electromagnetic field distribution of a radiator, calculating a deformation amount of an inner wall of the radiator, and calculating an output electromagnetic field distribution according to the deformation amount.

[0027] Specifically, setting the target electromagnetic field distribution of the radiator includes: The target electromagnetic field distribution is set to have at least two concentrated electromagnetic field distributions in a Brillouin zone before the radiation aperture.

[0028] It should be noted that this embodiment constructs at least two concentrated electromagnetic field distributions within the Brillouin zone preceding the radiator output aperture, aiming to achieve directional beam splitting of high-power millimeter-wave waveguides and suppress spurious mode interference. The Brillouin zone is defined as a region extending one waveguide wavelength along the propagation direction (z-axis) relative to the plane of the radiator output aperture. This region, defined as the "previous Brillouin zone," corresponds to the periodic boundary of electromagnetic wave phase changes and is used to constrain mode coupling and energy redistribution processes. The target electromagnetic field distribution is set to at least two areas of concentrated field intensity (peak points). The specific number and spatial location of these areas are determined by the beam splitting requirements, such as two peak points for a two-way split and three peak points for a three-way split.

[0029] Furthermore, the deformation of the inner wall of the radiator is irregular. By changing the irregular deformation of the inner wall of the radiator and the boundary conditions of the radiator, the electromagnetic field distribution can be controlled to achieve the target electromagnetic field distribution.

[0030] Specifically, the method for calculating the deformation amount of the inner wall of the radiator includes: The deformation of the inner wall of the radiator is calculated using the following formula: : ; (1) in, Indicates the location The deformation of the inner wall of the radiator at represents the radiator angular angle, represents the radiator length coordinate, It represents the phase difference between the forward and reverse propagation of the electromagnetic field distribution of the high-order waveguide mode in the inner wall of the radiator. It is used to describe the phase change of the electromagnetic field at different positions on the inner wall of the radiator. k represents the free space wave number, which is related to the wavelength and represents the wave number per unit distance. It represents the angle factor, which is used to describe the propagation direction of electromagnetic waves in the radiator. It is related to the waveguide structure and mode. From formula (1), it can be seen that the deformation of the inner wall of the radiator is The relationship between the phase difference between the forward and reverse propagation electromagnetic field distributions of high-order waveguide modes in the inner wall of the radiator is represented. By adjusting the phase difference, the deformation of the inner wall of the waveguide, that is, the inner wall of the radiator, can be controlled, thereby affecting the distribution of the electromagnetic field.

[0031] Specifically, the method for calculating the output electromagnetic field distribution according to the deformation variable includes: The output electromagnetic field distribution is calculated using the following formula: ; (2) Where i represents the number of iterations, Indicates the +1 output electromagnetic field distribution after iteration, represents the output electromagnetic field distribution after the i-th iteration, Indicates the location The deformation of the inner wall of the radiator at represents the length of the radiator, R0 represents the initial radius of the radiator, k represents the free space wave number, represents the Green's function, which is used to describe the source point of the propagation of high-order waveguide modes To the target point The electromagnetic field contribution, represents the normal vector of the inner wall of the radiator, the symbol + represents the forward propagation of the high-order waveguide mode, and the symbol - represents the reverse propagation.

[0032] It can be understood that the above formula (2) is the core part of the iterative algorithm of the present invention, which is used to gradually approximate the final electromagnetic field distribution inside the radiator, calculate the contribution of the previous iteration result at the current point by integration, and take into account the influence of the irregular deformation of the inner wall of the radiator on the current output electromagnetic field.

[0033] Specifically, the Green's function The calculation method is as follows: ; (3) ; (4) in, Indicates the source point of the propagation of higher-order waveguide modes To the destination The Green’s function represents the electromagnetic field distribution generated by a point source in free space and is the basis for calculating electromagnetic field propagation. Formula (4) gives the distance expression between the source and target points in the cylindrical coordinate system, which is used to calculate the distance term in the Green’s function.

[0034] Specifically, the angle factor The calculation method is as follows: = ; (5) in, Indicates the The derivative of the Bessel function of order, Indicates the mode parameters, represents the free space wave number, Indicates the initial radius of the radiator, angle factor It is one of the key parameters of the propagation characteristics of electromagnetic waves in waveguides.

[0035] S300: Using an iterative algorithm to update the deformation of the inner wall of the radiator until the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution.

[0036] Specifically, the method of updating the deformation amount of the inner wall of the radiator using an iterative algorithm includes: The output electromagnetic field distribution of the high-order waveguide mode during forward propagation and the output electromagnetic field distribution of the target electromagnetic field distribution during reverse propagation are calculated, and then the phase difference between the electromagnetic field distribution of the high-order waveguide mode during forward propagation and the electromagnetic field distribution of the target electromagnetic field distribution during reverse propagation is calculated, and the deformation of the inner wall of the radiator is updated according to the phase difference.

[0037] Furthermore, the above formulas (1)-(5) together constitute an iterative algorithm for calculating the conversion and splitting effects of the irregular deformation of the inner wall of the open waveguide radiator on the high-order waveguide mode. Through continuous iterative optimization, the ideal electromagnetic field distribution, that is, the target electromagnetic field distribution, can be obtained, thereby realizing efficient spatial beam conversion and splitting functions.

[0038] Specifically, the output electromagnetic field distribution of the high-order waveguide mode during forward propagation is: the electromagnetic field distribution when the high-order waveguide mode propagates from the entrance of the radiator to the exit of the radiator, which is expressed as: ; (6) The output electromagnetic field distribution of the target electromagnetic field distribution during reverse propagation is: the electromagnetic field distribution when the target electromagnetic field distribution propagates from the outlet of the radiator to the entrance of the radiator, and its expression is: ; (7) in, Represents the target electromagnetic field distribution.

[0039] Specifically, the method of using an iterative algorithm to update the deformation of the inner wall of the radiator until the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution includes: Determine whether the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution. If so, stop using the iterative algorithm to update the deformation of the inner wall of the radiator and output the current multi-path spatial beam; If not, the deformation of the inner wall of the radiator is continuously updated using the iterative algorithm until the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution.

[0040] It can be understood that this application is based on relevant waveguide theory and iterative algorithms. By constructing a reasonable target electromagnetic field distribution, the electromagnetic field distribution in the radiator is changed by using waveguide wall perturbations, and the complex electromagnetic field distribution of the waveguide mode is converted into a low-loss spatial beam at the radiator (open waveguide). At the same time, multiple beams of electromagnetic waves are generated, realizing the beam splitting function, reducing the transmission power of each electromagnetic wave through the dielectric window area, and greatly improving the output power of a single gyrotron tube.

[0041] See also Figure 2 and Figure 3The following is a specific example to illustrate the working principle of the present invention of iteratively updating the deformation of the inner wall of the radiator. The specific implementation steps are as follows: Step 1: Initialization and start iteration Iteration start: start the iteration process; Feed waveguide mode: Input high-order waveguide mode (such as TE 0,n or TE m,n mode) as the initial electromagnetic field distribution; Objective function: defines the desired output field distribution, that is, the target electromagnetic field distribution, that is, the multi-path low-loss spatial beam after beam splitting. The key point of beam splitting is to reasonably select the target electromagnetic field distribution in order to realize the beam splitting function: See also Figure 3 , two or more concentrated electromagnetic field distributions should be selected in the Brillouin zone before the radiation aperture. The electromagnetic field distribution form can adopt Gaussian function distribution or other similar distributions to ensure that the final output is a multi-path low-loss spatial beam.

[0042] Figure 3 The middle part shows the angle of the radiator along the angular expansion. The left and right figures (a) and (b) respectively show different schematic diagrams of the target electromagnetic field distribution. The left figure (a) shows that there are multiple concentrated field distribution points in a Brillouin zone. Specifically, there are two concentrated points (marked with red circles) in the Brillouin zone before the radiation aperture, which are located at different positions. These two concentrated points can be expressed as Gaussian function distribution or other similar distribution forms. At these positions, the electromagnetic field intensity is high, while it gradually weakens in other areas.

[0043] The right image (a) also shows the existence of multiple concentrated field distribution points in the Brillouin zone, but the locations of these concentrated points are different from those on the left.

[0044] Step 2: Initial perturbation Initial perturbation: An initial irregular deformation ΔR0 is imposed on the inner wall of the radiator as the starting point of the iteration.

[0045] Step 3: Calculation of forward propagation of higher-order waveguide modes The output electromagnetic field of the high-order waveguide mode when it propagates from the radiator entrance to the radiator exit is calculated by formula (2), which is expressed as , that is, formula (6), represents the forward propagation result under the current deformation of the inner wall of the radiator.

[0046] Step 4: Back propagation calculation of target electromagnetic field distribution The target electromagnetic field distribution is calculated by formula (2) to calculate the output electromagnetic field when the high-order waveguide mode propagates from the radiator outlet to the radiator entrance, which is expressed as , that is, formula (7), represents the back propagation result under the current deformation of the inner wall of the radiator.

[0047] Step 5: Update the deformation ΔR Update ΔR using formula (1): According to the phase difference between the forward and reverse propagation of the high-order waveguide mode , use formula (1) to calculate the new deformation variable ΔR; Step 6: Forward propagate the high-order mode again to determine whether the current output electromagnetic field meets the target electromagnetic field distribution, that is, compare whether the current output electromagnetic field distribution is consistent with the objective function (target electromagnetic field distribution). If they are consistent, exit the iteration and complete the optimization. If not, return to step "Update perturbation" and continue to the next iteration.

[0048] Step 7: Update the perturbation Update perturbation: Update the deformation of the radiator inner wall according to the newly calculated ΔR and proceed to the next round of iteration.

[0049] Furthermore, the above iterative algorithm continuously adjusts the deformation of the inner wall of the radiator so that the actual output field distribution gradually approaches the target magnetic field distribution, ultimately achieving effective conversion and beam splitting of high-order waveguide modes. Each step is based on rigorous mathematical calculations and physical principles, ensuring the accuracy and efficiency of the algorithm.

[0050] It should be noted here that this embodiment provides a high-power millimeter-wave waveguide beam splitting method, which obtains the high-order waveguide mode of the gyrotron cavity input radiator and the geometric parameters of the radiator, sets the target electromagnetic field distribution of the radiator, calculates the deformation of the inner wall of the radiator, and calculates the output electromagnetic field distribution based on the deformation; uses an iterative algorithm to update the deformation of the inner wall of the radiator until the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution, thereby converting the complex electromagnetic field distribution of the waveguide mode into a low-loss spatial beam. At the same time, by setting the target electromagnetic field distribution and continuously iterating to approximate the target electromagnetic field distribution, multiple beams of electromagnetic waves can be generated to achieve the beam splitting function, which can significantly reduce the transmission power of each electromagnetic wave through the dielectric window area and improve the output power of a single gyrotron tube. Compared with existing gratings and dielectric beam splitters, it has high efficiency, only diffraction loss and ohmic loss of the waveguide wall, no dielectric loss, and high power capacity, which can realize high-power millimeter-wave mode conversion and beam splitting of several megawatts of continuous waves, and has good universality and can be used for most high-order waveguide modes.

[0051] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0052] The various technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification as long as such combination does not conflict.

[0053] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A high-power millimeter-wave waveguide beam splitting method, characterized in that: include: S100, obtaining high-order waveguide modes of the gyrotron cavity input radiator and geometric parameters of the radiator; S200, setting a target electromagnetic field distribution of a radiator, calculating a deformation of an inner wall of the radiator, and calculating an output electromagnetic field distribution based on the deformation; S300: Using an iterative algorithm to update the deformation of the inner wall of the radiator until the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution.

2. The high-power millimeter-wave waveguide splitting method according to claim 1, characterized in that: The geometric parameters of the radiator include: The length of the radiator, the initial radius of the radiator.

3. The high-power millimeter-wave waveguide splitting method according to claim 1, characterized in that: The setting of the target electromagnetic field distribution of the radiator includes: The target electromagnetic field distribution is set to have at least two concentrated electromagnetic field distributions in a Brillouin zone before the radiation aperture.

4. The high-power millimeter-wave waveguide splitting method according to claim 1, characterized in that: The method for calculating the deformation amount of the inner wall of the radiator includes: The deformation of the inner wall of the radiator is calculated using the following formula: : ； in, Indicates the location The deformation of the inner wall of the radiator at It represents the phase difference between the forward propagation and reverse propagation of the electromagnetic field distribution of the high-order waveguide mode in the inner wall of the radiator, k represents the free space wave number, Represents the angle factor, which is used to describe the propagation direction of electromagnetic waves in the radiator.

5. The high-power millimeter-wave waveguide splitting method according to claim 4, characterized in that: The method for calculating the output electromagnetic field distribution according to the deformation variable includes: The output electromagnetic field distribution is calculated using the following formula: ； Where i represents the number of iterations, Indicates the +1 output electromagnetic field distribution after iteration, represents the output electromagnetic field distribution after the i-th iteration, Indicates the location The deformation of the inner wall of the radiator at represents the length of the radiator, R0 represents the initial radius of the radiator, k represents the free space wave number, represents the Green's function, which is used to describe the source point of the propagation of high-order waveguide modes To the target point The electromagnetic field contribution, represents the normal vector of the inner wall of the radiator, the symbol - represents the forward propagation of the high-order waveguide mode, and the symbol + represents the reverse propagation of the high-order waveguide mode.

6. The high-power millimeter-wave waveguide splitting method according to claim 5, characterized in that: The Green's function The calculation method is as follows: ； ； in, Indicates the source point of the propagation of higher-order waveguide modes To the destination distance.

7. The high-power millimeter-wave waveguide splitting method according to claim 6, characterized in that: The angle factor The calculation method is as follows: = ； in, Indicates the The derivative of the Bessel function of order, Indicates the mode parameters, represents the free space wave number, Indicates the initial radius of the radiator.

8. The high-power millimeter-wave waveguide splitting method according to claim 5, characterized in that: The method of updating the deformation amount of the inner wall of the radiator by using an iterative algorithm includes: The output electromagnetic field distribution of the high-order waveguide mode during forward propagation and the output electromagnetic field distribution of the target electromagnetic field distribution during reverse propagation are calculated, and then the phase difference between the forward propagation of the high-order waveguide mode and the reverse propagation electromagnetic field distribution of the target electromagnetic field distribution is calculated, and the deformation of the inner wall of the radiator is updated according to the phase difference.

9. The high-power millimeter-wave waveguide splitting method according to claim 8, characterized in that: The output electromagnetic field distribution of the high-order waveguide mode during forward propagation is: the electromagnetic field distribution when the high-order waveguide mode propagates from the entrance of the radiator to the exit of the radiator; The output electromagnetic field distribution of the target electromagnetic field distribution during reverse propagation is: the electromagnetic field distribution when the target electromagnetic field distribution propagates from the outlet of the radiator to the entrance of the radiator.

10. The high-power millimeter-wave waveguide splitting method according to claim 9, characterized in that: The method of using an iterative algorithm to update the deformation of the inner wall of the radiator until the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution includes: Determine whether the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution. If so, stop using the iterative algorithm to update the deformation of the inner wall of the radiator and output the current multi-path spatial beam; If not, the deformation of the inner wall of the radiator is continuously updated using the iterative algorithm until the current output electromagnetic field distribution is consistent with the target electromagnetic field distribution.

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