CN104134834A - Waveguide mode exciting device - Google Patents

Abstract

Translated fromChinese

本发明提供了一种波导模式激励装置。该波导模式激励装置包括：第一模式变换组件，用于实现毫米波由TE₁₀基模向圆波导TE₆₁模式的转换；以及第二模式变换组件，与所述第一模式变换组件相连通，用于实现毫米波由圆波导TE₆₁模式向圆波导TE_6，2模式的转换。本发明波导模式激励装置通过矩形波导TE₁₀模到圆波导TE_6，2模的模式变换链的变换，得到了高纯度的目标模式输出，有效地抑制了杂模，得到的高纯度目标模式可以用于回旋管互作用电路及其准光模式变换器系统的冷测。

The invention provides a waveguide mode excitation device. The waveguide mode excitation device includes: a first mode conversion component, which is used to convert the millimeter wave from the TE₁₀ fundamental mode to the circular waveguide TE₆₁ mode; and a second mode conversion component, which communicates with the first mode conversion component, It is used to realize the conversion of the millimeter wave from the circular waveguide TE₆₁ mode to the circular waveguide TE_6,2 mode. The waveguide mode excitation device of the present invention obtains the high-purity target mode output through the conversion of the mode conversion chain of the rectangular waveguide TE₁₀ mode to the circular waveguide TE_6,2 mode, effectively suppresses the miscellaneous modes, and the obtained high-purity target mode can be It is used for the cold measurement of the gyrotron interaction circuit and its quasi-optical mode converter system.

Description

Translated fromChinese

波导模式激励装置Waveguide Mode Excitation Device

技术领域technical field

本发明涉及电子行业真空电子学技术领域，尤其涉及一种波导模式激励装置。The invention relates to the technical field of vacuum electronics in the electronics industry, in particular to a waveguide mode excitation device.

背景技术Background technique

回旋管在毫米波段具有高功率、长脉冲、连续波输出等优点，在毫米波雷达、受控热核聚变的等离子体加热、材料处理和生物医学等领域具有广泛的应用前景。The gyrotron has the advantages of high power, long pulse, and continuous wave output in the millimeter wave band, and has broad application prospects in the fields of millimeter wave radar, plasma heating of controlled thermonuclear fusion, material processing, and biomedicine.

回旋管为了提高功率容量通常采用尺寸比较大的腔体作为互作用电路，并且工作在高阶边廊模或高阶体模，回旋管工作的高阶模式需要经过准光模式变换器变换为便于传输或直接利用的低阶模式。这类回旋管的高频互作用电路及其准光模式变换器系统在安装之前通常需要进行冷测，而冷测中需要激励高纯度的目标模式作为待测器件的输入信号。In order to improve the power capacity of the gyrotron, a cavity with a relatively large size is usually used as an interactive circuit, and it works in a high-order side gallery mode or a high-order phantom. Low-order modes for transmission or direct exploitation. The high-frequency interaction circuit of this type of gyrotron and its quasi-optical mode converter system usually need to be cold-tested before installation, and the high-purity target mode needs to be excited as the input signal of the device under test during the cold test.

传统的模式激励装置采用准光模式激励的方法，对器件加工精度要求较高，同时在装配过程还需要对各个部件精确对准，对实验条件要求较高。The traditional mode excitation device adopts the method of quasi-optical mode excitation, which requires high processing accuracy of the device. At the same time, it also needs to accurately align each component during the assembly process, which requires high experimental conditions.

发明内容Contents of the invention

(一)要解决的技术问题(1) Technical problems to be solved

鉴于上述技术问题，本发明提供了一种对器件加工精度和实验条件要求较低的波导模式激励装置。In view of the above technical problems, the present invention provides a waveguide mode excitation device with lower requirements on device processing accuracy and experimental conditions.

(二)技术方案(2) Technical solution

根据本发明的一个方面，提供了一种波导模式激励装置。该波导模式激励装置包括：第一模式变换组件，用于实现毫米波由TE₁₀基模向圆波导TE₆₁模式的转换；以及第二模式变换组件，与所述第一模式变换组件相连通，用于实现毫米波由圆波导TE₆₁模式向圆波导TE_6，2模式的转换。According to one aspect of the present invention, a waveguide mode excitation device is provided. The waveguide mode excitation device includes: a first mode conversion component, which is used to convert the millimeter wave from the TE₁₀ fundamental mode to the circular waveguide TE₆₁ mode; and a second mode conversion component, which communicates with the first mode conversion component, It is used to realize the conversion of the millimeter wave from the circular waveguide TE₆₁ mode to the circular waveguide TE_6,2 mode.

(三)有益效果(3) Beneficial effects

本发明波导模式激励装置通过矩形波导TE₁₀模到圆波导TE_6，2模的模式变换链的变换，得到了高纯度的目标模式输出，有效地抑制了杂模，得到的高纯度目标模式可以用于回旋管互作用电路及其准光模式变换器系统的冷测。The waveguide mode excitation device of the present invention obtains the high-purity target mode output through the conversion of the mode conversion chain of the rectangular waveguide TE₁₀ mode to the circular waveguide TE_6,2 mode, effectively suppresses the miscellaneous modes, and the obtained high-purity target mode can be It is used for the cold measurement of the gyrotron interaction circuit and its quasi-optical mode converter system.

附图说明Description of drawings

图1是TE₆₂模波导模式激励结构的模式激励流程图；Figure 1 is the mode excitation flow chart of the TE₆₂ -mode waveguide mode excitation structure;

图2是矩形波导TE₁₀模到圆波导TE₆₁模式的第一模式变换组件的结构示意图；Fig. 2 is a schematic structural diagram of the first mode conversion component from the rectangular waveguide TE₁₀ mode to the circular waveguide TE₆₁ mode;

图3是圆波导TE₆₁模到圆波导TE₆₂模式的第二模式变换组件的结构示意图；Fig. 3 is a structural schematic diagram of the second mode conversion assembly from the circular waveguide TE₆₁ mode to the circular waveguide TE₆₂ mode;

图4是TE₆₂模波导模式激励结构内场形激励示意图；Figure 4 is a schematic diagram of the field shape excitation in the TE₆₂ -mode waveguide mode excitation structure;

图5(a)为圆波导端口处标准的TE₆₂模式图；Figure 5(a) is a standard TE₆₂ mode diagram at the circular waveguide port;

图5(b)为采用本发明得到的输出端口处TE₆₂模式图。Fig. 5(b) is a model diagram of the TE₆₂ at the output port obtained by the present invention.

具体实施方式Detailed ways

为使本发明的目的、技术方案和优点更加清楚明白，以下结合具体实施例，并参照附图，对本发明进一步详细说明。需要说明的是，在附图或说明书描述中，相似或相同的部分都使用相同的图号。附图中未绘示或描述的实现方式，为所属技术领域中普通技术人员所知的形式。另外，虽然本文可提供包含特定值的参数的示范，但应了解，参数无需确切等于相应的值，而是可在可接受的误差容限或设计约束内近似于相应的值。实施例中提到的方向用语，例如“上”、“下”、“前”、“后”、“左”、“右”等，仅是参考附图的方向。因此，使用的方向用语是用来说明并非用来限制本发明的保护范围。In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be noted that, in the drawings or descriptions of the specification, similar or identical parts all use the same figure numbers. Implementations not shown or described in the accompanying drawings are forms known to those of ordinary skill in the art. Additionally, while illustrations of parameters including particular values may be provided herein, it should be understood that the parameters need not be exactly equal to the corresponding values, but rather may approximate the corresponding values within acceptable error margins or design constraints. The directional terms mentioned in the embodiments, such as "upper", "lower", "front", "rear", "left", "right", etc., are only referring to the directions of the drawings. Therefore, the directional terms used are for illustration and not for limiting the protection scope of the present invention.

在本发明的一个示例性实施例中，提供了一种波导模式激励装置。本实施例波导模式激励装置实现由矩形波导TE₁₀模式向圆波导TE₆₂模式的变换。其中，TE₆₂模式的模式激励流程如图1所示，即：矩形波导TE₁₀模式→同轴波导TE₆₁模式→圆波导TE₆₁模式→圆波导TE₆₂模式。其中，本实施例的波导模式激励装置包括：矩形波导TE₁₀模式到圆波导TE₆₁模式的第一模式变换组件和圆波导TE_6，1模式到圆波导TE_6，2模式的第二模式变换组件两部分。以下对第一模式变换组件和第二模式变换组件分别进行详细说明。In an exemplary embodiment of the present invention, a waveguide mode excitation device is provided. The waveguide mode excitation device in this embodiment realizes the transformation from the rectangular waveguide TE₁₀ mode to the circular waveguide TE₆₂ mode. Among them, the mode excitation process of TE₆₂ mode is shown in Figure 1, namely: rectangular waveguide TE₁₀ mode → coaxial waveguide TE₆₁ mode → circular waveguide TE₆₁ mode → circular waveguide TE₆₂ mode. Wherein, the waveguide mode excitation device of this embodiment includes: a first mode conversion component from a rectangular waveguide TE₁₀ mode to a circular waveguide TE₆₁ mode and a second mode conversion component from a circular waveguide TE_6,1 mode to a circular waveguide TE_6,2 mode The component has two parts. The first mode conversion component and the second mode conversion component will be described in detail below.

1、第一模式变换组件1. The first mode conversion component

图2是矩形波导TE₁₀模式到圆波导TE₆₁模式的第一模式变换组件的结构示意图。如图2所示，矩形波导到圆波导的第一模式变换组件主要包括：Fig. 2 is a schematic structural diagram of the first mode conversion component from the rectangular waveguide TE₁₀ mode to the circular waveguide TE₆₁ mode. As shown in Figure 2, the first mode conversion components from a rectangular waveguide to a circular waveguide mainly include:

1.1标准矩形波导，波导尺寸采用W波段标准波导(波导尺寸：宽边长度2.54mm，窄边长度1.27mm)，以传输该W波段的TE₁₀基模；该标准矩形波导的上部端口采用标准的FUGP900法兰，用于与功率源的FUGP900法兰对接，如图2所示。1.1 Standard rectangular waveguide, the waveguide size adopts W-band standard waveguide (waveguide size: wide side length 2.54mm, narrow side length 1.27mm), to transmit the TE₁₀ fundamental mode of the W-band; the upper port of the standard rectangular waveguide adopts a standard The FUGP900 flange is used to connect with the FUGP900 flange of the power source, as shown in Figure 2.

1.2同轴波导，同轴波导由内导体和外导体组成。该同轴波导分为两段-均匀段和渐变段。1.2 Coaxial waveguide, coaxial waveguide is composed of inner conductor and outer conductor. The coaxial waveguide is divided into two sections - a uniform section and a tapered section.

在均匀段中，同轴波导的左侧通过盲法兰封闭，其包括：外导体和与该外导体同轴的内导体，其中，外导体的内径R_b为4mm，内导体的外径R_a为2.5mm，该均匀段长度L₁为9.85mm。外导体与标准矩形波导通过焊接固定为一体，外导体通过侧壁的耦合槽与标准矩形波导相通，耦合槽的形状和尺寸与标准矩形波导相同，且耦合槽和标准矩形波导的长边与同轴波导的轴向平行。In the uniform section, the left side of the coaxial waveguide is closed by a blind flange, which includes: an outer conductor and an inner conductor coaxial with the outer conductor, wherein the inner diameter_R of the outer conductor is 4mm, and the outer diameter R of the inner conductor_a is 2.5 mm, and the uniform segment length L₁ is 9.85 mm. The outer conductor and the standard rectangular waveguide are fixed together by welding, and the outer conductor communicates with the standard rectangular waveguide through the coupling groove on the side wall. The axes of the waveguides are parallel to each other.

在非均匀段，保持内导体半径不变，同轴外导体的内径连续变大，非均匀段的长度L₂为55mm，外导体的内径R₀为8.5mm。在非均匀段的末端，外导体的内径R₀和内导体的外径的比例8.5/2.5＝3.4，此时，内导体可以忽略，从而实现同轴波导到圆波导的过渡，激励产生圆波导TE₆₁模式。In the non-uniform section, keeping the inner conductor radius constant, the inner diameter of the coaxial outer conductor continuously increases, the length_L of the non-uniform section is 55mm, and the inner diameter_R of the outer conductor is 8.5mm. At the end of the non-uniform section, the ratio of the inner diameter R₀ of the outer conductor to the outer diameter of the inner conductor is 8.5/2.5=3.4. At this time, the inner conductor can be ignored, so as to realize the transition from the coaxial waveguide to the circular waveguide, and the excitation produces a circular waveguide TE₆₁ pattern.

2、第二模式变换组件2. The second mode conversion component

图3是圆波导TE₆₁模式到圆波导TE₆₂模式的第二模式变换组件的结构示意图。如图3所示，第二模式变换组件为波导半径轴向周期扰动的圆波导，其前端通过非标准法兰连接至第一模式变换组件的末端，其末端与其它部件连接。该圆波导将第一模式变换组件激励产生的圆波导TE₆₁模式变换为圆波导TE₆₂模式。波导半径轴向周期扰动的圆波导的轮廓函数为：Fig. 3 is a schematic structural diagram of the second mode conversion component from the circular waveguide TE₆₁ mode to the circular waveguide TE₆₂ mode. As shown in Figure 3, the second mode conversion component is a circular waveguide whose radius is disturbed periodically in the axial direction. Its front end is connected to the end of the first mode conversion component through a non-standard flange, and its end is connected to other components. The circular waveguide transforms the circular waveguide TE₆₁ mode generated by the excitation of the first mode conversion component into the circular waveguide TE₆₂ mode. The profile function of a circular waveguide with a periodic perturbation of the waveguide radius in the axial direction is:

$\mathrm{<span><span>a</span>a</span>}<span><span>(</span>(</span>\mathrm{<span><span>z</span>z</span>}<span><span>)</span>)</span><span><span>=</span>=</span>\frac{{\mathrm{<span><span>a</span>a</span>}}_{\mathrm{<span><span>0</span>0</span>}}<span><span>[</span>[</span>\mathrm{<span><span>1</span>1</span>}<span><span>-</span>-</span>{\mathrm{<span><span>\&epsiv;</span>\&epsiv;</span>}}_{\mathrm{<span><span>0</span>0</span>}}\mathrm{<span><span>cos</span>cos</span>}<span><span>(</span>(</span>\mathrm{<span><span>2</span>2</span>}\mathrm{<span><span>\&pi;z</span>\&pi;z</span>}<span><span>/</span>/</span>{\mathrm{<span><span>\&lambda;</span>\&lambda;</span>}}_{\mathrm{<span><span>W</span>W</span>}}<span><span>)</span>)</span><span><span>-</span>-</span>{\mathrm{<span><span>\&epsiv;</span>\&epsiv;</span>}}_{\mathrm{<span><span>1</span>1</span>}}\mathrm{<span><span>cos</span>cos</span>}<span><span>(</span>(</span>\mathrm{<span><span>4</span>4</span>}\mathrm{<span><span>\&pi;z</span>\&pi;z</span>}<span><span>/</span>/</span>{\mathrm{<span><span>\&lambda;</span>\&lambda;</span>}}_{\mathrm{<span><span>W</span>W</span>}}<span><span>)</span>)</span><span><span>]</span>]</span>}{\mathrm{<span><span>1</span>1</span>}<span><span>-</span>-</span>{\mathrm{<span><span>\&epsiv;</span>\&epsiv;</span>}}_{\mathrm{<span><span>0</span>0</span>}}<span><span>-</span>-</span>{\mathrm{<span><span>\&epsiv;</span>\&epsiv;</span>}}_{\mathrm{<span><span>1</span>1</span>}}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>1</span>1</span>}<span><span>)</span>)</span>$

式中，z为圆波导的轴向长度，a(z)为在轴向坐标为z处的圆波导内径，a₀为初始半径，即第一模式变换组件中同轴波导非均匀端的半径，ε₀和ε₁为扰动参数，λ_W为扰动周期。该实例中圆波导的初始半径为8.5mm，相对微扰幅度ε₀＝0.0536，ε₁＝0.008，扰动周期λ_W＝20.6mm。In the formula, z is the axial length of the circular waveguide, a(z) is the inner diameter of the circular waveguide at the axial coordinate z, a₀ is the initial radius, that is, the radius of the non-uniform end of the coaxial waveguide in the first mode conversion component, ε₀ and ε₁ are the disturbance parameters, and λ_W is the disturbance period. In this example, the initial radius of the circular waveguide is 8.5 mm, the relative perturbation amplitude ε₀ =0.0536, ε₁ =0.008, and the perturbation period λ_W =20.6 mm.

需要说明的是，上述参数仅为示例实用，本领域技术人员可以根据需要来设计相应参数：相对扰动幅度，0.001≤ε₀≤0.1，0.001≤ε₀≤0.1，扰动周期10mm≤λ_W≤80mm。It should be noted that the above parameters are only practical examples, and those skilled in the art can design corresponding parameters according to needs: relative disturbance amplitude,_{0.001≤ε0≤0.1} ,_{0.001≤ε0≤0.1} , disturbance period_{10mm≤λW≤80mm} .

利用这种半径轴向周期微扰的波导可以将输入的圆波导TE₆₁模式变换到TE₆₂模式，如图3所示。The TE₆₁ mode of the input circular waveguide can be transformed into the TE₆₂ mode by using the waveguide with radial axial periodic perturbation, as shown in FIG. 3 .

本实施例波导模式激励装置的内部场形激励的示意图如图4所示，整个结构中标准矩形波导、同轴波导以及圆波导的加工均采用无氧铜材料，并对其内表面镀金处理以降低损耗。The schematic diagram of the internal field excitation of the waveguide mode excitation device in this embodiment is shown in Figure 4. The processing of the standard rectangular waveguide, coaxial waveguide and circular waveguide in the whole structure is made of oxygen-free copper material, and the inner surface is gold-plated. Reduce loss.

请参照图1、图2和图3，本实施例波导模式激励装置的工作原理如下：Please refer to Fig. 1, Fig. 2 and Fig. 3, the working principle of the waveguide mode excitation device in this embodiment is as follows:

(1)功率源发出TE₁₀基模的毫米波；(1) The power source emits the millimeter wave of TE₁₀ fundamental mode;

(2)该TE₁₀基模的毫米波通过FUGP900法兰进入到标准矩形波导内；(2) The millimeter wave of the TE₁₀ fundamental mode enters the standard rectangular waveguide through the FUGP900 flange;

(3)标准矩形波导内的TE₁₀基模的毫米波通过侧壁馈入同轴波导的均匀段，耦合产生同轴TE₆₁模式；(3) The millimeter wave of the TE₁₀ fundamental mode in the standard rectangular waveguide is fed into the uniform section of the coaxial waveguide through the side wall, and the coupling generates the coaxial TE₆₁ mode;

(4)在非均匀段，由均匀段耦合产生的同轴TE₆₁模式的毫米波转换为圆波导TE₆₁模式；(4) In the non-uniform section, the millimeter wave of the coaxial TE₆₁ mode generated by the coupling of the uniform section is converted into the circular waveguide TE₆₁ mode;

(5)在第二模式变换组件中，通过引入波导半径轴向周期的扰动，实现毫米波由圆波导TE₆₁模式向圆波导TE₆₂模式的转换。(5) In the second mode conversion component, the conversion of the millimeter wave from the TE₆₁ mode of the circular waveguide to the TE₆₂ mode of the circular waveguide is realized by introducing the disturbance of the axial period of the waveguide radius.

图5(a)为圆波导端口处标准的TE₆₂模式图，图5(b)为采用本实例得到的输出端口处TE₆₂模式图。Fig. 5(a) is a standard TE₆₂ mode diagram at the circular waveguide port, and Fig. 5(b) is a TE₆₂ mode diagram at the output port obtained by using this example.

至此，已经结合附图对本实施例毫米波TE_6，2模回旋管冷测的波导模式激励装置进行了详细描述。依据以上描述，本领域技术人员应当对本发明用于波导模式激励装置有了清楚的认识。So far, the waveguide mode excitation device for the millimeter-wave TE_{6, 2} -mode gyrotron cold measurement of this embodiment has been described in detail with reference to the accompanying drawings. Based on the above description, those skilled in the art should have a clear understanding of the present invention for waveguide mode excitation devices.

此外，上述对各元件和方法的定义并不仅限于实施例中提到的各种具体结构、形状或方式，本领域普通技术人员可对其进行简单地更改或替换，例如：In addition, the above definitions of each element and method are not limited to the various specific structures, shapes or methods mentioned in the embodiments, and those of ordinary skill in the art can easily modify or replace them, for example:

(1)标准矩形波导、同轴波导以及圆波导也可以采用铝或黄铜代替无氧铜材料；(1) The standard rectangular waveguide, coaxial waveguide and circular waveguide can also use aluminum or brass instead of oxygen-free copper material;

(2)非标准法兰可以用适当规格的标准法兰来代替；(2) Non-standard flanges can be replaced by standard flanges of appropriate specifications;

(3)本发明除了用于毫米波TE_6，2模式回旋管冷测之外，还可以应用于其他领域。(3) The present invention can be applied to other fields besides being used for the cold measurement of the millimeter wave TE_6,2 mode gyrotron.

综上所述，本发明可以用来激励产生圆波导TE_6，2模式，采用该模式激励结构可以得到高纯度、高效率、稳定性好的目标模式。In summary, the present invention can be used to excite and generate circular waveguide TE_6,2 mode, and the target mode with high purity, high efficiency and good stability can be obtained by adopting the mode excitation structure.

以上所述的具体实施例，对本发明的目的、技术方案和有益效果进行了进一步详细说明，所应理解的是，以上所述仅为本发明的具体实施例而已，并不用于限制本发明，凡在本发明的精神和原则之内，所做的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. a waveguide mode exciting bank, is characterized in that, comprising:

First mode conversion assembly, for realizing millimeter wave by TE₁₀basic mode is to circular waveguide TE₆₁the conversion of pattern; And

The second mode conversion assembly, is connected with described first mode conversion assembly, for realizing millimeter wave by circular waveguide TE₆₁pattern is to circular waveguide TE_6,2the conversion of pattern.

2. waveguide mode exciting bank according to claim 1, is characterized in that, described first mode conversion assembly comprises:

Rectangular waveguide, is connected with power source, the TE producing for through-put power source₁₀basic mode;

Coaxial waveguide, its one end is sealed by blind flange, and the other end is communicated to the second mode conversion assembly, and it is divided into two sections-even section and non-homogeneous section, wherein:

Evenly one end and the described rectangular waveguide of the sealing of section coaxial waveguide are welded as a whole, its outer conductor communicates with rectangular waveguide by the coupling slot of sidewall, the shape and size of this coupling slot are identical with described rectangular waveguide, and the long limit of described coupling slot and rectangular waveguide is with the axially parallel of coaxial waveguide, and millimeter wave is by TE₁₀basic mode is converted to coaxial TE₆₁pattern;

The inner conductor outer diameter of non-homogeneous section of coaxial waveguide remains unchanged, and it is large that outer conductor internal diameter becomes continuously, realizes coaxial waveguide to the transition of circular waveguide, and millimeter wave is by coaxial TE₆₁pattern is converted to circular waveguide TE₆₁pattern.

3. waveguide mode exciting bank according to claim 2, is characterized in that:

The length L of described even section of coaxial waveguide₁for 9.85mm, the internal diameter R of its outer conductor_bfor 4mm, the external diameter R of inner wire_afor 2.5mm;

The length L of described non-homogeneous section of coaxial waveguide₂for 55mm, at its front end, the internal diameter R of outer conductor_bfor 4mm, the external diameter R of inner wire_afor 2.5mm; At its end, the internal diameter R of outer conductor₀for 8.5mm, the external diameter R of inner wire_afor 2.5mm.

4. waveguide mode exciting bank according to claim 2, is characterized in that, described rectangular waveguide is the waveguide of W waveguide standard, and its upper port adopts FUGP900 flange to be connected to power source.

5. waveguide mode exciting bank according to claim 2, is characterized in that, described the second mode conversion assembly is the circular waveguide of waveguide radius axial-periodic disturbance, and its front end is connected to the end of first mode conversion assembly, its end output circular waveguide TE_6,2the millimeter wave of pattern.

6. waveguide mode exciting bank according to claim 5, is characterized in that, the profile function of the circular waveguide of described waveguide radius axial-periodic disturbance is:

$a\left(z\right)=\frac{a_0[1-{\mathrm{\&epsiv;}}_0\cos (2\mathrm{\&pi;z}/{\mathrm{\&lambda;}}_W)-{\mathrm{\&epsiv;}}_1\cos (4\mathrm{\&pi;z}/{\mathrm{\&lambda;}}_W)]}{1-{\mathrm{\&epsiv;}}_0-{\mathrm{\&epsiv;}}_1}$

Wherein, the axial length that z is circular waveguide, a (z) is is the circular waveguide internal diameter at z place in axial coordinate, a₀for initial radium, i.e. the radius of first mode conversion assembly end, ε₀and ε₁for disturbance parameter, λ_wfor the disturbance cycle.

7. waveguide mode exciting bank according to claim 6, is characterized in that, described disturbance parameter and disturbance cycle meet: 0.001≤ε₀≤ 0.1,0.001≤ε₁≤ 0.1,10mm≤λ_w≤ 80mm.

8. waveguide mode exciting bank according to claim 7, is characterized in that ε₀=0.0536, ε₁=0.008, λ_w=20.6mm.

9. waveguide mode exciting bank according to claim 5, is characterized in that, one of them is prepared from by following material for described rectangular waveguide, coaxial waveguide and circular waveguide: oxygen-free copper, aluminium and brass.

10. according to the waveguide mode exciting bank described in any one in claim 1 to 9, it is characterized in that, for millimeter wave TE_6,2the cold survey of mould gyrotron.