Extended Interaction Klystron

Abstract

The invention relates to an extended interaction klystron, comprising: a body, the body having a cylindrical outer contour, in which: a first resonant cavity, a second resonant cavity, and at least one intermediate resonant cavity arranged coaxially in the axial direction of the body, wherein each of the first resonant cavity, the second resonant cavity, and the intermediate resonant cavity comprises: a plurality of resonant portions, which are spaced and distributed in the circumferential direction in the body; and a plurality of grating portions, which are arranged to be alternately arranged with the plurality of resonant portions in the circumferential direction in the body, each of the grating portions being connected with two adjacent resonant portions; and a plurality of electron injection channels, each of which penetrates the body and extends in the axial direction, and is connected with the grating portions aligned in the axial direction in the first resonant cavity, the second resonant cavity, and the intermediate resonant cavity.

Description

Technical Field

[0001] The invention belongs to the technical field of high-power microwaves in vacuum electronic devices, and in particular relates to an extended interaction klystron. Background Art

[0002] As a power amplifier, the klystron has the advantages of high power, high efficiency, high stability and long life. It has important applications in high-power millimeter-wave radar, long-distance high-speed wireless communications, millimeter-wave electronic countermeasures, national security, controlled nuclear fusion and industrial applications.

[0003] In recent years, with the development of large-scale scientific experimental equipment and microwave electronic systems, higher requirements have been placed on the performance of millimeter-wave devices. The extended interaction klystron (EIK) combines the advantages of coupled cavity traveling wave tubes and traditional klystrons, and is expected to achieve high output power and high efficiency in the high frequency band. The extended interaction technology uses a multi-gap resonant section as an interaction circuit, which has the characteristics of high characteristic impedance and high unit length gain. At the same time, the shorter interaction length is suitable for permanent magnet focusing and can effectively reduce the risk of interception of the electron beam by the drift tube. However, in order to obtain efficient beam-wave interaction, the diameter of the electron beam channel needs to be much smaller than the working wavelength, so the power level of the traditional single-beam EIK will drop sharply in the high frequency band.

[0004] Since the strip injection technology and multi-injection technology can greatly increase the output power while maintaining a reasonable current density and operating voltage, they have been used in extended interaction devices with a trapezoidal structure. The common EIK uses a trapezoidal resonant part working in the fundamental mode as the interaction structure. However, as the frequency increases, the size of the cavity will decrease rapidly. At this time, the strong electric field is concentrated in the small-sized cavity, which increases the risk of voltage breakdown. At the same time, due to the limitation of the cathode emission current density, the traditional EIK trapezoidal cavity is difficult to meet the requirements of the cavity cross-sectional size of the high-power electron optical system. Summary of the invention

[0005] In view of the problems in the prior art, the present invention provides an extended interaction klystron, which is used to at least partially solve the above technical problems.

[0006] An embodiment of the present invention provides an extended interaction klystron, comprising: a body having a cylindrical outer contour, wherein a first resonant cavity, a second resonant cavity, and at least one intermediate resonant cavity coaxially arranged in the axial direction of the body are formed in the body, wherein each of the first resonant cavity, the second resonant cavity, and the intermediate resonant cavity comprises: a plurality of resonant portions spaced apart in the circumferential direction in the body; and a plurality of grating portions arranged to be alternately arranged in the circumferential direction in the body with the plurality of resonant portions, wherein each of the grating portions is connected to two adjacent resonant portions, wherein at least one grating portion of the first resonant cavity is connected to an input waveguide, and at least one grating portion of the second resonant cavity is connected to an output waveguide, and a plurality of electron injection channels are formed in the body, wherein each electron injection channel extends through the body in the axial direction and is connected to the grating portions aligned in the axial direction in the first resonant cavity, the second resonant cavity, and the intermediate resonant cavity.

[0007] According to an embodiment of the present disclosure, each of the grating portions includes a plurality of sector-shaped resonance gaps spaced apart in the axial direction and extending in the radial direction.

[0008] According to an embodiment of the present disclosure, the input waveguide includes: an annular input cavity, extending from a first end in the axial direction of the body into the body, and connected to one of the fan-shaped resonance gaps of the grating portion of the first resonance cavity; the output waveguide includes: an annular output cavity, extending from a second end in the axial direction of the body into the body, and connected to one of the fan-shaped resonance gaps of the grating portion of the second resonance cavity.

[0009] According to an embodiment of the present disclosure, the main body is also formed with: an input waveguide transformation portion, which is formed as a chamber extending integrally from the inner side in the axial direction of the annular input cavity toward the inner side in the radial direction of the fan-shaped resonance gap of the first resonance cavity, and the input waveguide transformation portion is connected to a fan-shaped resonance gap of the first resonance cavity; and an output waveguide transformation portion, which is formed as a chamber extending integrally from the inner side in the axial direction of the annular output cavity toward the inner side in the radial direction of the fan-shaped resonance gap of the second resonance cavity, and the output waveguide transformation portion is connected to a fan-shaped resonance gap of the second resonance cavity.

[0010] According to an embodiment of the present disclosure, the input waveguide transformation portion is connected to the fan-shaped resonance gap through a fan-shaped input coupling hole; and the output waveguide transformation portion is connected to the fan-shaped resonance gap through a fan-shaped output coupling hole.

[0011] According to an embodiment of the present disclosure, the center distance between two adjacent fan-shaped resonances in the grating portion serves as a period length of the grating portion; the width of each fan-shaped resonance gap in the grating portion is the same, and the width of each fan-shaped resonance gap is 1 / 3-1 / 2 times the period length of the fan-shaped resonance gap.

[0012] According to an embodiment of the present disclosure, the width of the resonance portion is N times the period length of the fan-shaped resonance gap, wherein N represents the number of the fan-shaped resonance gaps in one of the grating portions connected to the resonance portion.

[0013] According to an embodiment of the present disclosure, the inner diameter of the electron injection channel is 1 / 6-1 / 4 times the operating wavelength of the klystron.

[0014] According to an embodiment of the present disclosure, each of the first resonant cavity, the second resonant cavity, and the intermediate resonant cavity includes: 5 multiple resonant parts and 5 grating parts; wherein each of the grating parts of the first resonant cavity includes 3-5 fan-shaped resonant gaps; wherein each of the grating parts of the intermediate resonant cavity includes 3-5 fan-shaped resonant gaps; wherein each of the grating parts of the second resonant cavity includes 5-7 fan-shaped resonant gaps. According to an embodiment of the present disclosure, the curvature of the resonant part of each of the first resonant cavity, the second resonant cavity, and the intermediate resonant cavity is 28-32°; the curvature of each of the fan-shaped resonant gaps of the grating part of each of the first resonant cavity, the second resonant cavity, and the intermediate resonant cavity is 44-40°; the geometric centers of the fan-shaped resonant gaps and each of the resonant parts are located on the same concentric circle.

[0015] According to the above-mentioned embodiment of the present invention, an extended interaction klystron is provided. The above-mentioned klystron adopts axially spaced grating parts and resonance parts for matching, is not constrained by the size co-variance effect, still has a large interaction cross-section at a higher working frequency band, and has good high-order mode selectivity, and can further enhance the working mode electric field near the drift tube, and can achieve high-power output in the millimeter wave band in a relatively stable and efficient manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic structural diagram of a klystron according to an exemplary embodiment of the present disclosure is shown;

[0017] Figure 2 Schematically shows Figure 1 A cross-sectional view of the klystron along the axial direction is shown;

[0018] Figure 2a yes Figure 2 A radial cross-sectional view of the portion along the AA direction shown;

[0019] Figure 2b yes Figure 2a A three-dimensional schematic diagram of the input waveguide transformation portion and the fan-shaped grating gap connection portion shown;

[0020] Figure 2c yes Figure 2 A radial cross-sectional view of the portion along line BB shown;

[0021] Figure 2d yes Figure 2 A radial cross-sectional view of the CC portion shown;

[0022] Figure 2e yes Figure 2 An enlarged schematic diagram of section D is shown;

[0023] Figure 3 A graph showing the peak output power of an amplified signal of a klystron according to an exemplary embodiment of the present disclosure is shown;

[0024] Figure 4 A diagram showing an output signal spectrum of a klystron according to an exemplary embodiment of the present disclosure; and

[0025] Figure 5 A schematic diagram of electric field distribution of a klystron according to an exemplary embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure.

[0027] The terms "include", "comprising", etc. used herein indicate the presence of the features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components. All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0028] In the case of using expressions such as "at least one of A, B, and C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.). In the case of using expressions such as "at least one of A, B, or C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, or C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0029] Figure 1 A schematic structural diagram of a klystron according to an exemplary embodiment of the present disclosure is shown; Figure 2

[0030] Figure 2 Schematically shows Figure 1 A cross-sectional view of the klystron along the axial direction is shown.

[0031] According to a general inventive concept of the present disclosure, as Figure 1 and Figure 2 As shown, an extended interaction klystron is provided, comprising: a body 1, the body 1 having a cylindrical outer profile and formed inside the body (1); a first resonant cavity, a second resonant cavity, and at least one intermediate resonant cavity located between the first resonant cavity and the second resonant cavity coaxially arranged in the axial direction of the body 1; and a plurality of electron injection channels 2.

[0032] Further, each of the first resonant cavity, the second resonant cavity, and the intermediate resonant cavity comprises: a plurality of resonant portions 6 spaced apart in the circumferential direction in the body 1; and a plurality of grating portions 4 arranged to be alternately arranged with the plurality of resonant portions 6 in the circumferential direction in the body 1. Each of the grating portions 4 is connected to two adjacent resonant portions 6, wherein at least one grating portion 4 of the first resonant cavity is connected to the input waveguide, and at least one grating portion 4 of the second resonant cavity is connected to the output waveguide. Each of the plurality of electron injection channels 2 extends in the axial direction through the body 1, and is connected to the grating portions 4 aligned in the axial direction in the first resonant cavity, the second resonant cavity, and the intermediate resonant cavity.

[0033] In an exemplary embodiment, the resonant portion 6 and the grating portion 4 are both made into a substantially fan-shaped structure.

[0034] In an exemplary embodiment, each of the grating portions 4 includes a plurality of substantially fan-shaped resonance gaps 41 spaced apart in the axial direction and extending in the radial direction.

[0035] Figure 2a yes Figure 2 A radial cross-sectional view of the portion along the AA direction shown; Figure 2b yes Figure 2a A schematic diagram of the structure of the input waveguide transformation part and the fan-shaped grating gap connection part shown; Figure 2c yes Figure 2 A radial cross-sectional view of the portion along line BB shown; Figure 2d yes Figure 2 A radial cross-sectional view of the CC portion shown; Figure 2e yes Figure 2 An enlarged schematic diagram of portion D is shown.

[0036] In an exemplary embodiment, Figure 2a As shown, the input waveguide includes an annular input cavity 30 formed around the axis of the body 1, and the annular input cavity 30 extends from the first end in the axial direction of the body 1 into the body 1, and is connected to one of the fan-shaped resonance gaps 41 of the grating part 4 of the first resonance cavity to input the initial waveguide signal.

[0037] In an exemplary embodiment, the input waveguide is communicated with a fan-shaped resonance gap 41 located in the middle or adjacent to the middle of at least one grating portion among the plurality of grating portions 4 of the first resonant cavity.

[0038] In an exemplary embodiment, Figure 2d As shown, the output waveguide includes: an annular output cavity 50 formed around the axis of the body 1, the annular output cavity 50 extends from the second end of the axial direction of the body 1 into the body 1, and is connected to one of the fan-shaped resonance gaps 41 of the grating part 4 of the second resonance cavity to output high-frequency waveguides, such as terahertz waves.

[0039] In an exemplary embodiment, the output waveguide is communicated with a fan-shaped resonance gap 41 located in the middle or adjacent to the middle of at least one grating portion among the plurality of grating portions 4 of the second resonant cavity.

[0040] In an alternative embodiment, the input waveguide is connected to a sector-shaped resonant gap 41 of a grating portion 4 of the first resonant cavity in a radial direction to input an initial waveguide signal; the output waveguide is connected to a sector-shaped resonant gap 41 of a grating portion 4 of the second resonant cavity in a radial direction to output a high-frequency waveguide, such as a terahertz wave. That is, the input waveguide and the output waveguide are both independently provided from the body 1.

[0041] In an exemplary embodiment, Figure 2a and Figure 2b As shown, the main body is also formed with an input waveguide transformation portion 32, and the input waveguide transformation portion 32 is formed as a cavity extending integrally from the inner side in the axial direction of the annular input cavity 30 toward the inner side in the radial direction of the fan-shaped resonance gap 41 of the first resonance cavity, and the input waveguide transformation portion 32 is connected to a fan-shaped resonance gap 41 of the first resonance cavity.

[0042] like Figure 2d As shown, the body is further formed with an output waveguide transformation portion 52, which is formed as a cavity extending integrally from the inner side of the annular output cavity 50 in the axial direction toward the inner side of the fan-shaped resonance gap 41 of the second resonance cavity in the radial direction, and the output waveguide transformation portion 52 is connected to a fan-shaped resonance gap 41 of the second resonance cavity. It can be understood that the connection structures of the input waveguide transformation portion 32 and the output waveguide transformation portion 52 and the fan-shaped resonance gap 41 are substantially the same.

[0043] In an exemplary embodiment, the input waveguide transformation portion 32 is connected to the fan-shaped resonance gap 41 through a fan-shaped input coupling hole 31 ; similarly, the output waveguide transformation portion 52 is connected to the fan-shaped resonance gap 41 through a fan-shaped output coupling hole 51 .

[0044] In an exemplary embodiment, Figure 2e As shown, the center distance a between two adjacent fan-shaped resonances 41 in the grating portion 4 is taken as a period length of the above-mentioned grating portion 4.

[0045] For example, the width b of each of the fan-shaped resonant gaps 41 in the grating portion 4 is the same, and the width b of each of the fan-shaped resonant gaps 41 is 1 / 3-1 / 2 times the period length of the fan-shaped resonant gap 41. The width c of the resonator portion 6 is N times the period length of the fan-shaped resonant gap 41, wherein N represents the number of the fan-shaped resonant gaps 41 in the grating portion 4 connected to the resonator portion 6.

[0046] In an exemplary embodiment, the inner diameter of the electron injection channel 2 is 1 / 6 to 1 / 4 times the operating wavelength of the klystron.

[0047] In an exemplary embodiment, Figure 2a-2eAs shown, each of the first resonant cavity, the second resonant cavity, and the intermediate resonant cavity includes: 5 multiple resonant portions 6 and 5 grating portions 4; each of the grating portions 4 of the first resonant cavity includes 3-5 fan-shaped resonant gaps 41; each of the grating portions 4 of the intermediate resonant cavity includes 3-5 fan-shaped resonant gaps 41; each of the grating portions 4 of the second resonant cavity includes 5-7 fan-shaped resonant gaps 41. Those skilled in the art understand that the number of the intermediate resonant cavity and the number of resonant gaps in each gap cavity can be set according to requirements.

[0048] In an exemplary embodiment, Figure 2c yes Figure 2 In the cross-sectional view taken along the BB direction, in an exemplary embodiment: the curvature β of the resonance portion 6 of each of the first resonance cavity, the second resonance cavity and the intermediate resonance cavity is 28-32°; the curvature α of each of the fan-shaped resonance gaps of the grating portion 4 of each of the first resonance cavity, the second resonance cavity and the intermediate resonance cavity is 44-40°; the geometric centers of the fan-shaped resonance gaps 41 and each of the resonance portions 6 are located on the same concentric circle.

[0049] In an exemplary embodiment, Figure 2 As shown, it includes: a body 1, a first resonant cavity, a second resonant cavity and two intermediate resonant cavities coaxially arranged in the axial direction of the body 1, and a plurality of electron injection channels 2, each of which runs through the body 1 and extends in the axial direction, and is connected to the grating parts 4 aligned in the axial direction in the first resonant cavity, the second resonant cavity and the two intermediate resonant cavities. The four resonant cavities all work in the TM51-2π mode.

[0050] In detail, the first resonant cavity includes five resonant parts 6, five grating parts 4 and a ring input cavity 30. The parameters of the resonant part 6 are as follows: inner diameter is 2.8 mm, outer diameter is 5.6 mm, arc β is 30°, and width c is 2.58 mm. Each grating part 4 includes three fan-shaped resonant gaps 41.

[0051] In an exemplary embodiment, the parameters of the above-mentioned fan-shaped resonance gap 41 are as follows: the inner diameter is 3.3 mm, the outer diameter is 5.1 mm, the arc α is 42°, the width b is 0.38 mm, and the period length a is 0.86 mm. The parameters of the above-mentioned annular input cavity 30 are as follows: the inner diameter of the inner ring is 1 mm, the inner diameter of the outer ring is 1.35 mm, and the axial length is 5 mm. The input waveguide conversion part 32 is connected to the fan-shaped resonance gap 41 located in the middle, and the above-mentioned connection position forms a fan-shaped input coupling hole 31. The inner diameter of the inner ring of the input waveguide conversion part 32 is 1 mm, the inner diameter of the outer ring is 2.5 mm, and the width is 0.38 mm; wherein, the inner diameter of the fan-shaped input coupling hole 31 is 2.5 mm, the outer diameter is 3.3 mm, the arc is 28°, and the width is 0.38 mm.

[0052] In the descriptions of the widths involved in the above-mentioned resonance part, grating part and annular input cavity, the widths are characterized as the lengths relative to the axial direction of the body 1 .

[0053] In detail, the second resonant cavity includes five resonant parts 6, five grating parts 4 and a ring output cavity 50. The parameters of the resonant part 6 are as follows: the inner diameter is 2.85 mm, the outer diameter is 5.5 mm, the arc β is 30°, and the width c is 4.2 mm. Each grating part 4 includes five fan-shaped resonant gaps 41. The parameters of the fan-shaped resonant gaps 41 are as follows: the inner diameter is 3.3 mm, the outer diameter is 5.1 mm, the arc α is 42°, the width b is 0.38 mm, and the period length a is 0.86 mm.

[0054] In an exemplary embodiment, the parameters of the annular output cavity 50 are as follows: the inner diameter of the inner ring is 1.1 mm, the inner diameter of the outer ring is 1.4 mm, the axial length is 6 mm, and it is connected to the adjacent fan-shaped resonance gap 41 located in the middle through the output waveguide transformation part 52, and the above-mentioned connection position forms a fan-shaped output coupling hole 52; wherein, the inner diameter of the inner ring of the output waveguide transformation part 52 is 1.1 mm, the inner diameter of the outer ring is 2.6 mm, and the width is 0.38 mm; wherein, the inner diameter of the fan-shaped output coupling hole 51 is 2.6 mm, the outer diameter is 3.3 mm, the arc is 28°, and the width is 0.38 mm.

[0055] In the description of the width involved in the above-mentioned resonance part, grating part and annular input cavity, the width is characterized as the length relative to the axial direction of the body 1. In detail, the intermediate cavity includes three resonance parts 6 and three grating parts 4. The parameters of the above-mentioned resonance part 6 are as follows: the inner diameter is 2.8 mm, the outer diameter is 5.6 mm, the arc β is 30°, and the width c is 2.58 mm. Each grating part 4 includes three fan-shaped resonance gaps 41. The parameters of the above-mentioned fan-shaped resonance gaps 41 are as follows: the inner diameter is 3.3 mm, the outer diameter is 5.1 mm, the arc α is 42°, the width b is 0.38 mm, and the period length a is 0.86 mm.

[0056] In detail, the number of electron injection channels 2 is the same as the number of grating parts 4 in the same resonant cavity, which is 5. The inner diameter of each electron injection channel 2 is 0.6 mm; the length of the electron injection channel 2 between the first resonant cavity and the adjacent middle resonant cavity is 2.2 mm; the length of the electron injection channel 2 between the two middle resonant cavities is 2.2 mm; and the length of the electron injection channel 2 between the second resonant cavity and the adjacent middle resonant cavity is 2.1 mm.

[0057] Each of the electron injection channels 2 is located at the end of the first resonant cavity 7 ( Figure 2 An electron generating device is provided at the left end of the second resonant cavity, and the electron generating device includes: a cathode, a control electrode and an anode for generating electrons, and the control electrode and the anode work together to gather the electrons generated by the cathode into an electron beam suitable for injecting into the electron injection channel; each of the electron injection channels 2 is located at the end of the second resonant cavity ( Figure 2 A collecting electrode is provided at the right end of the electron beam, and the collecting electrode is used to receive the electron beam from the electron injection channel.

[0058] According to the parameters published in the embodiments of the present disclosure, when the voltage of the electron beam is 25KV, the current of the electron beam is 7A (5×1.4A), the magnetic induction intensity used to focus the electron beam is 0.85T, and the input signal is 100mW, the peak output power of the amplifier is 30.1kW.

[0059] Figure 3 FIG. 2 shows a peak output power diagram of an amplified signal of a klystron according to an exemplary embodiment of the present disclosure. Figure 3 As shown, the corresponding electronic efficiency and gain are 17.2% and 54.8dB respectively.

[0060] Figure 4 FIG. 2 shows an output signal spectrum diagram of a klystron tube according to an exemplary embodiment of the present disclosure. Figure 4 As shown, the output signal is Fourier transformed to obtain a signal spectrum diagram, the spectrum is pure and free of noise, and the frequency is 94.4GHz.

[0061] Figure 5 FIG. 2 shows a schematic diagram of electric field distribution of a klystron according to an exemplary embodiment of the present disclosure. Figure 5 As shown in the figure, the axial electric field distribution of the extended interaction klystron is in operation. Each cavity works stably in the TM51-2π mode, and the electric field strength gradually increases from the input cavity C1 to the output cavity C4. It can be seen that the interaction structure of the coaxial high-order mode extended interaction klystron can stably and efficiently interact with the five electron beams uniformly distributed in the angular direction.

[0062] According to an embodiment of the present disclosure, the electrons generated by the cathode in the external electron generating device are converged into a DC electron beam through the control electrode and the anode. The DC electron beam enters the first resonant cavity through the electron injection channel. At the same time, the seed signal enters the first resonant cavity through the annular input cavity. The DC electron beam is preliminarily modulated in the first resonant cavity to form a certain speed cluster. Then the DC electron beam is continuously modulated through the intermediate resonant cavity, and the speed modulation is gradually converted into density modulation in the drift section between adjacent resonant cavities to form a clustered bunch. Finally, the clustered bunch has a stronger beam-wave interaction with the gap electric field in the second resonant cavity, transfers energy to the electromagnetic wave, and finally radiates the generated output signal through the annular output cavity.

[0063] The present invention provides an extended interaction klystron, in which the resonant part and the grating part have different lateral dimensions. According to the electric field distribution characteristics of the coaxial high-order TM mode, the adjacent electric field extremes can be equivalent to ideal electric walls, and the working mode electric field extremes are respectively in each resonant part and the grating part (sector-shaped cavity), and this angularly non-uniform structure has good mode selectivity. In addition, the present invention uses the TM51-2π mode as the interaction mode. Under the same frequency operation, the lateral TM51 mode operation has a larger lateral cavity size than the TM01 mode operation. At the same time, according to the injection-wave synchronization condition, the axial 2π mode makes the cavity have the largest axial size, so the power capacity and heat dissipation performance of the cavity can be improved, which is more suitable for millimeter wave high-power application scenarios. Furthermore, compared with the existing angularly uniform coupling structure, the design makes the interaction electric field more concentrated near the electron injection channel, thereby improving the characteristic impedance at the injection-wave interaction position.

[0064] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. The scope of the present disclosure is defined by the attached claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. An extended interaction klystron comprising: A body (1) having a cylindrical outer contour, wherein: A first resonant cavity, a second resonant cavity, and at least one intermediate resonant cavity located between the first resonant cavity and the second resonant cavity are coaxially arranged in the axial direction of the body (1), each of the first resonant cavity, the second resonant cavity, and the intermediate resonant cavity comprising: A plurality of resonating parts (6) are distributed at intervals along a circumferential direction in the body (1); and A plurality of grating sections (4) are arranged to be alternately arranged with the plurality of resonant sections (6) in the body (1) along a circumferential direction, each of the grating sections (4) being connected to two adjacent resonant sections (6), wherein at least one grating section (4) of the first resonant cavity is connected to an input waveguide, and at least one grating section (4) of the second resonant cavity is connected to an output waveguide, and a plurality of electron injection channels (2), each electron injection channel (2) extending through the body (1) in the axial direction and communicating with the first resonant cavity, the second resonant cavity, and the grating portions (4) aligned in the axial direction in the intermediate resonant cavity; Each of the grating sections (4) comprises a plurality of fan-shaped resonance gaps (41) spaced apart in the axial direction and extending in the radial direction, and a center distance (a) between two adjacent fan-shaped resonance gaps (41) in the grating section (4) serves as a period length of the grating section (4); The width (b) of each of the fan-shaped resonance gaps (41) in the grating portion (4) is the same, and the width (b) of each of the fan-shaped resonance gaps (41) is 1 / 3 to 1 / 2 times the period length of the fan-shaped resonance gap (41).

2. The klystron according to claim 1, wherein: The input waveguide comprises: An annular input cavity (30) extending from a first end in the axial direction of the body (1) into the body (1) and communicating with one of the fan-shaped resonance gaps (41) of the grating portion (4) of the first resonance cavity; The output waveguide comprises: The annular output cavity (50) extends from the second end of the body (1) in the axial direction into the body (1) and is connected to one of the fan-shaped resonance gaps (41) of the grating portion (4) of the second resonance cavity.

3. The klystron according to claim 2, wherein: The body is also formed with: an input waveguide transformation portion (32), the input waveguide transformation portion (32) being formed as a cavity extending integrally from the inner side of the annular input cavity (30) in the axial direction toward the inner side of the fan-shaped resonance gap (41) of the first resonance cavity in the radial direction, the input waveguide transformation portion (32) being in communication with a fan-shaped resonance gap (41) of the first resonance cavity; as well as An output waveguide transformation portion (52) is formed as a cavity extending integrally from the inner side of the annular output cavity (50) in the axial direction toward the inner side of the fan-shaped resonance gap (41) of the second resonance cavity in the radial direction, and the output waveguide transformation portion (52) is connected to a fan-shaped resonance gap (41) of the second resonance cavity.

4. The klystron according to claim 3, wherein the input waveguide conversion portion (32) is connected to the fan-shaped resonance gap (41) through a fan-shaped input coupling hole (31); The output waveguide conversion portion (52) is connected to the fan-shaped resonance gap (41) via a fan-shaped output coupling hole (51).

5. The klystron according to claim 1, wherein: The width (c) of the resonant portion (6) is N times the period length of the fan-shaped resonant gap (41), wherein N represents the number of the fan-shaped resonant gaps (41) in one of the grating portions (4) connected to the resonant portion (6).

6. The klystron according to claim 1, wherein: The inner diameter of the electron injection channel (2) is 1 / 6 to 1 / 4 times the working wavelength of the klystron.

7. The klystron according to claim 1, wherein: Each of the first resonant cavity, the second resonant cavity, and the intermediate resonant cavity comprises: 5 multiple resonant sections (6) and 5 grating sections (4); Wherein, each of the grating portions (4) of the first resonant cavity comprises 3-5 fan-shaped resonant gaps (41); Wherein, each of the grating portions (4) of the intermediate resonant cavity comprises 3-5 fan-shaped resonant gaps (41); Wherein, each of the grating sections (4) of the second resonant cavity comprises 5 to 7 fan-shaped resonant gaps (41).

8. The klystron according to claim 7, wherein: The arc (β) of the resonant portion (6) of each of the first resonant cavity, the second resonant cavity and the intermediate resonant cavity is 28-32°; The arc angle (α) of each of the fan-shaped resonant gaps of the grating portion (4) of each of the first resonant cavity, the second resonant cavity and the intermediate resonant cavity is 44-40°; The geometric centers of the fan-shaped resonance gap (41) and each of the resonance parts (6) are located on the same concentric circle.

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