High-efficiency phase-locked relativistic klystron based on hybrid modulation-extraction mechanism

Abstract

The invention relates to a relativistic klystron in the technical field of high-power microwaves, in particular to a high-efficiency phase-locked relativistic klystron based on a hybrid modulation-extraction mechanism, and belongs to the technical field of high-power microwaves. Comprising an anode cylinder, an inner conductor, a reflection cavity, a tail front cavity, an extraction cavity, an electron beam collector, a conical waveguide, a feedback ring and a microwave output port. The distance between the last front cavity and the extraction cavity is optimized, energy coupling between the two cavities is enhanced, the modulation capacity of the last front cavity is improved, electron beams are still modulated in the energy exchange process of the extraction cavity and microwaves, the bunching state of the electron beams is further deepened, and therefore high-efficiency microwave output of the compact relativistic klystron is achieved.

Description

Technical Field

[0001] The invention relates to a relativistic klystron in the technical field of high-power microwaves, and in particular to a high-efficiency phase-locked relativistic klystron based on a hybrid modulation-extraction mechanism, belonging to the technical field of high-power microwaves. Background Art

[0002] High power microwave (HPM) usually refers to electromagnetic waves with a power greater than 100MW and a frequency between 1GHz and 300GHz. High power microwave technology is an extension of traditional vacuum devices to higher output power levels. It is widely used in research fields such as radar, power transmission, plasma heating, high energy particle acceleration, and directed energy. The high power microwave source is the core component of the high power microwave system. It generates high power microwaves based on the interaction between the intense relativistic electron beam (IREB) and the high frequency structure.

[0003] In recent years, driven by the needs of research fields such as radar, power transmission, plasma heating, high-energy particle acceleration, and directed energy, high-power microwave technology has developed rapidly. After decades of development, the output power of a single microwave source has reached 10GW, but due to physical mechanisms such as RF breakdown and space charge effect, as well as limitations of materials and processing technology, the output power of a single microwave source is difficult to increase further. Spatial coherent power synthesis technology is to synthesize the high-power microwaves output by N microwave sources in space to obtain N 2 times the peak power density, this technology is expected to achieve hundreds of GW of equivalent microwave output in the coherent region. The core difficulty of high-power microwave spatial coherent power synthesis is to control the frequency and phase of the output microwave, which can be achieved through a phase-locked high-power microwave amplifier and a phase-locked high-power microwave oscillator. The phase of the relativistic klystron is controlled by the injected seed source, and it is one of the ideal devices for achieving spatial coherent synthesis. At present, the efficiency of the relativistic klystron is often improved by increasing the drift tube length or increasing the seed source injection power. This leads to problems such as the device being too large and difficulty in dissipating the magnetic field, which seriously restricts the compact miniaturization of the device.

[0004] In 2019, Dr. Zhang Wei of the National University of Defense Technology proposed an X-band high-gain and high-efficiency relativistic klystron amplifier based on positive feedback [Wei Zhang, Jinchuan Ju, Jun Zhang, Yunxiao Zhou, Huihuang Zhong, Theoretical research on TEM mode feedback for compact design of an X-band triaxial klystron amplifier, Physics Of Plasmas, 2019, 26(5): 053102] (hereinafter referred to as prior art 1). The structure is mainly composed of a cathode seat, a cathode, an anode outer tube, an inner conductor, an input cavity, a first cascade modulation cavity, a second cascade modulation cavity, an extraction cavity, a reflector, an electron beam collector, a feedback loop, a microwave output port, and a spiral tube magnetic field. The overall structure is rotationally symmetric about the central axis. When the device is in operation, the annular electron beam generated by the cathode is transmitted to the right under the guidance of the magnetic field. It is first pre-modulated by the externally injected microwave signal in the input cavity; then the electron beam clustering depth is increased through the two-stage cascade modulation cavity; the modulated electron beam converts energy into microwave energy in the extraction cavity, and the generated microwave is output from the microwave output port. In the experiment, 1.71GW of microwave output was obtained, with a frequency of 8.4GHz and an efficiency of about 31.8%, and it was able to achieve good frequency and phase locking, with the phase difference locked within 10 degrees. This structure has important reference value for the design of high-efficiency and high-gain klystron amplifiers in the X-band. However, this technical solution has the following shortcomings: (1) This technical solution improves the modulation ability of the cavity to the electron beam by establishing a positive feedback state between the input cavity and the first-stage modulation cavity, thereby shortening the drift section length; however, the drift tube length of this technical solution is still relatively long, resulting in an axial length of the device that is too long, about 450 mm (about 13 wavelengths), which will cause the volume and mass of the device to be too large, which is not conducive to the miniaturization of the device; and shortening the drift section length will lead to a weakening of the modulation of the electron beam, resulting in a decrease in the microwave output efficiency of the device; (2) The multi-gap modulation cavity will aggravate the energy coupling between the cavities, resulting in self-oscillation and non-rotationally symmetric mode competition problems in the device, resulting in a decrease in the microwave output efficiency of the device and a loss of phase and frequency lock.

[0005] In 2018, Xiao Renzhen from the Northwest Institute of Nuclear Technology proposed an injection-locked klystron backward wave oscillator [Renzhen Xiao, Yuqun Deng, Changhua Chen, Yanchao Shi, Jun Sun, Generation of powerful microwave pulses by channel power summation of two X-band phase-locked relativistic backward wave oscillators. Physics Of Plasmas, 2018, 25(3): 033109] (hereinafter referred to as prior art 2). The structure consists of a cathode seat, a cathode, an injection cavity, a premodulation cavity, a reflector, a slow-wave structure, and an extraction cavity, and the overall structure is symmetrical about the central axis. The device adopts a hybrid beam action mechanism, combining the Cherenkov radiation and transition radiation mechanisms to achieve high-efficiency microwave output, and controls the microwave phase through an external injection signal. In the experiment, when the injection power is 100kW, the output power is 3.4GW, the efficiency is about 36%, and the phase jitter of the output microwave is about 20°. This structure has important research significance for the phase-locking research of high-efficiency X-band klystron return wave oscillator, but this technical solution has the following shortcomings: (1) The magnetic field of the device is very large (greater than 2T), which makes the magnetic field volume and mass of the device too large. At the same time, the heat dissipation of the magnetic field is difficult, which is not conducive to the compact miniaturization of the device; (2) The phase-locking of the device requires a high-power injection signal (hundreds of kW). When the injection signal power decreases, the modulation ability of the electron beam decreases, and the phase-locking characteristics of the device deteriorate. It is found in the experiment that when the injection power is 210kW, 100kW, and 30kW, the maximum phase jitter values ​​are 10°, 20°, and 30°, respectively.

[0006] It is not difficult to find from the analysis of the above research status that although the research on phase-locked relativistic klystron has made great progress, the existing technical solutions still have shortcomings such as long axial length of the device, too large magnetic field leading to difficulty in heat dissipation of the solenoid, and large external injection power. However, whether shortening the drift tube length, reducing the magnetic field or reducing the injection power will affect the modulation effect of the electron beam, resulting in reduced device efficiency and deterioration of phase-locked characteristics, which seriously restricts the development of compact and miniaturized klystrons. Therefore, it is urgent to study a new working mechanism that can improve the modulation depth of the electron beam of compact klystrons with short axial length, low magnetic field, and low injection power, and improve the working efficiency of the device. Summary of the invention

[0007] The technical problem to be solved by the present invention is: the present invention proposes a high-efficiency phase-locked relativistic klystron based on a hybrid modulation-extraction mechanism, which overcomes the shortcomings of the compact relativistic klystron such as the difficulty in modulating the electron beam and the low efficiency, and optimizes the distance between the final front cavity and the extraction cavity, thereby enhancing the energy coupling between the two cavities and improving the modulation capability of the final front cavity. At the same time, the electron beam is still modulated in the process of energy exchange between the extraction cavity and the microwave, further deepening the clustering state of the electron beam, thereby realizing the high-efficiency microwave output of the compact relativistic klystron.

[0008] The technical solution of the present invention is: a high-efficiency phase-locked relativistic klystron based on a hybrid modulation-extraction mechanism, comprising an anode cylinder 01, an inner conductor 02, a reflection cavity 03, a final front cavity 04, an extraction cavity, an electron beam collector 06, a conical waveguide 07, a feedback loop 08, and a microwave output port 09, and the overall structure is rotationally symmetrical about the central axis.

[0009] Anode cylinder 01 is a 1 The inner conductor 02 is a thin-walled cylinder with a radius of R 2 A solid cylinder that satisfies R 2 <R 1 ; Reflection cavity 03 has an outer radius R 3 , inner radius R 4 , width is L 2 The annular groove is opened at a distance L from the left end surface of the inner conductor 02 1 At, satisfying R 3 >R 1 >R 2 >R 4 , L 1 The value of L is 0.8-1.2 times of the working wavelength λ. 2 The value is 0.3-0.5 times of the working wavelength λ; the reflection cavity 03 is used to suppress the leakage of the TEM mode to the upstream of the device to avoid self-oscillation and mode competition; at a distance L from the right end face of the reflection cavity 03 3 At the inner and outer conductor walls, a channel with an outer radius of R is opened. 5 , inner radius is R 6 , an annular groove with an isosceles trapezoidal cross section, satisfying R 5 >R 1 >R 2 >R 6 , L 3 The value of is 0.1-0.3 times the working wavelength λ, and the length of the lower base (short side) of the "isosceles trapezoid" is L 4 , the length of the upper base (long side) is L 5 , L 4 The value of L is 0.2-0.5 times of the working wavelength λ. 5The value is 0.25-0.6 times of the working wavelength λ; at the right end surface L of the front cavity 04 6 At the point, open a hole with an outer radius of R 7 , inner radius is R 8 , width is L 7 The first annular groove 05a satisfies R 7 >R 1 >R 2 >R 8 , L 6 The value of L is 0.4-0.8 times of the working wavelength λ. 7 The value is 0.1-0.3 times of the working wavelength; at a distance L from the right end surface of the first annular groove 05a 8 At the same time, a radius of R is opened 9 , inner radius is R 10 , width is L 9 The second annular groove 05b satisfies R 9 >R 1 >R 2 >R 10 , L 8 The value of L is 0.05-0.2 times of the working wavelength λ. 9 The value is 0.1-0.3 times of the working wavelength. The first annular groove 05a and the second annular groove 05b together form an extraction cavity. The electron beam collector 06 is an annular cavity with a right-angled trapezoidal cross section. The upper base width L of the right-angled trapezoid is 10 , bottom width L 11 , outer radius (radius at the upper base) R 11 , the inner radius (the radius of the lower base) is R 12 , satisfying R 11 <R 1 And R 12 >R 2 , L 10 The value of L is 0.7-1.2 times of the working wavelength λ. 11 The value of is 1.0-1.5 times of the working wavelength λ, and the tilt angle θ 1 The value is 10°-30°; the tapered waveguide 07 is a circular ring cavity with a right-angle trapezoidal cross section, and the distance from the left end surface of the second circular ring groove 05b is L 12 Department, L 12 The value of is 0.5-0.8 times of the working wavelength λ, and the length of the upper bottom side of the tapered waveguide 07 is (R 13 -R 10 ), the length of the lower base is (R 13 -R 15 ), height is L 13 , L 13The value of is 0.5-0.7 times the working wavelength λ, and the hypotenuse forms an angle θ with the horizontal direction 2 ,θ 2 The value is 10°-30°; on the right side of the tapered waveguide 07, there is a 13 , inner radius is R 14 , width is L 14 Feedback loop 08, R 13 Equal to R 2 , R 14 <R 13 , L 14 The value is 0.1-0.2 times of the working wavelength λ. The feedback loop 08 is a stainless steel metal ring, which is used to adjust the Q value of the extraction cavity. The circular ring space between the anode cylinder 01 and the inner conductor 02 on the right side of the tapered waveguide 07 forms a microwave output port 09, and the outer radius of the microwave output port 09 is R 13 , the inner radius is R 15 ; The antenna is connected to the right side of the microwave output port 09.

[0010] The final front cavity 04 works in TM01 mode, which is used to further modulate the electron beam and improve the clustering depth of the electron beam; the extraction cavity works in TM012 mode, which is used to convert the electron beam energy into microwave energy; at the same time, the extraction cavity will also re-modulate the electron beam, and through this mixed modulation-extraction mechanism, the effect of simultaneous extraction and modulation is achieved, further improving the clustering depth of the electron beam and the efficiency of beam-wave interaction; by adjusting the inner radius R of the feedback loop 08 14 To adjust the Q value of the extraction cavity.

[0011] The working principle of the present invention is: the reflection cavity 03 is placed in front of the final front cavity 04, and the distance L from the final front cavity 04 to the extraction cavity is optimized. 6, establish a positive feedback mechanism between the final front cavity 04 and the extraction cavity, enhance the modulation ability of the final front cavity 04, and at the same time allow the electrons in the extraction cavity to still be modulated in the process of exchanging energy to microwaves. Through this hybrid modulation-extraction mechanism, the working state of simultaneous extraction and modulation is realized, further improving the modulation depth of the electron beam, and finally being collected by the electron beam collector 06; the modulated electron beam enters the final front cavity 04, and will excite the TM01 mode in the gap of the final front cavity 04, and its axial electric field will modulate the speed of the electron beam. This positive feedback mechanism will enhance the TM01 standing wave field in the final front cavity 04, so that the electron beam is rapidly modulated; after the modulated electron beam reaches the extraction cavity, it exchanges energy with the microwave field of the TM012 mode, exciting high-power microwaves, and the total energy of the electron beam decreases; at the same time, due to the positive feedback effect, a hybrid modulation-extraction mechanism is established in the extraction cavity, which will not only have an extraction effect on the electron beam, but also continue to modulate the electron beam, and the electron beam clustering depth is further increased; finally, the excited high-power microwave is transmitted to the antenna through the microwave output port 09, and is fed into the free space by the antenna.

[0012] In the present invention, the formula (1) in the literature [Zhang Wei. Research on X-band high-power and high-efficiency relativistic three-axis klystron amplifier [D]. null, 2019] is used to calculate the shortest drift distance L corresponding to the positive feedback. 6 :

[0013]

[0014] Where c is the speed of light in a vacuum, v e is the initial velocity of the electron beam entering the final front cavity 04, and f is the operating frequency. L can be calculated by formula (1): 6 ≈14mm. After a large number of simulation experiments, it was found that L 6 When taking 16mm, the positive feedback is more obvious.

[0015] Compared with the prior art, the present invention can achieve the following technical effects:

[0016] (1) The high-efficiency phase-locked relativistic klystron with hybrid modulation-extraction mechanism proposed in the present invention optimizes the distance L between the final front cavity O4 and the extraction cavity. 6 , establish the positive feedback state between the final front cavity 04 and the extraction cavity, enhance the modulation ability of the final front cavity 04 on the electron beam, and realize the deep modulation of the electron beam at a short drift distance, L 6 The value of is 0.4 to 0.8 times of the working wavelength λ, which is much smaller than the drift section length in the prior art 1, thus achieving compactness and miniaturization of the device;

[0017] (2) Compared with the prior art 1, the high-efficiency phase-locked relativistic klystron with a hybrid modulation-extraction mechanism proposed in the present invention continues to be modulated in the process of exchanging energy with microwaves, and the modulation depth of the electron beam is further improved. In the embodiment of the present invention, the high-efficiency phase-locked relativistic klystron with a hybrid modulation-extraction mechanism can achieve a modulation depth of more than 140%, and the working efficiency of the device reaches more than 45%, meeting the design requirements of high efficiency of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the structure of a high-efficiency phase-locked relativistic klystron front end cavity-output cavity based on a hybrid modulation-extraction mechanism provided by the present invention;

[0019] Figure 2 The invention provides a high-efficiency phase-locked relativistic klystron with positive and negative power flows in the front cavity and output cavity based on a hybrid modulation-extraction mechanism;

[0020] Figure 3 A schematic diagram of the electric field distribution in the front cavity-output cavity region of a high-efficiency phase-locked relativistic klystron based on a hybrid modulation-extraction mechanism provided by the present invention;

[0021] Figure 4 A schematic diagram of the variation of electron beam power and fundamental current in the front cavity-output cavity region of a high-efficiency phase-locked relativistic klystron based on a hybrid modulation-extraction mechanism provided by the present invention;

[0022] Figure 5 A schematic diagram of the power output of a 50kW injected high-efficiency phase-locked relativistic klystron based on a hybrid modulation-extraction mechanism provided by the present invention;

[0023] Figure 6 A schematic diagram of power output of a high-efficiency phase-locked relativistic klystron with 0kW injection based on a hybrid modulation-extraction mechanism provided by the present invention; DETAILED DESCRIPTION

[0024] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0025] Figure 1 The present invention provides a schematic structural diagram of a high-efficiency phase-locked relativistic klystron final front cavity-output cavity based on a hybrid modulation-extraction mechanism. The present invention consists of an anode cylinder 01, an inner conductor 02, a reflection cavity 03, a final front cavity 04, an extraction cavity, an electron beam collector 06, a conical waveguide 07, a feedback loop 08, and a microwave output port 09. The overall structure is rotationally symmetrical about the central axis.

[0026] Figure 2 The present invention provides a high-efficiency phase-locked relativistic klystron with positive and negative power flows in the final front cavity-output cavity region based on a hybrid modulation-extraction mechanism. It can be seen from the figure that at the position of the final front cavity 04, the positive power flow and the negative power flow are equivalent, indicating that there is energy coupling between the final front cavity 04 and the extraction cavity, that is, the modulation capability of the electron beam in the final front cavity 04 is enhanced, and the electron beam depth modulation under a short drift distance is achieved; and further modulation of the electron beam in the extraction cavity is achieved, and the modulation depth is further improved, which is conducive to overcoming the problem of difficulty in electron beam modulation in a compact relativistic klystron, and has important reference value for the design of a compact relativistic klystron.

[0027] Figure 3 A schematic diagram of the electric field distribution in the final front cavity-output cavity region of a high-efficiency phase-locked relativistic klystron based on a hybrid modulation-extraction mechanism provided by the present invention. It is not difficult to see from the figure that the electric fields of the final front cavity 04 and the first annular groove 05a are connected as a whole, which once again verifies the energy coupling between the two cavities; the working mode of the final front cavity 04 is the TM01 mode, and the working mode of the extraction cavity is the TM012 mode; in order to prevent radio frequency breakdown, the final front cavity 04 adopts a rectangular modulation cavity, and the sharp corners of the extraction cavity are chamfered.

[0028] Figure 4 The present invention provides a schematic diagram of the decrease in electron beam power and the increase in fundamental current in the final front cavity-output cavity region of a high-efficiency phase-locked relativistic klystron based on a hybrid modulation-extraction mechanism; from the figure, it is not difficult to find that when the electron beam reaches the final front cavity 04, the fundamental current rises rapidly, and increases by about 2.5kA at a distance within one wavelength, and the electron beam quickly clusters; in the extraction cavity, the electron beam exchanges its own energy with the microwave field, excites high-power microwaves, and the total energy of the electron beam decreases. At this time, the fundamental current continues to rise, indicating that the electron beam continues to be modulated in the extraction cavity, and the modulation depth of the electron beam is further improved.

[0029] Figure 5 A schematic diagram of the power output of a high-efficiency phase-locked relativistic klystron with 50kW injection based on a hybrid modulation-extraction mechanism provided by the present invention; under 50kW injection, the output power of the device is 1.38GW and the microwave output efficiency is 46%, overcoming the problem of low output efficiency of compact klystron devices.

[0030] Figure 6 The figure is a schematic diagram of the power output of a high-efficiency phase-locked relativistic klystron under 0kW injection based on a hybrid modulation-extraction mechanism provided by the present invention. Under 0kW injection, the output power of the device remains stable after 100ns, and is only about 80MW, which is much smaller than the output power of the device. It can be considered that the hybrid modulation-extraction working mechanism provided by the present invention will not cause self-oscillation of the device, thereby affecting the frequency-locked and phase-locked characteristics of the device.

[0031] When the present invention is in operation, by optimizing the distance L between the last front chamber 04 and the extraction chamber 6 , establish a positive feedback state between the final front cavity 04 and the extraction cavity; the modulated electron beam enters the final front cavity 04, and will excite the TM01 mode in the gap of the final front cavity 04, and its axial electric field will modulate the speed of the electron beam. The positive feedback mechanism will enhance the TM01 standing wave field in the final front cavity 04, the electron beam is rapidly modulated, and the fundamental current rises rapidly; after the modulated electron beam reaches the extraction cavity, it exchanges energy with the microwave field of the TM012 mode, exciting high-power microwaves, and the total energy of the electron beam decreases; at the same time, the electron beam will continue to be modulated by the extraction cavity, and through this mixed modulation-extraction mechanism, the working state of extraction and modulation is realized, further increasing the clustering depth of the electron beam and improving the beam-wave interaction efficiency of the device; finally, the excited high-power microwaves are transmitted to the antenna through the microwave output port 09, and fed into the free space by the antenna.

[0032] This embodiment realizes a coaxial relativistic klystron amplifier for X-band (central frequency is 10.0 GHz, corresponding to the working wavelength λ = 30.0 mm) with a front end cavity-output cavity region (the corresponding size is designed as: R 1 =40mm, R 2 =30mm, R 3 =48mm, R 4 =22mm, R 5 =44mm, R 6 =26.5mm, R 7 =46mm, R 8 =24mm, R 9 =46mm, R 10 =24.5mm, R 11 =38mm, R 12 =33mm, R 13 =30mm, R 14 =26mm, R 15 =20mm, L 1 =25mm, L 2 =10.5mm, L 3 =6mm, L 4 =7.5mm, L 5 =10.5mm, L 6 =16mm, L 7 =5mm, L 8 =3.5mm, L 9 =6mm, L 10 =25mm, L 11 =45mm, L 12 =18mm, L 13=20mm,L 14 =6mm,θ 1 =15°,θ 2 (=25°).

Claims

1. A high-efficiency phase-locked relativistic klystron based on a hybrid modulation-extraction mechanism, characterized by: It comprises an anode cylinder (01), an inner conductor (02), a reflection cavity (03), a final front cavity (04), an extraction cavity, an electron beam collector (06), a tapered waveguide (07), a feedback loop (08), and a microwave output port (09), and the overall structure is rotationally symmetrical about the central axis; The anode cylinder (01) is a thin-walled cylinder with an inner radius of R1, and the inner conductor (02) is a solid cylinder with a radius of R2, satisfying R2<R1; the reflection cavity (03) is a circular ring-shaped groove with an outer radius of R3, an inner radius of R4, and a width of L2, which is opened at a distance of L1 from the left end face of the inner conductor (02), satisfying R3>R1>R2>R4, the value of L1 is 0.8-1.2 times the working wavelength λ, and the value of L2 is 0.3-0.5 times the working wavelength λ; the reflection cavity (03) is used to suppress the leakage of TEM mode to the upstream of the device, and avoid self-excited oscillation and mode competition; at a distance of L3 from the right end face of the reflection cavity (03), a groove with an outer radius of R5, an inner radius of R6, and a cross section of "isosceles trapezoid" is opened on the inner and outer conductor walls. The annular groove satisfies R5>R1>R2>R6, the value of L3 is 0.1-0.3 times of the working wavelength λ, the lower base length of the "isosceles trapezoid" is L4, the upper base length is L5, the value of L4 is 0.2-0.5 times of the working wavelength λ, and the value of L5 is 0.25-0.6 times of the working wavelength λ; at a distance of L6 from the right end face of the front end cavity (04), a first annular groove (05a) with an outer radius of R7, an inner radius of R8, and a width of L7 is opened, satisfying R7>R1>R2>R8, the value of L6 is 0.4-0.8 times of the working wavelength λ, and the value of L7 is 0.1-0.3 times of the working wavelength; at a distance of L8 from the right end face of the first annular groove (05a), a first annular groove (05a) with an outer radius of R9, an inner radius of R10, and a width of L11 is opened. 10 , a second annular groove (05b) with a width of L9, satisfying R9>R1>R2>R 10 , L8 is 0.05-0.2 times of the working wavelength λ, L9 is 0.1-0.3 times of the working wavelength, the first annular groove (05a) and the second annular groove (05b) together form an extraction cavity; the electron beam collector (06) is a circular ring cavity with a right-angled trapezoidal cross section, and the upper base width L of the right-angled trapezoid is 10 , bottom width L 11 , outer radius R 11 , the inner radius is R 12 , satisfying R 11 <R1 and R 12 >R2,L 10 The value of L is 0.7-1.2 times of the working wavelength λ. 11 The value of is 1.0-1.5 times of the working wavelength λ, and the value of the tilt angle θ1 is 10°-30°; the tapered waveguide (07) is a circular ring cavity with a right-angle trapezoidal cross section, and the distance from the left end face L of the second circular ring groove (05b) ... 12 Department, L 12 The value of is 0.5-0.8 times of the working wavelength λ, and the length of the upper bottom side of the tapered waveguide (07) is (R 13 -R 10 ), the length of the lower base is (R 13 -R 15 ), height is L 13 , L 13 The value of is 0.5-0.7 times of the working wavelength λ, the hypotenuse forms an angle θ2 with the horizontal direction, and the value of θ2 is 10°-30°; the annular space between the anode tube (01) and the inner conductor (02) on the right side of the tapered waveguide (07) forms a microwave output port (09), and the outer radius of the microwave output port (09) is R 13 , the inner radius is R 15 ; The right side of the microwave output port (09) is connected to the antenna.

2. The high-efficiency phase-locked relativistic klystron based on the hybrid modulation-extraction mechanism according to claim 1, characterized in that: The final front cavity (04) works in the TM01 mode, which is used to further modulate the electron beam and improve the clustering depth of the electron beam; the extraction cavity works in the TM012 mode, which is used to convert the electron beam energy into microwave energy; at the same time, the extraction cavity will also re-modulate the electron beam, and through this mixed modulation-extraction mechanism, the effect of simultaneous extraction and modulation is achieved, further improving the clustering depth of the electron beam and improving the beam-wave interaction efficiency.

3. The high-efficiency phase-locked relativistic klystron based on the hybrid modulation-extraction mechanism according to claim 1, characterized in that: On the right side of the tapered waveguide (07) is a 13 , inner radius is R 14 , width is L 14 Feedback loop (08), R 13 Equal to R2, R 14 <R 13 , L 14 The value of is 0.1-0.2 times of the working wavelength λ, and the feedback loop (08) is a stainless steel metal ring used to adjust the Q value of the extraction cavity.

4. The high-efficiency phase-locked relativistic klystron based on the hybrid modulation-extraction mechanism according to claim 3, characterized in that: By adjusting the inner radius R of the feedback ring (08) 14 To adjust the Q value of the extraction cavity.

5. The high-efficiency phase-locked relativistic klystron based on a hybrid modulation-extraction mechanism according to any one of claims 1 to 4, characterized in that: The coaxial relativistic klystron amplifier used in X-band with a center frequency of 10.0 GHz and a corresponding working wavelength of λ = 30.0 mm has the following dimensions: R1 = 40 mm, R2 = 30 mm, R3 = 48 mm, R4 = 22 mm, R5 = 44 mm, R6 = 26.5 mm, R7 = 46 mm, R8 = 24 mm, R9 = 46 mm, R 10 =24.5mm, R 11 =38mm, R 12 =33mm, R 13 =30mm, R 14 =26mm, R 15 =20mm, L1=25mm, L2=10.5mm, L3=6mm, L4=7.5mm, L5=10.5mm, L6=18mm, L7=5mm, L8=3.5mm, L9=6mm, L 10 =25mm, L 11 =45mm, L 12 =18mm, L 13 =20mm, L 14 =6mm, θ1=15°, θ2=25°.

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