K-band TE11 mode microwave oscillator

Abstract

The invention relates to the technical field of forward wave oscillators, in particular to a K-band TE11 mode microwave oscillator. Comprising a cylindrical waveguide, and sequentially comprises a cut-off transition section, an interaction section and an output transition section, the cathode structure is mounted in the cut-off transition section; the anode waveguide structure comprises a plurality of slotted circular ring metamaterial units which are arranged in the interaction section at intervals in the axial direction, are linked through a metal cylinder to form a serial structure and are connected to the wall of the cylindrical waveguide to form a double-spiral anode slow wave structure; electron beams generated by the cathode structure rotate in the axial direction under the action of an external electromagnetic field, interact with each other in the anode slow wave structure to excite forward waves in a TE11 mode, and radiate outwards along an output transition section; the collector is arranged in the output transition section. On the basis of realizing a Gaussian beam TE11 mode, a traditional mode conversion structure is omitted, the structure is more compact, and light weight and miniaturization are easy to realize.

Description

Technical Field

[0001] This invention relates to the field of traveling wave oscillator technology, specifically to a K-band TE... 11 Mode microwave oscillator. Background Technology

[0002] The K-band ranges from 18 GHz to 27 GHz. K-band traveling wave oscillators, thanks to their high frequency and high resolution, can accurately identify and locate targets. They are widely used in satellite internet systems, radio astronomy observations, microwave radiation measurements, radar, and automotive applications based on satellite internet phased array terminals. In addition to basic collision avoidance functions, they can provide complex environmental perception for autonomous driving. Furthermore, their applications extend to medical imaging, industrial inspection, and weather radar.

[0003] However, most traditional K-band high-power microwave sources use overmode structures or multimode operation to improve their power conversion efficiency, resulting in large size. Furthermore, most operate at high current to achieve high output power, and most cannot directly radiate TE. 11 The device's operating mode needs to be converted to a different mode, requiring an additional mode converter. 11 Mode shift. Currently, high-power microwave sources require compactness and lightweight design for easy mobile deployment and integration. This necessitates the miniaturization of high-frequency high-power microwave devices, such as K-band devices, and their direct TE radiation. 11 The mode technology is quite challenging and is one of the bottlenecks in the current research on lightweight high-power microwave sources.

[0004] Currently, TE 11 Mode generation is typically achieved by incorporating mode-switching structures into high-power microwave devices. However, these structures are prone to breakdown and discharge under high power and strong electromagnetic field conditions. Furthermore, the mode-switching structures themselves increase the size and weight of high-power microwave devices, hindering their lightweight and miniaturization. Currently, lightweight and compact high-power microwave systems can be mounted on interceptor drones. These mobile platforms can actively seek out and approach target drones, activating electromagnetic sources within a range of tens of meters. Therefore, achieving lightweight and miniaturized high-power microwave systems for mobile deployment is a new trend in the development of high-power microwave sources. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a K-band TE 11 Mode microwave oscillator.

[0006] This invention utilizes slotted annular metamaterial units to construct a compact structure capable of directly radiating TE. 11 The double-helix slow-wave structure of the mode is proposed, and a traveling-wave oscillator based on this slow-wave structure is then proposed to realize direct radiation of TE in the K-band.11 The new design eliminates the need for traditional mode conversion structures and achieves a low operating magnetic field through optimized design, providing technical support for the compact and lightweight design of K-band high-power traveling wave oscillators.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows.

[0008] This invention provides a K-band TE 11 A mode microwave oscillator includes: a cylindrical waveguide with a hollow cavity, comprising a cutoff transition section, an interaction section, and an output transition section; a cathode structure installed within the cutoff transition section; and an anode waveguide structure comprising multiple slotted annular metamaterial units, which are axially spaced within the interaction section and connected in series via metal cylinders, forming a double-helix anode slow-wave structure. The cathode structure generates an electron beam that rotates axially under the influence of an applied electromagnetic field and interacts with the anode slow-wave structure to excite the generation of a Teflon. 11 The pattern is a traveling wave that radiates outward along the output gradient section; a collector electrode, disposed within the output gradient section, is used to collect electrons generated after the interaction.

[0009] This invention utilizes the ring cathode in the cathode structure to generate high-energy electrons under an applied voltage. Under the action of an axial guiding magnetic field, these electrons interact with the double-helix-shaped slow-wave anode structure formed by the slotted ring metamaterial unit. The electrons generated after the interaction are collected by the collecting electrode.

[0010] This invention utilizes the novel electromagnetic properties of slotted toroidal metamaterial units to construct a double-helix anodic slow-wave structure, achieving tuning of its dispersion relation; and releases electromagnetic energy into the desired Gaussian beam TE. 11 In this mode, the oscillation threshold current is reduced to approximately 950A, thereby enabling miniaturization of the high-frequency K-band relativistic traveling wave oscillator with an electron conversion efficiency of up to 20%. Compared to traditional high-frequency oscillators, the optimized design allows operation under a 0.25T magnetic field, reducing the weight of the external magnetic field system and eliminating the need for a traditional mode conversion structure. Therefore, it is structurally more compact and easier to achieve lightweight and miniaturization.

[0011] This invention achieves high-frequency and K-band dispersion relation modulation through arrangement and combination within a cylindrical waveguide, constructing a double-helix anodic slow-wave structure, thereby releasing electromagnetic energy at the expected TE range. 11 In the working mode, and TE 11 The mode operates below the cutoff frequency.

[0012] Preferably, the K-band TE 11The mode microwave oscillator generates high-power microwaves with an operating frequency of 25.36 GHz and an output power of 118 MW under the following conditions: an applied electromagnetic field of 0.25 T, a voltage of 540 kV between the cathode structure and the anode waveguide structure, and an electron beam current of 1.09 kA.

[0013] Preferably, the width of the slotted annular metamaterial unit is 1.2 mm; the period of the slotted annular metamaterial unit in the anode slow wave structure is 2 mm.

[0014] Preferably, the slotted annular metamaterial unit has a slot, and the angle between the slot and the radial direction is 50°, and the depth of the slot is 200°.

[0015] Preferably, the slotted annular metamaterial unit has a stepped side groove, a third groove, a second groove, and a first groove sequentially formed along the radial direction; the width of the third groove is greater than the width of the second groove, and the width of the second groove is greater than the width of the first groove; the stepped side groove includes a first side groove, a second side groove, and a third side groove sequentially along the radial direction, and the widths decrease sequentially; the width of the second side groove is less than the width of the second groove; and the width of the first side groove is less than the width of the first groove.

[0016] This invention utilizes a slotted metamaterial unit sequence to realize the anode slow-wave structure of a K-band relativistic traveling-wave oscillator, which is used to manipulate the release of electromagnetic wave energy in a Gaussian beam TE. 11 In the radiation mode, by designing and arranging the anode functional material structural units in the relativistic traveling-front oscillator, and sequentially constructing the slotted circular ring metamaterial units, a double-helix slow-wave structure is formed, realizing the miniaturization of the K-band relativistic traveling-front oscillator and its operation at TE. 11 Radiation mode.

[0017] Preferably, the outer radius of the first groove is 2.3 mm and the inner radius of the first groove is 1.77 mm; the outer radius of the third groove is 1.68 mm and the inner radius of the third groove is 1.4 mm; the outer radius of the second side groove is 1.4 mm and the inner radius of the second side groove is 1.2 mm.

[0018] Preferably, the axial length of the cutoff transition section is 4 mm, the axial length of the interaction section is 16 mm, the axial length of the output transition section is 6.8 mm, and the axial length of the collecting electrode is 3.8 mm.

[0019] Preferably, the cathode structure includes a support plate, an annular cathode, and a cathode emitter, which are connected sequentially along the axial direction; the axial length of the support plate is 0.5 mm, the axial length of the annular cathode is 3 mm, and the length of the cathode emitter is 0.8 mm.

[0020] Preferably, the cutoff gradient section is used to cut off the low-frequency return wave generated within the cylindrical waveguide. The cutoff gradient section of this invention is primarily used to cut off the low-frequency return wave generated within the cylindrical waveguide, preventing it from oscillating within the cylindrical waveguide.

[0021] The beneficial effects of this invention are: 1. This invention utilizes a ring cathode in a cathode structure to generate high-energy electrons under an applied voltage. These electrons interact with a double-helix-shaped slow-wave anode structure formed by a slotted ring metamaterial unit under the influence of an axial guiding magnetic field. The electrons generated after the interaction are collected by a collecting electrode. The novel electromagnetic properties of the slotted ring metamaterial unit are used to construct the double-helix-shaped slow-wave anode structure, achieving tuning of its dispersion relation; electromagnetic energy is released into the desired Gaussian beam TE. 11 In this mode, the oscillation threshold current is reduced to approximately 950A, thereby enabling miniaturization of the high-frequency K-band relativistic traveling wave oscillator with an electron conversion efficiency of up to 20%. Compared to traditional high-frequency oscillators, the optimized design allows operation under a 0.25T magnetic field, reducing the weight of the external magnetic field system and eliminating the need for a traditional mode conversion structure. Therefore, the design is more compact and easier to achieve in terms of weight reduction and miniaturization.

[0022] 2. This invention provides technical support for the compact and lightweight design of K-band high-power traveling wave oscillators by arranging and combining components within a cylindrical waveguide and optimizing the design to achieve a low operating magnetic field. Attached Figure Description

[0023] Figure 1 This invention relates to the K-band TE under loading of a slotted circular ring metamaterial unit. 11 A schematic diagram of the structure of a mode microwave oscillator. Wherein, (a) is the K-band TE... 11 (a) is a schematic diagram of the structure of the mode microwave oscillator; (b) is the dimensioning of (a).

[0024] Figure 2 The traveling wave employs an arrangement of eight slotted circular metamaterial units in a cylindrical waveguide.

[0025] Figure 3 This is a structural schematic diagram of a slotted circular ring metamaterial unit. Among them, (a) is an axial cross-sectional view of the slotted circular ring metamaterial unit; (b) is the dimensioning of (a); and (c) is a radial cross-sectional view of the slotted circular ring metamaterial unit.

[0026] Figure 4 These are the electromagnetic property curves of a slotted toroidal metamaterial unit. Among them, (a) represents the relationship between the equivalent permittivity and frequency, and (b) represents the relationship between the equivalent permeability and frequency.

[0027] Figure 5The graphs show the dispersion relations of a traveling wave in a cylindrical waveguide with eight slotted circular metamaterial units. (a) represents the low-order intrinsic mode TE. 11 and TM 01 (a) Phase variation curve; (b) Low-order intrinsic mode TE at operating frequency 25.36GHz. 11 and TM 01 Enlarged view of a local area as the phase changes.

[0028] Figure 6 These are high-energy electrons generated on the ring cathode.

[0029] Figure 7 It is the movement of electrons emitted by the ring cathode under the influence of the axial guiding magnetic field.

[0030] Figure 8 The radiation TE in a traveling wave oscillator under loading of a slotted circular ring metamaterial unit. 11 Model electric field distribution diagram.

[0031] Figure 9 This is a schematic diagram of the electron spokes in the staggered slow-wave sequence structure of a slotted ring metamaterial unit. Among them, (a) is a schematic diagram of the electron spokes on the inner side of the slotted ring metamaterial unit; (b) is a schematic diagram of the electron spokes on the outer side of the slotted ring metamaterial unit.

[0032] Figure 10 These are schematic diagrams showing the axial distribution of high-energy electrons at different times in a slotted circular ring metamaterial unit. Among them, (a) is a schematic diagram of the axial distribution at t=1.75ns; (b) is a schematic diagram of the axial distribution at t=75.3ns; and (c) is a schematic diagram of the axial distribution at t=381.95ns.

[0033] Figure 11 The optimized TE is when the voltage is 540kV and the magnetic field is 0.25T. 11 The mode is defined as follows: (a) operating electric field; (b) output power 118 MW; (c) operating frequency 25.36 GHz; and (d) electron beam current 1.19 kA.

[0034] Figure 12 yes Figure 11 When the device output power is 118MW, the electric field distribution inside the device is shown.

[0035] Figure 13 When the voltage is U = 540kV and the magnetic field is 0.25T, TE 11 A schematic diagram showing how the output power and electron conversion efficiency change with current.

[0036] Figure 14 When the current is I = 1.15 kA and the magnetic field is 0.25 T, TE 11Schematic diagram showing the variation of output power and electronic conversion efficiency with voltage.

[0037] Explanation of reference numerals in the attached figures: 1. Cylindrical waveguide; 11. Cutoff transition section; 12. Interaction section; 13. Output transition section; 2. Cathode structure; 21. Support plate; 22. Ring cathode; 23. Cathode emitter; 3. Anode waveguide structure; 31. Slotted annular metamaterial unit; 311. First slot; 312. Second slot; 313. Third slot; 314. Stepped side slot; 4. Collector electrode. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0039] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Prior Art 1: Physics of Plasma 26(10):103301 (2019) DOI:org / 10.1063 / 1.5097319. Prior Art 1 proposes a "crab-type" twelve-cavity relativistic magnetron to realize high-power S-band TE 11 Pattern radiation is less efficient.

[0041] Prior Art 2: IEEE TPS 52 (2), pp. 285-290, DOI: 10.1109 / TPS.2024.3369932. Prior Art 2 proposes an S-band compact magnetron radiating TE 11 The mode, TEM-TE, is achieved by inserting a mode converter within the relativistic magnetron cavity. 11 Mode conversion. However, prior art 2 requires the addition of a mode converter to achieve TE. 11 The modes are generated, but they are all limited to the low-frequency band and the S-band.

[0042] Existing technology 3: Yu Zhuang, Ju Jinchuan and Zhang Wei et al. Research on K-band coaxial transit time oscillator [J]. Modern Applied Physics, 2023, 14(4): 133-139. The transit time oscillator proposed in Existing Technology 3 operates at 18.55 GHz and has an output power of about 2.2 GW. However, it has a high operating magnetic field of 0.74 T, a high current of 10 kA, and operates in TM mode. 012 Pattern, not TE 11 model.

[0043] TE 11 The mode possesses advantages such as narrow beamforming, low sidelobes, and directional radiation characteristics. This invention utilizes slotted toroidal metamaterial units to construct a compact, directly radiating TE beam. 11 The double-helix slow-wave structure of the mode is proposed, and a traveling-wave oscillator based on this slow-wave structure is then proposed to realize direct radiation of TE in the K-band. 11 The new design eliminates the need for traditional mode conversion structures and achieves a low operating magnetic field through optimized design, providing technical support for the compact and lightweight design of K-band high-power traveling wave oscillators.

[0044] This invention proposes a compact K-band TE based on slotted toroidal metamaterials. 11 The mode microwave oscillator device utilizes the novel electromagnetic properties of slotted toroidal metamaterial units to construct a double-helix anodic slow-wave structure, achieving tuning of its dispersion relation and releasing electromagnetic energy into the expected Gaussian beam TE. 11 In this mode, the oscillation threshold current is reduced to approximately 950A, thereby enabling the miniaturization of the high-frequency K-band relativistic traveling wave oscillator, with an electron conversion efficiency of up to 20%. Furthermore, compared to traditional high-frequency oscillators, the optimized design allows it to operate under a 0.25T magnetic field, reducing the weight of the external magnetic field system.

[0045] This invention utilizes a ring cathode to generate high-energy electrons under an applied voltage. These electrons then interact with a slotted ring metamaterial slow-wave structure under the influence of an axial guiding magnetic field. The resulting electrons are collected by a collecting electrode. Therefore, the structure is more compact, making it easier to achieve lightweight and miniaturization.

[0046] The technical solution of the present invention will be further described below through specific embodiments.

[0047] In the following embodiments, unless otherwise specified, the methods described are conventional methods; and unless otherwise specified, the reagents and materials described are commercially available.

[0048] like Figures 1 to 3 A K-band TE 11 The mode microwave oscillator includes a cylindrical waveguide 1, a cathode structure 2, an anode waveguide structure 3, and a collector electrode 4.

[0049] like Figure 1The cylindrical waveguide 1 has a hollow cavity and sequentially includes a cutoff transition section 11, an interaction section 12, and an output transition section 13. The microwave oscillator mainly comprises three parts: the first part is the cutoff transition section 11, used to cut off the low-frequency return wave generated within the cylindrical waveguide 1. Specifically, the cutoff transition section 11 blocks the low-frequency return wave, preventing it from oscillating within the cavity of the cylindrical waveguide 1; the second part is the interaction section 12, in which slotted annular metamaterial units 31 are installed to control the dispersion relation and enhance beam-wave interaction, manipulating the directional radiation of electromagnetic energy to the TE. 11 The third part is the output gradient section 13, which causes the electromagnetic energy to be in TE... 11 The pattern radiates outwards. Output gradient segment 13 is shaped like an output horn.

[0050] like Figure 1 The cathode structure 2 is installed within the cutoff transition section 11. The cathode structure 2 includes a support plate 21, an annular cathode 22, and a cathode emitter 23 connected sequentially along the axial direction. Here, the annular cathode 22 is used to generate high-energy electrons, which rotate as a whole along the axial direction under the action of an external electromagnetic field, and the electrons that have completed energy transfer are finally collected by the collecting electrode 4.

[0051] The anode waveguide structure 3 includes multiple slotted annular metamaterial units 31. These slotted annular metamaterial units 31 are arranged axially at intervals within the interaction section 12 and linked in series by metal cylinders. They are then connected to the wall of the cylindrical waveguide 1, forming a double-helix anode slow-wave structure. The cathode structure 2 generates an electron beam that rotates axially under the influence of an external electromagnetic field and interacts with the anode slow-wave structure to excite the generation of TE waves. 11 The pattern travels forward and radiates outward along the output gradient section 13. Specifically, in the microwave oscillator, slotted annular metamaterial units 31 are arranged inside the cylindrical waveguide 1, with a certain interval between the units. The units are connected by a metal cylinder to form a serial structure, and finally suspended on the wall of the cylindrical waveguide 1 by a metal rod. The cylindrical waveguide 1 has a hollow cavity in the middle, and a cathode structure 2 is placed in the cavity at one end. The cathode structure 2 is equipped with an annular cathode 22 on a cylindrical support plate 21. The external voltage is applied through the anode waveguide structure 3 and the annular cathode 22 column.

[0052] The collecting electrode 4 is configured within the output gradient section 13 to collect electrons generated after the interaction.

[0053] In this embodiment of the invention, high-energy electrons are generated by the annular cathode 22 in the cathode structure 2 under an applied voltage. These electrons interact with the double-helix-shaped slow-wave anode structure formed by the slotted annular metamaterial unit 31 under the influence of an axial guiding magnetic field. The electrons generated after the interaction are collected by the collecting electrode 4. Specifically, the novel electromagnetic properties of the slotted annular metamaterial unit 31 are used to construct the double-helix-shaped slow-wave anode structure, achieving tuning of its dispersion relation; electromagnetic energy is released into the expected Gaussian beam TE. 11 In this mode, the oscillation threshold current is reduced to approximately 950A, thereby enabling miniaturization of the high-frequency K-band relativistic traveling wave oscillator with an electron conversion efficiency of up to 20%. Compared to traditional high-frequency oscillators, the optimized design allows operation under a 0.25T magnetic field, reducing the weight of the external magnetic field system and eliminating the need for a traditional mode conversion structure. Therefore, it is structurally more compact and easier to achieve lightweight and miniaturization.

[0054] like Figure 2 The embodiments of the present invention achieve high-frequency and K-band dispersion relation modulation by arranging and combining elements within a cylindrical waveguide 1, constructing an anode slow-wave structure with a double-helix shape, thereby releasing electromagnetic energy at the expected TE. 11 In the working mode, and TE 11 The mode operates below the cutoff frequency.

[0055] Based on the above technical solutions, such as Figure 1 and Figure 3 The width of the slotted annular metamaterial unit 31 is 1.2 mm; the period of the slotted annular metamaterial unit 31 in the anode slow wave structure is 2 mm. Based on the above technical solution, the slotted annular metamaterial unit 31 has a slot, and the included angle of the slot with respect to the radial direction is 50°, and the depth of the slot is 200°.

[0056] Based on the above technical solutions, such as Figure 3 The slotted annular metamaterial unit 31 is provided with stepped side grooves 314, a third groove 313, a second groove 312, and a first groove 311 in a radial direction. The width of the third groove 313 is greater than the width of the second groove 312, and the width of the second groove 312 is greater than the width of the first groove 311. The stepped side groove 314 includes a first side groove, a second side groove, and a third side groove in a radial direction, and the widths decrease sequentially. The width of the second side groove is less than the width of the second groove 312. The width of the first side groove is less than the width of the first groove 311.

[0057] This invention utilizes slotted annular metamaterial unit 31 to sequentially construct the anode slow-wave structure of a K-band relativistic traveling-wave oscillator, which is used to manipulate the release of electromagnetic wave energy in the Gaussian beam TE. 11In the radiation mode, by designing and arranging the anode functional material structural units in the relativistic traveling wave oscillator, such as... Figure 2 The slotted annular metamaterial unit 31 is arranged to form a double-helix slow-wave structure, realizing the miniaturization of the K-band relativistic traveling-wave oscillator and its operation in the TE band. 11 Radiation mode.

[0058] Based on the above technical solution, the outer radius of the first groove 311 is 2.3mm, and the inner radius of the first groove 311 is 1.77mm; the outer radius of the third groove 313 is 1.68mm, and the inner radius of the third groove 313 is 1.4mm; the outer radius of the second side groove is 1.4mm, and the inner radius of the second side groove is 1.2mm.

[0059] Based on the above technical solution, the axial length of the cutoff transition section 11 is 4mm, the axial length of the interaction section 12 is 16mm, the axial length of the output transition section 13 is 6.8mm, and the axial length of the collecting electrode 4 is 3.8mm.

[0060] Based on the above technical solution, the cathode structure 2 includes a support plate 21, an annular cathode 22 and a cathode emitter 23, which are connected sequentially along the axial direction; the axial length of the support plate 21 is 0.5 mm, the axial length of the annular cathode 22 is 3 mm, and the length of the cathode emitter 23 is 0.8 mm.

[0061] This invention utilizes the novel electromagnetic response characteristics of slotted toroidal metamaterial unit 31, which reduces the operating magnetic field and oscillation threshold current compared to traditional K-band oscillators, thus improving the compactness of the traveling-forward oscillator structure. Through further optimization of the slotted toroidal metamaterial unit 31 and its structure, as well as the optimized arrangement of its ordered structure, particle simulations confirmed that the electron conversion efficiency can reach 20% at 25.36 GHz. This enables a miniaturized device for high-frequency traveling-forward oscillators.

[0062] The present invention proposes to utilize slotted circular ring metamaterial units 31, and through the design of the geometric structure and arrangement of the slotted circular ring metamaterial units 31, to achieve the adjustment and optimization of the equivalent dielectric parameters in the traveling-forward oscillator tube, ultimately realizing the TE in the relativistic traveling-forward oscillator. 11 The activation mode of the pattern and its energy release.

[0063] When high-energy electrons emitted from cathode structure 2 enter the beam-wave interaction region in the traveling wave, they interact with the slow-wave structure of the slotted annular metamaterial unit 31. When the periodicity of the anode slow-wave structure changes, the electromagnetic characteristic parameters of the anode waveguide structure 3 will change. The scattering of high-energy moving electrons generated by the double-cyclotron slow-wave structure formed by the slotted annular metamaterial unit 31 will change, thereby altering the distribution of the operating mode in the traveling wave. Therefore, by optimizing and designing the slow-wave periodic structure, TE can be achieved. 11 The mode is excited. Furthermore, by optimizing the design of the anode slow-wave structure sequence, the beam-wave interaction efficiency can be improved, achieving a power of up to 118MW. The optimized TE in this embodiment of the invention... 11 The efficiency of this model can reach 20%.

[0064] In summary, the compact K-band TE based on slotted annular metamaterials proposed in this invention has achieved significant results. 11 The mode microwave oscillator device utilizes the novel electromagnetic properties of slotted toroidal metamaterial unit 31 to construct a double-helix shaped anode slow-wave structure, achieving tuning of its dispersion relation and releasing electromagnetic energy into the expected Gaussian beam TE. 11 In this mode, the oscillation threshold current is reduced to approximately 950A, thereby enabling the miniaturization of the high-frequency K-band relativistic traveling wave oscillator, with an electron conversion efficiency of up to 20%. Furthermore, compared to traditional high-frequency oscillators, the optimized design allows it to operate under a 0.25T magnetic field, reducing the weight of the external magnetic field system.

[0065] Figure 1 The K-band TE under loading of the slotted annular metamaterial unit 31 shown. 11 The parameters corresponding to the structural design diagram of the mode microwave oscillator are shown in Table 1.

[0066] Table 1 K-band TE 11 Parameters of mode microwave oscillator in, Figure 1 and in Table 1, R WG This represents the outer radius of the cylindrical waveguide with the loaded anode slow-wave structure; R IG This represents the inner radius of the cylindrical waveguide with the loaded anode slow-wave structure; R N1 Indicates the inner radius of the cylindrical waveguide on which the annular cathode is mounted; R A This indicates the outer radius of the cylindrical waveguide connected to the anode and fitted with a ring cathode; R B This represents the inner radius of the cylindrical waveguide that connects to the anode and is fitted with the cathode. RC Indicates the outer radius of the annular cathode; R IN Indicates the inner radius of the annular cathode; R H1 This represents the radius of the contact point between the output horn and the outer side of the cylindrical waveguide with the loaded slow-wave structure. R H2 This indicates the radius of the contact point between the output gradient section and the inner side of the cylindrical waveguide with the anode slow wave structure. R H3 Indicates the outer radius of the output gradient segment interface cylindrical waveguide; R CO This represents the outer radius of the cylindrical waveguide used as the collector electrode; L CO Indicates the axial length of the cylindrical waveguide used as the collector electrode; L A This indicates the total length of the cathode emitter, ring cathode, and support plate; L B This indicates the axial length of the cylindrical waveguide on which the annular cathode is mounted. L XA This indicates the axial length of the support plate on one side of the annular cathode; L XB Indicates the axial length of the annular cathode; L XC Indicates the axial length of the cathode emitter; L WG The axial length of the cylindrical waveguide with an anode slow-wave structure incorporating slotted annular metamaterial units is indicated. L H This indicates the vertical length of the output gradient segment; L O This indicates the longitudinal length of the external cylindrical waveguide of the output gradient segment; D H This indicates the axial length of the connection between the cylindrical waveguide with the anode slow-wave structure and the output tapered antenna.

[0067] The traveling wave employs an arrangement of eight slotted circular metamaterial units within a cylindrical waveguide, such as... Figure 2 As shown. Figure 2 middle, P This represents the period of the slotted annular metamaterial unit in the anodic slow-wave structure; This indicates the angle between the slot and the radial direction (vertical direction) in the arrangement of slotted annular metamaterial units; L WG The axial direction of the cylindrical waveguide with a loaded anode slow wave structure is indicated. Length.

[0068] A schematic diagram of the structure of a slotted circular ring metamaterial unit, as shown below. Figure 3 As shown.Figure 3 The parameters corresponding to the structural design diagram of the slotted annular metamaterial unit shown in the figure are shown in Table 2.

[0069] Table 2 Parameters of slotted annular metamaterial units Figure 3 And in Table 2, L 1 This indicates the width or axial length of the slotted annular metamaterial unit; L 2 Indicates the width of the first slot in the unit; L 3 This indicates the remaining length of the second slot in the unit; L 4 This indicates the remaining width after the cell is hollowed out; L 5 Indicates the width of the second side slot of the unit; L 6 This indicates the remaining width after the two sides of the unit have been hollowed out; R 1 This represents the outer radius of the slotted annular metamaterial unit; R 2 This represents the inner radius of the first groove in the slotted annular metamaterial unit; R 3 This represents the radius of the second groove in the slotted annular metamaterial unit; R 4 This represents the outer radius of the third groove in the slotted annular metamaterial unit; R 5 This represents the inner radius of the third groove in the slotted annular metamaterial unit; R 6 This represents the outer radius of the second side groove in the slotted annular metamaterial unit; R 7 This represents the inner radius of the second side groove in the slotted annular metamaterial unit.

[0070] The electromagnetic property curves of the slotted toroidal metamaterial unit are shown below. Figure 4 As shown. The real parts of the equivalent permittivity and the equivalent permeability are both positive, and the TE is adjusted... 11 The mode propagates forward in this slow-wave structure.

[0071] The forward wave employs the dispersion relation curve of eight slotted circular ring metamaterial units loaded in a cylindrical waveguide, as shown in the figure. Figure 5 As shown. Wherein, TE 11 The slope of the mode dispersion curve (where group velocity and phase velocity propagate in the same direction) is positive.

[0072] High-energy electrons generated on the ring cathode, such as Figure 6As shown in the diagram, high-energy electrons are emitted from the cathode and enter the interaction region, releasing their kinetic energy into electromagnetic waves.

[0073] Electrons emitted from a ring cathode move under the influence of an axial guiding magnetic field, such as Figure 7 As shown in the diagram, electrons emitted from the ring cathode undergo axial rotation, generating electron clusters that release their kinetic energy into electromagnetic waves, thus achieving the desired electromagnetic wave emission (TE). 11 Mode field amplification and enhancement.

[0074] Radiation TE in a traveling wave oscillator under loading of a slotted toroidal metamaterial unit 11 Model electric field distribution diagram, such as Figure 8 As shown. Schematic diagram of electron spokes in the staggered slow-wave sequence structure of a slotted annular metamaterial unit, as shown. Figure 9 As shown in the figure. A schematic diagram of the axial distribution of high-energy electrons at different times in a forward traveling wave oscillator based on a slotted toroidal metamaterial unit sequence. Figure 10 As shown.

[0075] Based on the above technical solution, the K-band TE 11 The mode microwave oscillator, under an applied electromagnetic field of 0.25T, a voltage of 540kV between the cathode structure and the anode waveguide structure, and an electron beam current of 1.09kA, generates high-power microwaves with an operating frequency of 25.36GHz and an output power of 118MW. Figure 11 .exist Figure 11 When the output power of the device is 118MW, the electric field distribution inside the device is as follows: Figure 12 As shown. Figure 12 The relationship between the maximum allowable surface electric field and operating frequency for estimating the "lower breakdown probability" under vacuum conditions in accelerators and high-power RF cavities is given in the following:

[0076] f(MHz) = 1.63E 2 exp(-8.5 / E); where f represents the operating frequency; E represents the maximum surface electric field. This corresponds to a frequency of 26.35 GHz in the embodiment of the present invention, and the estimated maximum electric field is 1.2892 MV / cm, which is greater than... Figure 12 The maximum electric field value is at this frequency. Therefore, the power output described in this embodiment of the invention will not be at this operating frequency, and the device will not be damaged.

[0077] When the voltage is U = 540 kV and the magnetic field is 0.25 T, TE 11 A schematic diagram showing the variation of output power and electron conversion efficiency with current, as shown below. Figure 13 When the voltage is constant, the output power and conversion efficiency cannot reach their maximum values ​​simultaneously.

[0078] When the current is I = 1.03 kA and the magnetic field is 0.25 T, TE 11 A schematic diagram showing the variation of output power and electronic conversion efficiency with voltage, as shown below. Figure 14 As shown, the output power and conversion efficiency increase synchronously with the voltage within a given range.

[0079] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A K-band TE 11 A mode microwave oscillator, characterized in that, include: A cylindrical waveguide with a hollow cavity, comprising, in sequence, a cutoff transition section, an interaction section, and an output transition section; A cathode structure is installed within the cutoff gradient section; The anode waveguide structure includes multiple slotted annular metamaterial units, which are spaced apart axially within the interaction section and linked in series by metal cylinders. These units are then connected to the wall of the cylindrical waveguide, forming a double-helix anode slow-wave structure. The cathode structure generates an electron beam that rotates axially under an applied electromagnetic field and interacts with the anode slow-wave structure to excite the generation of electron beams (TE). 11 The pattern's traveling wave radiates outwards along the output gradient segment; The collecting electrode, located within the output gradient section, is used to collect electrons generated after the interaction.

2. The K-band TE according to claim 1 11 A mode microwave oscillator, characterized in that, The K-band TE 11 The mode microwave oscillator generates high-power microwaves with an operating frequency of 25.36 GHz and an output power of 118 MW under the following conditions: an applied electromagnetic field of 0.25 T, a voltage of 540 kV between the cathode structure and the anode waveguide structure, and an electron beam current of 1.09 kA.

3. The K-band TE according to claim 1 11 A mode microwave oscillator, characterized in that, The width of the slotted annular metamaterial unit is 1.2 mm; the period of the slotted annular metamaterial unit in the anodic slow wave structure is 2 mm.

4. The K-band TE according to claim 1 11 A mode microwave oscillator, characterized in that, The slotted annular metamaterial unit has a slot, and the angle between the slot and the radial direction is 50°, and the depth of the slot is 200°.

5. The K-band TE according to claim 1 11 A mode microwave oscillator, characterized in that, The slotted annular metamaterial unit has stepped side grooves, a third groove, a second groove, and a first groove sequentially formed along the radial direction; the width of the third groove is greater than the width of the second groove, and the width of the second groove is greater than the width of the first groove. The stepped side groove includes a first side groove, a second side groove, and a third side groove in the radial direction, with the width decreasing sequentially; the width of the second side groove is less than the width of the second groove; the width of the first side groove is less than the width of the first groove.

6. The K-band TE according to claim 5 11 A mode microwave oscillator, characterized in that, The outer radius of the first groove is 2.3 mm, and the inner radius of the first groove is 1.77 mm; the outer radius of the third groove is 1.68 mm, and the inner radius of the third groove is 1.4 mm. The outer radius of the second side groove is 1.4 mm, and the inner radius of the second side groove is 1.2 mm.

7. The K-band TE according to claim 1 11 A mode microwave oscillator, characterized in that, The axial length of the cutoff transition section is 4 mm, the axial length of the interaction section is 16 mm, the axial length of the output transition section is 6.8 mm, and the axial length of the collecting electrode is 3.8 mm.

8. The K-band TE according to claim 1 11 A mode microwave oscillator, characterized in that, The cathode structure includes a support plate, an annular cathode, and a cathode emitter, which are connected sequentially along the axial direction; the axial length of the support plate is 0.5 mm, the axial length of the annular cathode is 3 mm, and the length of the cathode emitter is 0.8 mm.

9. The K-band TE according to claim 1 11 A mode microwave oscillator, characterized in that, The cutoff gradient section is used to cut off the low-frequency return wave generated within the cylindrical waveguide.

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