Vacuum electronic device

Abstract

The invention provides a vacuum electronic device. The vacuum electronic device is an extended interaction klystron amplifier with a planar extended interaction resonant cavity as a transduction structure, wherein the planar extended interaction resonant cavity is composed of two groups of symmetrical planar circuits. The amplifier combines the advantages of a klystron and a traveling wave tube transduction structure, and has the characteristics of stability (unidirectivity), planarization and miniaturization under the condition of small and medium power.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and more particularly, to a vacuum electronic device. Background Art

[0002] As a core device of electronic systems such as radars and communications, vacuum electronic devices (e.g., traveling wave tubes, klystrons, backward wave tubes, gyrotrons, etc.) applied in microwave, millimeter wave, and terahertz frequency bands are currently developing towards miniaturization and integration.

[0003] Among them, as a power amplifier, the klystron has the advantages of high power, high efficiency, high stability, and long life, and has important applications in high-power millimeter wave radars, long-range high-speed wireless communications, millimeter wave electronic countermeasures, national security, controlled nuclear fusion, and industrial applications.

[0004] In recent years, with the development of large-scale scientific experimental devices and microwave electronic systems, higher requirements have been put forward for the performance of millimeter wave devices. The extended interaction klystron (EIK) combines the advantages of coupled cavity traveling wave tubes and traditional klystrons. Based on resonant cavities, in the resonant cavities, the electron beam can effectively interact with the structural wave, and at the same time, the modulation of the electron beam can be carried out on the cavity chain, enabling the device to obtain a wider operating frequency band and higher interaction efficiency.

[0005] How to miniaturize the extended interaction klystron, improve stability, and achieve mass production is an urgent problem to be solved. Summary of the Invention

[0006] This application provides a vacuum electronic device, an extended interaction klystron amplifier using a planarized extended interaction resonant cavity as an energy conversion structure. This amplifier combines the respective advantages of the klystron and the traveling wave tube energy conversion structures, and has the characteristics of stability (unidirectionality), planarization, and miniaturization in the face of medium and low power.

[0007] In a first aspect, a vacuum electronic device is provided, characterized in that it includes an input resonant unit and an output resonant unit. The input resonant unit is connected to an input device, the output resonant unit is connected to an output device, and the input resonant unit and the output resonant unit are connected through a drift section. Among them, in the input resonant unit and the output resonant unit, two sets of planar circuit structures that are symmetrical to each other are provided. The gap between the two sets of planar circuits forms a vacuum electron beam channel. The two sets of planar circuits constitute an interaction circuit. The interaction circuit is used to convert the energy of the electron beam in the electron beam channel into the energy of electromagnetic waves and interact with the electric field in the interaction to form an energy exchange. The electron beam channel is connected to the drift section.

[0008] In this application, an interaction circuit is formed by two sets of symmetric planar circuits for the energy exchange between the electron beam and the input signal. The resonant units constructed by the two sets of planar circuits achieve a planar structure point, which is beneficial to the miniaturization of the device. At the same time, due to the structural characteristics of the planar structure, it is beneficial to mass production. For example, it can be obtained by laser cutting metal sheets. In addition, the input / output structure and the planar extended interaction resonant cavity structure can be manufactured using the same materials and the same type of process, which is convenient for integrated production. Further, for the amplifier with the planar extended interaction resonant cavity structure in this application, due to the structural characteristics of the input cavity, output cavity, and drift section, it naturally overcomes the reflection oscillation or electromagnetic wave backward wave transmission phenomenon, has stable amplification characteristics, and improves the amplification gain. At the same time, due to the planar structural characteristics, the resonant cavity has the advantages of small volume, easy processing, and high power, and has application potential in the generation and amplification of terahertz sources.

[0009] Combined with the first aspect, in some implementation manners of the first aspect, the vacuum electronic device further includes: N intermediate resonant units, the N intermediate resonant units are located between the input resonant unit and the output resonant unit, the input resonant unit, the N intermediate resonant units, and the output resonant unit are connected through a drift section, and the two sets of symmetric planar circuit structures and the vacuum electron beam channel are arranged in the N intermediate resonant units, where N is a positive integer greater than or equal to 1.

[0010] In this technical solution, by expanding one or more intermediate resonant units, the bandwidth can be expanded and the energy conversion gain can be improved. In practical applications, the number of intermediate resonant units can be designed based on the performance requirements of the amplifier.

[0011] Combined with the first aspect, in some implementation manners of the first aspect, each set of planar circuits in the two sets of planar circuits includes a grid-shaped structure in which a plurality of metal microstrips and a plurality of vacuum gaps are periodically arranged.

[0012] In this application, the grid-shaped structure on the planar circuit is used for the energy generated by the interaction with electrons to be coupled over a long distance. It can be understood that in the cavity of the extended interaction resonant cavity, different electric fields are usually formed through multiple gaps to construct an interaction circuit. In this application, an interaction circuit is constructed by forming an electric field through a grid-shaped circuit.

[0013] In this application, the number of metal microstrips and vacuum gaps in the grid-shaped structure is not limited.

[0014] In combination with the first aspect, in some implementations of the first aspect, in the input device and the output resonant device, an input coupler and an output coupler are respectively provided. The input coupler is connected to an input waveguide, the output coupler is connected to an output waveguide, and the input waveguide or the output waveguide is connected to the grating structure of the planar circuit.

[0015] In combination with the first aspect, in some implementations of the first aspect, the two planar circuits are respectively disposed on the bottom surface and the top surface of two mutually symmetric dielectric substrates.

[0016] In combination with the first aspect, in some implementations of the first aspect, the number of resonant gaps in the input resonant unit, the N intermediate resonant units, and the output resonant unit is M, where M is an odd number.

[0017] In combination with the first aspect, in some implementations of the first aspect, the vacuum electronic device is used to generate or amplify signals.

[0018] For an extended interaction resonant cavity, theoretically it has an infinite number of operating modes. Different operating modes correspond to different operating voltages and interaction efficiencies. Different devices can be realized according to different operating modes. For example, it can include an oscillator and an amplifier.

[0019] In combination with the first aspect, in some implementations of the first aspect, the input resonant unit, the N intermediate resonant units, and the output resonant unit operate in the standing wave point 2π mode.

[0020] In combination with the first aspect, in some implementations of the first aspect, the vacuum electronic device further includes a focusing system, an electron gun, and a collector.

[0021] In a second aspect, a communication device is provided. The communication device includes the vacuum electronic device in any possible implementation of the first aspect.

[0022] In a third aspect, a communication system is provided. The communication system includes the communication device in the second aspect. Description of the Drawings

[0023] Figure 1 It is a schematic diagram of an application scenario in an embodiment of the present application.

[0024] Figure 2 It is a schematic diagram of the structure of an electron vacuum device in an embodiment of the present application.

[0025] Figure 3 It is a schematic diagram of the structure of a resonant unit in an embodiment of the present application.

[0026] Figure 4It is a schematic diagram of the working mode of the planar extended interaction resonator obtained through simulation in the embodiments of the present application.

[0027] Figure 5 It is a schematic diagram of the dispersion characteristics corresponding to the working mode of the planar extended interaction resonator in the embodiments of the present application.

[0028] Figure 6 It is a schematic diagram of a dual-cavity resonator structure in the embodiments of the present application.

[0029] Figure 7 It is a schematic diagram for simulating and verifying the wave injection interaction of the dual-cavity resonator structure in the embodiments of the present application.

[0030] Figure 8 It is a schematic diagram of a triple-cavity resonator structure in the embodiments of the present application.

[0031] Figure 9 It is a schematic diagram for simulating and verifying the wave injection interaction of the triple-cavity resonator structure in the embodiments of the present application.

[0032] Figure 10 It is a schematic diagram for simulating and verifying the output power of the triple-cavity resonator structure under different working voltages in the embodiments of the present application. Detailed implementation manners

[0033] Next, the technical solutions in the embodiments of the present application will be described with reference to the accompanying drawings.

[0034] As a device capable of realizing functions such as power amplification and oscillation, vacuum electronic devices can be widely applied in many fields. Specifically, reference can be made to Figure 1 .

[0035] Reference Figure 1 , as an example, Figure 1 It is a schematic diagram of the application scenario in the embodiments of the present application. As shown in Figure 1 , vacuum electronic devices can be applied to electronic systems such as radars, communications, and particle accelerators, and serve as indispensable core devices in the above-mentioned electronic systems. For example, in a communication electronic system, vacuum electronic devices can be used as oscillators and amplifiers. In a radar system, vacuum electronic devices can be used as receivers and transmitters, and as signal sources for active phased array antennas. In addition, in an information system, vacuum electronic devices can be used as transmit sources for radio and television stations, repeaters for microwave communications and satellite communications, and base stations in mobile communications. In addition, vacuum electronic devices can also be used as signal sources in millimeter-wave and terahertz imaging systems, non-destructive testing, biomedical systems, and security inspection systems, signal sources for plasma diagnosis and heating, and high-power microwave sources in controlled thermonuclear reactions, etc.

[0036] Vacuum electronic devices can be applied to frequency bands such as microwave, millimeter wave, and terahertz. Among them, there are various types of vacuum electronic devices. For example, they include different types such as traveling wave tubes, klystrons, gyrotrons, backward wave tubes, magnetrons, etc.

[0037] Microwave tubes, magnetrons, klystrons, traveling wave tubes, and gyrotrons were successively born in the 20th century. Among them, the most widely studied and applied are klystrons and traveling wave tubes. The traveling wave tube is a typical linear beam device, mainly including the helix traveling wave tube with medium and small power and broadband characteristics, and the coupled cavity traveling wave tube with high power capacity characteristics. Another typical linear beam device is the klystron. It is an electronic device that converts the DC energy of the electron beam into high-frequency energy based on the principle that when the electron beam passes through the gap of the resonant cavity, it is speed-modulated by the high-frequency field, and then density modulation is formed by using the transit time effect in the drift tube.

[0038] With the development of science and technology, higher requirements for the miniaturization and stability of vacuum electronic devices have been put forward in the fields of communication, medical treatment, and radio astronomy. At the same time, vacuum electronic devices are also constantly developing in the directions of miniaturization, high frequency, high power, wide bandwidth, high reliability, and long life. And some new types of vacuum electronic devices have gradually emerged during the development process. Among them, the extended interaction device is a new type of vacuum electronic device that combines the respective advantages of traveling wave tubes and klystrons. Its main feature is that it uses an extended interaction resonant cavity instead of a conventional reentrant resonant cavity as the interaction circuit to interact with the electron beam. Therefore, it has the stability and high gain characteristics of the klystron discrete resonant cavity. At the same time, the extended interaction structure uses multiple resonant cavities in cascade to achieve a higher characteristic impedance, and compared with the conventional reentrant resonant cavity, it has the effect of expanding the bandwidth. However, the narrowband high gain characteristic of the conventional klystron makes it mainly used as a high-power microwave source or amplifier, and there is a risk of breakdown in achieving miniaturization. The traveling wave tube has unique advantages in medium and small power and broadband, but there are also problems of complex structure and stability.

[0039] Existing klystron amplifiers mainly include klystrons with conventional reentrant resonators as the interaction structure and extended interaction klystrons with extended interaction resonators as the interaction structure. Since the operating mode of the reentrant resonator is the cavity mode of the resonator, it has the inherent characteristics of large volume and narrow bandwidth. Therefore, a conventional klystron composed of multiple such reentrant resonators also has the characteristics of narrow bandwidth and large volume. Although the extended interaction klystron (EIK) uses an extended interaction resonator with multiple gaps, which expands a certain bandwidth compared with the conventional reentrant resonator, it also has the characteristic of large volume. Conventional EIKs use a trapezoidal structure as their interaction structure to interact with the electron beam, thereby converting the energy of the electron beam into the energy of electromagnetic waves. Its physical process includes: the generation, formation, and focusing of the electron beam, the interaction between the electron beam and the high-frequency interaction system, the dissipation and cooling of the electron beam energy. The working principle of the klystron is as follows: electrons emitted from the cathode form an electron beam with a certain kinetic energy under the action of the electron gun, converting the energy of the power supply into the kinetic energy of the electron beam; when the electron beam passes through the input resonator, its speed is modulated under the action of the high-frequency electric field in the input cavity. The speed-modulated electron beam generates density modulation after passing through a field-free drift tube, forming electron bunching; the bunched electron beam contains fundamental wave and higher harmonic current components of the operating frequency. When the bunched electron beam passes through the second resonator, a high-frequency current corresponding to the fundamental wave is induced in the resonator, and a stronger high-frequency electric field is established across the resonator gap. This high-frequency electric field causes the electron beam to be more strongly speed-modulated and further generates density modulation in the second drift tube. The electron beam passes through multiple resonators and drift tubes, and during this process, it undergoes repeated physical processes of speed modulation, bunching, exciting the resonator, remodulation, and rebunching. The electron beam reaching the entrance of the output resonator has achieved good bunching and contains a strong fundamental wave current component. When the bunched electron beam passes through the output cavity, it is decelerated by the high-frequency electric field across the gap, converting the kinetic energy of the electron beam into high-frequency energy, and is sent to the load or antenna through the output waveguide via the coupling port, thus realizing the amplification of high-frequency signals. During this process, a part of the energy of the electron beam is converted into high-frequency energy, and the remaining energy is converted into heat energy when the electrons bombard the collector. In summary, precisely because discrete resonators or extended interaction resonators are used as the interaction circuit, there is no electromagnetic wave transmission path in the direction of electron beam transmission in both klystrons and extended interaction klystrons, so there will be no backward wave oscillation or reflection oscillation similar to that of traveling wave tubes, and thus the stability is higher than that of traveling wave tubes.

[0040] In addition, as a typical broadband amplifier, the helix traveling wave tube has obvious advantages in medium and small power requirements, including miniaturization, broadband, high efficiency, etc. Its core energy conversion structure is the helix slow wave structure, including input and output couplers, a metal tube shell, a metal helix connecting the input and output couplers, and a ceramic support rod fixed on the tube shell to support the central helix. And for high-gain helix traveling wave tubes, truncation and internal concentrated attenuation methods are usually used to achieve it. Similar to the klystron, only the structure - the helix slow wave structure is used as the energy conversion circuit on the interaction circuit, including an electron gun. Its working principle is as follows: At the beginning of the interaction, the electromagnetic field performs velocity modulation on the electron beam emitted from the electron gun. Electrons with different phases have different velocity changes due to different electromagnetic field forces. At this time, the electron beam absorbs part of the energy from the electromagnetic field, causing the electromagnetic wave to weaken, and it cannot transfer energy to the electromagnetic field. Then, after the electron beam drifts for a certain length, the electrons gradually bunch, and their main energy enters the deceleration field, and the energy transferred is greater than the energy absorbed from the electromagnetic field. Overall, it shows that the energy of the electron beam is transferred to the electromagnetic field, and the electromagnetic wave is amplified. The strengthened electromagnetic field further strengthens the electron velocity modulation and accelerates the electron bunching, prompting the electrons to decelerate faster and transfer more energy. Overall, it shows that the electron bunching and the electromagnetic field mutually stimulate and continuously strengthen, which is the linear amplification region of the interaction. If there are cut-offs and concentrated attenuators in the slow wave structure, although the electromagnetic wave is absorbed, the bunched electron beam is still bunched after passing through the cut-offs and concentrated attenuators, and quickly excites an electromagnetic field on the slow wave line and amplifies it. However, as the interaction accumulates to a certain extent, the distribution of the bunched electron density in terms of phase is very complex, and the increasing speed of the excited electromagnetic field gradually slows down. Finally, it shows that it absorbs the energy of the electromagnetic field, and the electromagnetic wave shows that its amplitude first increases and then slowly decreases after reaching the highest point, that is, the saturation phenomenon appears. This part of the interaction region is the non-linear amplification region. The appearance of the saturation phenomenon is because after the electron beam transfers a large amount of energy, its speed gradually decreases. When its average speed is lower than the phase velocity of the electromagnetic wave, the electron bunching block begins to withdraw from the deceleration field. Before it completely withdraws, the electrons can still transfer energy, but less and less. Until it enters the acceleration field, the electrons not only cannot transfer energy, but instead absorb energy from the electromagnetic field, resulting in a decrease in the amplitude of the electromagnetic wave.

[0041] For a klystron, according to its working principle, it can be found that its core energy conversion structure uses a resonant cavity to pre-bunch the electron beam, and finally converts the energy of the bunched electron beam into electromagnetic wave energy in the output cavity and outputs it to the external circuit through a coupler. Since a resonant cavity is used as the interaction circuit, the klystron has the natural disadvantages of narrow bandwidth and large size. The traveling wave tube uses a helix structure as the device for converting the energy of the electron beam and electromagnetic waves. Since the electromagnetic wave fed from the input port travels along the helix and converts energy with the transmitted electron beam, and the helix structure has a small structural size due to the transmission of the traveling wave, and the signal is transmitted from the input end to the output end without truncation, which also provides a feedback path for the reflected signal and the backward wave signal. Therefore, there is a risk of oscillation when achieving high gain; usually, the method of truncation or a concentrated attenuator is used to cut off the feedback path of the reflected and backward wave signals to improve the gain of the traveling wave tube. However, using truncation and adding an attenuator makes the structure of the traveling wave tube more complex; at the same time, the three-dimensional helix structure using ceramic rod clamping is not suitable for mass production, which also makes it extremely difficult to scale up the application of a microwave power amplifier with high gain and miniaturization.

[0042] In view of the above technical problems, the present application provides a vacuum electronic device, an extended interaction klystron amplifier using a planarized extended interaction resonant cavity as the energy conversion structure. This amplifier combines the respective advantages of the energy conversion structures of the klystron and the traveling wave tube, and has the characteristics of stability (unidirectionality), planarization, and miniaturization for medium and low power applications.

[0043] The following will combine Figure 2 to further describe the vacuum electronic device in the embodiments of the present application.

[0044] Refer to Figure 2 , as an example, Figure 2 is a schematic structural diagram of the vacuum electronic device 200 in the embodiments of the present application. It should be noted that Figure 2 the structure of the vacuum electronic device 200 shown is only a partial structure of the complete structure of the vacuum electronic device 200, not all of its structure. As Figure 2 shown, the vacuum electronic device 200 includes:

[0045] an electron gun 210, a resonant unit 220, an input device 230, an output device 240, a focusing system 250, and a collector 260.

[0046] In a possible implementation, the vacuum electronic device 200 may further include an attenuator.

[0047] Optionally, the vacuum electronic device 200 can be used as a power amplifier or an oscillator. The vacuum electronic device 200 can determine different units or components according to different application types. For example, when the vacuum electronic device 200 is used as an oscillator, it may not include an attenuator.

[0048] In the embodiment of the present application, the application fields of the vacuum electronic device 700 may include: broadcasting (radio, television, satellite live broadcast, etc.), telecommunications (point-to-point links, satellite communications, deep space communications, etc.), civil radar (airborne radar, weather radar, air traffic control radar, etc.), industrial applications (industrial heating, household microwave ovens), and scientific applications (scientific particle accelerators, civil accelerators, etc.).

[0049] The electron gun 210 is used to form an electron beam that meets the design requirements. The electron beam can pass through the slow-wave circuit and finally enter the collector.

[0050] In the present application, the electron gun 210 can be a Pierce parallel flow electron gun, a Pierce convergence electron gun, a high conductivity electron gun, a positive control electron gun, a grid-controlled electron gun, a non-intercepted grid-controlled electron gun, a low noise electron gun, etc., and the embodiments of the present application are not limited to this.

[0051] Among them, the resonance unit 220, as the core component of the transducer structure, the electron beam can interact with the input electromagnetic wave signal through the structure to realize the conversion of the kinetic energy of the electron beam and the energy of the electromagnetic wave, thereby realizing signal amplification.

[0052] In the present application, a vacuum electronic device may include multiple resonance units 220, such as an input resonance unit, an output resonance unit, and N intermediate resonance units, where the N intermediate resonance units are located between the input resonance unit and the output resonance unit, and the input resonance unit, the N intermediate resonance units, and the output resonance unit are connected through a drift section, and N is a positive integer greater than or equal to 1.

[0053] In the present application, the resonance unit is an extended interaction resonance cavity with a planar structure, and the specific structure can be found in the detailed description below.

[0054] The input device 230 couples the signal of the external circuit into the planar extended interaction resonant cavity through a waveguide in the input cavity to realize signal input.

[0055] The output device 240 converts the energy of the electron beam into the energy of the electromagnetic wave in the output cavity and couples it to the external circuit to realize the output of the signal.

[0056] Among them, the focusing system 250 is used to provide a bunching effect on the electron beam. The electron beam enters the conversion of the line-of-sight energy in the planar extended interaction resonant cavity 220 under the bunching of the focusing system. Or rather, the focusing system 250 is used to keep the electron beam in the required shape or direction to ensure that the electron beam can pass through the slow-wave circuit smoothly.

[0057] Among them, the collector 260 is used to recover the remaining energy of the electrons after exchanging energy with the planar extended interaction resonant cavity 220 and receive the electron beam that has exchanged energy with the electromagnetic wave.

[0058] The following provides a detailed description of the resonant unit 220 provided in the embodiments of the present application.

[0059] The resonant unit 220 can be used as an input resonant unit, an output resonant unit, or an intermediate resonant unit.

[0060] Reference Figure 3 , as an example, Figure 3 is a schematic structural diagram of the resonant unit 220 in the embodiments of the present application. It should be noted that Figure 3 the structure of the resonant unit 220 shown is only a part of the complete structure of the resonant unit 220, not all of its structure. As Figure 3 shown, the resonant unit 220 includes:

[0061] A planar circuit 310 (the planar circuit 310 includes mutually symmetric planar circuits 310-1 and 310-2), an electron beam channel 320, a ceramic substrate 330, and a metal casing 340.

[0062] As Figure 3 shown, the overall structure of the resonant unit 220 is symmetric about the central longitudinal line and the central axis. Among them, in this structure, two sets of mutually symmetric planar circuit structures are provided: the planar circuit 310-1 and the planar circuit 310-2. The gap between the planar circuit 310-1 and the planar circuit 310-2 forms a vacuum electron beam channel 320. The planar circuit 310-1 and the planar circuit 310-2 constitute an interaction circuit for the electron beam in the electron beam channel to interact with the electric field in the interaction circuit, thereby realizing the conversion of the kinetic energy of the electron beam and the energy of the electromagnetic wave.

[0063] Among them, the symmetric distribution of the planar circuit 310-1 and the planar circuit 310-2 can be symmetric up and down or symmetric left and right. The embodiments of the present application do not limit this.

[0064] Among them, as Figure 3As shown, in the planar circuits 310-1 and 310-2, there is a grating structure in which a plurality of metal microstrips and a plurality of vacuum gaps are arranged periodically. The energy generated by the interaction with electrons in this grating structure can be coupled over a long distance.

[0065] In this application, the number of metal microstrips and vacuum gaps in the grating structure is not limited.

[0066] As Figure 3 shown, the period p is the sum of the widths of one metal gap and one vacuum gap. The length of this period p has a direct impact on important characteristics such as the cut-off frequency of the field in the cavity and the operating voltage.

[0067] An optional understanding is that the length of the period p determines the dispersion characteristics of the grating structure, that is, the magnitude of the interacting field and the magnitude of the corresponding synchronous voltage. Therefore, the period length can be adjusted according to the target requirements, and the performance such as the target output power and gain can be adjusted by changing the voltage and the magnitude of the interacting field.

[0068] It can be understood that in the cavity of an extended interaction resonator, different electric fields are usually formed through multiple gaps to construct an interaction circuit. In this application, an interaction circuit is constructed by forming an electric field through a grating circuit. In other words, the grating structures on the planar circuits 310-1 and 310-2 constitute the interaction circuit.

[0069] It should be noted that for a common cavity structure, an electric field in the same direction as the electron beam is required to act on the electron beam. Therefore, a specific operating mode needs to be selected to achieve the electric field in this direction. However, in this application, the two planar circuits form a planarized cavity, and this planarized cavity structure itself can achieve an electric field in a fixed direction (for example, along the direction of the channel formed by the two planar circuits). In other words, the characteristics of this planarized cavity structure can be used to achieve a specific operating mode and an electric field in a specific direction.

[0070] It should be noted that the height of the gap formed by the planar circuits 310-1 and 310-2 is greater than or equal to the height of the electron beam, so that the electron beam can pass through the electron beam channel smoothly.

[0071] It should be understood that both the front end and / or the rear end of the electron beam channel can be connected to the drift section. That is, the electron beam exchanges energy with electromagnetic waves through the interaction circuit in the electron beam channel, and then moves towards the drift section to achieve the bunching of the electron beam.

[0072] Among them, the ceramic substrate 330 is used to fix the grating structure, and the two planar circuits are respectively arranged on the bottom surface and the top surface of two symmetric ceramic substrates.

[0073] Among them, the metal casing 340 is used to fix the ceramic substrate and the planar circuit. The metal casing 340 can be made of copper, stainless steel, nickel-copper alloy, etc., and the embodiments of the present application do not limit this.

[0074] When the resonant unit 220 serves as an input resonant unit or an output resonant unit, a coupler is provided in the resonant unit 220. The coupler is connected to the input waveguide or the output waveguide, and the input waveguide or the output waveguide is connected to the grating structure of the planar circuit 310 to form an input structure or an output structure.

[0075] The working modes of the resonant unit proposed in the present application are described below.

[0076] For an extended interaction resonant cavity, theoretically, it has an infinite number of working modes. Different working modes correspond to different working voltages and interaction efficiencies. Different devices can be realized according to different working modes. For example, it can include an oscillator and an amplifier.

[0077] Refer to Figure 4 , as an example, Figure 4 shows a schematic diagram of the working mode of a planarized extended interaction resonant cavity obtained by simulation. Figure 4 shows the axial field distribution in different working modes. As Figure 4 shown, there is an electric field between two metal gaps. The arrows in the figure are used to indicate the axial component of the electric field. The electric field in this direction is used to modulate the electron beam. The denser the arrows, the greater the field strength and the greater the modulation intensity.

[0078] Refer to Figure 5 , as an example, Figure 5 shows a schematic diagram of the dispersion characteristics corresponding to the working mode of a planarized extended interaction resonant cavity. As Figure 5 shown, the abscissa is the phase shift of the planarized extended interaction resonant cavity, and the ordinate is the working frequency of the planarized extended interaction resonant cavity. Among them, the oblique line c0 represents the light speed line, the oblique line 0sc represents the π-mode working point, and the oblique line Amp represents the 2π-mode working point. The closer the working point is to the light speed line, the greater the energy and voltage required. When the phase shift is between 0 and π, it is the 0th space harmonic, and when it is between π and 2π, it is the -1st space harmonic.

[0079] When the resonant cavity operates in a specific mode, signal generation or amplification can be achieved. For example, when operating in the standing wave point π mode, it can be used as an oscillator, and when operating in the standing wave point 2π mode, it can be used as an amplifier.

[0080] It should be noted that an ordinary klystron can operate at one standing wave point, a conventional extended interaction klystron can operate at multiple standing wave points, and the planarized extended interaction resonant cavity of the present application can operate in an infinite number of working modes.

[0081] The amplifier applying the resonant unit structure provided in the embodiments of the present application is described below by way of example.

[0082] Figure 2 The shown resonant unit can be used as an input resonant unit (hereinafter referred to as an input cavity) or an output resonant unit (hereinafter referred to as an output cavity).

[0083] Referring to Figure 6 , by way of example, Figure 6 is a schematic diagram of a dual-cavity resonant cavity structure in the embodiments of the present application.

[0084] As shown in Figure 6 (a) thereof, the dual-cavity resonant cavity structure includes an input cavity 610, an output cavity 620, and a drift section 630 connecting the input and output cavities. Among them, the input cavity 610 is connected to an external circuit through an input coupler 640, and the output cavity 620 is connected to an external circuit through an output coupler 650.

[0085] Among them, both the input cavity 610 and the output cavity 620 adopt the Figure 3 structure of the shown resonant unit. Details are not described herein again.

[0086] Figure 6 (b) thereof shows the internal working principle of the cavity resonant cavity structure.

[0087] The specific working principle includes the following steps:

[0088] S1. Formation and feeding of an electron beam

[0089] Electrons emitted from the cathode obtain kinetic energy under the action of the high voltage of the electron gun and form an electron beam with a certain kinetic energy, converting the energy of the power supply into the kinetic energy of the electron beam. Under the bunching of the focusing magnetic field, the electron beam with a specific speed is fed from one end of the input cavity 610, and the electron beam reaches the input cavity 610.

[0090] S2. Feeding of an input signal

[0091] The input signal is fed from the input coupler 640, and this input signal can be understood as a signal to be amplified.

[0092] There is no limitation on the sequence of this step S2 and S1. For example, S2 can be executed first and then S1, and the embodiments of the present application do not make any limitation thereto.

[0093] S3. Electron bunching.

[0094] Under the action of the high-frequency electric field in the input cavity 610, the electron beam interacts with the input signal in the interaction circuit in the input cavity 610. The electron beam is modulated by the input signal to form pre-bunching. Further, the electron beam enters the drift section. After passing through a field-free offset section, density modulation occurs, making the distribution of electrons in the electron beam uneven, thus forming electron bunching in the drift section.

[0095] S4. Energy conversion.

[0096] After passing through a drift section, the bunched electron beam enters the output cavity 620. The bunched electron beam contains the fundamental wave and harmonic components of the high-frequency electric field, and a high-frequency field with the same frequency as the working mode of the resonant cavity is established in the output cavity 620. The electron beam interacts with the high-frequency field to convert the energy of the electron beam into the energy of electromagnetic waves, realizing the amplification of the input signal.

[0097] S5. Signal output

[0098] The high-frequency energy is coupled to the external circuit through the output coupler 650, thus realizing the amplification of the input signal. The remaining energy of the electron beam after the interaction is recovered by the collector.

[0099] It should be noted that the input cavity 610 and the output cavity 620 are only connected by the drift section 630, and the structural dimensions of the drift section can only allow the electron beam to pass through without interception, while the input signal of the input cavity 610 cannot enter the output cavity 620. Therefore, this structure realizes the cut-off of the reflection signal or the backward wave signal loop, thus having stability. And due to the planar structure, this structure has miniaturization and is convenient for batch manufacturing, thus reducing the cost of the vacuum amplifier.

[0100] Reference Figure 7 , as an example, Figure 7 shows a schematic diagram of the beam-wave interaction simulation verification of the double-cavity resonant cavity structure in the embodiment of the present application. As Figure 7 shown, the abscissa is time (unit: nanosecond), and the ordinate is watt (unit: volt). Actually, the ordinate represents the voltage value in volts. The black area in the figure is the input signal, and the gray area is the output signal. For this double-cavity resonant cavity structure, when the amplitude of the input signal is 1V, the amplitude of the signal at the output port gradually increases and stabilizes. The amplitude of the signal at the output port stabilizes at 8.3V, realizing the amplification of the signal. The corresponding gain is 18.4dB, and the structure is simple and small in volume.

[0101] In a possible implementation, in order to achieve higher gain and expand the bandwidth, the above double-cavity structure can be extended to obtain a multi-cavity resonant cavity. In other words, N intermediate cavities can be added between Figure 6 the input cavity 610 and the output cavity 620 shown, where N is a positive integer greater than or equal to 1.

[0102] An alternative understanding is that a planar extended interaction klystron amplifier may include one or more intermediate cavities, multiple drift sections, and input and output couplers; further, to increase the gain and expand the bandwidth, the planar multi-cavity extended interaction amplifier may add 1 or even N intermediate cavities as needed.

[0103] Hereinafter, taking N equal to 1 and a three-cavity structure as an example for exemplary illustration.

[0104] Refer to Figure 8 , as an example, Figure 8 is a schematic diagram of a three-cavity resonator structure in an embodiment of the present application.

[0105] As Figure 8 shown in (a) of

[0106] an intermediate cavity 830 is added between the input cavity 810 and the output cavity 820, and the intermediate cavity 830 is respectively connected to the input cavity 810 and the output cavity 820 through the drift section 840-1 and the drift section 840-2. Among them, the input cavity 810 is connected to an external circuit through the input coupler 850, and the output cavity 820 is connected to an external circuit through the output coupler 860. Figure 3 The input cavity 810, the output cavity 820, and the intermediate cavity 830 all adopt the structure of the resonant unit (planar extended interaction resonator) shown in

[0107] Figure 8 . (b) of

[0108] shows the internal working principle of the cavity resonator structure.

[0109] In a possible implementation, the drift section 840-1 and the drift section 840-2 can be set to different lengths or the same length according to the performance requirements of the amplifier, and the embodiments of the present application do not limit this.

[0110] It can be understood that when the planar extended interaction klystron amplifier includes multiple drift sections, each drift section can be set to different lengths or the same length according to the performance requirements of the amplifier, and the embodiments of the present application do not limit this.

[0111] In a possible implementation, the resonant frequency of the intermediate cavity 830 can be the same as or different from the resonant frequencies of the input cavity 810 and the output cavity 820, and the embodiments of the present application do not limit this.

[0112] It can be understood that when the planar extended interaction klystron amplifier includes multiple intermediate cavities, the resonant frequency domain of each intermediate cavity can be the same as or different from the resonant frequencies of the input cavity and the output cavity. The embodiments of the present application do not limit this.

[0113] In a possible implementation, the number of resonant gaps of the input cavity 810, the intermediate cavity 830, and the output cavity 820 is M, where M is an odd number, and the number of gaps of each planarized extended interaction resonant cavity can be different or the same. The embodiments of the present application do not limit this.

[0114] It can be understood that regardless of the number of intermediate cavities included in the planar extended interaction klystron amplifier, the number of gaps of each planarized extended interaction resonant cavity can be different or the same. The embodiments of the present application do not limit this.

[0115] Reference Figure 9 , as an example, Figure 9 shows a schematic diagram of the injection-wave interaction simulation verification of the three-cavity resonant cavity structure in the embodiments of the present application. As Figure 9 shown, the abscissa is the input power, and the ordinate is the output power and the electron efficiency. For this three-cavity resonant cavity structure, it can be found that when the input power is greater than 0.6 W, the output power is greater than 50 W, and the electron efficiency is greater than 6%; compared with the two-cavity resonant cavity structure, the three-cavity resonant cavity structure can significantly improve the output power and gain of the amplifier.

[0116] Reference Figure 10 , as an example, Figure 10 shows a schematic diagram of the output power simulation verification of the three-cavity resonant cavity structure at different operating voltages in the embodiments of the present application. As Figure 10 shown, the abscissa is the operating voltage, and the ordinate is the output power and the gain. It can be found that the output power is the largest when the operating voltage is 5.1 kV, and the corresponding gain is 20 dB.

[0117] Based on the above technical solutions, the planarized extended interaction resonant cavity structure provided by the embodiments of the present application can achieve the miniaturization of the device. At the same time, due to the structural characteristics of the planarized structure, it is conducive to mass production. For example, it can be obtained by laser cutting metal sheets. In addition, the input-output structure and the planarized extended interaction resonant cavity structure can both be manufactured using the same materials and the same type of process, which is convenient for integrated production. Further, for the amplifier with the planarized extended interaction resonant cavity structure in the present application, due to the structural characteristics of the input cavity, the output cavity, and the drift section, it naturally overcomes the reflection oscillation or the electromagnetic wave backward wave transmission phenomenon, has stable amplification characteristics, and improves the amplification gain. At the same time, due to the planarized structural characteristics, this resonant cavity has the advantages of small volume, easy processing, and high power, and has application potential in the generation and amplification of terahertz sources.

[0118] Those of ordinary skill in the art will realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0119] In several embodiments provided by this application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0120] Another point is that the couplings or direct couplings shown or discussed with each other can be through some interfaces, and the indirect couplings of devices or units can be in electrical, mechanical or other forms.

[0121] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they can be located in one place, or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0122] In addition, the functional units in each embodiment of this application can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0123] As described above, this is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, which should all be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A vacuum electronic device, characterized in that, It includes an input resonant unit and an output resonant unit. The input resonant unit is connected to an input device, the output resonant unit is connected to an output device, and the input resonant unit and the output resonant unit are connected through a drift section. Among them, in the input resonant unit and the output resonant unit, there are two sets of plane circuit structures that are symmetric to each other. The gap between the two sets of plane circuits forms a vacuum electron beam channel. The two sets of plane circuits constitute an interaction circuit. The interaction circuit is used for the electron beam in the electron beam channel to interact with the electric field in the interaction, so as to form energy exchange. The electron beam channel is connected to the drift section.

2. The method according to claim 1, characterized in that The vacuum electronic device further includes: N intermediate resonant units. The N intermediate resonant units are located between the input resonant unit and the output resonant unit. The input resonant unit, the N intermediate resonant units and the output resonant unit are connected through a drift section. The N intermediate resonant units are provided with the two sets of plane circuit structures that are symmetric to each other and the vacuum electron beam channel. N is a positive integer greater than or equal to 1.

3. The method according to claim 1 or 2, characterized in that, Each set of plane circuits in the two sets of plane circuits includes a grid structure in which a plurality of metal gaps and a plurality of vacuum gaps are arranged periodically.

4. The method according to any one of claims 1 to 3, characterized in that In the input device and the output device, an input coupler and an output coupler are respectively provided. The input coupler is connected to an input waveguide, the output coupler is connected to an output waveguide, and the input waveguide or the output waveguide is connected to the grid structure of the plane circuit.

5. The method according to any one of claims 1-4, characterized in that, The two plane circuits are respectively arranged on the bottom surface and the top surface of two mutually symmetric dielectric substrates.

6. The method according to any one of claims 1-5, characterized in that, The number of resonant gaps in the input resonant unit, the N intermediate resonant units and the output resonant unit is M, where M is an odd number.

7. The method according to any one of claims 1-6, characterized in that, The vacuum electronic device is used to generate or amplify signals.

8. The method according to claim 7, wherein The input resonant unit, the N intermediate resonant units and the output resonant unit operate in the standing wave point 2π mode.

9. The method according to any one of claims 1-8, characterized in that, The vacuum electronic device further includes a focusing system, an electron gun and a collector.

10. A communication device, characterized in that, The communication device includes: the vacuum electronic device according to any one of claims 1-9.

11. A communication system, characterized in that, The communication system includes: the communication device according to claim 10.

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