CN105304437B - A kind of microwave modulation cold cathode miniature array radiation source and its implementation - Google Patents

Abstract

The invention discloses a microwave-modulated cold cathode micro-array radiation source and a realization method thereof, which solves the problems in the prior art. The microwave-modulated cold-cathode micro-array radiation source uses a microwave-modulated cold-cathode electron gun as an electron source; the array-type interaction resonator is used in conjunction with the microwave-modulated cold-cathode electron gun; the array-type interaction resonator includes two More than one interaction resonant cavities arranged equidistantly, and the distance L between the centers of adjacent interaction resonant cavities is greater than zero. The invention only needs to use one resonant cavity to realize the same-frequency/multiple-frequency amplification output of a radiation source signal in the array, thereby reducing the structural volume and processing difficulty of each radiation source device in the array, and at the same time, the phase of each radiation source in the array can be adjusted. Control is of positive significance to the miniaturization and integration of microwave electric vacuum devices.

Description

A microwave-modulated cold-cathode micro-array radiation source and its realization method

technical field

The invention belongs to the technical field of microwave, millimeter wave, submillimeter wave and terahertz frequency band radiation sources, and relates to an electric vacuum radiation source device, in particular to a microwave-modulated cold cathode micro-array radiation source and its realization method .

Background technique

Microwave, millimeter wave, and submillimeter wave electric vacuum radiation source devices have been widely valued as indispensable core devices for military electronic systems such as radar, electronic countermeasures, and space communications. Electron guns in traditional electric vacuum radiation source devices generally use a thermal emission cathode system. After decades of development, the thermal emission cathode process has become very mature and has been widely used in various electric vacuum radiation source devices. However, the thermal emission cathode has the following Significant disadvantages: complex structure, high cost, the cathode system is composed of a variety of metal and ceramic components, because the hot cathode works in a high temperature environment of thousands of degrees, the heating filament in the cathode is easy to break or short circuit, resulting in device damage; on the other hand , due to the need for heating power, the complexity of the system is increased, the efficiency of the system is reduced, and it takes a long time to reach the working temperature, especially for high-power devices, the startup time is often as long as several minutes, which brings great inconvenience to use; At the same time, the complex structure of the hot cathode is also one of the main reasons why the integration of electric vacuum radiation source devices is difficult.

Compared with the hot cathode electric vacuum radiation source, the solid-state semiconductor radiation source device has the advantages of small size, integration, and fast response speed, but it has the disadvantages of weak anti-interference, radiation resistance, and low power, especially in the space environment. The reliability of solid-state radiation source devices is difficult to be guaranteed.

Miniature electric vacuum radiation source devices are expected to solve the problems of the above two types of devices. Compared with hot-cathode electric vacuum devices, it has the characteristics of small size and can be integrated. Compared with solid-state radiation source devices, it has strong anti-interference and radiation resistance. , high output power and so on. In the miniature electric vacuum radiation source device, it is first necessary to use field emission cold cathodes to solve the generation of free electron sources. Compared with thermionic emission, field emission cold cathodes have low power consumption, integration, small size, and fast response. A series of advantages, compared with solid-state devices, it has the advantages of anti-interference, strong radiation resistance and high power. Therefore, it is an ideal electron emission source for miniature electric vacuum radiation source devices.

The output power of the klystron in traditional microwave electric vacuum devices can now be very high, but the volume of the klystron is relatively large, and it is difficult to integrate. The traditional klystron needs at least one input and output cavity to realize the signal. enlarge.

Contents of the invention

The object of the present invention is to overcome the above-mentioned defects and provide a microwave-modulated cold cathode micro-array radiation source with simple structure and convenient implementation.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

A microwave-modulated cold cathode micro-array radiation source, comprising:

A cold-cathode electron gun modulated by microwaves for use as an electron source;

An array interaction resonant cavity is used in conjunction with the cold-cathode electron gun modulated by microwaves;

The arrayed interaction resonator includes more than two interaction resonators equidistantly arranged, and the center-to-center distance L between adjacent interaction resonators is greater than zero;

The interaction resonant cavity includes a resonant cavity shell, two electron beam drift pipes that are opposite and respectively arranged at the upper and lower ends of the resonant cavity shell, there is a gap between the two electron beam drift pipes, and are located at the upper end The electron injection drift pipeline is the collector;

An outer conductor protruding from the resonant cavity shell and an inner conductor located inside the outer conductor are also arranged on one side of the resonant cavity shell, and a ceramic output window is also set between the two , and the outer conductor, the inner conductor and the ceramic output window are coaxial; the outer conductor is hollow and communicated with the resonant cavity shell;

A coupling ring is also provided on the same side as the inner conductor in the resonant cavity housing, one end of the coupling ring is connected to the inner conductor, and the other end is connected to the inner wall of the resonant cavity housing.

Further, the coupling ring, the outer conductor, the inner conductor and the ceramic output window are arranged at the upper end inside the resonant cavity shell and on one side of the electron injection drift pipe.

Further, the cold cathode electron gun modulated by microwaves includes an electron gun shell, and an electron gun core composed of a microwave input layer, a lower electrode plate, a cold cathode, and an upper electrode plate;

The gun core of the electron gun traverses the housing of the electron gun, the microwave input layer is arranged between the lower electrode plate and the upper electrode plate, and its upper and lower surfaces are respectively connected to the upper electrode plate and the lower electrode plate. Fixed electrode plate;

The upper end of the electron gun housing is sealed with the interaction resonance cavity to form a vacuum chamber, and the lower end is sealed with the lower electrode plate;

In the middle section of the microwave input layer, there is an interaction gap between the electron beam and the modulated microwave facing the electron beam drift pipe, and the cold cathode is embedded in the lower part of the bottom of the electron beam and modulated microwave interaction gap. on the electrode plate, so that the electron beam drift pipeline is aligned with the electron beam channel of the electron gun;

On the upper electrode plate facing the cold cathode and the interaction gap between the electron beam and the modulated microwave, an arrayed electron beam output hole is provided; the size of each hole in the array type electron beam output hole is smaller than that of the microwave wavelength.

Further, the number of the cold cathodes matches the number of the interaction resonant cavities.

Further, the center-to-center spacing L of the adjacent interaction resonators satisfies the following relationship:

When the phases of two adjacent interacting resonators are required to be the same, the center distance L between the two interacting resonators is an even multiple of the microwave half-wavelength in the microwave input layer;

When two adjacent interaction resonant cavities are required to have opposite phases, the center-to-center distance between the two interaction resonant cavities is an odd multiple of the microwave half-wavelength in the microwave input layer.

Further, the even multiples of the microwave half wavelength are 2, 4, 6, 8, 10, 12 or 14 times; the odd multiples of the microwave half wavelength are 3, 5, 7, 9, 11, 13 or 15 times

Further, the arrayed electron injection and output holes are placed at the axial position of the inner cavity of the electron gun housing, and the lower electrode plate, both sides of the electron gun core and the top surface of the upper electrode plate, and the resonant cavity housing are sealed and fixed into one body through the electron gun housing. .

Further, the arrayed electron injection and output holes are formed by laser etching, and the shapes of the holes are round holes, square holes or strip holes.

Further, the microwave input layer is an insulating medium with a dielectric constant of 2-10.

A method for realizing microwave-modulated refrigerated cathode micro-array radiation source comprises the following steps:

(1) Steps in which the upper electrode plate is connected to DC voltage and the lower electrode plate is grounded;

(2) The step of inputting microwaves from the left end of the microwave input layer; at this time, the surface of the cold cathode simultaneously obtains multiple modulated electron beams under the action of the electrostatic field and the high-frequency field generated by microwaves;

(3) Steps in which each modulated electron beam enters the electron beam drift pipeline through its respective arrayed electron beam output hole;

(4) The modulated electron beams are self-excited and oscillated in their respective vacuum resonators to generate microwave radiation of the same frequency/double frequency, and the energy of the modulated electron beams is converted into microwaves;

(5) Microwave is output through the coupling ring and coaxial structure to realize the same frequency/multiplication frequency amplification output of the input signal, and the input signal is separated from the output signal at the same time;

(6) According to the specific position of each cold cathode/resonator in the direction of modulated microwave transmission, the phase of each output microwave signal is controlled to achieve phase control.

Compared with the prior art, the present invention has the following beneficial effects:

The invention uses a microwave-modulated cold cathode array electron gun as the electron source, cooperates with the array interaction resonant cavity, and uses the high-frequency electric field in the microwave to modulate the emission density of each electron beam between the cathode and anode, and then each electron beam passes through the respective upper electrode plate 1. After the output holes of the array type electronic injection enter their respective resonant cavities, they are self-excited to generate microwave radiation of the same frequency/double frequency and further interact with it. The electronic injection delivers its energy to the microwave to generate electromagnetic radiation, which only needs to use one resonance The cavity can realize the same frequency/multiplication frequency amplification output of the signal, thereby reducing the structural volume and processing difficulty of the device, and at the same time, the phase of each radiation source in the array can be controlled, which is positive for the miniaturization and integration of microwave electric vacuum devices. significance.

Description of drawings

Fig. 1 is a schematic cross-sectional view of the present invention-embodiment 1.

Fig. 2 is a schematic cross-sectional view of Embodiment 2 of the present invention.

Fig. 3 is a schematic cross-sectional view of Embodiment 3 of the present invention.

In the above drawings, the names of the parts corresponding to the reference signs are as follows: 1. Collector, 2. Resonant cavity shell, 3. Coupling ring, 4. Inner conductor, 4-1. Outer conductor, 5. Ceramic output window, 6. Upper electrode plate, 7. Lower electrode plate, 8. Cold cathode, 9. Array electron injection and output holes, 10. Electron gun shell, 11. Microwave input layer, 11-1. Electron injection and modulated microwave interaction gap, 12. Electronic note drift pipeline.

detailed description

The present invention will be further described below with reference to the accompanying drawings and examples, and the embodiments of the present invention include but not limited to the following examples.

Example 1

As shown in Figure 1, this embodiment provides a microwave-modulated cold cathode micro-array radiation source, the array radiation source is composed of several radiation sources arranged equidistantly, and each radiation source is based on microwave modulation The cold cathode electron gun, combined with the interaction resonant cavity on this basis, makes the resonant cavity interact with the electron beam modulated by a specific frequency microwave, and generates electromagnetic oscillation radiation to amplify the same frequency and double frequency high frequency electromagnetic wave of the specified frequency. Signal, the design principle is as follows: the pre-modulated electron beam emitted by a microwave-tuned cold cathode electron gun of a specific frequency passes through a drift section, and then passes through a high-frequency resonant cavity, where a high-frequency field is excited and interacts in the resonant cavity to complete the injection wave interaction to realize energy exchange, and then output the high-frequency signal energy in the resonant cavity through a coupling device and an output window structure.

A radiation source consists of a microwave-modulated cold-cathode electron gun and an interactive resonant cavity (Fig. 1 only shows a part of the microwave-modulated cold-cathode electron gun). The cold cathode electron gun modulated by microwave comprises an electron gun shell and an electron gun gun core composed of a microwave input layer, a lower electrode plate, a cold cathode, and an upper electrode plate. The electron gun core traverses the electron gun housing, the microwave input layer is arranged between the lower electrode plate and the upper electrode plate, and its upper and lower surfaces are respectively fixed with the upper electrode plate and the lower electrode plate; the upper end of the electron gun housing is connected to the The interaction resonant cavity is sealed to form a vacuum chamber, and its lower end is sealed with the lower electrode plate.

In this embodiment, a microwave input layer is added between the upper and lower electrode plates of the electron gun, and a cavity is set above the cold cathode in the middle section of the microwave input layer as an interaction gap between the electron beam and the modulated microwave. The cold cathode is embedded in the electron beam. On the lower electrode plate at the bottom of the interaction gap with the modulated microwave, a group of arrayed electron injection and output holes with each hole size smaller than the microwave wavelength are set up on the upper electrode plate facing the electron beam and the modulation microwave interaction gap and the upper part of the cold cathode, as the electron injection and output holes. Note that the size of the output hole is smaller than the microwave wavelength (electromagnetic field wave), and the opening of the array hole has little effect on the electric field distribution on the cathode surface. At the same time, because the size of the hole is smaller than the microwave wavelength, it does not affect the microwave transmission.

Using microwave-modulated cold-cathode electron guns in a vacuum environment, after the upper electrode plate is charged with a static positive potential, the cold cathode on the lower electrode plate can generate a stable field emission current; when the microwave is input in quasi-plane wave mode, the microwave medium-high The direction of the electric field vector is parallel to the electrostatic field. When its direction is consistent with the electrostatic field, the electric field intensity on the surface of the cold cathode will be strengthened, and it will be weakened when it is opposite to the electrostatic field; microwaves of a certain frequency in the interaction gap between the electron beam and the modulated microwave Acting on the cold cathode emission electric field, the frequency of the electric field also changes with the microwave frequency, so that the frequency of the generated electron beam is the same as the input microwave frequency, thus effectively realizing the modulation of the cold cathode emission current by microwaves. Under the same conditions In the present invention, the interaction gap between the electron beam and the modulated microwave is less than one-tenth of the conventional technology. The greater the amplitude of the microwave power, the greater the modulation amplitude of the electron beam. At the same time, by changing the frequency and intensity of the input microwave, electron beams in different frequency and intensity modulation states can be obtained to achieve broadband modulation; for microwaves with the same input power and frequency , by increasing the potential difference between the upper and lower electrode plates, that is, increasing the strength of the electrostatic field, the modulation amplitude of the electron beam can also be increased.

The structure of the interaction resonant cavity is as follows: the interaction resonant cavity is mainly composed of a resonant cavity shell, and the upper and lower ends of the resonant cavity shell are respectively provided with electron drift pipes, and there is a gap between the two electron beam drift pipes, and The electron injection drift pipeline at the upper end is the collector; on one side of the resonant cavity housing, an outer conductor protruding from the resonant cavity housing and an inner conductor located in the outer conductor are also arranged, and at the same time, a There is a ceramic output window, and the outer conductor, inner conductor and ceramic output window are coaxial; the outer conductor is hollow and communicated with the resonant cavity shell; a coupling ring is provided on the same side as the inner conductor in the resonant cavity shell, and one end of the coupling ring It is connected with the inner conductor, and the other end is connected with the inner wall of the resonant cavity shell. Wherein, the coupling ring, the outer conductor, the inner conductor and the ceramic output window are arranged at the upper end inside the resonant cavity shell and on one side of the electron injection drift pipe. The modulated electron beam enters the electron beam drift pipeline through the arrayed electron beam output hole, and after a period of drift, the electron beam achieves the best clustering, and then passes through the resonant cavity to excite the same-frequency or double-frequency microwave in the resonant cavity and communicate with it Further interact, complete injection wave interaction, realize energy exchange, and finally output the same-frequency or double-frequency microwave signal energy in the resonant cavity through the coupling device and the ceramic output window.

Since the spacing of each cold cathode is phase-matched with the transmission parameters of the high-frequency field, the modulation phases of each electron beam will also be matched to achieve phase control. The number of resonant cavities and cathodes is determined according to the number of actually required array radiation sources, and the number n of resonant cavities is 2-200. The center distance L of each interaction resonator is sequentially determined according to whether the phase of the microwave transmitted in the microwave input layer is the same between two adjacent interaction cavities, that is, when the phase of two adjacent interaction resonators is required to be the same, the two The center distance between the interaction resonators is an even multiple of the half wavelength of the microwave in the microwave input layer, and the value of the even multiple is 2, 4, 6, 8, 10, 12 or 14 times; When the phases of the resonators are opposite, the center-to-center distance between the two interacting resonators is an odd multiple of the microwave half-wavelength in the microwave input layer, and the value of the odd multiple is 3, 5, 7, 9, 11, 13 or 15 times. Among them, the microwave half-wavelength in the microwave input layer is obtained through 3D electromagnetic simulation software simulation after first determining the number and structure size of the interaction cavity. The interaction resonant cavity is a rectangular cavity, a cylindrical cavity or a prism cavity.

Example 2

The three-cavity array radiation source with the same frequency and phase of manufacturing one S wave band, the method is as follows:

Taking the S-band (2.45 GHz) array radiation source as an example, FIG. 2 shows a schematic cross-sectional structure diagram of the radiation source device in this embodiment. As shown in Figure 1, the electron gun housing 10 has an inner diameter of φ5.45mm, an outer diameter of φ8mm, and a height of 2mm. The material is 99# ceramics. Its lower end is sealed with the lower electrode plate, and its upper end is sealed with the interaction resonance cavity to form a sealed vacuum chamber. The resonator material is oxygen-free copper. The electron gun core composed of the microwave input layer, the lower electrode plate, the cold cathode, and the upper electrode plate traverses the electron gun shell, the distance between the upper electrode plate and the lower electrode plate is 0.2mm, and the electron injection and output holes are placed in the shell The position of the cavity axis, the lower electrode plate, both sides of the electron gun gun core and the top surface of the upper electrode plate, and the resonant cavity shell are sealed and fixed together by the electron gun shell; the lower electrode plate (length×width×thickness) is 20×7×0.75mm , The material is non-magnetic stainless steel, the diameter of the cold cathode on it is φ2.8mm, the thickness is 1µm, and carbon nanotube sheet; the microwave input layer (length×width×thickness) is 20×7×0.25mm, and the material is polytetrafluoroethylene , the interaction gap area in the middle is 7×7mm, and the height is the same as the thickness of the microwave input layer; the upper electrode plate (length×width×thickness) is 20×7×0.05mm, and the material is non-magnetic stainless steel. In the corresponding range of the cavity, 20×20=400 display-type square holes with a side length of 0.16×0.16mm are laser-etched as electron injection and output holes. The inner diameter of the interaction resonance cavity is φ61.2mm, the cavity thickness is 2mm, the height is 25mm, and the material is copper. The inner diameter of the drift pipe of the interaction resonant cavity is φ10.9mm; the gap length is 4.3mm. Coupling ring 3 ring body thickness 1mm, ring body width 4mm, ring axial height a=9mm, ring radial width b=8mm; inner conductor inner diameter 1.5mm, outer diameter 3.5mm. The coaxial output port is sealed with 99# ceramic material, that is, the ceramic output window. Radiation source structures of the same size are sequentially processed on the microstrip structure to form an array, and the spacing L between the radiation sources is adjusted to obtain high-frequency signals with different phases. In this case, the center-to-center spacing L of the radiation sources is L=122mm to obtain high-frequency signals with the same phase The output signal, its structural diagram is shown in Figure 2, all components are welded together, exhausted on the exhaust table, and finally a sealed vacuum tube with ultra-high vacuum is obtained.

In this implementation case, the upper electrode plate 6 is connected to a 2000V DC voltage, and the lower electrode plate is grounded; using a suitable carbon nanotube cold sheet as the cathode, the frequency is 2.45GHz (also can be other frequencies), and the power is 5W microwave E ( t) Input from the left end of the microwave input layer. At this time, the three cathode surfaces are simultaneously under the action of the electrostatic field and the microwave high-frequency field to obtain three electron beams whose emission density is modulated. By adjusting the length of the drift pipe, each electron beam can be optimized. Clustering, and then let each grouping electron beam pass through its own resonant cavity, excite the same frequency and phase microwave in the resonant cavity and further interact with it, complete the injection wave interaction, realize energy exchange, and finally output through their respective coupling devices and ceramics The window structure outputs microwave signal energy of the same frequency and phase in the respective resonant cavities.

Example 3

To manufacture a C-band (4.9GHz) double-frequency in-phase five-cavity array radiation source, the method is as follows:

Taking the C-band (4.9 GHz) double frequency radiation source as an example, the structure schematic diagram of this frequency double radiation source is shown in FIG. 3 . The inner diameter of the electron gun shell is φ2.67mm, the outer diameter is φ5mm, and the height is 1mm. The material is 99# ceramics. The lower end is sealed with the lower electrode plate, and the upper end is sealed with the interaction resonance cavity to form a sealed vacuum chamber. The interaction resonance cavity material is oxygen-free copper. . The electron gun core composed of the microwave input layer, the lower electrode plate, the cold cathode and the upper electrode plate traverses the electron gun shell, the distance between the upper electrode plate and the lower electrode plate is 0.2mm, and the electron injection and output holes are placed in the shell The position of the cavity axis, the lower electrode plate, both sides of the electron gun gun core and the top surface of the upper electrode plate, and the resonant cavity shell are sealed and fixed together by the electron gun shell; the lower electrode plate (length×width×thickness) is 10×4×0.75mm , The material is non-magnetic stainless steel, the diameter of the cold cathode on it is φ1.8mm, the thickness is 1µm, and carbon nanotube sheet; the microwave input layer (length×width×thickness) is 10×4×0.25mm, and the material is polytetrafluoroethylene , the interaction gap area in the middle is 4×4mm, and the height is the same as the thickness of the microwave input layer; the upper electrode plate (length×width×thickness) is 10×4×0.05mm, and the material is non-magnetic stainless steel. In the range corresponding to the gap, 20×20=400 display-type square holes with a side length of 0.1×0.1mm are laser-etched as electron injection and output holes. The inner diameter of the interaction resonance cavity is φ30mm, the cavity thickness is 2mm, the height is 18mm, and the material is copper. The inner diameter of the drift pipe of the interaction resonator is φ5.34mm; the gap length is 2.3mm. Coupling ring 3 ring body thickness 0.5mm, ring body width 2mm, ring axial height a=5mm, ring radial width b=4mm; inner conductor inner diameter 0.75mm, outer diameter 1.5mm. The coaxial output port is sealed with 99# ceramic material, that is, the ceramic output window. Radiation source structures of the same size are sequentially processed on the microstrip structure to form an array, and the spacing L between the radiation sources is adjusted to obtain high-frequency signals of different phases. In this case, the spacing L between the centers of the radiation sources is 122mm. The high-frequency output signal of the same phase is obtained, and its structural diagram is shown in Figure 3. The components are welded together, exhausted on the exhaust table, and finally a sealed vacuum tube with ultra-high vacuum is obtained.

In this implementation case, the upper electrode plate is connected to 1800V DC voltage, and the lower electrode plate 7 is grounded; a suitable carbon nanotube cold sheet is used as the cathode, and a microwave with a frequency of 2.45GHz (other frequencies can also be used) and a power of 0.1W is used. E(t) is input from the left end of the microwave input layer. At this time, the five cathode surfaces are simultaneously under the action of the electrostatic field and the microwave high-frequency field to obtain five in-phase electron beams with modulated emission current densities. By adjusting the length of the drift pipe, each The electron injection achieves the best clustering, and then passes through the respective resonant cavities to excite frequency-multiplied and in-phase microwaves in their respective resonant cavities and further interact with them to complete the injection-wave interaction and realize energy exchange, and finally output through the coupling device and ceramics. The windows output the frequency multiplied and in-phase microwave signal energy in each resonant cavity.

According to the above-mentioned embodiments, the present invention can be well realized. It is worth noting that, based on the premise of the above-mentioned design principle, in order to solve the same technical problem, even if some insubstantial changes or modifications are made on the basis of the structure disclosed in the present invention, the essence of the adopted technical solution is still Like the present invention, it should also be within the protection scope of the present invention.

Claims (10)

1. A microwave-modulated cold cathode micro-array radiation source, comprising: A cold-cathode electron gun modulated by microwaves for use as an electron source; An array interaction resonant cavity is used in conjunction with the cold-cathode electron gun modulated by microwaves; The arrayed interaction resonator includes more than two interaction resonators equidistantly arranged, and the center-to-center distance L between adjacent interaction resonators is greater than zero; The interaction resonant cavity includes a resonant cavity shell (2), two electron beam drift pipes (12) facing each other and respectively arranged at the upper and lower ends of the resonant cavity shell (2), and two electron beam drift pipes (12). There is a gap between the pipes (12), and the electron injection drift pipe (12) at the upper end is the collector (1); An outer conductor (4-1) protruding from the resonant cavity housing (2) and an inner conductor located in the outer conductor (4-1) are also provided on one side of the resonant cavity housing (2). conductor (4), and at the same time, a ceramic output window (5) is arranged between the two, and the outer conductor (4-1), the inner conductor (4) and the ceramic output window (5 ) coaxial; the outer conductor (4-1) is hollow and communicates with the resonant cavity shell (2); A coupling ring (3) is also provided on the same side as the inner conductor (4) in the resonant cavity housing (2), one end of the coupling ring (3) is connected to the inner conductor (4), and the other end is connected to the inner conductor (4). It is connected with the inner wall of the resonant cavity housing (2). 2. The microwave-modulated cold cathode micro-array radiation source according to claim 1, characterized in that, the coupling ring (3), the outer conductor (4-1), the inner conductor (4) and the ceramic output window ( 5) It is arranged at the upper end inside the resonant cavity housing (2) and on one side of the electron injection drift pipe (12). 3. The microwave-modulated cold-cathode micro-array radiation source according to claim 2, characterized in that, the cold-cathode electron gun modulated by microwaves comprises an electron gun housing (10), and a microwave input layer (11) and a lower An electron gun core composed of an electrode plate (7), a cold cathode (8), and an upper electrode plate (6); The electron gun core traverses the electron gun housing (10), the microwave input layer (11) is arranged between the lower electrode plate (7) and the upper electrode plate (6), and its upper and lower surfaces respectively fixed with the upper electrode plate (6) and the lower electrode plate (7); The upper end of the electron gun housing (10) is sealed with the interaction resonance cavity to form a vacuum chamber, and the lower end is sealed with the lower electrode plate (7); In the middle of the microwave input layer (11), there is an electron beam and modulated microwave interaction gap (11-1) facing the electron beam drift pipe (12), and the cold cathode (8) is embedded in the on the lower electrode plate (7) at the bottom of the electron beam and modulated microwave interaction gap (11-1), so that the electron beam drift pipe (12) is aligned with the electron beam channel of the electron gun; On the upper electrode plate (6) facing the cold cathode (8) and the interaction gap (11-1) between the electron beam and the modulated microwave, there are arrayed electron injection and output holes (9); The size of each hole of the arrayed electron injection and output holes (9) is smaller than the microwave wavelength. 4. The microwave-modulated cold cathode micro-array radiation source according to claim 3, characterized in that the number of the cold cathodes (8) matches the number of the interaction resonant cavities. 5. microwave modulation cold cathode micro-array radiation source according to claim 4, is characterized in that, the center-to-center distance L of adjacent described interaction resonant cavities satisfies the following relationship: When the phases of two adjacent interacting resonators are required to be the same, the center distance L between the two interacting resonators is an even multiple of the microwave half-wavelength in the microwave input layer; When two adjacent interaction resonant cavities are required to have opposite phases, the center-to-center distance between the two interaction resonant cavities is an odd multiple of the microwave half-wavelength in the microwave input layer. 6. The microwave-modulated cold-cathode micro-array radiation source according to claim 5, wherein the even multiples of the microwave half-wavelength are 2, 4, 6, 8, 10, 12 or 14 times; Odd multiples of half wavelength are 3, 5, 7, 9, 11, 13 or 15 times. 7. The microwave-modulated cold cathode micro-array radiation source according to claim 4, characterized in that the array electron injection and output holes (9) are placed at the axial position of the inner cavity of the electron gun housing (10), and the lower The electrode plate (7), both sides of the electron gun core, the top surface of the upper electrode plate (6), and the resonant cavity shell (2) are sealed and fixed into one body through the electron gun shell (10). 8. The microwave-modulated cold cathode micro-array radiation source according to claim 7, characterized in that the array electron injection and output holes (9) are formed by laser etching, and the shapes of the holes are round holes, square holes, holes or strip holes. 9. The microwave-modulated cold cathode micro-array radiation source according to claim 4, characterized in that the microwave input layer (11) is an insulating medium with a dielectric constant of 2-10. 10. The realization method of the micro-array type radiation source of micro-wave modulation cold cathode as described in any one of claim 1-9, it is characterized in that, comprises the following steps: A. Steps in which the upper electrode plate is connected to DC voltage and the lower electrode plate is grounded; B. The step of inputting microwaves from the left end of the microwave input layer; at this time, the surface of the cold cathode simultaneously obtains multiple modulated electron beams under the action of the electrostatic field and the high-frequency field generated by the microwaves; C. Steps in which each modulated electron beam enters the electron beam drift pipeline through its respective arrayed electron beam output hole; D. The steps of modulating the electron beam self-excited oscillation in their respective resonant cavities to generate microwave radiation of the same frequency/multiplied frequency, and converting the energy of the modulated electron beam into microwave; E. The step of outputting microwaves through the coupling ring and the coaxial structure to realize the same frequency/multiplication frequency amplification output of the input signal; F. The step of controlling the phase of each output microwave signal according to the specific position of each cold cathode/resonator cavity in the modulation microwave transmission direction to realize phase control.