An energy suppression device for high power microwave protection

Abstract

The application provides an energy suppression device for high-power microwave protection, wherein the device body is a rectangular waveguide, microwave isolation windows are arranged at both ends of the waveguide, and multiple discharge units are arranged in the waveguide. The microwave isolation window is composed of a thickened standard flange, a gas flow interface and a dielectric window; the gas flow interface is arranged at the narrow side of the flange, the dielectric window is arranged between the flange and the suppression device, the front and back surfaces of the dielectric material are closely attached to the flange and the end surface of the suppression device, and microwave leakage is reduced. The structure of the discharge unit is that multiple slits are cut in the middle of the narrow side of the waveguide, the slits are spaced apart by a certain distance; a through hole with a corresponding size is symmetrically arranged at the center of the wide side of the waveguide, a metal cylinder is vertically inserted into the waveguide along the through hole, and the metal cylinder is perpendicular to the wide surface of the waveguide. The application is suitable for electronic devices of rectangular waveguide transmission lines.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-power microwave protection of wide spectrum strong electromagnetic pulse. BACKGROUND

[0002] Radar is faced with "four threats": various electronic jamming, super-low altitude penetration and stealth weapons make radar unable to play the role; anti-radiation missiles, anti-radiation unmanned attack aircraft and directional energy weapons also pose a serious threat to the survival of radar. Therefore, the ability to resist strong electromagnetic pulse radiation plays an important role in modern war for electronic equipment. High-power microwave has the characteristics of wide spectrum range, large radiation power, high peak field strength, variable combined waveform, and wide killing range. It mainly realizes the combat purpose through the coupling effect between strong electromagnetic field and electronic equipment. The electromagnetic wave frequency of high-power microwave covers several hertz to several hundred gigahertz, basically realizing full coverage of the working frequency band of the electronic equipment at the present stage.

[0003] At present, the main high-power microwave protection technology abroad is: using electronic devices that are not easy to damage; adding high-power microwave protection circuit; installing filter circuit for filtering; using circuit isolation technology to isolate the circuit with strong electromagnetic pulse coupling; using shielding technology and grounding technology for electromagnetic reinforcement; high-power microwave protection mostly uses the protection mode of limiting amplitude. Foreign scholars have proposed to increase the discharge electrode in the limiter to enhance the local field strength, thereby increasing the speed of forming plasma by inert gas, and realizing the rapid start of the limiter.

[0004] The main principle of the existing energy suppression device for high-power microwave protection is that the multi-stage energy suppression device unit is spaced apart by a certain length, and for a specific frequency of microwave, an electric arc is formed between the upper and lower top ends of each independent energy suppression device unit. The arc discharge is equivalent to introducing a part of the loss in the channel. The high-power microwave energy passes through the multi-stage energy suppression device discharge, and the energy has been greatly attenuated. However, the discharge electrode of the existing energy suppression device has defects: when the external environment changes significantly or the discharge structure overheats, the performance of the energy suppression device will deteriorate or be damaged, and even cause microwave leakage. SUMMARY

[0005] In order to prevent high-power microwave radiation energy from entering the radio frequency front end of electronic equipment and causing damage to the system, the present application proposes an energy suppression device for high-power microwave protection.

[0006] The energy suppression device for high-power microwave protection proposed by the present application has the technical scheme comprising:

[0007] The microwave isolation window is arranged at each end of the rectangular waveguide, and the dielectric material is in close contact with the two side end faces to reduce microwave leakage; the rectangular waveguide narrow edge is cut into multiple slits, and a metal partition plate is inserted into the waveguide narrow wall at equal distances on both sides; the rectangular waveguide wide edge is provided with a through hole in the middle, and a matching pin is vertically inserted into the rectangular waveguide interior along the through hole and is perpendicular to the waveguide wide face.

[0008] Further, the rectangular waveguide wide edge through hole and the waveguide narrow edge slit are in the same plane; along the direction of the waveguide, multiple slit planes are parallel to each other.

[0009] Further, the height h1 cylindrical matching pin is inserted into the waveguide interior through the rectangular waveguide wide edge through hole, and the matching pin is perpendicular to the rectangular waveguide wide edge. There are two matching pins on a certain cross section of the rectangular waveguide interior, and a certain distance d1 is reserved between the matching pins.

[0010] Further, the metal partition plate with a thickness t is inserted into the waveguide cavity interior through the rectangular waveguide narrow edge slit, and a distance L1 is reserved between the metal partition plate and the matching pin, and the distance L1 is the distance from the edge of the metal partition plate to the center line of the pin.

[0011] Further, the height h1 of the matching pin, the distance d1 between the pins, and the distance L1 between the partition plate and the pin are determined according to the wavelength of the microwave frequency to be suppressed, that is, h1 < 0.45b.

[0012] Further, the depth L2 of the insertion of the partition plate into the rectangular waveguide is L2, which is the distance from the top end of the metal partition plate to the rectangular waveguide narrow edge. The depth is determined according to the wavelength of the electromagnetic wave to be suppressed, that is, L2 = (a - lambda g / 4) / 2, wherein lambda g is the waveguide wavelength corresponding to the electromagnetic field to be suppressed.

[0013] Further, the device is provided with a microwave isolation window at each end to block the attenuation of the energy suppression device performance caused by changes in the external environment.

[0014] Further, the typical dielectric material of the microwave isolation window is polytetrafluoroethylene, polyethylene, organic glass, and polystyrene; the thickness of the dielectric material is above one-fourth of the waveguide wavelength, and the surface roughness is above level 8.

[0015] The beneficial effects of the present application include: increasing the dielectric window at both ends of a rectangular waveguide to isolate the suppression device from the external environment. A through hole is added at the dielectric window at both ends to ensure the communication of external gas. When microwave energy reaches the through hole, the energy is greatly reduced at the through hole, effectively suppressing the leakage of microwaves. A plurality of partition plates and pins are arranged in parallel between the dielectric windows at both ends to form an energy shielding wall, so that the electromagnetic wave energy is reflected multiple times, thereby playing a role in microwave protection.

[0016] The foregoing and other features and advantages of the present invention will become clearer from the following detailed description taken in conjunction with the accompanying drawings. Attached Figure Description

[0017] Figure 1 It is an energy suppression device for high-power microwave protection, wherein 1 is a rectangular waveguide, 2 is an isolation window, and 3 is a multi-stage discharge unit;

[0018] Figure 2 Exploded view of the energy suppression device, where 4 is a thickened flange with a choke structure, 5 is a gas flow interface, 6 is a dielectric material, 7 is a matching pin, 8 is a narrow-side slot of the waveguide, 9 is a metal partition, and 10 is a wide-side through hole of the waveguide.

[0019] Figure 3 Cross-sectional view of a single-stage discharge unit. a is the length of the wide side of the rectangular waveguide, b is the length of the narrow side of the rectangular waveguide, L1 is the distance from the edge of the metal partition to the center line of the matching pin, L2 is the distance from the top of the metal partition to the narrow side of the waveguide, h1 is the length of the matching pin inside the cavity, and d1 is the spacing between the matching pins. Detailed Implementation

[0020] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0021] This invention proposes an energy suppression device for high-power microwave protection. A preferred embodiment includes two high-power microwave isolation windows and a multi-stage discharge unit. The isolation windows are filled with a dielectric material to isolate the energy suppression device from the external environment; one window is installed at the input end of the energy suppression device, and the other at the output end. A vent of a defined size is opened at the center of the narrow face of each high-power microwave isolation window, and the vent radius R satisfies the following formula:

[0022] λ<(λ c ) TM =2πRc / νμ mn

[0023] The input and output vents are used in combination to form the gas delivery channel of the transmission system. The discharge unit is composed of multiple metal partitions and discharge structures arranged in parallel and repeating order. High-power electromagnetic waves arrive at each discharge unit sequentially through the isolation window, generating light and heat between the upper and lower discharge electrodes of the unit, forming a reflective surface / microwave shielding wall. This causes total reflection of the high-power electromagnetic wave energy input from the outside, preventing it from entering the radio frequency front end of the electronic equipment, thus providing protection for it.

[0024] like Figure 1 As shown, the main structure of the energy suppression device for high-power microwave protection in the first embodiment of the present invention is a rectangular waveguide 1. The two ends of the waveguide are connected to the high-power microwave isolation window 2 by fasteners, and a multi-stage discharge unit 3 is set inside the waveguide.

[0025] As Figure 2 shown, the input port of the high-power microwave isolation window is a thickened flange 4 with a choke structure, and a small hole of fixed size is opened on the side to connect with the gas flow interface 5. The size of the gas flow interface 5 is determined by the pressure and flow rate of the dry gas inside the transmission channel. The gas flow interface 5 can be opened 2 or more, and the multiple interfaces must be opened on the narrow side of the RF transmission channel, parallel between interfaces. The gas flow interface 5 is recessed at the rear end with a depth X1 to install the dielectric material 6, which must retain a thickness L, generally greater than one quarter of the waveguide wavelength. The edge of the dielectric material 6 is rounded with an arc angle, and the surface roughness reaches more than 8 levels. The rectangular waveguide 1 is connected to one end of the thickened flange 4, which is designed with a depth X2 to ensure that X1+X2=L. The thickened flange 4, dielectric material 6, and rectangular waveguide 1 are connected by fasteners. A slit 8 is opened on the narrow side of the waveguide, and the slit 8 is perpendicular to the surface current of the rectangular waveguide. A metal partition 9 with a thickness t is inserted into the slit, and the positions of the left and right partitions correspond to each other. The length of the partition inserted into the rectangular waveguide is the same, which can compress the electromagnetic field mode of the waveguide, so that the partition can be equivalent to an inductor. The value of the inductor changes the absolute value of the reflection coefficient, and the impedance matching of the discharge unit is realized. The same through hole 10 is arranged at the corresponding position of the upper and lower of the wide side of the waveguide, and the matching pin 7 is inserted into the through hole. The gap d1 is retained between the upper and lower pins.

[0026] The specific structure of the single-stage discharge unit is shown in Figure 3 The pin is installed in the strongest electric field inside the rectangular waveguide, which can excite high-order modes of the electromagnetic field, and can be equivalent to a capacitor. The capacitor also changes the absolute value of the reflection coefficient, so the combination of the metal partition and the matching pin can realize the impedance matching of the discharge unit.

[0027] As Figure 1 , 2 shown, the multi-stage discharge unit is composed of multiple metal partitions + matching pins in cascade. When the cascade structure reaches more than 3, the suppression effect of the entire energy suppression device on the high-power microwave signal reaches saturation. The combination of the metal partition + the matching pin forms a rectangular waveguide resonance structure, which has small insertion loss in the passband and the signal can pass through almost without loss; the insertion loss gradually increases outside the passband. After cascading multiple resonance gaps, when the high-power microwave signal is input, the electromagnetic waves in the operating frequency band are reflected and consumed by discharge; and the signals outside the frequency band are reflected back and forth between the resonance gaps multiple times, realizing the suppression of the signals outside the frequency band.

[0028] As mentioned above, the installation of the discharge unit inside the energy suppression device is a necessary condition for the protection of high power microwave; the design of the high power microwave isolation window at both ends of the energy suppression device is determined by the severity of the environment in which the radio frequency front end of the electronic device is used and the complexity of the assembly process. Using this example, the radio frequency front end module of the electronic device can be protected from damage caused by high power microwave radiation; the coupling of broadband microwave signals into the radio frequency transmission channel is prevented to ensure the safety of the back-end signal processing module.

Claims

1. An energy suppression device for high-power microwave protection, characterized in that: A microwave isolation window (2) is set at each end of the rectangular waveguide (1). The dielectric material (6) is in close contact with the two end faces of the rectangular waveguide to reduce microwave leakage. Multiple slits (8) perpendicular to the surface current of the rectangular waveguide are cut into the narrow side of the rectangular waveguide. A metal partition (9) with a thickness of t is inserted. The positions of the metal partitions on both sides of the narrow wall of the waveguide are corresponding, and the lengths inserted into the rectangular waveguide are the same. A through hole (10) is opened in the middle of the wide side of the rectangular waveguide. A matching pin (7) is inserted vertically into the interior of the rectangular waveguide along the through hole and is perpendicular to the wide surface of the waveguide.

2. The energy suppression device for high-power microwave protection according to claim 1, characterized in that: The wide-side via (10) of the rectangular waveguide and the narrow-side slot (8) of the waveguide are on the same plane; along the direction of the waveguide, the multiple slot planes are parallel to each other.

3. The energy suppression device for high-power microwave protection according to claim 2, characterized in that: A cylindrical matching pin (7) of height h1 is inserted into the waveguide through the through hole (10) on the wide side of the rectangular waveguide. The matching pin is perpendicular to the wide side of the rectangular waveguide. There are two matching pins on the upper and lower cross sections of the rectangular waveguide, and a distance d1 is maintained between the matching pins.

4. The energy suppression device for high-power microwave protection according to claim 2, characterized in that: A metal partition (9) with a thickness of t is inserted into the waveguide cavity through the narrow side gap (8) of the rectangular waveguide. The thickness of the metal partition is t<2mm. A distance L1 is maintained between the metal partition and the matching pin. L1 is the distance from the edge of the metal partition to the center line of the pin.

5. The energy suppression device for high-power microwave protection according to claim 3, characterized in that: The matching pin height h1, the distance between matching pins d1, and the distance between the metal partition and the matching pins L1, where L1 is the distance from the edge of the metal partition to the center line of the pin, are determined by the microwave frequency wavelength to be suppressed, i.e., h1 < 0.45b, where b is the length of the narrow side of the rectangular waveguide.

6. The energy suppression device for high-power microwave protection according to claim 5, characterized in that: The metal partition is inserted into the rectangular waveguide to a depth L2, where L2 is the distance from the top of the metal partition to the narrow side of the rectangular waveguide, and is determined by the frequency wavelength for suppressing leakage, i.e., L2 = (a - λ) / 2. g / 4) / 2, where a is the length of the wide side of the rectangular waveguide, λ g The waveguide wavelength corresponds to the frequency of the electromagnetic wave for which leakage needs to be suppressed.

7. The energy suppression device for high-power microwave protection according to claim 1, characterized in that: The microwave isolation window is located at both ends of the rectangular waveguide to prevent the performance of the energy suppression device from degrading due to changes in the external environment.

8. An energy suppression device for high-power microwave protection according to claim 6, characterized in that: The typical dielectric material of the microwave isolation window is polytetrafluoroethylene, polyethylene, plexiglass, or polystyrene; the thickness of the dielectric reaches more than one-quarter of the waveguide wavelength, and the surface roughness is above level 8.

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