S-band radio frequency link strong electromagnetic protector and protection circuit thereof

Abstract

The invention relates to the technical field of electromagnetic protection, and discloses an S-band radio frequency link strong electromagnetic protector and a protection circuit thereof, and the protection circuit of the S-band radio frequency link strong electromagnetic protector comprises a first-stage clamping / discharging circuit, a second-stage filtering circuit and a third-stage precise clamping circuit. The output end of the first-stage clamping / discharging circuit is electrically connected with the input end of the second-stage filter circuit, and the output end of the second-stage filter circuit is electrically connected with the input end of the third-stage precise clamping circuit; the three-level protection circuit design is adopted, high-frequency strong electromagnetic pulse energy and low-frequency strong electromagnetic energy such as thunder and lightning can be comprehensively clamped, the electromagnetic pulse energy entering back-end equipment is remarkably reduced, direct-current components are isolated through the blocking capacitor C4, the whole protection circuit cannot interfere with the normal working performance of an original circuit, and the reliability of the protection circuit is improved. Therefore, in a strong electromagnetic environment, equipment such as a communication system can be effectively protected, and stable operation of the equipment is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic protection, and in particular to an S-band radio frequency link strong electromagnetic protector and a protection circuit thereof. Background Art

[0002] Modern warfare is a contest of comprehensive national strength under high-tech conditions. The rapid progress of science and technology has profoundly changed the mode of warfare. Electronic warfare based on electromagnetic attack and protection has become a new way of warfare. In recent wars in the world, electromagnetic pulse weapons have been widely used. They can generate transient strong electromagnetic fields in a short period of time, thereby destroying the enemy's electronic equipment, command systems, control systems and communication networks, playing a decisive role on the battlefield and directly affecting the direction of the war.

[0003] In the military field, radio frequency communication technology has made great progress, which has effectively promoted the military command to move towards transparency, flattening and coordination. At the same time, it has spawned new combat methods such as beyond-visual-range detection, beyond-visual-range attack, and electronic warfare. However, with the continuous development of science and technology, the space electromagnetic environment has become increasingly complex. In addition to natural hazards such as lightning and static electricity, communication equipment, radar, electronic warfare equipment, directed energy electromagnetic pulse weapons, electromagnetic pulse bombs and other strong artificial electromagnetic hazard sources are also constantly emerging. This complex and changeable strong electromagnetic environment, especially the high-intensity, ultra-wide spectrum electromagnetic pulse energy released instantly by lightning and high-power microwaves, poses a serious threat to the safety of RF front-end components.

[0004] Strong electromagnetic energy protection covers low-frequency strong electromagnetic energy such as lightning and energy forms such as high-power microwaves. This requires that the protection measures must meet both lightning protection standards and high-power microwave protection standards. The difficulty of protection lies in that the protection circuit must have an extremely fast response speed and be able to withstand instantaneous large current or high voltage shocks without self-destruction, while not having any adverse effects on the normal working performance of the protected circuit.

[0005] Therefore, studying the protection countermeasures in strong electromagnetic environment and improving the strong electromagnetic protection capability of the RF front end of the communication system are crucial to ensure the stable operation of the entire communication and command system. Based on this, we propose an S-band RF link strong electromagnetic protector and its protection circuit. Summary of the invention

[0006] In view of the problems existing in the existing technology, we propose an S-band radio frequency link strong electromagnetic protector and its protection circuit.

[0007] The technical solution of the present invention is: an S-band radio frequency link strong electromagnetic protector, comprising a protector shell, an input connection port, an output connection port and a radio frequency link strong electromagnetic protection circuit board, wherein the input connection port is connected to one side of the protector shell, the output connection port is connected to the other side of the protector shell, the radio frequency link strong electromagnetic protection circuit board is installed on the inner side of the protector shell, the input end of the radio frequency link strong electromagnetic protection circuit board is electrically connected to the input connection port, the output end of the radio frequency link strong electromagnetic protection circuit board is electrically connected to the output connection port, and a protection circuit is arranged on the radio frequency link strong electromagnetic protection circuit board.

[0008] Furthermore, the protector housing 1 is made of a conductive composite material composed of a polymer material and a conductive filler, and has an electromagnetic shielding function, which can prevent the influence of external electromagnetic interference on the protection circuit and protect the internal circuit components from physical damage.

[0009] Furthermore, the present application also provides a protection circuit for an S-band RF link strong electromagnetic protector, comprising a first-stage clamping / discharging circuit, a second-stage filtering circuit and a third-stage precise clamping circuit, wherein the output end of the first-stage clamping / discharging circuit is electrically connected to the input end of the second-stage filtering circuit, and the output end of the second-stage filtering circuit is electrically connected to the input end of the third-stage precise clamping circuit.

[0010] Furthermore, the first-stage clamping / discharging circuit includes a gallium arsenide high-power transient suppressor D2 and a DC blocking capacitor C4. The gallium arsenide high-power transient suppressor D2 is a customized gallium arsenide high-power transient suppressor with large current capacity, low insertion loss and fast response. The gallium arsenide high-power transient suppressor D2 and the DC blocking capacitor C4 are connected in series on the microstrip line. The DC component is isolated by the DC blocking capacitor C4 to ensure the accuracy of the radio frequency signal. The gallium arsenide high-power transient suppressor D2 can quickly clamp strong electromagnetic interference in the passband and reduce the damage amplitude of strong electromagnetic energy to the back end.

[0011] Further, the second-stage filter circuit includes capacitor C5, capacitor C6, capacitor C7, inductor L4, inductor L5, inductor L6, inductor L7 and inductor L8. The second-stage filter circuit adopts a distributed parameter filter network, specifically a high-pass LC lumped parameter filter network, and is designed based on a 5th-order LC filtering scheme. The second-stage filter circuit is connected to a microstrip line, and capacitor C5, capacitor C6 and capacitor C7 are arranged in series on the microstrip line. One end of the capacitor C5 is connected to the front-stage circuit, and the other end of the capacitor C5 is connected to one end of the capacitor C6. The other end of the capacitor C6 is connected to one end of the capacitor C7. The other end of the capacitor C7 is connected to the back-stage circuit. One end of the inductor L4 is connected to the microstrip line at one end of the capacitor C5, and one end of the inductor L5 is connected to the capacitor C5 and C6, one end of the inductor L7 is connected to the microstrip line between the capacitors C6 and C7, one end of the L8 is connected to the microstrip line at one end of C7, the other ends of the inductors L4, L5, L7 and L8 are all grounded, the inductor L6 is connected in parallel with the capacitor C6, and the high-pass characteristic is achieved through the above circuit structure, which can clamp the low-frequency electromagnetic energy and discharge it to the ground, while reducing the pulse width. At a frequency of 10MHz, the out-of-band suppression capability of the filter network reaches 70dB, which can effectively filter out the out-of-band low-frequency lightning and other out-of-band strong electromagnetic energy. After being processed by the filter circuit, the rising edge of the signal amplitude slows down, and the rising edge of the entire waveform is smoother, thereby reducing the response time requirement for the subsequent circuit, which helps the subsequent protection circuit to achieve better technical indicators.

[0012] Furthermore, the third-stage precise clamping circuit includes a gallium arsenide transient suppressor D1, which is a fast-response, high-current-carrying gallium arsenide transient suppressor. The gallium arsenide transient suppressor D1 is connected in series to the microstrip line processed by the second-stage filtering circuit, and is used to further accurately clamp the strong electromagnetic energy remaining after the first two stages of processing.

[0013] Beneficial effects of the present invention: The material of the protector shell in the S-band radio frequency link strong electromagnetic protector in the present invention is made of a conductive composite material composed of a polymer material and a conductive filler, has an electromagnetic shielding function, can prevent the influence of external electromagnetic interference on the protection circuit, and protect the internal circuit components from physical damage. In addition, the protector adopts a lightweight design and is more lightweight.

[0014] The protection circuit of the strong electromagnetic protector of the S-band radio frequency link in the present invention adopts a three-level protection circuit design. The first-level gallium arsenide high-power transient suppressor D2 cooperates with the DC blocking capacitor C4 to quickly clamp the strong electromagnetic interference in the passband, effectively reducing the damage amplitude of the strong electromagnetic energy to the back-end circuit; the second-level 5th-order LC high-pass lumped parameter filter network can clamp the low-frequency electromagnetic energy and discharge it into the ground, filter out the out-of-band low-frequency lightning and other out-of-band strong electromagnetic energy, and can also slow down the rising edge of the signal, reducing the response time requirement of the back-end circuit; the third-level gallium arsenide transient suppressor D1 further accurately clamps the residual strong electromagnetic energy. Through this multi-level protection, high-frequency strong electromagnetic pulse energy and low-frequency strong electromagnetic energy such as lightning can be fully clamped, so that the electromagnetic pulse energy entering the back-end equipment is significantly reduced.

[0015] By carefully designing circuit components and parameters at all levels, the response time of the entire circuit is successfully controlled within 2.5ns. Such a fast response speed ensures that the protection circuit can be activated in time at the moment a strong electromagnetic pulse appears, and the electromagnetic energy can be quickly processed, thereby minimizing the impact on the back-end circuit, and effectively improving the timeliness and effectiveness of protection.

[0016] During the protection process, the use of DC blocking capacitor C4 isolates the DC component and ensures the accuracy of the RF signal. The entire protection circuit will not interfere with the normal working performance of the original circuit, so that in a strong electromagnetic environment, equipment such as communication systems can be effectively protected while maintaining their original functions and performance, ensuring the stable operation of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the overall structure of the S-band radio frequency link strong electromagnetic protector in the present invention; Figure 2 This is a schematic diagram of the protection circuit of the S-band radio frequency link strong electromagnetic protector in the present invention; Figure 3 It is a circuit diagram of a high-pass filter network in the present invention; Figure 4 This is a schematic diagram of the strong electromagnetic protection circuit board for the radio frequency link in the present invention.

[0018] In the figure: 1. Protector housing; 2. Input connection port; 3. Output connection port. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0020] Example 1

[0021] Reference Figure 1 and Figure 4, which is the first embodiment of the present invention, provides an S-band radio frequency link strong electromagnetic protector, including a protector shell 1, an input connection port 2, an output connection port 3 and a radio frequency link strong electromagnetic protection circuit board, the input connection port 2 is connected to one side of the protector shell 1, the output connection port 3 is connected to the other side of the protector shell 1, the radio frequency link strong electromagnetic protection circuit board is installed on the inner side of the protector shell 1, the input end of the radio frequency link strong electromagnetic protection circuit board is electrically connected to the input connection port 2, the output end of the radio frequency link strong electromagnetic protection circuit board is electrically connected to the output connection port 3, and a protection circuit is arranged on the radio frequency link strong electromagnetic protection circuit board; the material of the protector shell 1 is made of a conductive composite material composed of a polymer material and a conductive filler, has an electromagnetic shielding function, can prevent the influence of external electromagnetic interference on the protection circuit, and protect internal circuit components from physical damage.

[0022] Specifically, the input connection port 2 is firmly connected to one side of the protector housing 1, and a high-precision docking process is adopted to ensure the stability and sealing of signal transmission, and prevent signal leakage and external interference. The output connection port 3 is connected to the other side of the protector housing 1 with the same standard to ensure the quality of the output signal. The RF link strong electromagnetic protection circuit board is carefully installed on the inner side of the protector housing 1. Through specific fixing brackets and insulating materials, it not only ensures the stability of the circuit board, but also avoids problems such as circuit short circuit. The input end of the RF link strong electromagnetic protection circuit board is electrically connected to the input connection port 2 through high-quality wires. The material of the wire is low-resistance, high-conductivity metal to ensure low signal transmission loss; the output end and the output connection port 3 are also connected with high-quality wires to ensure efficient output of the signal and protection. The device housing 1 is made of a conductive composite material formed by a polymer material and a conductive filler, specifically a composite of polycarbonate and carbon nanotubes. Polycarbonate (PC) has excellent mechanical properties, such as high strength and high toughness, and can effectively protect internal circuit components from physical damage. At the same time, it has good electrical insulation. After being compounded with a conductive filler, it helps to improve the overall performance of the material. Carbon nanotubes have unique electrical and mechanical properties. Their high conductivity and high aspect ratio enable them to effectively improve the conductivity of the composite material with a small amount of addition, thereby enhancing the electromagnetic shielding capability. At the same time, carbon nanotubes can also enhance the mechanical properties of polymer materials to a certain extent, such as improving the strength and toughness of the material. In addition, carbon nanotubes are light in weight and will not significantly increase the weight of the protector housing, which is conducive to the lightweight design of the equipment.

[0023] Example 2

[0024] Reference Figure 2 , Figure 3 and Figure 4, which is the second embodiment of the present invention, provides a protection circuit of an S-band radio frequency link strong electromagnetic protector, including a first-stage clamping / discharging circuit, a second-stage filtering circuit and a third-stage precise clamping circuit, the output end of the first-stage clamping / discharging circuit is electrically connected to the input end of the second-stage filtering circuit, and the output end of the second-stage filtering circuit is electrically connected to the input end of the third-stage precise clamping circuit; the first-stage clamping / discharging circuit includes a gallium arsenide high-power transient suppressor D2 and a DC blocking capacitor C4, the gallium arsenide high-power transient suppressor D2 is a customized gallium arsenide high-power transient suppressor with large current capacity, low insertion loss and fast response, and the gallium arsenide high-power transient suppressor D2 and the DC blocking capacitor C4 are connected in series at On the microstrip line, the DC component is isolated by the DC blocking capacitor C4 to ensure the accuracy of the RF signal. The gallium arsenide high-power transient suppressor D2 can quickly clamp the strong electromagnetic interference in the passband to reduce the damage amplitude of the strong electromagnetic energy to the back end. The second-stage filter circuit includes capacitor C5, capacitor C6, capacitor C7, inductor L4, inductor L5, inductor L6, inductor L7 and inductor L8. The second-stage filter circuit adopts a distributed parameter filter network, specifically a high-pass LC lumped parameter filter network, and is designed based on a 5th-order LC filter scheme. The second-stage filter circuit is connected to the microstrip line, and capacitors C5, C6 and C7 are arranged in series on the microstrip line. One end of capacitor C5 is connected to the front-stage capacitor C6. The other end of capacitor C5 is connected to one end of capacitor C6, the other end of capacitor C6 is connected to one end of capacitor C7, the other end of capacitor C7 is connected to the subsequent circuit, one end of inductor L4 is connected to the microstrip line at one end of capacitor C5, one end of inductor L5 is connected to the microstrip line between capacitors C5 and C6, one end of inductor L7 is connected to the microstrip line between capacitors C6 and C7, one end of L8 is connected to the microstrip line at one end of C7, the other ends of inductor L4, inductor L5, inductor L7 and inductor L8 are all grounded, inductor L6 is connected in parallel with capacitor C6, and the high-pass characteristic is realized by the above circuit structure, so that low-frequency electromagnetic energy can be clamped and discharged to the ground, and the pulse width is reduced at 1 At a frequency of 0MHz, the out-of-band suppression capability of the filter network reaches 70dB, which can effectively filter out out-of-band low-frequency lightning and other out-of-band strong electromagnetic energy. After being processed by the filter circuit, the rising edge of the signal amplitude becomes slower, and the rising edge of the entire waveform is smoother, thereby reducing the response time requirements for the subsequent circuit, which helps the subsequent protection circuit to achieve better technical indicators; the third-stage precise clamping circuit includes a gallium arsenide transient suppressor D1, which is a fast-response, high-current-carrying gallium arsenide transient suppressor. The gallium arsenide transient suppressor D1 is connected in series to the microstrip line processed by the second-stage filter circuit, and is used to further accurately clamp the residual strong electromagnetic energy after the first two stages of processing.

[0025] Specifically, the gallium arsenide high-power transient suppressor D2 in the first-stage clamping / discharging circuit is specially customized and has the characteristics of large current capacity, low insertion loss and fast response. In the actual circuit connection, the gallium arsenide high-power transient suppressor D2 and the DC blocking capacitor C4 are connected in series on the microstrip line. The width and material of the microstrip line are carefully designed to match the signal transmission characteristics. The DC blocking capacitor C4 is based on the basic principle of capacitance and uses its "isolating DC and passing AC" characteristics to effectively isolate the DC component to ensure the accuracy of the radio frequency signal. When a strong electromagnetic interference signal appears, the gallium arsenide high-power transient suppressor D2 can quickly detect the voltage change. When the voltage exceeds its clamping threshold, it quickly reduces its own impedance and bypasses most of the energy in the strong electromagnetic interference signal to the ground, thereby quickly clamping the strong electromagnetic interference in the passband and reducing the damage amplitude of the strong electromagnetic energy to the back end; the second-stage filtering circuit uses the capacitor to present low impedance to high-frequency signals and high impedance to low-frequency signals, and the inductor to high The filter network has the characteristics of high impedance to high-frequency signals and low impedance to low-frequency signals, realizing high-pass characteristics. At a frequency of 10MHz, after actual testing and data analysis, the out-of-band suppression capability of the filter network reaches 70dB, which can effectively filter out out-of-band low-frequency lightning and other out-of-band strong electromagnetic energy. At the same time, after the signal is processed by the filter circuit, due to the charging and discharging characteristics of the inductor and capacitor, the rising edge of the signal amplitude slows down, and the rising edge of the entire waveform is smoother, thereby reducing the response time requirements for the subsequent circuit, which helps the subsequent protection circuit to achieve better technical indicators; in the third-level precise clamping circuit, when the strong electromagnetic energy that remains after the first two stages of processing reaches this level, the gallium arsenide transient suppressor D1 can quickly detect the interference energy in the signal. When the interference signal voltage exceeds its set clamping threshold, it quickly reduces its own impedance and bypasses the residual strong electromagnetic energy to the ground, further accurately clamping the residual strong electromagnetic energy to ensure that the electromagnetic energy that finally reaches the back-end equipment is within a safe range.

[0026] Reference Figure 1-4 The working principle of the S-band radio frequency link strong electromagnetic protector and its protection circuit in the present invention is as follows: During use, at the moment of strong electromagnetic interference invasion, the first-stage clamping / discharging circuit responds quickly. The gallium arsenide high-power transient suppressor D2 in the circuit has the characteristics of large current capacity, low insertion loss and extremely fast response speed. When a strong electromagnetic interference signal enters the microstrip line, its voltage amplitude tends to increase sharply instantly. When the gallium arsenide high-power transient suppressor D2 detects that the voltage exceeds its clamping threshold, it can react in a very short time and quickly reduce its own impedance. At this time, it is like a low-resistance path, bypassing most of the energy in the strong electromagnetic interference signal to the ground, thereby quickly clamping the strong electromagnetic interference in the passband and limiting The voltage amplitude of the interference signal is controlled, and the damage amplitude of the strong electromagnetic energy to the back-end circuit is effectively reduced; in the RF communication system, the signal is often in the form of AC signal and DC bias superposition. If the DC component enters the subsequent circuit, it may affect the normal operation of the circuit, and even damage some components sensitive to DC. At this time, the DC blocking capacitor C4 plays an indispensable role. Based on the characteristics of capacitors "isolating DC and passing AC", the DC blocking capacitor C4 blocks the DC component at the front end and only allows the RF AC signal to pass smoothly, ensuring the accuracy and purity of the RF signal and avoiding the adverse effects of the DC component on the back-end circuit. After the signal is processed by the first-stage clamping / discharging circuit, although the amplitude of strong electromagnetic interference is suppressed to a certain extent, it may still contain some low-frequency electromagnetic energy, such as low-frequency interference generated by lightning, which may also cause harm to the back-end circuit. The high-pass LC lumped parameter filter network used in the second-stage filtering circuit realizes a specific filtering function by cleverly designing the combination of inductors and capacitors; the second-stage filtering circuit adopts a 5th-order LC filtering scheme, and capacitors C5 and C6 are connected in series on the microstrip line. C6 and capacitor C7, in parallel with inductor L4, inductor L5, inductor L7, inductor L8 to ground, and inductor L6 is connected in parallel with capacitor C6. The capacitor presents low impedance to high-frequency signals and high impedance to low-frequency signals; the inductor presents high impedance to high-frequency signals and low impedance to low-frequency signals. For low-frequency electromagnetic energy, inductor L4, inductor L5, inductor L6, inductor L7 and inductor L8 present low impedance, providing a low-resistance path for low-frequency energy, so that it can be smoothly clamped and discharged to ground, and capacitor C5 The high impedance characteristics of capacitors C6 and C7 to low-frequency signals further prevent the low-frequency energy from propagating to the back-end circuit; at 10MHz, the out-of-band suppression of the filter network reaches 70dB, which means that the low-frequency interference signal near the frequency point of 10MHz will be attenuated to one thousandth of the original amplitude after passing through the filter network, effectively filtering out the out-of-band low-frequency lightning and other out-of-band strong electromagnetic energy; in addition, another important role of the filter network for the signal is to slow down the rising edge of the signal amplitude. When the signal passes through this filter network, due to the charging and discharging characteristics of the inductor and capacitor, the rising process of the signal is no longer a steep mutation, but becomes more gentle, because the inductor hinders the current change and the charging process of the capacitor limits the rising speed of the signal. After the signal rising edge slows down, the rising edge of the entire waveform is smoother, which reduces the response time requirements for the subsequent circuit, and the subsequent circuit has more time to process the signal, which is more conducive to the design and operation of the subsequent protection circuit, thereby achieving better technical indicators.

[0027] After being processed by the first-stage clamping / discharging circuit and the second-stage filtering circuit, most of the strong electromagnetic energy has been effectively suppressed, but there may still be some residual strong electromagnetic energy. Although the amplitude of this energy has been reduced, the steep rising edge has been slowed down by the second-stage filtering circuit, and the pulse width has increased, which may still pose a potential threat to the back-end circuit. At this time, the gallium arsenide transient suppressor D1 in the third-stage precise clamping circuit has the characteristics of fast response and high current capacity. When the residual strong electromagnetic energy reaches this level, the gallium arsenide transient suppressor D1 plays a clamping role again. The gallium arsenide transient suppressor D1 can accurately detect the remaining interference energy in the signal. When the interference signal voltage exceeds its set clamping threshold, it quickly reduces its own impedance and bypasses the residual strong electromagnetic energy to the ground, further accurately clamping the residual strong electromagnetic energy, ensuring that the electromagnetic energy that finally reaches the back-end equipment is within a safe range, completely eliminating potential threats, and ensuring the stable operation of the back-end equipment.

[0028] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. S-band radio frequency link strong electromagnetic protector, characterized by: The invention comprises a protector housing (1), an input connection port (2), an output connection port (3) and a radio frequency link strong electromagnetic protection circuit board, wherein the input connection port (2) is connected to one side of the protector housing (1), the output connection port (3) is connected to the other side of the protector housing (1), the radio frequency link strong electromagnetic protection circuit board is installed on the inner side of the protector housing (1), the input end of the radio frequency link strong electromagnetic protection circuit board is electrically connected to the input connection port (2), the output end of the radio frequency link strong electromagnetic protection circuit board is electrically connected to the output connection port (3), and a protection circuit is arranged on the radio frequency link strong electromagnetic protection circuit board.

2. The S-band radio frequency link strong electromagnetic protector according to claim 1 is characterized in that: The protector housing 1 is made of a conductive composite material composed of a polymer material and a conductive filler, and has an electromagnetic shielding function, which can prevent the influence of external electromagnetic interference on the protection circuit and protect the internal circuit components from physical damage.

3. The protection circuit of the S-band radio frequency link strong electromagnetic protector adopts the S-band radio frequency link strong electromagnetic protector as claimed in any one of claims 1-2, characterized in that: The invention comprises a first-stage clamping / discharging circuit, a second-stage filtering circuit and a third-stage precise clamping circuit, wherein the output end of the first-stage clamping / discharging circuit is electrically connected to the input end of the second-stage filtering circuit, and the output end of the second-stage filtering circuit is electrically connected to the input end of the third-stage precise clamping circuit.

4. The protection circuit of the S-band radio frequency link strong electromagnetic protector according to claim 3 is characterized in that: The first-stage clamping / discharging circuit includes a gallium arsenide high-power transient suppressor D2 and a DC blocking capacitor C4. The gallium arsenide high-power transient suppressor D2 is a customized gallium arsenide high-power transient suppressor with large current capacity, low insertion loss and fast response. The gallium arsenide high-power transient suppressor D2 and the DC blocking capacitor C4 are connected in series on the microstrip line. The DC component is isolated by the DC blocking capacitor C4 to ensure the accuracy of the radio frequency signal. The gallium arsenide high-power transient suppressor D2 can quickly clamp strong electromagnetic interference in the passband and reduce the damage amplitude of strong electromagnetic energy to the back end.

5. The protection circuit of the S-band radio frequency link strong electromagnetic protector according to claim 3 is characterized in that: The second-stage filter circuit includes capacitor C5, capacitor C6, capacitor C7, inductor L4, inductor L5, inductor L6, inductor L7 and inductor L8. The second-stage filter circuit is connected to a microstrip line. Capacitor C5, capacitor C6 and capacitor C7 are arranged in series on the microstrip line. One end of the capacitor C5 is connected to a front-stage circuit, the other end of the capacitor C5 is connected to one end of the capacitor C6, the other end of the capacitor C6 is connected to one end of the capacitor C7, and the other end of the capacitor C7 is connected to a rear-stage circuit. One end of the inductor L4 is connected to the microstrip line at one end of the capacitor C5, one end of the inductor L5 is connected to the microstrip line between the capacitors C5 and C6, and one end of the inductor L7 is connected to the back-stage circuit. The microstrip line is connected between capacitors C6 and C7, one end of L8 is connected to the microstrip line at one end of C7, the other ends of the inductors L4, L5, L7 and L8 are grounded, and the inductor L6 is connected in parallel with the capacitor C6. The high-pass characteristic is achieved through the above circuit structure, and the low-frequency electromagnetic energy can be clamped and discharged to the ground, while the pulse width is reduced. At a frequency of 10MHz, the out-of-band suppression capability of the filter network reaches 70dB, which can effectively filter out out-of-band low-frequency lightning and other out-of-band strong electromagnetic energy. After being processed by the filter circuit, the rising edge of the signal amplitude becomes slower, and the rising edge of the entire waveform is smoother, thereby reducing the response time requirement for the subsequent circuit.

6. The protection circuit of the S-band radio frequency link strong electromagnetic protector according to claim 3 is characterized in that: The third-stage precise clamping circuit includes a gallium arsenide transient suppressor D1, which is a fast-response, high-current-carrying gallium arsenide transient suppressor. The gallium arsenide transient suppressor D1 is connected in series to the microstrip line processed by the second-stage filtering circuit, and is used to further accurately clamp the strong electromagnetic energy remaining after the first two stages of processing.

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